An aircraft engine, for example a gas turbine engine, includes a plurality of internal fluid channels for distributing fluids for different aspects of engine operation including lubrication distribution and coolant distribution. The internal components of the gas turbine engine can include power generators that require complicated routing in order to transfer fluid for lubrication and to transfer heat in order to maintain a functional temperature for the power generator. In some applications oil is utilized to transfer the heat.
In one aspect, the present disclosure relates to a fluid passage assembly for a power generator, the fluid passage assembly comprising an inlet conduit for receiving a fluid; a plenum fluidly coupled to the inlet conduit, and at least one distribution conduit fluidly coupled to and extending from the plenum for dispensing the fluid to the power generator, wherein a cross-section of the at least one distribution conduit has at least one corner.
In another aspect the present disclosure relates to a coolant fluid passage assembly for dispersing a coolant within an aircraft power generator comprising an inlet conduit for receiving the coolant, a plenum fluidly coupled to the inlet conduit, and at least one distribution conduit fluidly coupled to and extending from the plenum for dispensing the coolant to cool the aircraft power generator, wherein a cross-section of the at least one distribution conduit has a polygonal shape.
In yet another aspect the present disclosure relates to a method for manufacturing a fluid passage assembly for a power generator, the method comprising, additively manufacturing an inlet conduit having a first cross-section, and additively manufacturing at least one distribution conduit fluidly coupled to the inlet conduit and having a second cross-section comprising at least one corner.
In the drawings:
The present disclosure is related to a fluid passage assembly for a power generator having fluid passages for lubrication and coolant distribution. One non-limiting example the power generator is an electric power generator mounted to an accessory gear box. While the examples described herein are directed to application of a turbine engine and an electric power generator, the disclosure can be applied to any implementation of a fluid passage assembly for lubrication or cooling distribution.
All directional references (e.g., radial, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise) are only used for identification purposes to aid the reader's understanding of the disclosure, and do not create limitations, particularly as to the position, orientation, or use thereof. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto can vary.
As used herein, the term “forward” or “upstream” refers to moving in a direction toward the engine inlet, or a component being relatively closer to the engine inlet as compared to another component. The term “aft” or “downstream” refers to a direction toward the rear or outlet of the engine relative to the engine centerline. Additionally, as used herein, the terms “radial” or “radially” refer to a dimension extending between a center longitudinal axis of the engine and an outer engine circumference. It should be further understood that “a set” can include any number of the respectively described elements, including only one element.
Referring to
The turbine engine can be a turbofan engine, such as a General Electric GEnx or CF6 series engine, commonly used in modern commercial and military aviation or it could be a variety of other known turbine engines such as a turboprop or turboshaft. The turbine engine can also have an afterburner that burns an additional amount of fuel downstream of the low pressure turbine region 24 to increase the velocity of the exhausted gases, and thereby increasing thrust.
The AGB 12 is coupled to the turbine engine 14 at either the high pressure or low pressure turbine region 22, 24 by way of a mechanical power take-off 26. The mechanical power take-off 26 contains multiple gears and means for mechanical coupling of the AGB 12 to the turbine engine 14. Under normal operating conditions, the power take-off 26 translates power from the turbine engine 14 to the AGB 12 to power accessories of the aircraft for example but not limited to fuel pumps, electrical systems, and cabin environment controls. The starter/generator 10 can be mounted on the outside of either the air intake region containing the fan 16 or on the core near the high pressure compression region 18.
The starter/generator 10 and the mechanical power take-off 26 can include generator housings 28 for any known power generator including by way of non-limiting example synchronous or asynchronous generators, permanent magnet generators, low pole count generators, etc.
Referring now to
The generator housing 28 can be manufactured using additive manufacturing (AM). AM is an appropriate name to describe the technologies that build 3D objects by adding layer-upon-layer of material, whether the material is plastic or metal. AM technologies utilize a computer, 3D modeling software (Computer Aided Design or CAD), machine equipment and layering material. Once a CAD sketch is produced, the AM equipment reads in data from the CAD file and lays downs or adds successive layers of liquid, powder, sheet material or other, in a layer-upon-layer fashion to fabricate a 3D object. It should be understood that the term AM encompasses many technologies including subsets like 3D Printing, Rapid Prototyping (RP), Direct Digital Manufacturing (DDM), layered manufacturing and additive fabrication.
While illustrated as an electric generator the starter/generator 10 can be any generator know in the art. The starter/generator 10 can operate as a generator to provide power for accessories attached to the AGB 12 for example but not limited to a fuel pump, oil pump, or a separate engine starter. It is also contemplated that the starter/generator 10 can operate as a motor supplying mechanical output where necessary, for example but not limited to supplying mechanical output torque sufficient to start the engine.
The starter/generator 10 can include an output shaft 52 an input shaft 54 that can extend from within the output shaft 52 and is operably coupled to a portion of the AGB 12.
The generator housing 28 can include a fluid passage assembly 30 integral with the generator housing 28. As is illustrated, portions of the fluid passage assembly 30 can be located along an exterior 32 of the generator housing 28, while other portions (illustrated in dashed line) of the fluid passage assembly 30 can be located within the generator housing 28. The fluid passage assembly 30 can include an inlet conduit 34 for receiving fluids for lubrication or cooling. At least one distribution conduit 36, illustrated as a plurality of distribution conduits 36, is fluidly coupled to the inlet conduit 34.
In producing the fluid passage assembly 30 utilizing AM technologies, support devices 40 can become necessary during manufacturing if the diameter (D) extends beyond 10 mm (0.4 in), or an area greater than or equal to 80 millimeters squared (0.12 inches squared). When the diameter (D) meets or exceeds these parameters high stress/strain locations 42 which can range between 100 and 150 psi are produced along a surface perimeter 44 of the conduits 34, 36. When manufactured, the support devices 40 are printed along with the rest of the fluid passage assembly 30 and generator housing 28 to extend from the high stress/strain locations 42 and prevent collapse or deformation during the printing process. Due to small spaces and complicated branched design, not all of the support devices 40 can be removed when the fluid passage assembly 30 is complete. Support devices 40 can be any tab, pillar, stake, or otherwise small connecting structure between the conduits 34, 36 and the generator housing 28.
Oil is one possible fluid (F) received within the plenum 135 and passing through the inlet conduit 134 and the at least one distribution conduit 136. To ensure the required pressure drops within the conduits 134, 136, for an oil passage, the fluid passage assembly 130 can require conduits 134, 136 with diameters larger than 10 mm (0.4 in). However, as already described herein, conduits with parameters of diameters larger than 10 mm (0.4 in) require support devices 40. To eliminate any support devices 40 while maintaining the required pressure for oil passage, a polygonal shaped cross-section 150 is contemplated. Elimination of support devices decreases total weight which increases specific fuel consumption. The polygonal shaped cross-section has better buckling resistance than the circular cross section, especially if the corners are oriented correctly relative to gravity.
The at least one distribution conduit 136 can define the polygonal shaped cross-section 150. By way of non-limiting example the polygonal shaped cross-section 150 can include a diamond exterior cross-section 152 defined by a surface perimeter 144 of the at least one distribution conduit 136 and a smaller diamond interior cross-section 154 along an interior 146 of the at least one distribution conduit 136. A wall 156 having a thickness T1 extends axially with respect to the at least one distribution conduit 136 from the surface perimeter 144 to the interior 146. The thickness T1 can range between 2 and 5 mm (0.1 to 0.2) inches. The thickness T1 can be any thickness optimized to handle pressure while maintaining mechanical integrity.
It is further contemplated that the inlet conduit 134 has an inlet cross-section 160 that can include a tear drop shaped exterior cross-section 162 and a smaller tear drop interior cross-section 164. The inlet cross-section 160 can be in the shape of a tear drop where a polygonal corner is added to a circular cross-section. A wall 166 having a thickness T2, can extend between the interior and exterior cross-sections 162, 164. The thickness T2 can range between 2 and 5 mm (0.1 to 0.2) inches. The thickness T2 can be any thickness optimized to handle pressure while maintaining mechanical integrity. The inlet cross-section 160 can define at least one corner, by way of non-limiting example an inlet corner 168 of both the tear drop exterior and interior cross-sections 162, 164. The inlet corner 168 extends through an angle α, having a maximum value of 45°. It is contemplated that the inlet corner 168 defines a sharp corner 168a along the exterior cross-section 162 and a radiused corner 168b along the interior cross-section 164.
A method for manufacturing the fluid passage assembly 130 as described herein includes additively manufacturing the inlet conduit 134 having a first cross-section, by way of non-limiting example the inlet cross-section 160. The method further includes additively manufacturing at least one distribution conduit 136 fluidly coupled to the inlet conduit 134 and having a second cross-section, by way of non-limiting example the polygonal shaped cross-section 150 with the at least one corner 158. The method further includes printing the at least one distribution conduit 136 free from any support devices 40 (
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Any polygonal cross-sectional shape is contemplated and the number of sides are shown for illustrative purposes only and not meant to be limiting. As was described earlier, the structural support provided by two sides forming an angle of greater than or equal to 45° provides the structural integrity previously provided by the removed supports.
The disclosure as described herein relates to a fluid passage assembly for a generator housing and the method for additively manufacturing the fluid passages of the fluid passage assembly by changing the cross sectional shape from a typical circular cross-section to a polygon, as described herein a diamond shape. Fluid channels with the polygon shape will enable additive manufacturing without internal supports during the additive manufacturing process for any size to meet the pressure drop requirement. Also internal supports are eliminated for any build orientation.
The elimination of internal supports can be implemented for any build orientation of a fluid passage assembly as described herein. Eliminating supports optimizes parts by decreasing the weight of the part which improves specific fuel consumption. Benefits further include utilizing additive manufacturing which is commercially efficient compared to other manufacturing processes in certain environments.
To the extent not already described, the different features and structures of the various aspects can be used in combination with each other as desired. That one feature cannot be illustrated in all of the aspects is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different aspects can be mixed and matched as desired to form new examples, whether or not the new examples are expressly described. Combinations or permutations of features described herein are covered by this disclosure. Many other possible embodiments and configurations in addition to that shown in the above figures are contemplated by the present disclosure. Additionally, the design and placement of the various components such as starter/generator, AGB, or components thereof can be rearranged such that a number of different in-line configurations could be realized.
This written description uses examples to disclose aspects of the invention, including the best mode, and also to enable any person skilled in the art to practice aspects of the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.