Fluid Pump With Indirectly Cooled Sortor

Description

BACKGROUND

Centrifugal fluid pumps may be used, for example, as cooling circuit pumps for motor vehicles. The cooling circuit may cool a drive motor, a charge air heat exchanger, a battery and/or a control unit of the motor vehicle.

Electric coolant pumps that are air cooled are limited in the amount of hydraulic power that can be delivered by the pump by the difficulty in transferring the internally generated heat of the motor to the outside environment. Most of this heat is generated in the stator windings of the motor. The limiting factors of the heat dissipation include the low thermal conductivity of the motor housing which may be formed of a plastic material, and the lack of sufficient ambient air circulation around the outside of the motor housing to remove the heat.

Liquid cooled fluid pumps offer a considerable packaging advantage compared to an air-cooled design. In some liquid cooled fluid pumps, a generally cup-shaped, plastic motor pot separates the dry side of the pump including the stator from the wet side including the rotor. Due to manufacturing reasons, it is difficult to create a solid mechanical or thermal contact between the stator and any part of the pump which is in direct thermal contact to the fluid. In addition, some liquid cooled pumps may be approaching the thermal limit for stator winding temperatures.

It is desired to increase the efficacy of the heat transfer from the stator winding to the coolant. Increased heat transfer efficacy may result in increased power capacity for a given pump size. Taking advantage of lower coolant temperatures in battery electric vehicles (BEVs) to increase the power density of coolant pumps allows for smaller packaging in integrated modules while increasing the thermal limits of the pump.

SUMMARY

A fluid pump is described that addresses the drawbacks mentioned above. The fluid pump may be a volute-type centrifugal liquid-cooled fluid pump but is not limited thereto. The fluid pump is configured so that when fluid is pumped through a wet side of the motor, cooling of the stator coils, the control electronics and the rotor is improved relative to some conventional fluid pumps. The motor pot, which separates the wet side of the motor from the dry side of the motor, may be a deep drawn, thermally-conductive motor pot having an open end that faces the impeller and a closed end that faces the control electronics. The motor pot includes a first flange that encircles the motor pot open end and extends radially. As used herein, the term “radially” refers to a direction that is perpendicular to the rotational axis of the motor. A stator-facing surface of the first flange includes concavities that are arranged in series along a circumference of the first flange. Each concavity is axially aligned with and opens facing a respective one of the stator windings. As used herein, the term “axially” refers to a direction that is parallel to the rotational axis of the motor. Each concavity is shaped and dimensioned to receive a curved end portion of the one of the stator windings therein in a close fit such as a clearance fit. A thermal interface material (TIM) may be disposed in the gap between the curved end portion of the stator windings and the corresponding cavities, whereby heat from the stator windings is conducted to the motor pot and then to the fluid being pumped through the wet side of the motor.

In addition, or alternatively, TIM may be placed between a side of the stator winding and a sidewall of the motor pot and/or between a rotor-facing surfaces of the stator teeth and the sidewall of the motor pot, whereby heat from the stator windings is conducted to the motor pot and then to the fluid being pumped through the wet side of the motor.

In addition, or alternatively, the motor pot may include a second flange that encircles the motor pot closed end and extends radially with respect to a rotational axis of the motor. A stator-facing surface of the second flange includes concavities that are arranged in series along a circumference of the second flange. Each concavity is axially aligned with and opens facing a respective one of the stator windings. Each concavity is shaped and dimensioned to receive a curved end portion of the one of the stator windings therein in a close fit such as a clearance fit. A thermal interface material (TIM) may be disposed in the gap between the curved end portion of the stator windings and the corresponding cavities, whereby heat from the stator windings is conducted to the motor pot and then to the fluid being pumped through the wet side of the motor.

Thus, the fluid pump has a thermally conductive pot (for example, a pot formed of metal such as stainless steel, a thermally conductive plastic, etc.) which may be thermally connected to the stator via a TIM at the inner teeth and/or winding ends of the motor stator.

The benefit of this solution is a reduction of the stator temperatures when compared with the “air cooled” stator configuration. For example, in a liquid cooled fluid pump in which the stator operates at an air and coolant temperature of 90 degrees Celsius and has an upper limit temperature of 180 degrees Celsius, a reduction in stator temperatures of 30-40 degrees Celsius was achieved based on measurements using TIM only on the winding turns disposed next to the impeller. This allows a doubling of the hydraulic output of the fluid pump in the same physical package space.

This structure takes advantage of lower coolant temperatures in battery electric vehicles (BEVs) to increase the power density of the coolant pumps and allows for smaller packaging in integrated modules while increasing the thermal limits of the pump drive.

In some aspects, a fluid pump includes a pump casing that includes a pump housing and a motor pot. The fluid pump includes a drive casing that houses control electronics. The fluid pump also includes an impeller disposed in the pump housing and a motor that drives the impeller. The pump housing has a concave shape that includes a housing closed end and a housing open end opposite the housing closed end. The pump housing defines a pump inlet and a pump outlet. An inner surface of the pump housing includes a volute that directs fluid toward the pump outlet. The motor pot has a concave shape that includes a pot closed end and a pot open end opposite the pot closed end. The motor pot includes a pot sidewall that extends between the pot open end and the pot closed end. The pot open end is assembled with the housing open end so as to define a pump wet space between the motor pot and the pump housing. The motor includes a stator disposed in the pump housing in a dry area defined between the housing sidewall and the pot sidewall. The stator surrounds the pot sidewall. The motor also includes a rotor disposed in the motor pot so as to reside in the wet space and be surrounded by the stator. The rotor is connected to the impeller. The motor is configured so that the rotor is rotatable relative to the stator. The motor pot includes a first flange that protrudes radially outward from the pot sidewall and the first flange encircles the pot open end. A peripheral portion of the first flange is fixed relative to the pump casing. An inner portion of the first flange is radially disposed between the peripheral portion and the pot sidewall and a stator-facing surface of the inner portion of the first flange defines a plurality of first concavities.

In some embodiments, a thermally conductive material is in direct contact with a surface of the stator and a surface of the first flange.

In some embodiments, the stator comprises a stator body that defines stator teeth, each stator tooth supports a stator winding, and one of the first concavities of the stator-facing surface of the inner portion of the first flange is axially aligned with each stator winding.

In some embodiments, the first concavities are shaped and dimensioned to receive a portion of a stator winding in a clearance fit.

In some embodiments, a thermally conductive material is disposed between at least one stator winding and the respective one of the first concavities.

In some embodiments, the thermally conductive material is in direct contact with a surface of the at least one stator winding and a surface of the respective one of the first concavities.

In some embodiments, the motor pot includes a second flange that protrudes radially outward from the pot sidewall. The second flange encircles the pot closed end. The stator is axially disposed between the first flange and the second flange, and a thermally conductive material is disposed between the stator and the second flange.

In some embodiments, the thermally conductive material is in direct contact with a surface of the stator and a surface of the second flange.

In some embodiments, another thermally conductive material is disposed between the stator and the pot sidewall.

In some embodiments, the stator comprises a stator body that defines stator teeth. Each stator tooth supports a stator winding. A stator-facing surface of the second flange defines a plurality of second concavities, and one of the second concavities of the stator-facing surface of the second flange is axially aligned with each stator winding.

In some embodiments, the second concavities are shaped and dimensioned to receive a portion of a stator winding in a clearance fit.

In some embodiments, a thermally conductive material is disposed between at least one stator winding and the respective one of the second concavities.

In some embodiments, the thermally conductive material is in direct contact with a surface of the at least one stator winding and a surface of the respective one of the second concavities.

In some embodiments, a thermally conductive material is disposed between the stator and the pot sidewall.

In some embodiments, the thermally conductive material is in direct contact with a surface of the stator and a surface of the pot sidewall.

In some embodiments, the fluid pump includes control electronics disposed in the dry area, and thermally conductive material is disposed between the pot closed end and the control electronics.

In some embodiments, the thermally conductive material is in direct contact with a surface of the pot closed end and a surface of the control electronics.

In some embodiments, the motor pot is formed of a thermally conductive material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a fluid pump illustrating TIM disposed between a stator and a first flange of a motor pot.

FIG. 2 is a perspective view of the motor pot of FIG. 1 isolated from the fluid pump.

FIG. 3 is a perspective cross-sectional view of the motor pot of FIG. 2.

FIG. 4 is a cross-sectional view of the fluid pump of FIG. 1 illustrating TIM disposed between the stator and the first flange of a motor pot, and between the stator and a sidewall of the motor pot.

FIG. 5 is a cross-sectional view of an alternative embodiment fluid pump illustrating TIM disposed between the stator and the first flange of an alternative embodiment motor pot, and between the stator and a second flange of the motor pot.

FIG. 6 is a perspective cross-sectional view of the motor pot isolated from the fluid pump of FIG. 5.

FIG. 7 is a cross-sectional view of the fluid pump of FIG. 5 illustrating TIM disposed between the stator and the first flange of a motor pot, between the stator and a sidewall of the motor pot and between the stator and the second flange of the motor pot.

FIG. 8 is a cross-sectional view of another alternative embodiment fluid pump illustrating TIM disposed between the stator and the first flange of another alternative embodiment motor pot, and between the motor pot closed end and the control electronics of the fluid pump. In FIG. 8, the shroud is omitted.

FIG. 9 is a cross-sectional view of still another alternative embodiment fluid pump illustrating TIM disposed between the stator and the first flange of another alternative motor pot, between the motor pot closed end and a heat spreader, and between the heat spreader and the control electronics of the fluid pump.

FIG. 10 is another cross-sectional view of the fluid pump of FIG. 9 illustrating TIM disposed between the motor pot closed end and a heat spreader, and between the heat spreader and the control electronics of the fluid pump.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, a volute-type centrifugal liquid-cooled fluid pump 10 includes a pump casing 20 that defines a wet area through which fluid is pumped, and a drive casing 30 that houses an electric drive 32 that drives the pump 10. The pump casing 20 is formed by a first casing part referred to as the pump housing 22 and a second casing part referred to as the motor pot 80. The pump housing 22 is a generally cup-shaped structure and has an open end 25 that faces the motor pot 80. The motor pot 80 is also generally cup-shaped and includes an open end 81 that faces the pump housing 22. The pump housing 22 and motor pot 80 are assembled with the respective open ends 25, 81 adjoining to form an enclosed fluid chamber 12. The fluid chamber 12 forms the wet area of the pump 10. The motor pot 80 separates the wet area from the dry area 16, which is enclosed by the drive casing 30 and includes most components of the electric drive 32. The electric drive 32 has a rotor unit 60 that is disposed in the wet area and is rotatable about a rotational axis 14. The electric drive 32 has a stator 42 that is disposed in the dry area 16. In addition, the electric drive 32 has control electronics 38 including a controller (not shown) mounted on a printed circuit board 36 along with other ancillary electronic devices. The control electronics 38 are disposed in the dry area 16. Since the structure and functionality of a suitable electric motor are sufficiently known from the prior art, a detailed description of the electric drive 32 is omitted for the sake of brevity and simplicity of the description.

The motor pot 80 is a rigid structure that includes a generally cylindrical sidewall 83. The sidewall extends in parallel to the rotational axis 14 between the motor pot open end 81 and a motor pot closed end 82. An outer surface of the motor pot sidewall 83 faces the stator 42 and an inner surface of the motor pot sidewall 83 faces a rotor 61 of the rotor unit 60.

The motor pot open end 81 faces the pump housing 22 and is surrounded by a first flange 84. The first flange 84 protrudes generally radially outward from the motor pot sidewall 83 at the motor pot open end 81. The first flange 84 is used, in part, to secure the motor pot 80 relative to the pump casing 20. In the illustrated embodiment, a peripheral portion 84(1) of the first flange 84 is directly secured to the pump housing 22. In other embodiments, the first flange peripheral portion 84(1) may be directly secured to the drive casing 30, or alternatively, sandwiched between the pump housing 22 and the drive casing 30, while maintaining the above-described orientation.

A medial portion 84(3) of the first flange 84 is disposed between the peripheral portion 84(1) and the sidewall 83. The medial portion 84(3) is axially aligned with the stator 42 and is contoured to correspond to the shape of the stator 42. In particular, the stator-facing surface 84(4) of the medial portion 84(3) defines a plurality of first concavities 85 that are shaped and dimensioned to receive a portion of the stator winding curved ends 46 in a clearance fit. By this configuration, a narrow first gap g1 exists between stator-facing surface 84(4) of the first flange 84 and the stator 42.

The motor pot closed end 82 is opposite the motor pot open end 81. The motor pot closed end 82 is generally planar and parallel to the motor pot open end 81. An outer surface of the motor pot closed end 82 faces the control electronics 38. In the illustrated embodiment, a partition 31 segregates the stator 42 and motor pot 80 from the control electronics 38. The partition 31 is perpendicular to the rotational axis 14 and extends between opposed inner surfaces of the drive casing 30.

The motor pot 80 is formed of a thermally conductive material such as a metal or thermally conductive plastic.

The rotor unit 60 is disposed in the fluid chamber 12 in a concavity defined by the motor pot sidewall 83 and the motor pot closed end 82 so that the rotor unit 60 is disposed in the wet area. The rotor unit 60 includes a rotor 61 and an impeller 62, which are connected to one another in a rotationally fixed manner whereby movement of the rotor 61 is transmitted to the impeller 62. When the pump 10 is in operation, the rotor unit 60 conveys fluid from a pump housing inlet 24 to a pump housing outlet 23 by means of the impeller 62.

The stator 42 is disposed in the drive casing 30 and surrounds the motor pot sidewall 83 so that the stator 42 is disposed in the dry area 16. The stator 42 is controlled by the control electronics 38. The stator 42 includes a plurality of stator teeth 43 (best seen in FIG. 10) that protrude radially inward toward the rotational axis 14. The stator teeth 43 are axially elongated and are spaced apart around a circumference of the motor pot 80. The stator teeth 43 surround the motor pot sidewall 83 in the vicinity of the rotor 61. In particular, an end face 44 of each stator tooth 43 faces the outer surface of the motor pot sidewall 83 with the second gap g2 therebetween.

The stator 42 includes electrically conductive coils 45, each coil 45 being wound onto and supported by a respective stator tooth 43. Each coil 45 includes generally linear portions 47 that extend axially on opposed long sides of a given stator tooth 43, and curved ends 46 that join the linear portions 47. For each coil 45, the curved end 46 that faces the first flange 84 is received in a respective first concavity 85 with the first gap g1 disposed between the curved surface of the first concavity 85 and the curved end 46 of the stator coil 45.

When the electric drive 32 is in operation, the stator coils 45 generate a rotating magnetic field, by means of which the rotor unit 60 is driven to rotate about a rotational axis 14.

The rotor unit 60 is rotatably mounted on a pump shaft 48 via bearings 49, 50. The pump shaft 48 is fixed relative to the pump casing 20. In the illustrated embodiments, the bearing 50 is designed as a sleeve bearing but is not limited to this type of bearing. The rotational axis 14 runs through the center of the pump shaft 48 in the axial direction and thus corresponds to the center axis of the pump shaft 48.

A first end 48(1) of the pump shaft 48 faces the pump housing inlet 24 and is connected in a rotationally fixed manner to a stop element 51 that protrudes from an inner surface of the pump housing 22 so as to be centered on the rotational axis 14 in the vicinity of the inlet 24. In particular, the bearing 49 is provided on the shaft first end 48(1), and the sleeve bearing 50 surrounds the pump shaft 48 and extends between a hollow boss 86 and the bearing 49. The boss 86 is centered on the rotational axis 14 and protrudes integrally from a closed end 82 of the motor pot 80 toward the open end 81. The boss 86 receives and supports the shaft second end 48(2) in such a way that the pump shaft 48 is fixed relative to the boss 86. The stop element 51 is part of a bearing point for the rotor unit 60 and prevents the pump shaft 48 from moving in the radial and axial directions. The stop element 51 has a circular profile and includes holding webs 53. The holding webs 53 are arranged on the circumference of the stop element 51. The stop element 51 minimizes or restricts a displacement of the bearing 49 or the sleeve bearing 50 in the axial direction and, as a result, an axial displacement of the rotor unit 60. During operation, such an axial displacement of the rotor unit 60 may be generated, for example, by the axial thrust of the impeller 62.

The sleeve bearing 50 is designed as part of the rotor 61 and thus moves (e.g., rotates) relative to the stop element 51 during operation. In order to minimize the high frictional forces between the bearing 49 and the stop element 51 as well as the associated sluggishness of the rotor 61 and the resulting wear of the stop element 51, a thrust washer 52 is provided between the stop element 51 and the bearing 49. The thrust washer 52 is preferably designed in such a way that there is a friction-optimized material pairing between the thrust washer 52 and the bearing 49.

The impeller 62 is connected to the rotor 61 and the impeller 62 rotates about the rotational axis 14 in concert with the rotor 61. The impeller 62 includes impeller blades 68 that protrude toward a curved shroud 64. The impeller blades 68, which are disposed between the impeller base plate 63 and the shroud 64, face the pump housing inlet 24. The shroud 64 is disposed between the impeller blades 68 and the pump housing 22 and is configured to direct fluid from the pump housing inlet 24 into the impeller blades 68. The impeller 62 draws fluid from the pump housing inlet 24 in an axial direction and redirects the main volume flow of the fluid out of the fluid chamber 12 in the radial direction via a volute 26 that is incorporated into the pump housing 22. Fluid exiting the volute 26 is directed to the pump housing outlet 23.

In the embodiment illustrated in FIGS. 1-3, a thermally-conductive gap-filling material 100, e.g., a TIM, is disposed in the first gap g1 between the curved surface of the first concavity 85 and the curved end 46 of the stator coil 45 and establishes an efficient heat transfer pathway from the stator 42 to the motor pot first flange 84 and then to the pump housing 22 and drive casing 30. In addition, the motor pot 80 is cooled by the coolant flowing through the fluid chamber 12 as the pump operates.

The TIM 100 may be metal-based or polymer-based and may be in the form of a thermal paste, a thermal adhesive, a thermal gap filler, a thermally conductive pad, a phase-change material, etcetera. The TIM 100 is disposed between at least one stator coil 45 and the respective one of the first concavities 85. In particular, the TIM 100 fills the first gap g1 so that the TIM 100 is in direct contact with a surface of the at least one stator coil 45 and a surface of the respective one of the first concavities 85. In the illustrated embodiment, the TIM 100 fills the first gap g1 between each stator coil 45 and the respective one of the first concavities 85.

Referring to FIG. 4, in some embodiments, the TIM 100 is disposed both in the first gap g1 and in the second gap g2 between the outer surface of the motor pot sidewall 83 and the stator 42. Placement of the TIM 100 in the second gap g2 establishes an efficient heat transfer pathway between the stator teeth 43 and the motor pot sidewall 83 and then to the motor pot first flange 84, the pump housing 22 and drive casing 30. In addition, the motor pot 80 is cooled by the coolant flowing through the fluid chamber 12 as the pump operates.

The TIM 100 is disposed between at least one stator tooth 43 and the motor pot sidewall 83. In particular, the TIM 100 fills the second gap g2 so that the TIM 100 is in direct contact with the end surface 44 of the at least one stator tooth 43 and a surface of the motor pot sidewall 83. In the illustrated embodiment, the TIM 100 fills the second gap g2 between the end surface 44 of each stator tooth and the pot sidewall 83.

Referring to FIGS. 5 and 6, a fluid pump 110 includes an alternative embodiment motor pot 180. The fluid pump 110 is similar to the fluid pump 10 described above and common elements have common reference numbers. The motor pot 180 of the fluid pump 110 includes a second flange 88. The second flange 88 surrounds the motor pot closed end 82. The second flange 88 protrudes generally radially outward from the motor pot sidewall 83 at the motor pot closed end 82. In the illustrated embodiment, a peripheral portion 88(1) of the second flange 88 extends radially toward the drive casing 30. A medial portion 88(2) of the second flange 88 is disposed between, and connects, the peripheral portion 88(1) to the sidewall 83. The medial portion 88(2) is fixed to or made integral with the motor pot closed end 82. The medial portion 88(2) is axially aligned with the stator coils 45. A stator-facing surface 88(3) of the medial portion 88(2) is contoured to correspond to the shape of the stator 42. In particular, the stator-facing surface 88(3) of the medial portion 88(2) defines a plurality of second concavities 89. Each second concavity 89 is axially aligned with a corresponding one of the stator coils 45 and are shaped and dimensioned to receive a portion of the stator coil curved ends 46 in a clearance fit. By this configuration, the stator 42 is disposed between the first flange 84 and the second flange 88, and a narrow third gap g3 exists between the stator-facing surface 88(3) of the second flange 88 and the stator coil curved ends 46.

In the embodiment illustrated in FIG. 5, the TIM 100 is disposed in the first gap g1 between the curved surface of the first concavity 85 and the curved end 46 of the stator coil 45 and establishes an efficient heat transfer pathway from the stator 42 to the motor pot first flange 84. As in the earlier embodiments, the TIM 100 fills the first gap g1 so that the TIM 100 is in direct contact with a surface of the at least one stator coil 45 and a surface of the respective one of the first concavities 85. In the illustrated embodiment, the TIM 100 fills the first gap g1 between each stator coil 45 and the respective one of the first concavities 85.

In addition to being disposed in the first gap g1, the TIM 100 is also disposed in the third gap g3 between the curved surface of at least one second concavity 88 and the curved end 46 of the respective stator coil 45 and establishes an efficient heat transfer pathway from the stator 42 to the motor pot second flange 88. The TIM 100 fills the third gap g3 so that the TIM 100 is in direct contact with a surface of the at least one stator coil 45 and a surface of the respective one of the second concavities 89. In the illustrated embodiment, the TIM 100 fills the third gap g3 between each stator coil 45 and the respective one of the second concavities 89. Placement of the TIM 100 in the third gap g3 establishes an efficient heat transfer pathway between the stator coils 45 and the motor pot second flange 88 and then to the motor sidewall 83, the motor pot first flange 84, the pump housing 22 and drive casing 30. In addition, the motor pot 80 is cooled by the coolant flowing through the fluid chamber 12 as the pump operates.

Referring to FIG. 7, in some embodiments, the TIM 100 is disposed each of the first gap g1, the second gap g2 and the third gap g3. As discussed above with respect to FIG. 4, placement of the TIM 100 in the second gap g2 establishes an efficient heat transfer pathway between the stator teeth 43 and the motor pot sidewall 83 and then to the motor pot first flange 84, the pump housing 22 and drive casing 30. In addition, the motor pot 80 is cooled by the coolant flowing through the fluid chamber 12 as the pump operates.

Referring to FIG. 8, a fluid pump 210 includes another alternative embodiment motor pot 280. The fluid pump 210 is similar to the fluid pump 10 described above and common elements have common reference numbers. In the fluid pump 210, the central portion of the partition 31 of the drive casing 30 is omitted so that a central opening 31(1) exists in the partition 31. The fluid pump 210 includes an axially elongated motor pot 280 that extends through the opening 31(1). As a result, the sidewall 283 extends to the vicinity of the control electronics 38 and the closed end 282 is in proximity to the control electronics 38. The fluid pump 210 includes a shaft support 290 that is disposed in the fluid chamber 12 between the rotor 61 and the motor pot closed end 282. The shaft support 290 is configured to support the pump shaft second end 48(2).

The motor pot closed end 282 may be in direct contact with the PCB 36 and/or one or more electronic components thereof, whereby heat is conducted from the control electronics 38 to the coolant flowing through the pump 210.

In some embodiments, the motor pot closed end 282 may be in indirect contact with the PCB 36 and one or more electronic components thereof via the TIM 100. In such embodiments, the motor pot closed end 282 is closely spaced relative to the control electronics 38 whereby a fourth gap g4 exists between the motor pot closed end 282 and the control electronics 38. In the illustrated embodiment, the TIM 100 is disposed in both the first gap g1 and the fourth gap g4. The TIM 100 is disposed in the fourth gap g4 to promote heat transfer from the PCB 36 and its electronic components to the motor pot 280.

Referring to FIGS. 9 and 10, a fluid pump 310 includes another alternative embodiment motor pot 380. The fluid pump 310 is similar to the fluid pump 10 described above and common elements have common reference numbers. In the fluid pump 310, the central portion of the partition 31 of the drive casing 30 is omitted so that a central opening 31(1) exists in the partition 31. The fluid pump 310 includes a heat spreader 390 that is disposed in the dry area 16 of the pump casing 20 between the motor pot closed end 382 and the PCB 36. The heat spreader 390 is configured to conduct heat from the PCB 36 and control electronics 38 to the motor pot 380, where it can be dispersed via the fluid flowing through the fluid chamber 12.

The motor pot closed end 382 may be in direct contact with the heat spreader 390 (not shown), whereby heat is conducted from the control electronics 38 to the coolant flowing through the fluid pump 310.

In some embodiments, the motor pot closed end 382 may be in indirect contact with the heat spreader 390 via the TIM 100. In such embodiments, the motor pot closed end 382 is closely spaced relative to the heat spreader 390 whereby a fifth gap g5 exists between the motor pot closed end 382 and the heat spreader 390. In addition, the heat spreader 390 is closely spaced relative to the PCB 36 and the control electronics 38 whereby a sixth gap g6 exists between the heat spreader 390 and the control electronics 38. In the illustrated embodiment, the TIM 100 is disposed in both the first gap g1, the fifth gap g5 and the sixth gap g6. The TIM 100 is disposed in the fifth and sixth gaps g5, g6 to promote heat transfer from the PCB 36 and its electronic components to the motor pot 380.

In the above-described embodiments, the motor pot 80, 180, 280, 380 includes at least one flange 84, 88 in which the stator-facing surface 84(4) defines a plurality of first concavities 85 that are shaped and dimensioned to receive a portion of the stator winding curved ends 46 in a clearance fit. However, in some embodiments, concavities of the flange 84, 88 may not necessarily be aligned with the stator 42 or the stator coils 45. In these embodiments, the increased surface area of the flange 84, 88 improves heat transfer to the motor pot 80, 180, 280, 380. In other embodiments, the flange 84, 88 may be free of concavities.

In some embodiments, the rotor 61 may include one or more axially-extending internal passageways that provide fluid pathways (not shown) between the rotor base plate 63 and the motor pot closed end 82, 282, 382. The fluid pathways 292 promote the flow of coolant through the entire fluid chamber 12 and thereby increase the heat transfer away from the stator.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the inventive concepts that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.