US20180245596A1

US20180245596A1 - Integrated electric motor and pump assembly

Info

Publication number: US20180245596A1
Application number: US15/660,729
Authority: US
Inventors: Michael J. Van Steenburg; Gustavo Lopez
Original assignee: Reliax Motores SA De Cv
Current assignee: Reliax Motores SA De Cv
Priority date: 2016-07-26
Filing date: 2017-07-26
Publication date: 2018-08-30

Abstract

Fluid pumps with integrated electric motors may be implemented by a variety of techniques. In one example embodiment, a pump may include an electric motor with a magnetically driven impeller/rotor that eliminates the need for a mechanical roller bearing system and shaft seals, which are a common cause of failure in fluid pump systems.

Description

RELATED APPLICATIONS

This application claims priority to U.S. Patent Application No. 62/366,881, filed Jul. 26, 2016, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to fluid pumps driven by an electric 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.

BACKGROUND

Fluid pumps commonly have a discrete pumping section that is then coupled directly to an electric motor by means of a shaft coupling device that transmits the torque and rotation of the electric motor to the impeller of the pump, which is the mechanism by which energy is imparted into the fluid being pumped. Fluid pumps can have many configurations, three of which are centrifugal flow pumps, pitot tube pumps, and axial flow pumps, which all relate to the present invention.
In the past, pumps were 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 impeller. The pump impeller may or may not have one or more bearings that support the rotational loads of the impeller. Similarly, the electric motor may or may not have a set of bearings that support the rotational loads of the electric motor rotor. In some cases, the pump impeller could be attached directly to the shaft of the electric motor and utilize the bearings of the electric motor's rotor to support the rotational loads of both the electric motor rotor and the pump 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.
When pump failures occur, the failure typically involves a malfunction of the electric motor, bearings, and/or seals. Additionally, the greater the number of components in the pump and motor system, the greater likelihood that a failure can occur. The present disclosure attempts to minimize failures by reducing the number of components in the electrically driven pump system, with particular focus on common failure areas.

SUMMARY

The present disclosure addresses common pump failure problems by driving the pump impeller directly utilizing a magnetic force coupling between the magnetic field generated by the electric motor's stator and the pump impeller, which doubles as the rotor of the electric motor.
The attractive force of the electric motor's stator, which is located in the housing of the pump, may also enable the impeller to float in the center of the magnetic field and rotate as a result of the rotating magnetic field provided by the stator. The angle of the magnetic force gap between the stator poles and the impeller/rotor poles, with respect to the rotational axis of the impeller, is such to allow the magnetic forces to counteract the fluid forces on the impeller from the pumping action. Magnetically driving the impeller in this manner reduces and/or eliminates the need for a traditional mechanical bearing system and reduces rotational friction in the rotating components of the pump.
Magnetically driving the impeller, without the need for a shaft and bearings, eliminates the shaft seals that are a common source of failure in conventional pumps. The design of the pump housing where it interfaces with the rotating impeller may be such that a thin layer of fluid is directed to areas that function as a thin film bearing that assists the magnetic field in supporting the impeller during high speed rotation. When the pump is turned off, causing the impeller speed to decrease to a level where the thin film bearing no longer functions, a bushing material in the eventual contact area between the impeller and the housing may be specifically designed to allow the impeller to come to rest without damaging the impeller or the housing.
In one general aspect, an integrated electric motor and pump assembly may include an impeller/rotor assembly, a first stator assembly, a second stator assembly, and a housing. The impeller/rotor assembly may include a body having a number of poles located around its periphery and a number of vanes adapted pump a fluid when turned. The first stator assembly and the second stator assembly may be located on opposite sides of the impeller/rotor assembly, and each stator may include a body having a number of poles located around its periphery. The poles of the stator assemblies may be adapted to interact with the poles of the impeller/rotor assembly to drive impeller/rotor assembly to pump a fluid. The housing may be around the impeller/rotor assembly, the first stator assembly, and the second stator assembly. The pump assembly may be configured as a centrifugal pump, an axial pump, or a pitot-tube pump.
In particular implementations, the impeller/rotor assembly is suspended by the magnetic force field of the stator assemblies during operation. The impeller/rotor assembly may also be supported by a thin fluid film bearing derived from a specific directed flow of the fluid being pumped. The impeller/rotor assembly may include a bushing surface adapted to allow the impeller/rotor assembly to come to rest after the pump is turned off.
In some implementations, the impeller/rotor assembly may include one inlet, and in other implementations, the impeller/rotor assembly may include two inlets, each on opposite sides of the impeller/rotor assembly from one another.
In certain implementations, the integrated electric motor and pump assembly may include a motor controller integrated into the pump housing.
In particular implementations, the magnetic flux gap between the stator assemblies and the impeller/rotor assembly may be angled with respect to the rotational axis such as to counteract the reaction forces imposed on the impeller/rotor assembly by the fluid flow process.
In some implementations, the stator assemblies may be switched-reluctance stators.
In certain implementations, the poles of the impeller/rotor assembly may be composed of non-permanent magnets.
In particular implementations, the stator assemblies may be of an inductance motor type, and the impeller/rotor assembly poles comprise conductors.
In some implementations, the stator assemblies may be of a synchronous reluctance type, and the impeller/rotor assembly may be of a synchronous reluctance type.
In certain implementations, the stator assemblies are of a transverse flux type.
The poles of the stator assemblies may include C-shaped elements that each have a conductor wrapper therearound.
In some implementations, the stator assemblies may include auxiliary poles, and the impeller/rotor assembly may include at least one control ring. The auxiliary poles may be adapted to create a magnetic flux that interacts with the control ring to position the impeller/rotor assembly.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a line drawing illustrating a cross-section of an example single intake centrifugal pump in accordance with one embodiment of the present invention.

FIG. 2 is a line drawing illustrating a cross-section of an example dual intake centrifugal pump in accordance with one embodiment of the present invention.

FIG. 3 is a line drawing illustrating a cross-section of an example axial flow impeller/rotor in accordance with one embodiment of the present invention.

FIG. 4 is a line drawing illustrating an example impeller/rotor assembly in accordance with another embodiment of the present invention.

FIG. 4A is a line drawing illustrating another example impeller/rotor assembly in accordance with yet another embodiment of the present invention.

FIG. 5 is a line drawing illustrating an example axial flow impeller/rotor in accordance with an embodiment of the present invention.

FIG. 6 is a line drawing illustrating an example stator coil assembly in accordance with one embodiment of the present invention.

FIG. 6A is a line drawing illustrating another example stator coil assembly in accordance with another embodiment of the present invention.

FIG. 7 is a line drawing illustrating an example pump that includes an integrated motor controller.

FIG. 7A is a line drawing illustrating an example pump that includes an integrated motor controller.

FIG. 8 is a line drawing illustrating a cross-section of an example pump that includes a magnetically-driven pitot tube pump fluid volume.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a cross-section of an example single-intake centrifugal pump 100 in accordance with one embodiment of the present invention. As illustrated, pump 100 operates by a two-phase, transverse flux technique. In other embodiments, pump 100 may operate according to single-phase, transverse flux techniques, other poly-phase, transverse flux techniques, radial flux techniques, axial flux techniques, or other magnetic flux techniques. Among other things, pump 100 includes a housing 110, two stator assemblies 120 a and 120 b, and an impeller/rotor assembly 130. Multiple impeller/rotor assemblies and multiple stator assemblies may be utilized in other embodiments.
Housing 110 is primarily responsible for supporting stator assemblies 120 a and 120 b. Housing 110 includes an inlet for drawing in the fluid (e.g., liquid and/or gas) being pumped and an outlet for discharging the fluid be pumped. Housing 110 is typically made of a structural material (e.g., plastic, composite, or iron).
Each stator assembly 120 a and 120 b includes a body 122 and a number of poles 124. Body 122 is primarily responsible for supporting poles 124 and is typically made of a structural material (e.g., plastic or iron). Each pole 124 includes a C-shaped body 126 through which is wound an electrically conductive coil 128. Bodies 126 may generally be made any shape that enables completion of the magnetic circuit and be of a ferromagnetic material (e.g., steel). In particular implementations, bodies 126 may be made of laminated electrical steel or soft magnetic composite material. Coils 128 may be made of a conducting material (e.g., copper or aluminum). As illustrated, pump 100 includes 12 poles 124 for each stator assembly, but other numbers of poles may be used in other embodiments.
Impeller/rotor assembly 130 includes a body 132 having number of vanes 133 for moving the fluid being pumped once it enters the inlet. Spaced around the periphery of the impeller/rotor body 132 are a number of apertures 134 through which to discharge the fluid being pumped. Body 132 is preferably made of a non-ferromagnetic material (e.g., plastic or aluminum).
Also spaced around the periphery of impeller/rotor assembly 130 are a number of ferromagnetic poles 136. In the illustrated embodiment, the ferromagnetic poles 136 are shaped as elongated blocks. The ferromagnetic poles 136 may have other shapes (e.g., plates) appropriate for completing a magnetic circuit with the stator assemblies' poles. In this embodiment, the ferromagnetic poles 136 located on each side of impeller/rotor assembly 130 are angularly offset from each other circumferentially, rendering only one set viewable in FIG. 1 (i.e., on the inlet side). This allows pump 100 to operate in a 2-phase manner. Ferromagnetic poles 136 correspond to the poles 124 in the stator assemblies 120 a and 120 b. Ferromagnetic poles 136 may be made of ferromagnetic material (e.g., steel, iron, etc.).
Pump 100 also includes two fluid bearings 140 a and 140 b. Fluid bearings 140 a and 140 b help support the impeller/rotor assembly 130 during at least high-speed operation. Thus, impeller/rotor assembly 130 does not have a mechanical bearing upon which it rotates during high-speed operation.
Fluid bearings 140 a and 140 b may be separate inserts or formed in the design of the pump housing 110 where it interfaces with the impeller/rotor assembly 130 such that a thin layer of the fluid being pumped is directed to areas that function as a thin film bearing, which assists the magnetic field in supporting the impeller during high speed rotation. For pump 100, pump housing 110 is designed to allow an interface between the fluid bearings 140 a, 140 b and the impeller/rotor body 132.
During operation, when active, each conductive coil 128 induces a magnetic flux in the associated ferromagnetic pole 124 of the stators 120 a and 120 b, which creates a magnetic field. This created magnetic field is then used to attract the ferromagnetic poles 136 of the impeller/rotor assembly 130 toward the ferromagnetic poles of the stators 120 a and 120 b, creating a rotation, in an attempt to reduce the reluctance of the magnetic circuit between the ferromagnetic poles. Moreover, the impeller/rotor assembly 130 is suspended in the magnetic force field of the stator.
When the ferromagnetic poles 136 of the impeller/rotor assembly 130 begin to align with the poles of the stator assemblies 120 a and 120 b due to the rotation, the ferromagnetic poles 124 may be switched off, prior to complete alignment, resulting in no further attraction between the stator poles 120 a and 120 b and the ferromagnetic poles 136 of the impeller/rotor 130. In a single phase embodiment, once the ferromagnetic poles 136 of the impeller/rotor 130 have passed the aligned position of the ferromagnetic poles 124 of the stator 120 a and 120 b, the poles 124 of the stators 120 a and 120 b may then be activated again when the impeller/rotor assembly 130 has rotated a sufficient distance past the previous aligned position with the poles 124 (e.g., just past half the distance between the poles). In a multiphase embodiment, the next set of stator poles may be activated shortly after the first set are switched off (e.g., when the impeller/rotor assembly has rotate just passed the previously active stator poles).
The attractive force of the electric motor stator assemblies 120 a and 120 b, which are located in the housing 110 of the pump 100, allows the impeller/rotor 130 to float in the center of the magnetic field and rotate as a result of the rotating magnetic field provided by the stator assemblies 120 a and 120 b. In particular implementations, the angle of the magnetic force gap between the stator poles 124 and the impeller/rotor poles 136, with respect to the rotational axis of the impeller, may be such as to allow the magnetic forces to counteract the fluid forces on the impeller/rotor 130 from the fluid pumping action.
Magnetically driving the impeller/rotor 130 in this manner eliminates the need for a traditional mechanical bearing system and reduces rotational friction in the rotating components of the pump 100. When the magnetic field is shut off while the impeller/rotor poles 136 move past alignment with the stator poles 124, the fluid bearing and the latent magnetization act to maintain the impeller/rotor assembly 130 in the proper orientation.
When the pump 100 magnetic field is turned off, causing the impeller/rotor assembly 130 rotational speed to decrease to a level where the thin film bearings 140 a and 140 b no longer function, the impeller/rotor assembly 130 structural material functions as a bushing material in the eventual contact area between the impeller/rotor assembly 130 and the housing 110 that is specifically designed to allow the impeller/rotor assembly 130 to come to rest without damaging the impeller/rotor assembly 130 or the housing 110. The structural material may, for example, be a polymer bearing plastic or a more traditional bushing material (e.g., bronze). Alternately there may be a separate component located between the impeller/rotor assembly 130 and the housing 110 that serves this function as well. In some implementations, the fluid bearings 140 a, 140 b can function as the resting bushing.
Pump 100 solves a common pump failure problem by driving the pump impeller/rotor 130 directly utilizing a magnetic force coupling between the magnetic field generated by the electric motor stators 120 a and 120 b and the magnetic field induced into the pump impeller/rotor 130, which doubles as the salient impeller/rotor of the electric motor. Magnetically driving the impeller/rotor without the need for a shaft and bearings eliminates the shaft seals that are a common source of failure in conventional pumps. The design of the pump housing 110 and impeller/rotor 130 interface is such that fluid is directed specifically to desirable areas and kept away from less desirable areas in order to maximize the functionality, efficiency, and efficacy of the pump. Additionally, by not using an impeller shaft or seals, pump 100 may be utilized effectively in caustic or corrosive gaseous and cryogenic pumping applications.
In other embodiments, the electric motor stator assemblies may be of a single-phase transverse type or a poly-phase, transverse type (e.g., by winding the coils around the periphery of the stator between the arms of the C-shape bodies in a serpentine manner, instead of around the bases as in this embodiment). In some other embodiments, a synchronous reluctance stator type may be used with a synchronous reluctance impeller/rotor. In certain embodiments, the electric motor stator may be of a brushless DC stator type with permanent magnets located on the impeller/rotor 130. In particular embodiments, the stator coils 128 may be liquid cooled by the fluid being pumped.
In some implementations, only one stator assembly may be used. For example, if impeller/rotor assembly is held in place by a bearing and/or bushing on one side, only a single stator may be required to drive the impeller/rotor assembly.
In particular implementations, the impeller/rotor assembly may include an integral conductive coil that allows integral sensors and electronics to be powered through the inductance of the impeller/rotor. The sensors may be used to detect and transmit the pressure and flow characteristics of the fluid being pumped.
FIG. 2 illustrates a cross-section of an example dual intake centrifugal pump 200 in accordance with one embodiment of the present invention. As illustrated, centrifugal pump 200 operates by a single-phase, transverse flux technique. In other embodiments, pump 200 may operate according to poly-phase, transverse flux techniques, radial flux techniques, or other magnetic flux techniques.
Similar to pump 100, pump 200 includes a housing 210, two stator assemblies 220, and an impeller/rotor assembly 230. Additionally, stator assemblies 220 include a number of poles 226, and impeller/rotor assembly includes a number of poles 236. Housing 210 is also designed to create fluid bearings 240 for impeller/rotor assembly 230.
FIG. 3 illustrates a cross-section of an example axial flow pump 300 in accordance with one embodiment of the present invention. As illustrated, the axial flow pump 300 operates by a single phase, transverse flux technique. In other embodiments, the axial flow pump 300 may operate in poly phase, radial flux, axial flux or other magnetic flux techniques. Similar to pump 100 and 200, pump 300 includes a housing 310, stator poles 320, and impeller/rotor poles 336, a fluid inlet, and a fluid outlet. In this embodiment, however, stator poles 320 and impeller/rotor poles 336 are aligned at an angle to the outlet flow. In particular implementations, the angle of the magnetic force gap between the stator poles 320 and the impeller/rotor poles 336 with respect to the rotational axis of the impeller/rotor 330 is such to enable the magnetic forces to counteract the fluid forces on the impeller/rotor from the pumping action. Additionally, impeller/rotor assembly 330 generates an axial flow, and coil 322 is transverse.
Pump housing 310 forms fluid film bearings between it and the impeller/rotor assembly 330. The fluid bearings are not shown for clarity, but function in a similar manner as in the other embodiments of the present invention.
FIG. 4 illustrates an example centrifugal impeller/rotor assembly 400 in accordance with one embodiment of the present invention. Impeller/rotor assembly 400 includes a body 432 having a number of vanes 433 for moving the fluid being pumped once it enters the inlet. Spaced around the periphery of body 432 are a number of apertures 434 through which to discharge the fluid being pumped. Also spaced around the periphery of impeller/rotor assembly 400 are a number of ferromagnetic poles 436. Ferromagnetic poles 436 may be made of ferromagnetic material (e.g., steel, iron, etc.). The poles 436 on each side of impeller/rotor assembly 400 are offset from each other circumferentially because, as shown, the associated pump uses a two-phase motor configuration. The stator poles may be aligned and the rotors poles staggered, or the stator poles can be staggered and the rotor poles aligned in the two-phase embodiment.
FIG. 4A illustrates an example centrifugal impeller/rotor assembly 400′ in accordance with another embodiment of the present invention. Similar to impeller/rotor assembly 400, impeller/rotor assembly 400′ includes a body 432 having a number of vanes for moving the fluid being pumped once it enters the inlet, and spaced around the periphery of body 432 are a number of apertures through which to discharge the fluid being pumped. Also spaced around the periphery of impeller/rotor assembly 400′ are a number of ferromagnetic poles 436, which are circumferentially offset from each other on either side of impeller/rotor assembly 400 to provide for a two-phase motor configuration.
Impeller/rotor assembly 400′ also includes sensing targets 438 and two control rings 440 on either side of body 432, only of which is viewable here. Sensing targets 438 may allow sensing of the Euclidean position of impeller/rotor assembly 400′. This sensing may occur by magnetic, optical, inductive, or capacitive techniques. The sensed position may be provided to a controller, which will determine whether, and how, to adjust the Euclidean position of impeller/rotor assembly 400′. To adjust the position, the stator assemblies may include poles adapted to interact with control rings 440, which may be made of a ferromagnetic or permanent magnet material. This control system may be used to keep impeller/rotor assembly centered between the stators.
FIG. 5 illustrates an axial flow impeller/rotor assembly 500 in accordance with one embodiment of the present invention. Impeller/rotor assembly 500 may be operated by single-phase, transverse flux techniques, poly-phase, axial flux techniques, radial flux techniques, or other magnetic flux techniques.
Impeller/rotor assembly 500 includes a body 510. Body 510 is responsible for maintaining the shape of impeller/rotor assembly 500. Body 510 includes an inlet for drawing in the fluid being pumped and an outlet for discharging the fluid being pumped. To move the fluid, the body includes vanes 512 (only one of which is viewable). Body 510 is typically made of a non-magnetic material (e.g., aluminum or plastic).
Impeller/rotor 500 includes two sets of ferromagnetic elements 514, 514′, one on each axial side of body 510. Ferromagnetic elements 514, 514′ correspond to poles in the stator assemblies. Ferromagnetic elements 514, 514′ may be made of ferromagnetic material (e.g., steel, iron, etc.).
In operation, impeller/rotor assembly 500 may be supported by fluid bearings. The fluid bearings may support impeller/rotor assembly 500 during at least high-speed operation. Thus, impeller/rotor assembly 500 does not have a mechanical bearing upon which it rotates during high-speed operation.
FIG. 6 illustrates an example stator assembly 600 in accordance with an embodiment of the present invention. Stator assembly 600 includes a body 622 and a number of poles 624. Body 622 is primarily responsible for supporting poles 624 and is typically made of a structural material (e.g., plastic or iron). Each pole 624 includes a C-shaped body 626 around which is wound an electrically conductive coil 628. Bodies 626 may be made of a ferromagnetic material (e.g., steel). In particular implementations, bodies 626 may be made of laminated electrical steel. Coils 628 may be made of a conducting material (e.g., copper or aluminum). As illustrated, stator assembly 600 includes 12 poles 624, but other numbers of poles may be used in other embodiments.
FIG. 6A illustrates an example stator assembly 600′ in accordance with another embodiment of the present invention. Similar to stator assembly 600, stator assembly 600′ includes a body 622 and a number of poles 624. Body 622 is primarily responsible for supporting poles 624 and is typically made of a structural material (e.g., plastic or iron). Poles 624 may, for example, include C-shaped bodies around which is wound an electrically conductive coil (at their end or between their legs, for example).
Stator assembly 600′ also includes auxiliary poles 630 spaced around the inner circumference of body 622. As illustrated, each auxiliary pole 630 has C-shaped body 632 around which is wrapped a coil 634. Auxiliary poles 630 may be used to position a impeller/rotor assembly (e.g., to keep it centered) rotating near stator assembly 600′, such as impeller/rotor assembly 400′.
FIG. 7 illustrates a cross-section of an example single intake pump 700 in accordance with one embodiment of the present invention. As illustrated, pump 700 operates by a two-phase, transverse flux technique. In other embodiments, pump 700 may operate according to two-phase, transverse flux techniques, radial flux techniques, or other magnetic flux techniques. Among other things, pump 700 includes a housing 710, two stator assemblies 720, an impeller/rotor assembly 730, fluid bearings 740, and an integrated motor controller 750.
Controller 750 is responsible for controlling the switching on and off of the magnetic field of the poles of the stator assemblies 720. Controller 750 may, for example, include power semi-conductors and gate drivers for activating the stator poles and a processor (e.g., a microprocessor, a microcontroller, an application specific integrated circuit, a field-programmable gate array) in order to perform logical operations.
In one mode of operation, controller 750 may switch the magnetic field of certain stator poles on as a ferromagnetic element of the impeller/rotor 730 comes near a corresponding stator pole. This may induce a magnetic flux in the ferromagnetic elements of the impeller/rotor 730, which will create a magnetic field by which the ferromagnetic elements may try to align themselves with the poles of the stators 720.
When the ferromagnetic elements of the impeller/rotor assembly 730 and the stator poles are approximately aligned, the magnetic field may be turned off, and the momentum of impeller/rotor assembly 730 will carry the ferromagnetic elements of the impeller/rotor assembly past the aligned position. When the ferromagnetic elements of the impeller/rotor assembly come near the next set of poles of the stator, the magnetic field may again be turned on to attempt alignment of the ferromagnetic elements (poles). To determine when to activate and deactivate the magnetic field, controller 750 may sense the rotational position of the impeller/rotor 730 using a variety of techniques (e.g., electronic, optical, or magnetic).
The advantages of having the controller integrated into the motor include, in at least some cases, faster response time for activating the driving electronics (e.g., power semi-conductors and gate drivers), reduced resistance for the coil circuits, reduced inductance for the coil circuits, reduced product footprint and reduced wiring requirements for the motor/pump installation. A controller similar to controller 750 may be used in various embodiments of the invention.
FIG. 7A illustrates a cross-section of another example single intake pump 700′ in accordance with one embodiment of the present invention. As illustrated, pump 700′ operates by a single-phase, transverse flux technique. In other embodiments, pump 700′ may operate according to poly-phase, transverse flux techniques, radial flux techniques, or other magnetic flux techniques. Among other things, pump 700′ includes two stator assemblies 720, an impeller/rotor assembly 730, fluid bearings 740, an axial bushing 742, and an integrated motor controller 750.
Fluid bearings 740 assist in supporting impeller/rotor assembly 730 in high speed operations by directing a portion of the fluid being pumped between the impeller/rotor assembly 730 and the housing. Axial bushing 742 assists in maintaining impeller/rotor assembly 730 at the proper position axially.
FIG. 8 illustrates a cross-section of a pitot tube type pump 800 embodiment. Pump 800 may be driven by any of a variety of switched-reluctance motor techniques (e.g., by single-phase, transverse flux techniques, poly-phase, axial flux techniques, or radial flux techniques) or other magnetic flux techniques. In particular implementations, pump 800 may be driven by a hybrid of radial and axial flux techniques. Pump 800 may also be driven by other electric motor techniques (e.g., synchronous).
Traditionally, a fluid volume such as fluid housing 804 is driven by a coupling connected to a separate electric motor while the pitot tube pick up 806 is stationary inside the fluid volume. In the present embodiment, the fluid housing 804 is driven directly by a magnetic coupling to the rotating magnetic field of the stator assemblies 801 a, 801 b and suspended in that magnetic field, along with a thin film fluid bearing/seal 805. Thus, fluid housing 804 serves as the impeller and rotor of pump 800. Fluid housing 804 may be made of any appropriate non-magnetic material.
When the magnetic field is turned off, the fluid housing 804 subsequently comes to rest on an integrated bushing. In certain implementations, the fluid film bearing/seals 805 may also serve as the resting bushing when the fluid housing 804 comes to rest.
The pitot tube pick up 806 remains stationary and serves as the outlet of the pump. The rotor poles 803 are attached to the fluid housing 804, which is rotated and suspended in the magnetic field of the stator poles 802, which may, for example, be C-shaped or E-shaped. The fluid is then picked up by the stationary pitot tube 806, creating high fluid pressure at a low flow rate.
Pump 800 is contained in a pump housing 807 which also supports the fixed non-rotating inlet and the outlet of the pump. The magnetic air gap 808 between rotor poles and stator assemblies 801 is angled such as to counteract the hydraulic forces of the fluid pumping action of the pump and to radially and axially support the rotating fluid housing 804 during the pumping operation.
A variety of implementations have been described, and several others have been mentioned or suggested. Additionally, those of skill in the art will recognize that a variety of additions, deletions, substitutions, and transformations may be made while still achieving an integrated electric motor and pump assembly. Thus, the scope of the protected matter should be judged on the following claims, which may encompass one or more concepts of one or more implementations.

Claims

1. An integrated electric motor and pump assembly, comprising:

an impeller/rotor assembly including a body having a number of poles located around its periphery, the assembly including a number of vanes adapted pump a fluid when turned;

a first stator assembly and a second stator assembly located on opposite sides of the impeller/rotor assembly, each stator including a body having a number of poles located around its periphery, the poles of the stator assemblies adapted to interact with the poles of the impeller/rotor assembly to drive impeller/rotor assembly to pump a fluid; and

a housing around the impeller/rotor assembly, the first stator assembly, and the second stator assembly.

2. The integrated electric motor and pump assembly of claim 1, wherein the impeller/rotor assembly is suspended by the magnetic force field of the stator assemblies during operation.

3. The integrated electric motor and pump assembly of claim 1, wherein the impeller/rotor assembly is supported by a thin fluid film bearing derived from a specific directed flow of the fluid being pumped.

4. The integrated electric motor and pump assembly of claim 1, wherein the impeller/rotor assembly comprises a bushing surface adapted to allow the impeller/rotor assembly to come to rest after the pump is turned off.

5. The integrated electric motor and pump assembly of claim 1, wherein the impeller/rotor assembly comprises two inlets, each on opposite sides of the impeller/rotor assembly from one another.

6. The integrated electric motor and pump assembly of claim 1, further comprising a motor controller integrated into the pump housing.

7. The integrated electric motor and pump assembly of claim 1, wherein the pump assembly is configured as a centrifugal pump.

8. The integrated electric motor and flow pump assembly of claim 1, wherein the pump assembly is configured as an axial pump.

9. The integrated electric motor and pump assembly of claim 1, wherein the magnetic flux gap between the stators and the impeller/rotor assembly are angled with respect to the rotational axis such as to counteract the reaction forces imposed on the impeller/rotor assembly by the fluid flow process.

10. The integrated electric motor and pump assembly of claim 1, wherein the stator assemblies comprise switched-reluctance stators.

11. The integrated electric motor and pump assembly of claim 11, wherein the poles of the impeller/rotor assembly are composed of non-permanent magnets.

12. The integrated electric motor and pump assembly of claim 1, wherein the stator assemblies are of an inductance motor type, and the impeller/rotor assembly poles comprise conductors.

13. The integrated electric motor and pump assembly of claim 1, wherein the stators are of a synchronous reluctance type, and the impeller/rotor assembly is of a synchronous reluctance type.

14. The integrated electric motor and pump assembly of claim 1, wherein the stator assemblies are of a transverse flux type.

15. The integrated electric motor and pump assembly of claim 1, wherein the integrated impeller/rotor assembly comprises a pitot-tube pump.

16. The integrated electric motor and pump assembly of claim 1, wherein the poles of the stator assemblies comprise C-shaped elements that each have a conductor wrapper therearound.

17. The integrated electric motor and pump assembly of claim 1, wherein:

the stator assemblies comprise auxiliary poles; and

the impeller/rotor assembly comprises at least one control ring, the auxiliary poles adapted to create a magnetic flux that interacts with the control ring to position the impeller/rotor assembly.