Patent Application
20240131595
Three-dimensional printing systems are used to print three-dimensional objects. Existing three-dimensional printing systems are relatively slow, have a low throughput, are expensive to operate, and/or generate excessive waste. There is a never ending search to increase the speed, the throughput and reduce the cost of operation for three-dimensional printing systems.
The present embodiment is directed to a processing machine for building a three-dimensional object from powder. The processing machine can include a build platform; a powder supply assembly that deposits the powder onto the build platform to form a powder layer; and an energy system that directs an energy beam at a portion of the powder on the build platform to form a portion of the object.
A number of different powder supply assemblies are disclosed herein. As an overview, these powder supply assemblies are uniquely designed to accurately, efficiently, evenly, and quickly distribute the powder onto the build platform. This will improve the accuracy of the built object, and reduce the time required to form the built object.
The powder supply assembly can include (i) a powder container that retains the powder; (ii) a supply outlet positioned over the build platform; and (ii) a flow control assembly that selectively controls the flow of the powder from the supply outlet.
In one implementation, the flow control assembly includes a flow controller and a vibration generator that selectively vibrates at least a portion of the powder supply assembly. In this design, the flow controller allows powder to flow therethrough upon sufficient vibration of the powder supply assembly by the vibration generator; and the flow controller inhibits flow therethrough when there is insufficient vibration of the powder supply assembly by the vibration generator. The control modes of this powder flow controller can include (1) the vibration generator selectively vibrates certain regions of the powder container, or (2) the vibration generator evenly vibrates the entire powder container.
The flow controller can include at least one mesh screen. The flow controller can include a flow structure having a plurality of flow apertures that extend through the flow structure. At least one of the flow apertures has an aperture size that is larger than a nominal powder particle size of the powder particles. Typically, a plurality of the flow apertures each have an aperture size that is larger than the nominal particle size of the powder.
The build platform can be moved relative to the powder supply assembly while the powder supply assembly deposits the powder onto the build platform. Additionally, or alternatively, the powder supply assembly can be moved relative to the build platform while the powder supply assembly deposits the powder onto the build platform.
In certain implementations, gravity urges the powder in the powder container against the flow controller; and/or the powder container can be funnel shaped.
Additionally, the flow control assembly can include a shutter assembly that selectively controls the flow of the powder from the supply outlet. The shutter assembly can include a first shutter, and a first shutter mover that selectively moves the first shutter to selectively control the flow of the powder from the supply outlet. Further, the shutter assembly can include a second shutter, and a second shutter mover that selectively moves the second shutter to selectively control the flow of the powder from the supply outlet.
In certain implementations, the powder supply assembly includes a plurality of supply modules that individually deposit powder on the build platform. These supply modules can be substantially aligned along an axis.
In one example, at least one of the supply modules includes (i) a powder container that retains the powder; (ii) a supply outlet positioned over the build platform; and (ii) a flow control assembly that selectively controls the flow of the powder from the supply outlet. Further, for the at least one supply module, the flow control assembly includes a flow controller and a vibration generator that selectively vibrates at least a portion of the supply module. In this design, the flow controller allows powder flow therethrough upon sufficient vibration of the supply module by the vibration generator; and the flow controller inhibits flow therethrough when there is insufficient vibration of the supply module by the vibration generator.
The flow control assembly can include a flow structure having flow apertures, the flow structure being moved relative to the powder container to release the powder through the flow structure.
Alternatively, the flow control assembly can include a first flow structure having first flow apertures and a second flow structure having second flow apertures. In this design, the first flow structure is moved relative to the second flow structure to release the powder through the flow structures.
Still alternatively, the flow control assembly includes a shaft shaped flow structure having surface features. In this design, the flow structure is rotated relative to the powder container to release the powder from the supply outlet.
In another implementation, the flow control assembly includes a first flow structure having a plurality of first flow apertures that extend through the first flow structure, and a structure mover that moves the first flow structure relative to the powder container to selectively control the flow of the powder from the supply outlet. For example, at least one, a plurality, or substantially all of the first flow apertures can have an aperture size that is larger than a nominal powder particle size of the powder particles. Further, the structure mover can move the first flow structure linearly in a reciprocating manner.
Additionally, the flow control assembly can include a second flow structure having a plurality of second flow apertures that extend through the second flow structure. In this design, structure mover can move the first flow structure and the second flow structure relative to each other to selectively control the flow of the powder from the supply outlet. Further, the first flow structure can be stacked on top of the second flow structure. Moreover, one or both flow structures can include at least one of a grating and a mesh.
In another implementation, the structure mover rotates the first flow structure in a reciprocating manner. Further, the flow control assembly can include a second flow structure having a plurality of second flow apertures that extend through the second flow structure. In this design, the structure mover rotates at least one of the first flow structure and the second flow structure relative to the other to selectively control the flow of the powder from the supply outlet.
The first flow structure can be stacked on top of the second flow structure. The first flow structure can include at least one of a grating and a mesh.
In another implementation, the powder supply assembly includes a plurality of supply modules that individually deposit powder on the build platform. In this design, at least one of the supply modules includes a flow structure having flow apertures that control the flow of powder, and a structure mover that rotates the flow structure relative to the supply module to release the powder through the flow structure.
In still another implementation, the flow control assembly can include a shaft shaped flow structure having surface features. In this design, the flow structure is rotated relative to the powder container to release the powder to the supply outlet. The surface features can have a feature cross-sectional area that is larger than a powder cross-sectional area of one of the powder particles.
In another implementation, the powder supply assembly includes a first supply module that deposit powder on the build platform, and a second supply module that deposits powder into the first supply module. At least one of the supply modules can include (i) a powder container that retains the powder; (ii) a supply outlet positioned over the build platform; and (ii) a flow control assembly that selectively controls the flow of the powder from the supply outlet. The supply modules can be arranged in series. Additionally, the powder supply assembly can include a third supply module that deposits powder into the second supply module.
Further, for at least one supply module, the flow control assembly includes a flow controller and a vibration generator that selectively vibrates at least a portion of the supply module. In this design, the flow controller allows powder flow therethrough upon sufficient vibration of the supply module by the vibration generator; and the flow controller inhibits flow therethrough when there is insufficient vibration of the supply module by the vibration generator.
Alternatively, for at least one supply module, the flow control assembly includes a flow structure having flow apertures, and the flow structure is moved relative to the powder container to release the powder through the flow structure. In another example, for the at least one supply module, the flow control assembly includes a first flow structure having first flow apertures, and a second flow structure having second flow apertures; and the first flow structure is moved relative to the second flow structure to release the powder through the flow structures.
Still alternatively, for the at least one supply module, the flow control assembly includes a shaft shaped flow structure having surface features; and the flow structure is rotated relative to the powder container to release the powder to the supply outlet.
In yet another implementation, the build platform is being moved at a platform velocity while the powder is being distributed onto the build platform, and the powder supply assembly directs the powder at an exit velocity towards the build platform. The exit velocity can be approximately equal to the platform velocity. For example, the exit velocity is within ten percent of the platform velocity.
Additionally, or alternatively, the build platform is being moved in a platform movement direction while the powder is being distributed onto the build platform; and the powder supply assembly directs the powder in an exit movement direction towards the build platform. The powder movement direction can be approximately parallel to the exit movement direction.
In an implementation, the powder supply assembly can include a ramp that directs the powder exiting the powder supply assembly to be moving substantially parallel to the build platform. The ramp can have a ramp curve of approximately ninety degrees. However, the ramp curve can be greater than or less than ninety degrees. Moreover, a ramp height of the ramp is designed to achieve the exit velocity of the powder directed at the build platform.
As provided herein, the build platform can be moved in a platform movement direction while the powder is being distributed onto the build platform; the powder supply assembly can direct the powder in an exit movement direction towards the build platform; and the exit movement direction can be approximately parallel to the platform movement direction.
In one implementation, the powder supply assembly includes (i) a delivery frame that retains the powder, the delivery frame having a plurality of delivery apertures that allow the powder to flow therethrough; and (ii) a frame mover that moves the delivery frame along a frame movement direction that is approximately parallel to the platform movement direction. With this design, the build platform is being moved at a platform velocity while the powder is being distributed onto the build platform; and the frame mover moves the delivery frame at a frame velocity that is approximately equal to the platform velocity.
Additionally, the powder supply assembly can include a rake that smooths the powder on the build platform.
In another implementation, the processing machine includes a support bed that supports the build platform and the powder supply assembly. In this design, a mover assembly can rotate the support bed with the build platform and powder supply assembly relative to the energy system. Further, a supply mover assembly can move the powder supply assembly linearly relative to the support bed and the energy system.
The powder supply assembly can include (i) a powder container that retains the powder; and (ii) a flow control assembly that selectively controls the flow of the powder from the powder container to the build platform. Additionally, or alternatively, the powder supply assembly can include a powder distributor that spreads and levels the powder on the build platform.
In a method implementation, the invention is directed to a method for building a three-dimensional object from powder including: (i) providing a build platform; (ii) distributing the powder onto the build platform to form a powder layer with a powder supply assembly; and (iii) directing an energy beam at a portion of the powder on the build platform to form a portion of the object with an energy system.
Additionally, one or more of the following implementations can be utilized with the method implementation: (i) retaining the powder with a powder container; (ii) positioning a supply outlet over the build platform; (iii) selectively controlling the flow of the powder from the supply outlet with a flow control assembly; (iv) selectively vibrating at least a portion of the powder supply assembly with a vibration generator; (v) the flow control assembly includes at least one mesh screen; (vi) the flow control assembly includes a flow structure having a plurality of flow apertures that extend through the flow structure, wherein at least one of the flow apertures has an aperture size that is larger than a nominal powder particle size of the powder particles; (vii) a plurality of the flow apertures have an aperture size that is larger than the nominal powder particle size of the powder; (viii) selectively controlling the flow of the powder from the supply outlet with a shutter assembly; (ix) the powder supply assembly having a plurality of supply modules that individually deposit powder on the build platform; and/or (x) substantially aligning the supply modules along an axis.
In another implementation, the processing machine includes (i) a mover that moves the build platform so a specific position on the build platform is moved along a moving direction; (ii) a powder supply assembly which supplies the powder to the moving build platform; (iii) an energy system irradiates at least a portion of the powder layer with an energy beam to form at least a portion of the object from the powder layer during a first period of time; and (iv) a measurement device which measures at least portion of the object during a second period of time; wherein at least part of the first period in which the energy system irradiates the powder with the energy beam and at least part of the second period in which the measurement device measures are overlapped.
In still another implementation, the processing machine includes: (i) a mover which moves the build platform so as to move a specific position on the build platform along a moving direction; (ii) a powder supply assembly which supplies a powder to the build platform which moves, and forms a powder layer; and (iii) an irradiation device that changes an irradiation position where the beam is irradiated to the powder layer along a direction crossing the moving direction.
In yet another implementation, the processing machine includes: (i) a mover which moves the build platform so as to move a specific position on the build platform along a moving direction; (ii) a powder supply assembly which supplies a powder to the build platform which moves, and forms a powder layer; and (iii) an irradiation device (also referred to as an energy system) including a plurality of irradiation systems which irradiate the layer with an energy beam to form a built part from the powder layer, wherein the irradiation systems arranged along a direction crossing the moving direction.
In still another implementation, the processing machine includes: (i) a build platform; (ii) a powder supply assembly that deposits the powder onto the build platform; and (iii) a mover that rotates at least one of the build platform and the powder supply device about a rotation axis while the powder supply device deposits the powder onto the build platform.
In another implementation, the processing machine includes: (i) a build platform including a support surface; (ii) a mover which moves the build platform so a specific position on the support surface is moved along a moving direction; (iii) a powder supply assembly which supplies a powder to the moving build platform to form a powder layer during a powder supply time; and (iv) an energy system device which irradiates at least a portion of the powder layer with an energy beam to form at least a portion of the object from the powder layer during an irradiation time; and wherein at least part of the powder supply time and the irradiation time are overlapped.
In still another implementation, the processing machine includes: (i) a build platform including a non-flat support surface; (ii) a powder supply device which supplies a powder to the build platform and which forms a curved powder layer; and (iii) an energy system which irradiates the layer with an energy beam to form a built part from the powder layer.
The novel features of this embodiment, as well as the embodiment itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:
The type of three-dimensional object(s) 11 manufactured with the processing machine 10 may be almost any shape or geometry. As a non-exclusive example, the three-dimensional object 11 may be a metal part, or another type of part, for example, a resin (plastic) part or a ceramic part, etc. The three-dimensional object 11 may also be referred to as a “built part”.
The type of powder 12 joined and/or fused together may be varied to suit the desired properties of the object(s) 11. As a non-exclusive example, the powder 12 may include metal powder grains (e.g., including one or more of titanium, aluminum, vanadium, chromium, copper, stainless steel, or other suitable metals) or alloys for metal three-dimensional printing. Alternatively, the powder 12 may be non-metal powder, a plastic, polymer, glass, ceramic powder, organic powder, an inorganic powder, or any other material known to people skilled in the art. The powder 12 may also be referred to as “material” or “powder particles”.
A number of different designs of the processing machine 10 are provided herein. In certain implementations, the processing machine 10 includes (i) a powder bed assembly 14; (ii) a pre-heat device 16; (iii) a powder supply assembly 18 (illustrated as a box); (iii) a measurement device 20 (illustrated as a box); (iv) an energy system 22 (illustrated as a box); and (v) a control system 24 (illustrated as a box) that cooperate to make each three-dimensional object 11. The design of each of these components may be varied pursuant to the teachings provided herein. Further, the positions of the components of the processing machine 10 may be different than that illustrated in
A number of different powder supply assemblies 18 are disclosed herein. As an overview, these powder supply assemblies 18 are uniquely designed to accurately, efficiently, evenly, and quickly distribute the powder layers 13 onto the powder bed assembly 14. Further, in certain implementations, the powder supply assembly 18 is centerless, and uniformly distributes a fine layer of the powder 12 over a large and broad powder bed assembly 14. This will improve the accuracy of the built object 11, and reduce the time required to form the built object 11.
The thickness of each powder layer 13 can be varied to suit the manufacturing requirements. In alternative, non-exclusive examples, one or more (e.g. all) of the powder layers 13 can have a uniform layer thickness (along the Z axis) of approximately twenty, thirty, forty, fifty, sixty, seventy, eighty, or ninety, or one hundred microns. However other layer thicknesses are possible. Particle sizes of the powder 12 can be varied. In one implementation, a common particle size is approximately fifty microns. Alternatively, in other non-exclusive examples, the particle size can be approximately twenty, thirty, forty, sixty, seventy, eighty, or ninety, or one hundred microns.
A number of Figures include an orientation system that illustrates an X axis, a Y axis that is orthogonal to the X axis, and a Z axis that is orthogonal to the X and Y axes. It should be noted that any of these axes can also be referred to as the first, second, and/or third axes. Further, as used herein, movement with six degrees of freedom shall mean along and about the X, Y, and Z axes.
In
It should be noted that any of the processing machines 10 described herein may be operated in a controlled environment, e.g. such as a vacuum, using an environmental chamber 23 (illustrated in
It should be noted that these zones may be spaced apart different, oriented differently, or positioned differently from the non-exclusive example illustrated in
In
In the implementation illustrated in
In the simplified schematic illustrated in
In another implementation, the build platform 26A is flat, rectangular shaped, and the support side wall assembly 26B are rectangular tube shaped and extends upward around the build platform 26A. Alternatively, other shapes of the build platform 26A and/or support side wall assembly 26B may be utilized. As non-exclusive examples, the build platform 26A can be polygonal-shaped, with the support side wall assembly 26B having the corresponding tubular-shape. In another implementation, the support side wall can be built concurrently as a custom shape around the object 11, while the object 11 is being built.
The device mover 28 can move the powder bed 26 at a substantially constant or variable angular velocity about the rotation axis 25A. As alternative, non-exclusive examples, the device mover 28 may move the powder bed 26 at a substantially constant angular velocity of at least approximately 1, 2, 5, 10, 20, 30, 60, 100 or more revolutions per minute (RPM). Stated in a different fashion, the device mover 28 may move the powder bed 26 at a substantially constant angular velocity of between one and one hundred revolutions per minute. As used herein, the term “substantially constant angular velocity” shall mean a velocity that varies less than 10% over time. In one embodiment, the term “substantially constant angular velocity” shall mean a velocity that varies less 0.2% from the target velocity. The device mover 28 may also be referred to as a “drive device”.
Additionally or alternatively, the device mover 28 may move the powder bed 26 at a variable velocity or in a stepped or other fashion. For example, it may be desired to speed up or slow down the rotation of the powder bed 26 for some sections, either as part of a normal cycle like increase time under pre-heater, or as a smart corrective action during the build (e.g. to repair a defect). The rotation axis 25A may be aligned along with gravity direction, and may be along with an inclination direction about the gravity direction.
In
The powder 12 used to make the object 11 is deposited onto the powder bed 26 in a series of powder layers 13. Depending upon the design of the processing machine 10, the powder bed 26 with the powder 12 may be very heavy. With the present design, this large mass may be rotated at a constant or substantially constant speed to avoid accelerations and decelerations, and the required motion is a continuous rotation of a large mass, with no non-centripetal acceleration other than at the beginning and end of the entire exposure process. The melting process may be performed during the period when the motion is constant velocity motion.
The pre-heat device 16 selectively preheats the powder 12 in the pre-heat zone 16A that has been deposited on the powder bed 26 during a pre-heat time. In certain embodiments, the pre-heat device 16 heats the powder 12 to a desired preheated temperature in the pre-heat zone 16A when the powder 12 is moved through the pre-heat zone 16A. The number of the pre-heat devices 16 may be one or plural.
In one embodiment, the pre-heat device 16 is positioned along a pre-heat axis (direction) 16B and is arranged between the measurement device 20 and the energy system 22. However, the pre-heat device 16 can be positioned at another location.
The design of the pre-heat device 16 and the desired preheated temperature may be varied. In one embodiment, the pre-heat device 16 may include one or more pre-heat energy source(s) 16C that direct one or more pre-heat beam(s) 16C at the powder 12. Each pre-heat beam 16D may be steered as necessary. As alternative, non-exclusives examples, each pre-heat energy source 16C may be an electron beam system, a mercury lamp, an infrared laser, a supply of heated air, thermal radiation system, a visual wavelength optical system or a microwave optical system. The desired preheated temperature may be 50% 75% 90% or 95% of the melting temperature of the powder material used in the printing. It is understood that different powders have different melting points and therefore different desired pre-heating points. As non-exclusive examples, the desired preheated temperature may be at least 300, 500, 700, 900, or 1000 degrees Celsius. Energy input may also vary dependent on melt duty of previous layers, specific regions on a layer, or progress though the build.
The powder supply assembly 18 deposits the powder 12 onto the powder bed 26. In certain embodiments, the powder supply assembly 18 supplies the powder 12 to the powder bed 26 in the deposit zone 18A while the powder bed 26 is being moved to form each powder layer 13 on the powder bed 26.
In one implementation, the powder supply assembly 18 extends along a powder supply axis (direction) 18B and is arranged between the measurement device 20 and the energy system 22. The powder supply assembly 18 can include one or more powder containers (not shown in
With the present design, the powder supply assembly 18 deposits the powder 12 onto the powder bed assembly 14 to sequentially form each powder layer 13. Once a portion of the powder layer 13 has been melted with the energy system 22, the powder supply assembly 18 evenly and uniformly deposits another (subsequent) powder layer 13.
It should be noted that the three-dimensional object 11 is formed through consecutive fusions of consecutively formed cross sections of powder 12 in one or more powder layers 13. For simplicity, the example of
A number of alternative powder supply assemblies 18 are described in more detail below. In these embodiments, the powder supply assembly 18 is an overhead powder supply that supplies the powder 12 onto the top of the powder bed assembly 14.
The measurement device 20 inspects and monitors the melted (fused) layers of the object 11 as that are being built, and/or the deposition of the powder layers 13. The number of the measurement devices 20 may be one or plural. For example, the measurement device 20 can measure both before and after the powder 12 is distributed.
As non-exclusive examples, the measurement device 20 may include one or more optical elements such as a uniform illumination device, fringe illumination device (structured illumination device), cameras that function at one or more wavelengths, lens, interferometer, or photodetector, or a non-optical measurement device such as an ultrasonic, eddy current, or capacitive sensor.
In one implementation, the measurement device 20 is arranged between the powder supply assembly 18 and the pre-heat device 16, however, the measurement device 20 may be alternatively located.
The energy system 22 selectively heats and melts the powder 12 in the energy zone 22A to sequentially form each of the layers of the object 11 while the powder bed 26 and the object 11 are being moved. The energy system 22 can selectively melt the powder 12 at least based on a data regarding to the object 11 to be built. The data may be corresponding to a computer-aided design (CAD) model data. The number of the energy systems 22 may be one or plural.
In one embodiment, the energy system 22 is positioned along an energy axis (direction) 22B and is arranged between the pre-heat device 16 and the powder supply assembly 18. The design of the energy system 22 can be varied. In one embodiment, the energy system 22 may include one or more energy source(s) 22C (“irradiation systems”) that direct one or more irradiation (energy) beam(s) 22D at the powder 12. The one or more energy sources 22C can be controlled to steer the energy beam(s) 22D to melt the powder 12.
As alternative, non-exclusives examples, each of the energy sources 22C can be designed to include one or more of the following: (i) an electron beam generator that generates a charged particle electron beam; (ii) an irradiation system that generates an irradiation beam; (iii) an infrared laser that generates an infrared beam; (iv) a mercury lamp; (v) a thermal radiation system; (vi) a visual wavelength system; (vii) a microwave wavelength system; or (viii) an ion beam system.
Different powders 12 have different melting points. As non-exclusive examples, the desired melting temperature may be at least 1000, 1400, 1700, 2000, or more degrees Celsius.
The control system 24 controls the components of the processing machine 10 to build the three-dimensional object 11 from the computer-aided design (CAD) model by successively melting portions of one or more of the powder layers 13. For example, the control system 24 can control (i) the powder bed assembly 14; (ii) the pre-heat device 16; (iii) the powder supply assembly 18; (iii) the measurement device 20; and (iv) the energy system 22. The control system 24 can be a distributed system.
The control system 24 may include, for example, a CPU (Central Processing Unit) 24A, a GPU (Graphics Processing Unit) 24B, and electronic memory 24C. The control system 24 functions as a device that controls the operation of the processing machine 10 by the CPU executing the computer program. This computer program is a computer program for causing the control system 24 (for example, a CPU) to perform an operation to be described later to be performed by the control system 24 (that is, to execute it). That is, this computer program is a computer program for making the control system 24 function so that the processing machine 10 will perform the operation to be described later. A computer program executed by the CPU may be recorded in a memory (that is, a recording medium) included in the control system 24, or an arbitrary storage medium built in the control system 24 or externally attachable to the control system 24, for example, a hard disk or a semiconductor memory. Alternatively, the CPU may download a computer program to be executed from a device external to the control system 24 via the network interface. Further, the control system 24 may not be disposed inside the processing machine 10, and may be arranged as a server or the like outside the processing machine 10, for example. In this case, the control system 24 and the processing machine 10 may be connected via a communication line such as a wired communications line (cable communications), a wireless communications line, or a network. In case of physically connecting with wired, it is possible to use serial connection or parallel connection of IEEE1394, RS-232x, RS-422, RS-423, RS-485, USB, etc. or 10BASE-T, 100BASE-TX, 1000BASE-T or the like via a network. Further, when connecting using radio, radio waves such as IEEE 802.1x, OFDM, or the like, radio waves such as Bluetooth (registered trademark), infrared rays, optical communication, and the like may be used. In this case, the control system 24 and the processing machine 10 may be configured to be able to transmit and receive various types of information via a communication line or a network. Further, the control system 24 may be capable of transmitting information such as commands and control parameters to the processing machine 10 via the communication line and the network. The processing machine 10 may include a receiving device (receiver) that receives information such as commands and control parameters from the control system 24 via the communication line or the network. As a recording medium for recording the computer program executed by the CPU, a CD-ROM, a CD-R, a CD-RW, a flexible disk, an MO, a DVD-ROM, a DVD-RAM, a DVD-R, a DVD+R, a DVD-RW, a magnetic medium such as a magnetic disk and a magnetic tape such as DVD+RW and Blu-ray (registered trademark), a semiconductor memory such as an optical disk, a magneto-optical disk, a USB memory, or the like, and a medium capable of storing other programs. In addition to the program stored in the recording medium and distributed, the program includes a form distributed by downloading through a network line such as the Internet. Further, the recording medium includes a device capable of recording a program, for example, a general-purpose or dedicated device mounted in a state in which the program can be executed in the form of software, firmware or the like. Furthermore, each processing and function included in the program may be executed by program software that can be executed by a computer, or processing of each part may be executed by hardware such as a predetermined gate array (FPGA, ASIC) or program software, and a partial hardware module that realizes a part of hardware elements may be implemented in a mixed form.
It should also be noted that with the unique designs provided herein, multiple operations may be performed at the same time (simultaneously) to improve the throughput of the processing machine 10. Stated in another fashion, one or more of (i) pre-heating with the pre-heat device 16, (ii) measuring with the measurement device 20, (iii) depositing powder 12 with the powder supply assembly 18, and (iv) melting the powder with the energy system 22 may be partly or fully overlapping in time on different parts of the powder bed 26 to improve the throughput of the processing machine 10. For example, two, three, four, or all five of these functions may be partly or fully overlapping.
In certain implementations, the powder bed 26 may be moved down with the device mover 28 along the rotation axis 25A in a continuous rate via a fine pitch screw or some equivalent method. With this design, a height 29 between the most recent (top) powder layer 13 and the powder supply assembly 18 (and other components) may be maintained substantially constant for the entire process. Alternatively, the powder bed 26 may be moved down in a step down fashion at each rotation, which could lead to the possibility of a discontinuity at one radial position in the powder bed 26. As used herein, “substantially constant” shall mean the height 29 varies by less than a factor of three, since the typical thickness of each powder layer is less than one millimeter. In another embodiment, “substantially constant” shall mean the height 29 varies less than ten percent of the height 29 during the manufacturing process.
In this implementation, only the powder bed 26 is primarily moved, while everything else (pre-heat device 16, powder supply assembly 18, measurement device 20, energy system 22) are all fixed, making the overall system simpler. Also, the throughput of a rotary based powder bed 26 system is much higher since one or more steps can be performed in parallel rather than serially.
In the simplified example of
It should be noted that processing machine 10 can be designed to have one or more of the following features: (i) one or more of the pre-heat device 16, the powder supply assembly 18, the measurement device 20, and the energy system 22 can be selectively moved relative to the component housing 30 and/or the powder bed 26 with one or more of the six degrees of freedom; (ii) the component housing 30 with one or more of the pre-heat device 16, the powder supply assembly 18, the measurement device 20, and the energy system 22 can be selectively moved relative to the powder bed 26 with one or more of the six degrees of freedom; and/or (iii) the powder bed 26 can be selectively moved relative to the component housing 30 with one or more of the six degrees of freedom.
In a specific, alternative implementation, the housing mover 32 can move the top assembly (or a portion thereof) upward (e.g. along and/or transverse to the rotation axis 25A) relative to the powder bed 26 at a continuous (or stepped) rate while the powder 12 is being deposited to maintain the desired height 29.
Additionally, or alternatively, the housing mover 32 can rotate the top assembly (or a portion thereof) relative to the powder bed 26 about the rotation axis 25A relative to the powder bed 26 during the printing of the object 11. In this implementation, the powder bed 26 can be stationary, rotated about the rotation axis in the clockwise direction, rotated about the rotation axis in the counterclockwise direction, and/or or moved linearly along and/or transverse to the rotation axis 25A.
Stated in another fashion, the processing machine 10 illustrated in
As a non-exclusive example, the housing mover 232 may rotate the component housing 230 with the pre-heat device 216, the powder supply assembly 218, the measurement device 220, and the energy system 222 (collectively “top assembly”) at a constant or variable velocity about the rotation axis 225A. Additionally or alternatively, the housing mover 232 may move the top assembly along the rotation axis 225A.
It should be noted that the processing machine 210 of
In this embodiment, the powder bed assembly 214 can be generally circular disk shaped or rectangular shaped.
In alternative, non-exclusive implementations, the build platform 326A can have a build area 326D that is (i) flat, circular disk shaped for use with a corresponding support side wall 326B that is circular tube shaped; (ii) flat rectangular shaped for use with a corresponding support side wall 326B that is rectangular tube shaped, or (iii) polygonal-shaped for use with a corresponding support side wall 326B that is polygonal tube shaped.
It should be noted that the processing machine 310 of
In
In
In one, non-exclusive embodiment, the support platform 426A with the build assemblies 434 can be rotated like a turntable during printing of the objects 411 in a moving direction 425 about a support rotation axis 425A (illustrated with a “+”, e.g. the Z axis). With this design, each build assembly 434 is rotated about at least one axis 425A during the build process. Further, in this embodiment, the separate build assemblies 434 are spaced apart on the large common support platform 426A. The build assemblies 434 can be positioned on or embedded into the support platform 426A. As non-exclusive examples, the support platform 426A can be disk shaped or rectangular shaped.
As provided herein, each of the build assemblies 434 defines a separate, discrete build region. For example, each build assembly 434 can include a build platform 434A, and a sidewall assembly 434B. In one embodiment, each build assembly 434 is an open container in which the object 411 can be built. In this design, after the object 411 is printed, the build assembly 434 with the printed object 411 can be removed from the support platform 426A via a robotic arm (not shown in
As non-exclusive examples, each build platform 434A can define a build area 434C that is rectangular, circular, or polygonal shaped.
In an alternative embodiment, one or more of the build platforms 434A can be moved somewhat like an elevator vertically (along the Z axis) relative to its side wall assembly 434B with a platform mover assembly 434D (illustrated in phantom with a box) during fabrication of the objects 411. Each platform mover assembly 434D can include one or more actuators. Fabrication can begin with the build platform 434A placed near the top of the side wall assembly 434B. The powder supply assembly (not shown in
In some embodiments, one or more platform mover assemblies 434D can also or alternatively be used to move (e.g. rotate) one or more of the build assemblies 434 relative to the support platform 426A and each other in a platform direction 434E about a platform rotation axis 434F (illustrated with a “+”, e.g. the Z axis). With this design, each build platform 434A can be rotated about two, separate, spaced apart and parallel axes 425A, 434F during the build process.
In one, non-exclusive example, the support platform 426A can be rotated (e.g., at a substantially constant rate) in the moving direction 425 (e.g. counterclockwise), and one or more of the build assemblies 434 can be moved (e.g. rotated) relative to the support platform 426A in the opposite direction 434E (e.g. clockwise) during the printing process. In this example, the rotational speed of the support platform 426A about the support rotational axis 425A can be approximately the same or different from the rotational speed of each build assembly 434 relative to the support platform 426A about the platform rotational axis 434F.
Alternatively, the support platform 426A can be rotated (e.g., at a substantially constant rate) in the moving direction 425 (e.g. counterclockwise), and one or more of the build assemblies 434 can be moved (e.g. rotated) relative to the support platform 426A in the same direction 434E (e.g. counterclockwise) during the printing process.
In
In
In this Figure, each build platform 534A defines a circular shaped build area 534C that receives the powder (not shown in
Additionally, the support platform 526A can be annular shaped and powder bed 526 can include a central, support hub 526D. In this implementation, there can be relative movement (e.g. rotation) between the support platform 526A and the support hub 526D. As a result thereof, one or more of the other components (e.g. the powder supply assembly) of the processing machine (not shown in
In one, non-exclusive embodiment, the support platform 526A with the build assemblies 534 can be rotated like a turntable during printing of the objects in a moving direction 525 about the support rotation axis 525A (illustrated with a “+”) relative to the support hub 526D. With this design, each build platform 534A is rotated about at least one axis 525A during the build process.
In some embodiments, one or more platform mover assemblies 534D can be used to move (e.g. rotate) one or more of the build assemblies 534 relative to the support platform 526A and each other in a platform direction 534E about a platform rotational axis 534F (illustrated with a “+”, e.g. along the Z axis). With this design, each build platform 534A can be rotated about two, separate, spaced apart and parallel axes 525A, 534F during the build process.
In one, non-exclusive example, the support platform 526A can be rotated (e.g., at a substantially constant rate) in the moving direction 525 (e.g. counterclockwise), and one or more of the build assemblies 534 can be moved (e.g. rotated) relative to the support platform 526A in the opposite, platform direction 534E (e.g. clockwise) during the printing process. In this example, the rotational speed of the support platform 526A about the support rotational axis 525A can be approximately the same or different from the rotational speed of each build assembly 534 relative to the support platform 526A about the platform rotational axis 434F.
Alternatively, the support platform 526A and one or more of the build assemblies 534 can be rotated in the same rotational direction during the three dimensional printing operation.
It should be noted that in
It should be noted that the powder bed assembly 614 and the powder supply assembly 618 can be designed to have any combination of the Movement Characteristics (i)-(viii). For example, the powder bed assembly 614 and the powder supply assembly 618 can be designed to have one, two, three, four, five, six, seven, or all eight of the Movement Characteristics (i)-(viii). Further, the build platform 634A can be circular, rectangular or other suitable shape.
In the implementation illustrated in
Further, in
With reference to
The supply frame assembly 638 supports and couples the powder container assembly 640 and the flow control assembly 642 to the rest of the processing machine 10, 210, 310. The supply frame assembly 638 can fixedly couple these components to the support hub 626D. In one, non-exclusive implementation, the supply frame assembly 638 includes (i) a riser frame 638A that is fixedly coupled to and extends upwardly along the Z axis from the support hub 624D; and (ii) a transverse frame 638B that is fixedly coupled to and cantilevers radially away from the riser frame 638A. It should be noted that either the riser frame 638A, and the transverse frame 638B can be referred to as a first frame or a second frame.
The riser frame 638A is rigid and includes (i) a riser proximal end 638C that is secured to the support hub 624D, and (ii) a riser distal end 638D that is positioned above the support hub 624D. Further, the transverse frame 638B is rigid and includes (i) a transverse proximal end 638E that is secured to the riser distal end 638D, and (ii) a transverse distal end 638F that extends over an outer perimeter of the build platform 634A. In one, non-exclusive implementation, the riser frame 638A is right cylindrical shaped (e.g. hollow or solid), and the transverse frame 638A is rectangular beam shaped. However, other shapes and configurations can be utilized.
Additionally, the transverse frame 638B can include a frame passageway 638G that allows the powder 612 from the flow control assembly 642 to flow therethrough. For example, the frame passageway 638G can be rectangular shaped. Further, the frame passageway 638G can define the supply outlet 639 of the powder 612 from the powder supply assembly 618. The supply outlet 639 is in fluid communication with the powder container assembly 640 and the flow control assembly 642.
In one embodiment, the supply outlet 639 is positioned above and spaced apart a separation distance 643 from the build platform(s) 634A or uppermost powder layer on the build platform 634A. The size of the separation distance 643 can vary depending on the environment around the powder supply assembly 618. For example, the separation distance 643 can be larger if operated in a vacuum environment. As a non-exclusive embodiment, the separation distance 643 can be as small as the largest powder particle size. As a non-exclusive example, the separation distance 643 can be between approximately zero to fifty millimeters.
Alternatively, the powder supply assembly 618 can be designed so that the supply outlet 639 is directly adjacent to and/or against the build platform(s) 634A or uppermost powder layer on the build platform 634A.
The powder container assembly 640 retains the powder 612 prior to being deposited onto the build platform(s) 634A. The powder container assembly 640 can be positioned above and coupled to the transverse frame 638B of the supply frame assembly 638. In one nonexclusive implementation, the powder container assembly 640 is open at the top and the bottom, and can include a powder container 640A that retains the powder 612, and a container base 640B that couples the powder container 640A to the transverse frame 638B with the flow control assembly 642 positioned therebetween. For example, the powder container 640A and the container base 640B can be integrally formed or secured together during assembly. In this implementation, the opening at the top of the powder container assembly 640 is larger than the opening at its bottom.
The size and shape of the powder container 640A can be varied to suit the powder 612 supply requirements for the system. In one non-exclusive implementation, the powder container 640A is tapered, rectangular tube shaped (V shaped cross-section) and includes (i) a bottom, container proximal end 640C that is coupled to the container base 640B, and that is an open, rectangular shape; (ii) a top, container distal end 640D that is an open, rectangular tube shaped and positioned above the proximal end 640C; (iii) a front side 640E; (iv) a back side 640F; (v) a left side 640G; and (vi) a right side 640H. Any of these sides can be referred to as a first, second, third, etc side. The powder container 640A can function as a funnel that uses gravity to urge the powder 612 against the flow control assembly 642.
In one design, the left side 640G and the right side 640H extend substantially parallel to each other; while the front side 640E and a back side 640F taper towards each other moving from the container distal end 640D to the container proximal end 640C. The sides 640E, 640F can be steep (near vertical). As non-exclusive examples, the angle of taper relative to normal (vertical) can be at approximately 0, 0.5, 1, 2, 4, 6, 8, 10, 20, 30 degrees or other angles. The angle of taper can be determined based upon the characteristics (e.g. size) of the powder particles, the material of the powder particles, the amount of powder to be retained in the powder container 640A and other factors. In certain implementations, the powder container 640A comprises two slopes (walls 640E, 640F) getting closer to each other from one end (top 640D) to the other end (bottom 640C) on which the flow controller 642A is provided, and the at least one vibration generator 642C is provided on the at least one wall 640E, 640F. Stated in another fashion, the powder container 640A comprises two walls 640E, 640F that slope towards each other from a first end 640D to the second end 640C in which the flow controller 642C is located. An angle between two slopes of the walls 640E, 640F can be determined based upon a type of powder 612. As provided herein, the plurality of vibration generators 642C are provided at the both of two walls 640E, 640F. Further, in certain implementations, the flow controller 642A is elongated a first direction (e.g. along the Y axis) that crosses the build platform 634A, and the plurality of vibration generators 642C are provided at the both of two walls 640E, 640F along the first direction.
The container base 640B can be rectangular tube shaped to allow the powder 612 to flow therethrough.
It should be noted that other shapes and configurations of the powder container 640A can be utilized. For example, the powder container 640A can have a tapering, oval tube shape, or another suitable shape.
The control system 424 controls the flow control assembly 642 to selectively and accurately control the flow of the powder 612 from the supply outlet 639 onto the build platform(s) 634A. In one implementation, the flow control assembly 642 includes a flow controller 642A and an activation system 642B. In this implementation, (i) the flow controller 642A can be a flow restrictor such as one or more mesh screen(s) or other porous structure; and (ii) the activation system 642B can include one or more vibration generators 642C that are controlled by the control system 624 to selectively vibrate the powder container 640A. Each vibration generator 642C can be a vibration motor.
With this design, sufficient vibration of the powder container 640A by the vibration generator(s) 642C causes the powder 612 to flow through the flow controller 642A to the build platform(s) 634A. In contrast, if there is insufficient vibration of the powder container 640A by the vibration generator(s) 642C, there is no flow through the flow controller 642A. Stated in another fashion, the rate (amplitude and frequency) of vibration by the vibration generator(s) 642C can control the flow rate of the powder 612 through the flow controller 642A to the build platform(s) 634A. Generally speaking, no vibration results in no flow of the powder 612, while the flow rate of the powder 612 increases as vibration rate increases. Thus, the vibration generator(s) 642C can be controlled to precisely control the flow rate of powder 612 to the build platform(s) 634A. The location of the flow controller 642A can be varied. In
The number and location of the vibration generator(s) 642C can be varied. In the non-exclusive implementation in
The five vibration generators 642C on each side 640E, 640F can be spaced apart linearly moving left to right. In
With the present design, when it is desired to deposit the powder 612 onto the build platform 634A, the vibration generator(s) is(are) 642C turned ON to start the vibration motion. At this time, the powder 612 will pass from the powder container 640A through the flow controller 642A to deposit the powder 612. In contrast, when it is desired to stop the deposit of the powder 612, the vibration generators 642C are OFF, and the powder 612 will remain inside the powder container 640A.
With the present design, a thin, accurate, even layer of powder 612 can be supplied to the build platform(s) 634A without having to spread the powder 612 (e.g. with a rake) using the top-down vibration activated, powder supply assembly 618 disclosed herein. This powder supply assembly 618 is cost-effective, simple, and reliable method for delivering powder 612. Further, it requires a minimal amount of hardware to achieve even powder layers 612 on the build platform(s) 634A.
In certain embodiments, the flow controller 642A can be grounded to reduce static charges of the metal powder 612.
Additionally, or alternatively, the powder supply assembly 618 can include one or more preheaters 645A-645D on the inner or outer surface of powder container 640, on the transverse frame 638B, and/or near the separation distance 643. The non-exclusive implementation illustrated in
Additionally, or alternatively, the powder supply assembly 618 can be used with a powder recoater (not shown) such as a rake, roller, wiper, squeegee, and/or a brush to further improve the flat powder surface.
The flow apertures 642E can have a circular, oval, square, polygonal, or other suitable shape. Further, flow apertures 642E can follow a straight or curved path through the flow structure 642D. Moreover, in this implementation, one or more (typically all) of the flow apertures 642E have an aperture size that is larger than a nominal powder particle size of each of the powder particles 612. In alternative, non-exclusive examples, the aperture size is at least approximately 1, 1.25, 1.5, 1.7, 2, 2.5, 3 or 4 times the nominal powder particle size. Further, in alternative, non-exclusive examples, the aperture size is less than approximately 5, 6, 7, 8 or 10 times the nominal powder particle size. Stated in a different fashion, one or more (typically all) of the flow apertures 642E have an aperture cross-sectional area that is larger than a nominal powder particle cross sectional area of the individual particles of powder 612 (illustrated in
With reference to
More specifically, in
However, in
In one implementation, the shutter assembly 744 can include (i) a left, first shutter subassembly 745 positioned by the left side 740G of the powder container 740A, and (ii) a right, second shutter subassembly 746 positioned by the right side 740H of the powder container 740A. For example, (i) the first shutter subassembly 745 can include a first shutter 745A, and a first shutter mover 745B; and (ii) the second shutter subassembly 746 can include a second shutter 746A, and a second shutter mover 746B.
In this embodiment, each shutter 745A, 746A can be a plate secured to a guide (e.g. a linear guide), and each mover 745B, 746B can be an actuator (e.g. a linear motor) that is controlled by the control system 624. With this design, for example, (i) the first mover 745B can selectively move (e.g. slide) the first shutter 745A relative to the powder container 740A and the flow controller 742A along the Y axis; and/or (ii) the second mover 746B can selectively move (e.g. slide) the second shutter 746A relative to the powder container 740A and the flow controller 742A along the Y axis to selective control the flow through the flow controller 742A. In
Further, with this design, (i) the position of the first shutter 745A can be controlled to selectively control flow of the powder 712 to the inner region of the powder bed assembly 614 (illustrated in
In
With this design, the control system 624 may control the vibration generators 642C and the shutter assembly 744 based on feedback results from the measurement device 20 (illustrated in
In
However, instead of one big powder container 640A as illustrated in
The number of different powder containers 840A can be varied. In
Further, in this embodiment, each of the powder containers 840A includes a separate flow controller 842A and one or more vibration generators 842C that can individually be controlled with the control system 824. Each flow controller 842A and vibration generator 842C can be similar to the corresponding components described above and illustrated in
With this design, the vibration generators 842C can be independently controlled to control the distribution of the powder from each supply module 844 across the build platform 834A. Stated in another fashion, the vibration generator(s) 842C is (are) controlled to selectively vibrate the individual powder containers 840A to deposit the powder in the desired pattern on the build platform 834A.
In
In a specific example, in
With this design, the control system 824 may individually control the vibration generators 842C of each supply module 844 based on feedback results from the measurement device 20 (illustrated in
In one implementation, (i) one or more supply modules 844 (e.g. four) are positioned on a first axis 840AB; and (ii) one or more supply modules 844 (e.g. three) are positioned on a second axis 840AC. In
Additionally, or alternatively, the flow control assembly 842 for one or more for the supply modules 844 can be modified to include a shutter assembly 744 as illustrated in
As an overview, the powder supply assembly 918 illustrated in
In
The bed frame 927 supports the other components of the powder bed assembly 914. Further, in this implementation, the bed frame 927 can support and guide the movement of the powder supply assembly 918 relative to the powder bed assembly 914. In the non-exclusive implementation of
The device mover 928 can move the powder bed 926 relative to the bed frame 927 and the powder supply assembly 918. In
The powder supply assembly 918 is designed to provide a centerless, uniform distribution of a fine layer of powder 912 over the relatively large and broad build platform 926A. In one implementation, the powder supply assembly 918 includes a supply frame assembly 938, a powder container assembly 940, and a flow control assembly 942 (illustrated with a box in
Optionally, the powder supply assembly 918 can includes a powder distributor 948 that levels and/or smooths the powder 912 on the build platform 926A. The powder distributor 948 can function as a rake to smooth a top surface of the powder 912 on the build platform 926A. In this embodiment, a supply outlet 939 of the powder 912 from the powder supply assembly 918 is positioned adjacent to and against the layer of powder on the build platform 926A.
Additionally, or alternatively, the powder supply assembly 918 can include a large, bulk powder tank 950 (illustrated with a box) that supplies powder 912 to the powder container assembly 940. The bulk powder tank 950 can retain a large amount of powder 912. For example, the powder container assembly 940 can include one or more powder inlets 9401 that are in fluid communication with the bulk powder tank 950, e.g. via a flexible hose. In
In certain implementations, the powder supply assembly 918 is controlled to be moved relative to the build platform 926A while simultaneously and accurately distributing the powder 912 to the build platform 926A. In
Additionally, for example, the powder supply assembly 918 can be parked or positioned on either side of the build platform 926A so as to not interfere with the energy beam 22D (illustrated in
The supply frame assembly 938 (i) is rigid, (ii) extends over the powder bed assembly 914 between the frame guides 927D, and (iii) supports the powder container assembly 940, and the flow control assembly 942 above the build platform 926A. In
Additionally, the powder container assembly 940 can include one or more vibration generator(s) 952 (only one is illustrated in
Additionally, the powder supply assembly 918 can be designed to include one or more additional rakes and/or rollers.
The supply frame assembly 938 can support the powder container assembly 940, the flow control assembly 942, and the powder distributor above the build platform 926A. In
The powder container assembly 940 retains the powder 912 (illustrated in
The size and shape of the powder container 940A can varied to suit the powder 912 supply requirements for the system. The powder container 940A can be somewhat similar to the corresponding component described above and illustrated in
In certain implementations, the powder container 940A is shaped to allow gravitational forces to urge the powder against the flow control assembly 942 positioned adjacent to the container bottom 940C.
The flow control assembly 942 precisely controls the flow of the powder 912 to the build platform 926A. In certain implementations, the flow control assembly 942 simultaneously distributes the powder 912 while the powder supply assembly 918 is being moved either linearly or in a rotating fashion. In this embodiment, the flow control assembly 942 includes a flow controller 942A and an activation system 942B (illustrated with a box). These components are described in more detail below when discussing
The powder distributor 948 levels and/or smooths the powder 912 on the build platform 926A. In the non-exclusive implementation of
In this embodiment, the flow control assembly 942 includes the flow controller 942A and the activation system 942B (illustrated as a box in
In this implementation, (i) the flow controller 942A includes one or more flow structures 942D (e.g. one or more mesh screen(s), grating(s) or other porous structure(s)); and (ii) the activation system 942B can include one or more actuators that selectively move the one or more of the flow structures 942D relative to each other and/or the powder container 940A (illustrated in
In
In this non-exclusive implementation, (i) the second flow structure 942DS is somewhat “V” shaped and includes opposed inner slots 942G for guiding the movement of the first flow structure 942DF; and (ii) the first flow structure 942DF is long, rectangular plate shaped and includes angled sides 942H that fit in the slots 942G. With this design, the first flow structures 942DF can be moved relative to the second flow structure 942DS.
In one implementation, the activation system 942B includes a structure mover that individually moves one or multiple of the flow structures 942D in a reciprocating (linear) fashion along a reciprocating axis 9421 (e.g the Y axis) in order to evenly dispense and distribute the metal powder 912 over the powder build platform 926A. With this design, the flow control assembly 942 is a reciprocating grater 942A that evenly dispensing the metal powder.
For example, the second flow structure 942DS can be fixed, and the first flow structure 942DF can be moved relative to the second flow structure 942DS and the powder container 940A. In
Alternatively, the flow control assembly 942 can be designed so that both flow structures 942D are moved relative to each other and the powder container 940A with the activation system 942B.
Still alternatively, the flow control assembly 942 can be designed to have more than two flow structures 942D, with two or more of these flow structures 942D being movable with the activation system 942B.
With this design, sufficient movement of at least one of the flow structures 942D by the activation system 942B causes the powder 912 to flow through the flow controller 942A to the build platform(s) 916A. In contrast, if there is insufficient movement of the flow structure(s) 942D, there is no flow through the flow controller 942A. As provided herein, the rate (amplitude and frequency) of movement of the flow structure(s) 942D control the flow rate of the powder 912 through the flow controller 942A to the build platform(s) 926A. Thus, the movement of the flow structure(s) 942D can be controlled to precisely control the flow rate of powder 912 to the build platform(s) 926A.
For example, each of the flow structures 942D can be a mesh or grating.
The powder distributor 948 can include one or more spaced apart, scraping teeth 948A, and/or one or more roller elements 948B for spreading or levelling out the powder 912 on the build platform 926A. In one, non-exclusive implementation of
The scraping teeth 948A serve as a rough spreading mechanism for the powder 912 on the build platform 926A. The one or more roller elements 948B can be positioned on either side of the set of scraping teeth 948A to serve as a finer spreading or compacting mechanism to make the powder build layer more fine and even. The roller elements 948B can be free rolling or driven by a motor (not shown).
In this implementation, one, a plurality, or substantially all (typically all) of the first flow apertures 942EF have an aperture cross-sectional area that is larger than a powder cross sectional area of the individual particles of powder 912 (illustrated in
It should be noted that the second flow apertures 942ES of the second flow structure 942DS (illustrated in
With reference to
One of the advantages of this system is that it combines the reciprocating flow structures 942D with optional scraping teeth 948A and one or more roller elements 948B mounted on the movable powder supply assembly 918 to provide a centerless, thin layer of metal powder 912 distributed uniformly over a large powder build platform 926A.
In
With reference to
Additionally, or alternatively, the flow control assembly 942 can be modified to include a shutter assembly 744 as illustrated in
As an overview, the powder supply assembly 1018 illustrated in
In
In this implementation, the powder supply assembly 1018 can again be controlled to be moved relative to the build platform 1026A (e.g. linearly along the X axis on the frame guides 1027D of the bed frame 1027) while simultaneously and accurately distributing the powder to the build platform 1026A. Alternatively, the powder supply assembly 1018 could be attached to a support hub (not shown) similar to
The powder supply assembly 1018 uniformly distributes a fine layer of powder over the relatively large and broad build platform 1026A. In one implementation, the powder supply assembly 1018 again includes the supply frame assembly 1038, the powder container assembly 1040, and the flow control assembly 1042.
The supply frame assembly 1038 (i) is rigid, (ii) extends over the powder bed assembly 1014 between the frame guides 1027D, and (iii) supports the powder container assembly 1040, and the flow control assembly 1042 above the build platform 1026A. The supply frame assembly 1038 can be similar to the corresponding component described above and illustrated in
The powder container assembly 1040 retains the powder prior to distribution on the build platform 1026A. The powder container assembly 1040 includes the container top 10408 and the container bottom 1040C, and the powder container assembly 1040 can be somewhat similar to the corresponding component described above and illustrated in
Each container divider 1040D extends upward from the container bottom 1040C towards container top 1040B. In one implementation of
In this embodiment, each of the separate containers 1040E includes a separate flow controller 1042A. Each separate container 1040E with its corresponding flow controller 1042A can be collectively be referred to as a supply module 1044. In this example, the powder supply assembly 1018 includes eight separate supply modules 1044 that are aligned and stacked along the Y axis. Alternatively, it can be designed to include more than eight or fewer than eight separate supply modules 1044. The number of separate supply modules 1044 can be determined based upon the size and shape of the build platform 1026A, required depositing amount of powder, type of powder, and/or other factors. Further, these supply modules 1044 are configured to work in parallel to distribute the powder on the build platform 1026A.
It should be noted that a separate activation system 1042B (only one is illustrated in
The eight powder modules 1044 are positioned adjacent to each other along the Y axis. In
In a specific example, in
Alternatively, a common activation system 1042B can be used to concurrently activate multiple flow controllers 1042A. In this design, the supply modules 1044 that share a common activation system 1042B will operate concurrently.
Additionally, and optionally, the powder container assembly 1040 can include one or more vibration generator(s) 952 (illustrated in
Additionally, and optionally, the powder supply assembly 1018 can include a powder distributor 1048 (illustrated in
Additionally, and optionally, the powder supply assembly 1018 can include a large, bulk powder tank 950 (illustrated in
In one implementation, (i) each flow controller 1042A includes one or more flow structures 1042D (e.g. one or more sift cogs, mesh screen(s), grating(s) or other porous structure(s)); and (ii) the activation system 1042B (illustrated in
In
In this non-exclusive implementation, (i) each flow structure 1042D is circular disk shaped; (ii) the first flow structure 1042DF can include a first bearing assembly 1042F that rotatable couples the first flow structure 1042DF to the supply frame assembly 1038; and (iii) the second flow structure 1042DS can include a second bearing assembly 1042G that rotatable couples the second flow structure 1042DS to the supply frame assembly 1038.
In one implementation, for each supply module 1044, the activation system 1042B can include one or more structure movers that individually move (e.g. rotate) one or multiple of the flow structures 1042D in a reciprocating (rotational) fashion about a reciprocating axis 10421 (e.g. the Z axis) in order to evenly dispense and distribute the metal powder over the powder build platform 1026A. With this design, the flow controller 1042A for each supply module 1044 is a reciprocating sifter 1042A that evenly dispensing the metal powder.
For example, the flow controller 1042A can be designed so that both flow structures 1042D are moved relative to each other and the powder container 1040A to allow the powder to flow through both flow structures 1042D. Specifically, for each supply module 1044, the first flow structure 1042DF and the second flow structure 1042DS can be rotated in opposite directions, or in the same direction at different rates. This aids in dispensing the metal powder in a gradual even manner through the lower second flow structure 1042DS.
Alternatively, the second flow structure 1042DS can be fixed, and the first flow structure 1042DF can be moved relative to the second flow structure 1042DS and the powder container 1040A.
Still alternatively, the flow controller 1042A for each supply module 1044 can be designed to have more than two flow structures 1042D, with two or more of these flow structures 1042D being movable.
With this design, sufficient movement of at least one of the flow structures 1042D by the activation system 10428 causes the powder to flow through the flow controller 1042A to the build platform(s) 1016A. In contrast, if there is insufficient movement of the flow structure(s) 1042D, there is no flow through the flow controller 1042A. As provided herein, the rate (amplitude and frequency) of movement of the flow structure(s) 1042D control the flow rate of the powder through the flow controller 1042A. Thus, the movement of the flow structure(s) 1042D can be controlled to precisely control the flow rate of powder to the build platform(s) 1026A.
In this example, for each supply module 1044, the flow structures 1042S are each circular sift cog elements that are positioned adjacent to each other. Each sift cog is configured to have a screen or grid-like pattern to allow metal powder to gradually flow through each sift cog.
In certain embodiments, the first flow structures 1042DF of adjacent supply modules 1044 are aligned in a row along a first axis (parallel to the Y axis) and are coupled to each other such that when one of the first flow structures 1042DF is rotated in a direction (e.g., clockwise), its adjacent first flow structure 1042DF rotates in an opposite (e.g., counterclockwise) direction. Similarly, the second flow structures 1042DS of adjacent supply modules 1044 are aligned in a row along a second axis (parallel to the Y axis) and are coupled to each other such that when one of the second flow structures 1042DS is rotated in a direction (e.g., counterclockwise), its adjacent second flow structure 1042DS rotates in an opposite (e.g., clockwise) direction.
Optionally, the supply frame assembly 1038 and/or the second flow structure 1042DS can include the integrated powder distributor 1048, e.g. one or more knife edges. The knife edges can be used to improve the uniformity of the distribution of the metal powder.
In this implementation, one or more (typically all) of the first flow apertures 1042EF have an aperture cross-sectional area that is larger than a cross-sectional area of the powder. The first flow apertures 1042EF can be rectangular, circular or other suitable shape. Moreover, in this implementation, one or more (typically all) of the first flow apertures 1042EF have a first aperture size that is larger than a nominal powder particle size of each of the powder particles. In alternative, non-exclusive examples, the first aperture size is at least approximately 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, or 8 times the nominal powder particle size. Further, in alternative, non-exclusive examples, the first aperture size is less than approximately 10, 12, 15, or 20 times the nominal powder particle size. Stated in a different fashion, one or more (typically all) of the first flow apertures 1042EF have an aperture cross-sectional area that is larger than a nominal powder particle cross sectional area of the individual particles of powder. In alternative, non-exclusive examples, one or more (typically all) of the first flow apertures 1042EF have a first aperture cross-sectional area is equal to or larger than the nominal powder cross sectional area of the individual particles of powder by at least, but not limited to, 1, 2, 3, 5, 10, 20, 40, 50, 60, 70, 80, 90, 100, 150, 200, 300, or 400 percent. Stated differently, as non-exclusive examples, the first aperture cross-sectional area can be at least approximately ten, twenty, fifty, one hundred, one thousand, or two thousand times the nominal powder cross-sectional area. Stated in yet another fashion, one or more (typically all) of the first flow apertures 1042EF have an aperture diameter that is larger than a nominal powder particle diameter of the powder particles. In alternative, non-exclusive examples, the aperture diameter is at least approximately 1, 1.25, 1.5, 1.75, 2, 3, 4, 5, 6, 7 or 8 times the nominal powder particle diameter. Further, in alternative, non-exclusive examples, the aperture diameter is less than approximately 10, 15, or 20 times the nominal powder particle diameter. However, depending upon the design, other aperture sizes, diameters or cross-sectional areas are possible.
It should be noted that the second flow apertures of the second flow structure 1042DS (illustrated in
Further,
Alternatively, or alternatively, one of more of the power supply modules 1044 can be modified and/or designed to have (i) a flow control assembly 642 that is similar to that described above and illustrated in
Additionally, or alternatively, the flow controller 1042A for one or more for the supply modules 1044 can be modified to include a shutter assembly 744 as illustrated in
As an overview, the powder supply assembly 1118 illustrated in
In
In this implementation, the powder supply assembly 1118 can again be controlled to be moved relative to the build platform 1126A (e.g. linearly along the X axis on the frame guides 1127D of the bed frame 1127 with the device mover 1128) while simultaneously and accurately distributing the powder 1112 to the build platform 1126A. For example, the powder supply assembly 1118 can be controlled to simultaneously distribute the powder 1112 while being moved back and forth linearly in a reciprocating fashion. Alternatively, the powder supply assembly 1118 could be attached to a support hub (not shown) similar to
The powder supply assembly 1118 uniformly distributes a fine layer of powder over the relatively large and broad build platform 1126A. In one implementation, the powder supply assembly 1118 again includes the supply frame assembly 1138, the powder container assembly 1140, and the flow control assembly 1142 (illustrated in
The supply frame assembly 1138 (i) is rigid, (ii) extends over the powder bed assembly 1114 between the frame guides 1127D, and (iii) supports the powder container assembly 1140, and the flow control assembly 1142 above the build platform 1126A. The supply frame assembly 1138 can be similar to the corresponding component described above and illustrated in
The powder container assembly 1140 retains the powder prior to distribution on the build platform 1126A. The powder container assembly 1140 can be somewhat similar to the corresponding component described above and illustrated in
Additionally, and optionally, the powder container assembly 1140 can include one or more vibration generators 952 (illustrated in
Additionally, and optionally, the powder supply assembly 1118 can include a powder distributor 1148 that levels and/or smooths the powder 112 on the build platform 1126A. For example, the powder distributor 1148 can include an adjustable knife edge that engages the powder 1112 to function as a rake to smooth a top surface of the powder 1112 on the build platform 1126A. Additionally or alternatively, the powder distributor 1148 can include a roller.
Additionally, and optionally, the powder supply assembly 1118 can include a large, bulk powder tank 950 (illustrated in
More specifically, in one implementation, (i) the flow controller 1142A can include one or more shaft shaped flow structures 1142D (only one is shown) that extends along the container bottom 1140C along the Y axis; and (ii) the activation system 1142B can include one or more actuators that selective move (e.g. rotate) the one or more of the flow structures 1142D relative to the powder container 1140A to release the powder.
For example, the flow structure 1142D can be a rigid, circular shaped shaft that includes one or a plurality of surface features 1142E (represented with “X's”) such as grooves and/or indentations. The grooves 1142E in the flow structure 1142D can be formed in a helical pattern or a spiral screw pattern. The surface features 1142E have surface cross-sectional areas that are larger than a powder cross-sectional area of one of the powder particles 1112. The surface cross-sectional areas can be similar to the aperture cross-sectional areas described above. As non-exclusive examples, the surface features 1142E can have a feature size that is larger than a nominal powder particle size of each of the powder particles. In alternative, non-exclusive examples, the feature size is at least approximately 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, or 8 times the nominal powder particle size. Further, in alternative, non-exclusive examples, the feature size is less than approximately 10, 12, 15, or 20 times the nominal powder particle size. Stated in a different fashion, one or more (typically all) of the surface features 1142E have a feature cross-sectional area that is larger than a nominal powder particle cross sectional area of the individual particles of powder. In alternative, non-exclusive examples, one or more (typically all) of the surface features 1142E have a feature cross-sectional area is equal to or larger than the nominal powder cross sectional area of the individual particles of powder by at least, but not limited to, 1, 2, 3, 5, 10, 20, 40, 50, 60, 70, 80, 90, 100, 150, 200, 300, or 400 percent. Stated differently, as non-exclusive examples, the feature cross-sectional area can be at least approximately ten, twenty, fifty, one hundred, one thousand, or two thousand times the nominal powder cross-sectional area. In certain implementations, the surface features 1142E can have a depth of at least approximately ten, twenty, thirty, forty, fifty, or sixty percent larger than the individual, nominal powder particle size. However, depending upon the design, other feature sizes, feature depths, and/or cross-sectional areas are possible.
Further, the activation system 1142B can rotate the flow structure 1142D continuously or back and forth about a rotation axis 11421. With this design, the powder 1112 in the funnel shaped powder container 1140A moves in the surface features 1142E of the flow structure 1142D, and rotation of the flow structure 1142D will result in the powder 1112 being evenly dispensed.
In one implementation, the activation system 1142B include a rotary motor 1142BA, and a worm gear assembly 1142BB that couples the rotary motor 1142BA to the flow structure 1142D.
The design of the powder distributor 1148 can be varied. In
The rake(s) 1148A can be used to improve the uniformity of the distribution of the metal powder 1112 and remove of any center high spots.
In this embodiment, the grooved flow controller 1142A is combined with a set of symmetrical rakes 1148A. Further, the powder supply assembly 1118 can moved linearly and/or rotationally relative to the build platform 1126A to provide a centerless, thin layer of metal powder distributed uniformly over the build plane.
Additionally, or alternatively, the flow control assembly 1142 can be modified to include a shutter assembly 744 as illustrated in
With reference to
Instead of one big powder container 640A as illustrated in
The number of different powder containers 1240A can be varied to suit the design requirements of the system. For example, the powder supply assembly 1218 can include four, separate powder containers 1240A. Alternatively, it can be designed to include more than four or fewer than four powder containers 1240A. The four powder containers 1240A can be labeled A-D moving top to bottom for convenience.
The size and shape of each powder container 1240A can be varied to suit the powder 1212 supply requirements for the system. In one non-exclusive implementation, each powder container 1240A is tapered, rectangular tube shaped (truncated V shaped cross-section), and moving top to bottom (A to D) along the container axis 1241, each subsequent powder container 1240A is smaller than the previous powder container 1240A. Thus, (i) the powder container 1240A labeled “A” is larger than powder container 1240A labeled “B”; (ii) the powder container 1240A labeled “B” is larger than powder container 1240A labeled “C”; and (iii) the powder container 1240A labeled “C” is larger than powder container 1240A labeled “D”. In this implementation, the powder containers 1240A are similar shaped, but graduated in size. Alternatively, the sizes of the powder containers 1240A can be different from that illustrated in
Similar to
Further, in
With the present design, the vibration generators 1242C can be independently controlled to control the distribution of the powder 1212 from each powder container 1240A in the series. In one implementation, the goal is to keep the lowest supply module 1244 “D” at the proper level for accurately depositing the powder 1212 onto the build platform 1234A. With this design, (i) the vibration generator(s) 1242C are individually controlled for supply modules 1244 “A” “B” and “C” to maintain the proper level of powder 1212 in supply module 1244 “D”; and (ii) the vibration generator(s) 1242C for supply module 1244 “D” are individually controlled to accurately deposit the powder 1212 onto the build platform 1234A. More specifically, in this design, (i) supply module 1244 “A” is controlled to maintain supply module 1244 “B” at the desired level; (ii) supply module 1244 “B” is controlled to maintain supply module 1244 “C” at the desired level; (iii) supply module 1244 “C” is controlled to maintain supply module 1244 “D” at the desired level; and (iv) supply module 1244 “D” is controlled to accurately deposit the powder 1212 onto the build platform 1234A. This is a cascading supply module 1244 arrangement.
As provided herein, depending on the powder 1212, the vibration generator(s) 1242C can be less effective at activating powder flow through the respective flow controller 1242A when there is too much powder in the powder container 1240A. A large volume powder container 1240A is preferred to reduce how often the powder container 1240A needs to be refilled, however the weight of a large volume of powder 1212 in the powder container 1240A increases the likelihood of high powder “locking” forces at the flow controller 1242A reducing the accuracy of the powder flow through the flow controller 1242A when the vibration generator(s) 1242C are activated. Thus, the problem of large volume (exacerbating powder locking) in a single large powder container, is solved by the cascading supply modules 1244 arrangement.
In one implementation, the height of the powder container 1240A of each supply module 1244 is limited to reduce the locking force at the respective flow controller 1242A to what can be overcome by the corresponding vibration generator(s) 1242C.
Additionally, the powder supply assembly 1218 can include a container feedback system 1241B (illustrated with a box) that measures the level, volume, or other characteristic of powder 1212 in one or more of the powder containers 1240A to allow for the closed loop control of the flow control assembly 1242. For example, each of the powder containers 1240A can include a separate container sensor 1241C that provides information regarding the level of powder in the respective powder container 1240A. For example, each container sensor 1241C can be based on detecting powder physical properties (e.g. optical, mass, etc.).
With this design, (i) when supply module 1244 “D” is determined to be too low by the container sensor 1241C, supply module 1244 “C” can be activated and controlled in a closed loop fashion to fill supply module 1244 “D” to the desired level; (ii) when supply module 1244 “C” is determined to be too low by the container sensor 1241C, supply module 1244 “B” can be activated and controlled in a closed loop fashion to fill supply module 1244 “C” to the desired level; and (iii) when supply module 1244 “B” is determined to be too low by the container sensor 1241C, supply module 1244 “A” can be activated and controlled in a closed loop fashion to fill supply module 1244 “B” to the desired level.
Additionally, the flow controller 1242A of one or more of the supply modules 1244 can be designed to include one or more shutter assemblies 744 (illustrated in
Additionally, or alternatively, one of more of the power supply modules 1244 can be modified and/or designed to have (i) a flow controller 942A similar to that described above and illustrated in
In
As provided herein, the build platform 1326A and a previously deposited powder 1312A already on the build platform 1326A can be moved in a platform movement direction 1350 at a platform velocity while the new powder 1312 is being distributed onto the build platform 1326A. In one implementation, the powder supply assembly 1318 is designed so that the new powder 1312 exiting the powder supply assembly 1318 has an exit movement direction 1352 and an exit velocity just before the powder 1312 is distributed onto the build platform 1326A.
In certain implementations, the powder supply assembly 1318 is designed so that the exit velocity is approximately equal to the platform velocity. As non-exclusive examples, the powder supply assembly 1318 is designed so that the exit velocity is within (plus or minus) five, ten, fifteen, twenty or thirty percent of the platform velocity. In one specific implementation, the powder supply assembly 1318 directs the powder 1312 out, laterally, close to or at the speed of the spinning build platform 1326A so the power 1312 doesn't skid or tumble. This variability might be attributed to the fact that, in a rotating system, the build platform 1326A velocity varies depending on where along the radius the powder 1312 is being directed, and the powder velocity might be fixed across all radii. This percentage above will partly depend on how far off the powder 1312 is from the rotation axis of the build platform 1326A.
Additionally, or alternatively, the powder supply assembly 1318 is designed so that the exit movement direction 1352 is approximately parallel to the platform movement direction. As non-exclusive examples, the powder supply assembly 1318 can be designed so that the exit movement direction 1352 is within approximately ten, fifteen, twenty, thirty, or forty degrees of being parallel to the platform movement direction 1350. Stated in another fashion, the exit movement direction 1352 is approximately parallel to the build platform 1326A or somewhere between parallel and vertical.
The exit movement direction 1352 can be considered as having (i) a horizontal, first movement component 1352A that is parallel to the platform movement direction 1350 and the X axis; and (ii) a vertical, second movement component 1352B (e.g. along the Z axis and aligned with gravity) that is perpendicular to the platform movement direction 1350. In certain embodiments, the powder supply assembly 1318 is designed so that the powder velocity along the first movement component 1352A is approximately equal to the platform velocity. As non-exclusive examples, the powder supply assembly 1318 is designed so that the powder velocity along the first movement component 1352A is within five, ten, fifteen, twenty or thirty percent of the platform velocity.
With this design, the deposited powder 1312 and build platform 1326A are moving at approximately the same speed in approximately the same direction. The problem of limited powder application rate (hence throughput) is solved, for example, by matching the velocity of the powder 1312 and the velocity of the build platform 1326A before contact.
The powder supply assembly 1318 again includes a powder container assembly 1340, and a flow control assembly 1342. The supply frame assembly is not illustrated in this implementation. However, the supply frame assembly can be designed to support and couple the powder container assembly 1340, and the flow control assembly 1342 to the rest of the processing machine 10, 210, 310.
The powder container assembly 1340 can be a large hopper that retains the powder 1312 that is distributed over time onto the build platform 1326A.
The flow control assembly 1342 is controlled by the control system 1324 to selectively deposit the powder 1312 from the powder container assembly 1340 to the build platform 1326A. In
In one implementation, the flow controller 1342 can be a door that is selectively opened and closed as necessary by the actuation system 13428 (e.g. a motor). When the door is open, the gravitational force causes the powder 1312 to fall onto the ramp 1356.
In one embodiment, the ramp 1356 includes a ramp curve 1356A, and the ramp 1356 has a ramp height 1356B. In this embodiment, the ramp curve 1356A directs the powder 1312 to have the desired exit movement direction 1352, and the ramp height 1356B is selected so that the powder 1312 has the desired exit velocity. Thus, the characteristics of the ramp 1356 can be varied to achieve the desired exit movement direction 1352, and the ramp height 13568. Stated in another fashion, the shape of the ramp 1356 (e.g. height and curve) can be adjusted to adjust the exit velocity and exit movement direction 1352.
In one embodiment, the ramp 1356 has a ramp curve 1356A that is approximately ninety degrees. Alternatively, the ramp 1356 can be designed to have a ramp curve 1356A within plus or minus twenty, fifteen, ten, or five degrees of being ninety degrees.
With reference
In
In some embodiments, for a linearly moving build platform 1326A, the platform velocity across the build platform 1326A is substantially the same, and a ramp height 1356B can be uniform and be set such that the exit velocity of the applied powder 1312 leaving the ramp 1356 matches the platform velocity.
In this example, the ramp height 1356D of the gravity feed powder delivery system can vary along the Y axis. This would be beneficial in the case where the velocity of the build platform varies along the Y-axis (as in a rotating turntable 3D printer).
In a simple example, ignoring friction: If a rotating turntable 3D printer has a diameter of 0.7 meters and it is desired to apply a powder layer within one second, then the maximum tangential powder bed velocity would be V=2.2 m/s, and then the maximum height of a gravity feed powder delivery system would need to be about, H=V2/2 g=0.25 meters.
In an alternative embodiment, a forced powder delivery system (e.g. with pumps, brushes, and/or conduits) can be used instead of a gravity feed system to achieve the desired exit movement direction 1352 and exit velocity. For example, a rotational sweeper can direct the powder 1312 at the desired exit movement direction 1352 and exit velocity instead of relying on gravity and a sloping ramp.
Somewhat similar to the embodiment illustrated in
Further, similar to embodiment in
In the simplified illustration of
For example, the delivery frame 1460 can function as a sieve and can include a rigid plate having a plurality of spaced apart delivery apertures 1460A that allow the powder 1412 to flow therethrough. The delivery apertures 1460A can be organized in a grid or other pattern. Moreover, in this implementation, one or more (typically all) of the delivery apertures 1460A have an aperture size that is larger than a nominal powder particle size of each of the powder particles 1412. In alternative, non-exclusive examples, the aperture size is at least approximately ten, twenty, fifty, one hundred, or one thousand times the nominal powder particle size. Stated in a different fashion, one or more (typically all) of the delivery apertures 1460A have an aperture cross-sectional area that is larger than a nominal powder particle cross sectional area of the individual particles of powder 1412. As non-exclusive examples, the delivery apertures 1460A can have a cross-sectional area of approximately ten, twenty, fifty, one hundred, or one thousand times a nominal cross-sectional area of the powder 1412. However, depending upon the design, other aperture sizes, or cross-sectional areas are possible.
In certain implementations, the frame mover 1462 moves the delivery frame 1460 (i) along a frame movement direction 1468 that is approximately parallel to the platform movement direction 1450; and/or (ii) at a frame velocity that is approximately equal to the platform velocity. As non-exclusive examples, the frame mover 1462 can move the delivery frame 1460 so that (i) frame movement direction 1468 is within approximately one, two, three, or five degrees of being parallel to the platform movement direction 1350; and/or (ii) the frame velocity is within (plus or minus) five, ten, fifteen, twenty or thirty percent of the platform velocity.
The rake 1466 maintains the excess powder 1412 on the delivery frame 1460. In the non-exclusive implementation of
With this design, the moving delivery frame 1460 accelerates the supplied powder 1412 to approximately the platform velocity of the build platform 1432A. The rake 1466 is used to level the applied powder 1412 while the applied powder 1412 is retained by the moving delivery frame 1460. In one implementation, there is a slight velocity difference between the platform velocity and the frame velocity. For example, the velocity difference can be approximately equal to an aperture pitch of the delivery apertures 1462 divided by the powder spreading time. For example, if the aperture pitch is one millimeter and the application time is one second, then the velocity difference can be controlled to be about one millisecond. With this design, coarse raking is achieved with the delivery frame 1460, and finer raking can be achieved with another rake (not shown) that is downstream.
In certain implementations, for a build platform 1426A that is moved linearly, the frame mover 1462 can move the delivery frame 1460 linearly in a reciprocating. Further, the energy beam 22D (illustrated in
Alternatively, in certain implementations, for a build platform 1426A that is rotated, the delivery frame 1460 can be disk shaped, and the frame mover 1462 can rotate the delivery frame 1460 over the rotating build platform 1426A. Similarly, in this design, the energy beam 22D (illustrated in
In
In certain implementations, the build platform 1526A is quite large to allow for the forming large objects 11 (illustrated in
In one implementation, the powder bed assembly 1514 also includes a mover assembly 1528 (illustrated with a box) that concurrently moves the support bed 1526 with the build platform 1526A, and the powder supply assembly 1518 relative to the bed frame 1527, the energy zone 1522A, and the energy system 22. For example, the mover assembly 1528 can rotate the support bed 1526 with the build platform 1526A, and the powder supply assembly 1518 in a moving direction 1525 about a rotational axis 1525A (illustrated with a “+”, e.g. the Z axis) relative to the bed frame 1527 at a substantially constant or variable rate during the depositing of the powder 1512 and the forming of the object. Stated in another fashion, the support bed 1526, the build platform 1526A, and the powder supply assembly 1518 are rotated like a turntable during printing of the objects 11.
The large build platform 1526A can be very heavy, so the continued rotation of build platform 1526A to provide access to the energy zone 1522A will require less power than stop and start type movements. Stated in another fashion, an alternative design would require either moving the energy system 22 or the large build platform 1526A linearly in a reciprocating motion to provide the possibility of exposure to the whole build platform 1526A. This would require that the energy system 22 or the large build platform 1526A be accelerated and decelerated repeatedly. Further, this may require the stoppage of movement to allow a powder spreader or raking mechanism to sweep across the build platform 1526A before the next exposure. However, accelerating, decelerating, stopping and starting the movement of a large mass (e.g., the large object and build platform 152A) requires a lot of energy and time, is costly, inefficient, and limits the throughput. The present design solves these issues by rotating the build platform 1526 and the power supply assembly 1518 concurrently.
With the present design, the energy system 22 can be fixed source and positioned off to the side of the rotational axis 1525A. This allows the whole build platform 1526A rotate and pass underneath the fixed energy system 22. An advantage of this approach is, for example, that the fixed energy system 22 only needs to cover the radius and not the full diameter of the build platform 1526A, which as mentioned above, drastically reduces the size of the required energy zone 1522A needed to print a large object 11.
Additionally, and optionally, the build platform 1526A can be moved somewhat like an elevator vertically (along the Z axis) downward relative to the support bed 1526 with a platform mover assembly 1534D (illustrated in phantom with a box) during fabrication of the objects 11.
Additionally, or alternatively, the platform mover assembly 1534D can also be used to move (e.g. rotate) the build platform 1526A relative to the support bed 1526 somewhat similar to what is described in
In one embodiment, the powder supply assembly 1518 includes (i) a powder container assembly 1540 (illustrated as a box) that retains the powder 1512; and (ii) a flow control assembly 1542 (illustrated as a dashed box) that selectively controls the flow of the powder 1512 from the powder container assembly 1540 to the build platform 1526A. As non-exclusive examples, the powder container assembly 1540 can be similar to any of the powder container assemblies described herein; and/or the flow control assembly 1542 can be similar to any of the flow control assemblies described herein.
Additionally, or alternatively, the powder supply assembly 1518 can be designed to include a powder distributor 1548 (illustrated with a dashed box) that spreads and/or levels the powder 1512 on the build platform 1526A. The powder distributor 1548 can be similar to any of the powder distributors described herein. For example, the powder distributor 1548 can include one or more rakes and/or rollers.
In it should be noted that the powder supply assembly 1518 can be designed to include (i) the power container assembly 1540 and the flow control assembly 1542; (ii) the power container assembly 1540, the flow control assembly 1542, and the powder distributor 1548; or (iii) just the powder distributor 1548.
Additionally, the powder supply assembly 1518 can include a supply mover assembly 1532 that moves the powder supply assembly 1518 relative to the support bed 1526, the build platform 1526A, and the energy zone 1522A. For example, the supply mover 1532 can include one or more linear guides 1532A (illustrated with boxes) and one or more linear movers 15328 (illustrated with dashed boxes) that move the powder supply assembly 1518 back and forth linearly relative to the support bed 1526 and the build platform 1526A. With this design, the powder supply assembly 1518 can be moved back and forth to rapidly distribute and/or level the powder 1512 on the entire build platform 1526A, and subsequently be parked out of the way (e.g. off of the build platform 1526A) to allow the energy beam 22D to melt the powder 1512.
Moreover, with this design, the powder 1512 is rapidly distributed on the build platform 1526A without the need to stop rotation of the support bed 1526. Additionally, with this design, the powder supply assembly 1518 can extend over and straddle the entire, round build platform 1526A. As a result thereof, the powder supply assembly 1518 can access and provide an even, seamless, smooth layer of powder 1512 with one linear motion, and without any missed areas or powder buildup on the build platform 1526A.
Further, from the perspective of the powder supply assembly 1518, because the powder supply assembly 1518 is rotating with the build platform 1526A, the powder 1512 on the build platform 1526A is still. Thus, the powder supply assembly 1518 can be moved linearly straight across the build platform 1526A. In other words, the linear powder supply assembly 1518 is always in the same coordinate system relative to the build platform 1526A. Moreover, the linear powder supply assembly 1518 can actuate across the build platform 1526A at any time, regardless of the rotational position of the support bed 1526.
With regards to
In this embodiment, the problem of building a practical and low cost three dimensional printer 1610 for three dimensional printing of one or more metal parts 1611 (illustrated as a box) is solved by providing a rotating powder bed 1626, and the powder depositor 1618 is moved linearly across the powder bed 1626 as the powder bed 1626 is rotated in a moving direction 1625 about a rotation axis 1626D that is parallel to the Z axis. The part 1611 is built in the cylindrical shaped powder bed 1626.
In one embodiment, the powder bed 1626 includes the support surface 1626B having an elevator platform that may be moved vertically along the rotation axis 1626D (e.g. parallel to the Z axis), and the cylindrical side wall 1626C that surrounds an “elevator platform”. With this design, fabrication begins with the support surface 1626B (elevator) placed near the top of the side wall 1626C. The powder depositor 1618 translates across the powder bed 1626 spreading a thin powder layer across the support surface 1626B.
In
In an alternative embodiment, where lower throughput is acceptable, a single energy source may be used with the beam being steered in the radial direction. In this embodiment, the beam is scanned parallel to the irradiation axis 1622B that is transverse to the rotation axis 1626D and that crosses the movement direction. In another alternative embodiment, a single energy source with sufficient beam deflection width to cover the desired part radius may expose every point within the build volume.
The powder depositor 1618 distributes the powder across the top of the powder bed 1626. In this embodiment, the powder depositor 1618 includes a powder spreader 1619A and a powder mover assembly 16198 that moves the powder spreader 1619A linearly, transversely to the powder bed 1626.
In this embodiment, the powder spreader 1619A deposits the powder on the powder bed 1626. In some embodiments, the powder spreader 1619A comprises features that control the width of the powder distribution area to minimize or prevent powder from falling outside the cylindrical powder bed 1626. In other embodiments, the side walls 1626C may include flanges that extend into the corners of the powder spreading area, wherein the flanges prevent excess powder from being spread outside the cylindrical powder bed 1626.
The powder mover assembly 1619B moves the powder spreader 1619A linearly with respect to the powder bed 1626, while the powder bed 1626 and powder depositor 1618 are rotating together about the rotation axis 1626D. In one embodiment, the powder mover assembly 1619B includes a pair of spaced apart actuators 1619C (e.g. linear actuators) and a pair of spaced apart linear guides 1619D (illustrated in phantom) that move the powder spreader 1619A along the Y axis, transversely (perpendicular) to the rotation axis 1626D and the powder bed 1626. The powder spreader 1619A may be moved across the powder bed 1626 to the empty “parking space” 1619C shown in dotted lines at the top of the
After the powder spreader 1619A is parked at the opposite side of the rotating system, the irradiation device 1622 may be energized to selectively melt or fuse the appropriate powder into a solid part 1611.
In yet another embodiment, the powder bed 1626 may be rectangular and hold a larger volume of powder, but the maximum part volume is confined to a cylindrical volume within the rectangular powder bed 1626.
With this design, because the powder bed 1626 rotates relative to the irradiation device 1622, it is possible to reach every point in the part volume without requiring any acceleration or deceleration time. This feature provides a substantial throughput improvement over prior art systems. Because the only scanning part is the powder spreader 1619A with relatively low mass, high acceleration may be used to maintain high throughput.
Moreover, because the powder spreader 1619A is moved in a linear fashion relative to the powder bed 1626, the powder may be easily distributed in a flat and thin layer. This avoids an excess or lack of powder at the rotation center.
In another embodiment, the processing machine 1610 (i) may include more than one irradiation devices 1622 and more than one exposure areas (irradiation zones); and/or (ii) multiple parts 1611 may be made on the powder bed 1626 at one time to increase throughput. For example, the processing machine 1610 may include two irradiation devices 1622 that define two exposure areas, or three irradiation devices 1622 that define three exposure areas.
In certain embodiments, (i) the powder bed 1626 and the entire powder depositor 1618 are rotating at a substantially constant velocity about the rotation axis 1626D relative to irradiation device 1622, the pre-heat device, the cooler device, and/or the measurement device, and (ii) the powder depositor 1618 is moved linearly, with respect to the powder bed 1626 during the powder spreading operation. Alternatively, (i) the powder bed 1626 is rotated at a substantially constant velocity relative to the powder depositor 1618, irradiation device 1622, the pre-heat device, the cooler device, and/or the measurement device about the rotation axis 1626D, and (ii) the powder depositor 1618 is moved linearly relative to the irradiation device 1622, the pre-heat device, the cooler device, and/or the measurement device during the powder spreading operation.
Further, in yet another embodiment, (i) the powder bed 1626 is stationary, (ii) the irradiation device 1622, the pre-heat device, the cooler device, and/or the measurement device are rotated relative the powder bed 1626 about the rotation axis 1626D, and (iii) the powder depositor 1618 is moved linearly, transversely to the rotation axis 1626D, with respect to the stationary powder bed 1626 during the powder spreading operation.
In certain embodiments, the powder bed 1626 or the top assembly is continuously moved along the Z axis while printing to maintain a substantially constant height. Alternatively, the powder bed 1626 or the top assembly may be moved in a stepped like fashion along the Z axis. As another alternative, the powder bed 1626 or the top assembly may be ramped down gradually to the next print level.
The embodiments in which the powder bed 1626 is stationary and the top assembly is rotated may have the following benefits: (i) eliminate centrifugal forces on the melted metal and the dry powder at the surface, and, below the printing surface, on the powder bed's varied mixture of unused powder and parts in progress; (ii) eliminating the Z-stepping of the powder bed leaves the powder/melted metal/parts agglomeration truly undisturbed; (iii) Z-movement control may be easier with the much lighter and constant-mass top assembly than with the massive and growing powder bed; (iv) the top assembly could finish one complete rotation, then do nothing for 20 degrees of rotation, then start a new layer: this would distribute and perhaps average out any discontinuities or metallurgical differences at the stepping point, and each layer would start 20 degrees farther on, for example; (v) easier cooling system connections to the powder bed, if any are required; (vi) reduce controls complexity for the rotating part and Z-movement: a rotating powder bed is constantly gaining mass, but it needs a steady rotational speed and a steady Z-movement (or a uniform Z-step distance), so the control system has to adjust for that; (vii) a rotating top assembly is far lighter and of roughly constant mass (depending on whether powder replenishment is continuous or periodic); (viii) possibly simplify measurement system because everything is measured against the fixed floor of the powder bed 1626. In one embodiment, wireless communications and batteries may be used in the rotating top assembly. Further, printing could pause periodically to replenish power (via capacitors) and powder. Alternatively, if a pause would introduce build discontinuities, then continuous printing could be performed, and electricity might be supplied by continuous inductive charging or another non-contact method, and the powder hopper could be continuously replenished.
As provided above, in one embodiment, the powder bed 1626 is moved along the rotation axis 1626D, and the top assembly is rotated about the rotation axis 1626D at a constant angular velocity. If the powder bed 1626 is moved along the rotation axis 1626D at a constant speed, the relative motion between the powder bed 1626 and the top assembly will be spiral shaped (i.e., helical). In one embodiment, the flat surfaces in the parts 1611 may be inclined to match the trajectory of the powder bed 1626, or the axis of rotation 1626D may be tilted slightly with respect to the Z axis so that the exposure surface of the part 1611 is still planar.
In one embodiment, the powder depositor 1618 is designed to continuously feed powder to the powder bed 1626. In this embodiment, the powder depositor 1618 could include a powder hopper (not shown) with a funnel on the rotating top assembly that covers the rotation axis 1626D (center zone), and a non-rotating feeder (not shown) (e.g. a screw drive, conveyor belt, etc.) that terminates directly over the funnel. If the center zone is not available due to the needs of other components, then a donut shaped funnel would have one at least one point in its annular opening under a stationary off-axis feeder point at all times. In both of these embodiments it is advantageous to make the large and heavy powder supply mechanism stationary and feed the powder into the rotating top assembly.
If the “melting zone” of each column of the irradiation beam 1622D is approximately linear, it may be aligned to the slightly sloped radial surface of a helical surface. It doesn't matter if the helical surface is not planar, as long as it has a sufficiently straight radial line segment. It is also possible that some embodiments may treat a helical powder surface as “approximately flat” since the powder layer thickness is small compared to the part size, the powder bed size, and the energy beam depth of focus.
In the embodiment illustrated in
In
In this embodiment, the support surface 1727E may function as an annular “elevator platform” that may be moved vertically relative to the chamber walls 1727C, 1727D. In certain embodiments, fabrication begins with the elevator 1727E placed near the top of the chamber walls 1727C, 1727D. The powder depositor 1718 deposits a preferably thin layer of metal powder into the build chamber 1727B during relative movement between the build chamber 1727B and the powder depositor 1718. During fabrication of the part 1711, the elevator support surface 1727E may be slowly lowered down by one layer thickness per revolution so the next layer of powder may be distributed properly in a continuous fashion. In this way, instead of building parts as a stack of thin parallel planar layers, the part(s) are built in a continuous helical layer that spirals on itself many times.
In the embodiment illustrated in
With the present design, the problem of building a practical and low cost three dimensional printer 1710 for high volume 3D printing of metal parts 1711 is solved by providing a rotating turntable 1727A that supports a large annular build chamber 1727B suitable for continuous deposition of myriad small parts 1711 or individual large parts that fit in the annular region.
In
As provided herein, this processing machine 1710 requires no back and forth motion (no turn motion), so throughput may be maximized. Many parts 1711 may be built in parallel in the build chamber 1727B. Very large parts that fit within the annular shape may be fabricated. There are many applications that require large round parts with a central hole, so this capability may be valuable in some applications (such as jet engines).
In this embodiment, the irradiation device 1822 generates the irradiation energy beam 1822D to selectively heat the powder 1811 in each subsequent powder layer 1813 to form the part. In the embodiment of
Additionally, in
As provided herein scanning the energy beam 1822D across a large angle at a planar powder surface would create focus errors because the distance from the deflection center to the powder changes with the cosine of the deflection angle. To avoid focus errors, in one embodiment of the system shown in
For an alternative embodiment of the processing machine 1810 that uses linear scanning of the powder bed 1826 (or the column) into and out of the page, the curved support surface 1826B would be cylindrical shape. Alternatively, for an embodiment where the powder bed 1826 is rotated about a rotation axis, the curved surface support surface 18268 would be designed to have a spherical shape.
In these embodiments, the size and shape of the curved support surface 18268 is designed to correspond to (i) the beam deflection of the energy beam 1822D at the top powder layer 1813, and (ii) the type or relative movement between the energy beam 1822D and the powder layer 1813. Stated in another fashion, the size and shape of the curved support surface 18268 is designed so that the energy beam 1822D has a substantially constant focal distance to the top powder layer 1813 during relative movement between the energy beam 1822D and the powder layer 1813. As used herein the term substantially constant focus distance shall mean variations in the focal distance of less than five percent. In alternative embodiments, the term substantially constant focus distance shall mean the focus distance changes no more than ten, five, four, three, two, or one percent.
In
In this embodiment, the irradiation device 1922 includes multiple (e.g. three) irradiation energy sources 1922C that each generates a separate irradiation energy beam 1922D that may be steered (scanned) to selectively heat the powder 1911 in each subsequent powder layer 1913 to form the part. In
In
As provided above, scanning each energy beam 1922D across a large angle would create focus errors if the surface of the powder 1911 were a flat plane because the distance from the deflection center to the powder 1911 would change with the cosine of the deflection angle. In the embodiment illustrated in
In certain embodiments, such as a system where the powder support surface 19268 is rotating in a manner similar to the previously described embodiments, it may be more practical to distribute the powder across a single curved spherical surface. In this case, the columns providing each energy beam 1922D may be offset from each other in the vertical direction to more closely align the focal surface of each energy beam 1922D with the powder surface. In other words, the shape of the surface of the powder 1911 is not precisely matched to the focal distance of each energy beam 1922D, but the deviations from optimal focus are small enough with respect to the depth of focus of each energy beam 1922D that the proper part geometry may be formed in the powder 1911.
The processing machine 1910 illustrated in
In these embodiments, the size and shape of the curved support regions 1926E are designed to correspond to (i) the beam deflection of each energy beam 1922D at the top powder layer 1913, and (ii) the type of relative movement between the energy beam 1922D and the powder layer 1913. Stated in another fashion, the size and shape of each curved support region 1926E is designed so that the energy beam 1922D has a substantially constant focus distance at the top powder layer 1913 during relative movement between the energy beam 1922D and the powder layer 1913. Stated in yet another fashion, the shape of the support region 1926E, and the position of the energy beams 1922D are linked to the type of relative movement between the support region 1926E and the energy beams 1922D so that the energy beams 1922D have a substantially constant focus distance at the top powder layer 1913.
For example,
Alternatively, for example,
As provided herein, maintaining a constant focal distance will improve the part quality by controlling aberrations and the beam spot size.
Referring back
In this embodiment, the irradiation device 2022 includes multiple (e.g. three) irradiation energy sources 2022C that each generates a separate irradiation energy beam 2022D that may be steered (scanned) to selectively heat the powder 2011 in each subsequent powder layer 2013 to form the part. In
In
As provided above, scanning each energy beam 2022D across a large angle would create focus errors if the surface of the powder 2011 were a flat plane because the distance from the deflection center to the powder 2011 would change with the cosine of the deflection angle. In the embodiment illustrated in
In the embodiment illustrated in
The processing machine 2010 illustrated in
In
Further, in
As provided herein, the problem of manufacturing high precision rotationally symmetric parts 2111 by three dimensional printing is solved by using a rotating material bed 2126 (build platform), the wire source 2156 (wire feed mechanism) that supplies the wire 2158, and the irradiation energy beam 2154 for melting the wire 2158.
In one embodiment, as the material bed 2126 is rotated about the rotation axis 2126D, the material depositor 2150 may provide the molten material 2160 to form the part 2111. Further, material depositor 2150 (irradiation device 2152 and wire source 2156) may be moved transversely (e.g. along arrow 2162) with a depositor mover 2164 relative to the rotating material bed 2126 to build the part 2111. Further, the material bed 2126 and/or the material depositor 2150 may be moved vertically (e.g. by one of the movers 2128, 2164) to maintain the desired height between the material depositor 2150 and the part 2111.
Alternatively, the depositor mover 2164 may be designed to rotate the material depositor 2150 about a rotation axis and move the material depositor 2150 transversely to the rotation axis relative to the stationary material bed 2126. Still alternatively, the depositor mover 2164 may be designed to rotate the material depositor 2150 about a rotation axis relative to the material bed 2126, and the material bed 2126 may be moved transversely to the rotation axis with the device mover 2128.
Round, substantially rotationally symmetric parts 2111 may be built by rotating the material bed 2126 and depositing metal by using the energy beam 2154 to melt the wire feed 2158. The basic operation is analogous to a normal metal cutting lathe, except that the “tool” is depositing metal 2160 instead of removing it.
It is understood that although a number of different embodiments of the processing machine 10, 210, 310 and powder supply assembly 18, 218, 318, 618, 718, 818, 918, 1018, 1118, 1218, 1318, 1418 have been illustrated and described herein, one or more features of any one embodiment can be combined with one or more features of one or more of the other embodiments, provided that such combination satisfies the intent of the present disclosure.
While a number of exemplary aspects and embodiments of the processing machine 10 have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
This application claims priority on U.S. Provisional Application No. 62/869,853 filed on Jul. 2, 2019 and entitled “POWDER SPREADING FOR ADDITIVE MANUFACTURING”. As far as permitted the contents of U.S. Provisional Application No. 62/869,853 are incorporated herein by reference. As far as permitted the contents of PCT Application No: PCT/US18/67407 entitled “ADDITIVE MANUFACTURING SYSTEM WITH ROTARY POWDER BED” filed on Dec. 22, 2018, and the contents of PCT Application No: PCT/US18/67406 entitled “ROTATING ENERGY BEAM FOR THREE-DIMENSIONAL PRINTER” filed on Dec. 22, 2018 are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US20/40498 | 6/30/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62869853 | Jul 2019 | US |
