Patent Application
20190128267
The present invention is in the field of fluid pumps driven by an electrical motor, and in particular, to fluid pumps that utilize the power provided by the electric motor to add energy to the fluid in the form of increased fluid pressure and/or fluid flow velocity.
Fluid pumps commonly have a discrete pumping section that is then coupled directly to a separate electric motor by a shaft coupling device which transmits the torque and rotation of the electric motor to the impeller of the pump to impart energy into the fluid being pumped. Fluid pumps can have many configurations, some of which are centrifugal flow pumps, axial flow pumps, and pitot tube pumps, which all relate to the invention.
In the past, the pump was designed, engineered, and built as a standalone, discrete component with an input shaft directly connected to the pump impeller. The electric motor was a separate, discrete component that was connected to the pump by way of a coupling mechanism in order for the electric motor to drive the pump's impeller. The pump's impeller may or may not have had one or more bearings that support the rotational loads of the impeller. The electric motor also may or may not have had a set of bearings that support the rotational loads of the electric motor's rotor. In some cases, the pump impeller was attached directly to the shaft of the electric motor and utilized the bearings of the electric motor's rotor to support the rotational loads of both the electric motor's rotor and the pump's impeller. This is the most common configuration of pump and motor found in industry practice today for low power pumps. High power pumps utilize separate bearings for the pump and electric motor respectively.
In the fluid pump industry, there are classifications of pumps such as coupled pumps and close coupled pumps. The present disclosure is intended to create a new classification wherein the pump is an integral component of the electric motor. Designing and manufacturing pumps and motors to function as standalone components requires a redundancy of materials in the structures of each component as well as numerous other components that can be eliminated when a pump and motor are designed and manufactured into one cohesive unit.
Presently in the industry, pumps are typically operated at the synchronous speeds of the AC induction motor that is driving the pump. The specific speed of those pumps depends on the number of poles in the AC induction motor, with those typically being 2, 4, 6, 8, 10 and 12 pole motors. The speeds for these number of pole motors, utilizing a 60 Hz electrical frequency, are 3600, 1800, 1200, 900, 720, and 600 RPM, respectively. The speed of the electrical induction motor is determined by the power supply frequency and the number of poles in the motor winding, which is described by the following equation:
n=f(2/p)60
where
n=shaft rotation speed (rev/min, rpm)
f=frequency (Hz, cycles/sec, 1/s)
p=number of poles
In order to operate a conventional pump at speeds other than those tied to the electrical frequency delivered to the pump motor, a separate motor controller is required, which is typically referred to as a Variable Frequency Drive (VFD). Adding a VFD to a pump and being able to control the pump at higher speeds enables a smaller physical size pump to provide the same pressure and head as a slower speed larger physical sized pump. Additionally, the efficiency of the pump can be improved by utilizing a VFD in matching the speed of the pump to the required pressure and head desired for the application. Presently, the cost of adding a VFD to control pumps is prohibitively expensive for the low power pump market and difficult to justify in the high power pump market.
In particular aspects, the present disclosure relates to using the structural component of the fluid pump housing, the volute, as the front structural bearing housing of the electric motor. The electric motor shaft, bearing, and seal function as the shaft, impeller support bearing, and seal of the fluid pump. The integrated electric motor fluid pump embodied herein is of a high speed design and may utilize an integrated electric motor control located inside the motor/pump housing. The motor section may, for example, use a switched-reluctance stator.
In certain implementations, an integrated electric motor and fluid pump may include a pumping section, a control section, and motor section, and an outer housing. The motor section may include a stator, a rotor, and a shaft, the shaft located inside the rotor and rotated thereby. The outer housing may at least partially surround the motor section and be coupled to and support the pumping section and the control section.
In certain implementations, wherein the electric motor section may further include a bearing that supports the shaft. The bearing may be configured to support the pumping section.
In some implementations, the control section may include a controller that adjusts the speed of the pump to vary with respect to accommodate and respond dynamically to the load required by the pump.
In particular implementations, the housing may be composed of thermoplastics. The housing may include integrated non-thermoplastic elements that function as heatsink elements to allow thermal cooling of the motor pump components.
In certain implementations, the shaft may include a hollow center to convey the fluid being pumped into the pumping section. The pumping section may be a centrifugal, axial, or pitot-tube type pump in these implementations. The shaft may include an integral axial flow impeller to convey the fluid being pumped to the pumping section. Additionally, the pumping section may include a fluid volume housing that is an integral with of the shaft such that the fluid volume is rotate thereby or the pumping section may include a pitot tube that is integral with the shaft such that the pitot tube is rotated thereby.
Housing 110 protects motor section 130 and prevents users from accessing dangerous components of motor section 130 during operation. Additionally, pumping section 120 and controller 140 couple to and are supported by housing 110. Housing 110 may, for example, be made of plastic (e.g., thermoplastic) or any other appropriate material.
As illustrated, pumping section 120 includes an inlet 122, an outlet 124, and an impeller 126 and operates according to centrifugal flow techniques. In other embodiments, pump 120 may operate by other techniques (e.g., axial flow or pitot tube).
Motor section 130 includes a rotor 132, a stator 134, a shaft 136, and bearings 138. In the illustrated embodiment, rotor 132 and stator 134 each include a number of poles such that the rotor is driven by magnetic flux induced in the stator's poles. That is, the rotor's series of poles are controllably attracted to the stator's series of poles that surround the rotor. In particular, implementations, rotor 132 is driven by radial-flux switched reluctance techniques. In other embodiments, rotor 132 may be driven by other techniques (e.g., axial flux switched reluctance or transverse flux switched reluctance, or synchronous, whether single-phase or poly-phase). Shaft 136 is coupled to the interior of rotor and is driven by the rotation thereof. Shaft 136 may be hollow or solid. At either end of shaft 136 are bearings 138 that support the shaft longitudinally and allow it to rotate with minimal friction.
As can be seen in
In this implementation, control section 140 is coupled to the opposite end of pump 100 from pumping section 120. In other implementations, the control section may be located on the front, side, top, and/or bottom of the motor section and/or on the pumping section. Control section 140 may, for example, include power semi-conductors, gate drivers, and a controller (e.g., a microprocessor, a microcontroller, a field-programmable gate array, or an application specific integrated circuit). In this implementation, control section 140 includes a control board 142 upon which the controller is mounted.
Control section 140 is responsible for controlling the supply of current to the coils in the motor section 130. As part of this, controller 140 may include a sensor (not viewable here) to determine the position of shaft 136. Appropriate sensors may operate by electronic (e.g., Hall effect), optical (e.g., optical disks), or magnetic (e.g., reluctance or inductance sensing) techniques. Control section 140 allows the motor section 130 to work at variable speeds by adjusting the time that the stator poles are active and the amount of current supplied thereto. Also, control section 140 allows motor to dynamically adjust to the load required by the pump (e.g., by increasing rotation speed and/or torque). Control section 140 may also convert AC power to DC power.
As part of its adjustments, control section 140 may include and/or receive input from one or more sensors (e.g., pressure, flow, and/or temperature sensors). The control section may use relay the data from these sensors to a main controller, which may optimize the operation of a system in which the pump resides.
In certain implementations, control section 140 may include wireless communication capabilities (e.g., Ethernet, Bluetooth, or ZigBee). This may allow the pump to wirelessly communicate data with other pumps and industrial systems in order to increase the efficiency of the home or industrial process plant as a whole.
In operation, the sensor may provide an indication of the rotational position of the rotor and shaft 136 to the control section 140. When a pole of the rotor is approaching a pole of the stator (e.g., when a rotor pole is more than half way between two stator poles), the stator poles may be activated (assuming a single phase system) to attract the rotor poles. The activation of the stator poles produces a magnetic flux through the stator poles that causes the poles of the stator and the rotor to want to align, thereby moving the rotor poles towards the stator poles and a position in which the reluctance of the magnetic circuit is reduced to a minimum. As the rotor pole moves closer to being aligned with the stator pole, which may be the point at which the reluctance is a minimum, the current to the stator poles may be switched off to allow the rotor poles to move past the stator poles and continue toward the next stator pole turn-on position. In certain implementations of the present invention, the fluid being pumped may be used to thermally cool the stator and electric motor controller in order to improve the overall efficiency of the device.
Pump 100 has a variety of advantages. For example, it is smaller on a power basis than other pumps, making it easier to ship and install. The pump has an intelligent controller built-in, which enables the pump to actively adapt to changing pumping conditions of the fluid being pumped. The integral controller may also include a means of wireless communication that enables the pump to communicate data with other pumps and industrial systems in order to increase the efficiency of the home or industrial process plant as a whole. Additionally, pump 100 allows for variable speed operation. Thus, the pump may be configured for efficient operation after being manufactured.
Additionally, by integrating the pump, motor, and controller, the structural components may be shared, which reduces the amount of material for the completed device, reduces manufacturing costs of the collective unit, and improves the efficiency of the collective unit. Moreover, sharing the structural materials allows the device structure to be made of less costly materials, such as thermoplastics. Using materials such as thermoplastics also allows easier end-of-life recyclability of the device.
Housing 110 protects motor section 130 and prevents users from accessing dangerous components of motor section 130 during operation. Additionally, pumping section 120 and control section 140 couple to and are supported by housing 110. Housing 110 may, for example, be made of plastic (e.g., thermoplastic) or any other appropriate material.
As illustrated, pumping section 120 includes an inlet 122, an outlet 124, and an impeller 126 and operates according to centrifugal flow techniques. In other embodiments, pump 120 may operate by other techniques (e.g., axial flow or pitot tube). Pumping section 120 also includes a mechanical seal 128 to prevent the pump fluid from leaking into motor section 130.
Motor section 130 includes a rotor 132, a stator 134, a shaft 136, and bearings 138. In the illustrated embodiment, rotor 132 and stator 134 each include a number of poles such that rotor 132 is driven by magnetic flux induced in the stator's poles. That is, the rotor's series of poles are controllably attracted to the stator's series of poles that surround the rotor. In particular, implementations, rotor 132 is driven by radial-flux switched reluctance techniques. In other embodiments, rotor 132 may be driven by other techniques (e.g., axial flux switched reluctance or transverse flux switched reluctance, or synchronous, whether single-phase or poly-phase). Shaft 136 is coupled to the interior of rotor and is driven by the rotation thereof. Shaft 136 may be hollow or solid. At either end of shaft 136 are bearings 138 that support the shaft longitudinally and allow it to rotate with minimal friction.
In this implementation, control section 140 is split into two parts, 140a, 140b. Part 140a is coupled to the opposite end of pump 100 from pumping section 120, and part 140b is coupled to the top of the housing 110. Control section 140 may, for example, include power semi-conductors, gate drivers, and a controller (e.g., a microprocessor, a microcontroller, a field-programmable gate array, or an application specific integrated circuit). In this implementation, control section 140 includes a board (e.g., a printed circuit board) upon which the controller is mounted.
Control section 140 is responsible for controlling the supply of current to the coils in the motor section 130. As part of this, control section 140 may include a sensor (not viewable here) to determine the position of shaft 136. Appropriate sensors may operate by electronic (e.g., Hall effect), optical (e.g., optical disks), or magnetic (e.g., reluctance or inductance sensing) techniques. Control section 140 allows the motor section 130 to work at variable speeds by adjusting the time that the stator poles are active and the amount of current supplied thereto. Control section 140 may also convert AC power to DC power.
In certain implementations, control section 140 may include wireless communication capabilities (e.g., Ethernet, Bluetooth, or ZigBee). This may allow the pump to wirelessly communicate data with other pumps and industrial systems in order to increase the efficiency of the home or industrial process plant as a whole.
Control section 340 also contains also include a mechanical seal 344 to prevent the pumped fluid from reaching motor section 330. Additionally, control section 340 includes a control board 342 upon which the controller for the pump 300′ is mounted.
Control section 440 also includes a mechanical seal 444 to prevent the pumped fluid from reaching motor section 430. Additionally, control section 340 includes a control board 442 upon which the controller for the pump 400′ is mounted.
The pumping sectioning 530 includes a two-part pump housing 532a-b that houses a two-part rotating fluid volume housing 534a-b, which is coupled to the shaft 526 to be driven by the rotor 522. Pumping section 530 also includes a pitot-tube fluid pick up 536, which is stationary, to allow the rotated fluid to proceed to the outlet.
The pumping sectioning 530 includes a rotating fluid volume housing 534, which is coupled to the shaft 526 to be driven by the rotor 522 of the motor 520. Pumping section 530 also includes a pitot-tube fluid pick up 536, which is stationary, to allow the rotated fluid to proceed to the outlet. Additionally, pumping section 530 includes a mechanical seal 537 and an O-ring seal to prevent the pumped fluid from escaping the pumping section.
The pumping sectioning 530′ includes a fluid volume housing 534′, which is stationary, and a pitot-tube 536′, which is coupled to the shaft 526 to be driven by the rotor 522 of the motor 520. Additionally, pumping section 530 includes a mechanical seal 537. Pumping section 530 also includes an arm 539, which balances the pitot tube. In particular implementations, arm 539 may also be a pitot tube.
A variety of integrated pump embodiments have been discussed in detail, and several others have been mentioned or suggested. Additionally, those skilled in the art will also recognize that a variety of additions, deletions, substitutions, and transformations may be made while still achieving integrated pumps. Thus, the scope of the protected subject matter should be measured by the claims, which may encompass one or more concepts of one or more embodiments.
This application claims priority from U.S. Patent Application No. 62/368,509, filed Jul. 29, 2016, which is herein incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62368509 | Jul 2016 | US |
