Electric pump

Abstract

An electric pump including a shaft extending in an axial direction, a rotatable rotor located at an outer side of the shaft in a radial direction, a stator located at an outer side of the rotor in a radial direction and surrounding the rotor, a pump portion coupled to the rotor at one side in an axial direction, a housing to accommodate the rotor and the stator, a circuit board located at another side of the housing in an axial direction, and a cover configured to cover another side of the circuit board in an axial direction. The cover includes a base portion, heat dissipation portions protruding more toward another side than the base portion, and a raised portion protruding more toward another side in an axial direction than the base portion and the heat dissipation portions.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present invention claims priority under 35 U.S.C. § 119 to Japanese Patent Applications No. 2025-062799, filed on Apr. 4, 2025; No. 2025-062800, filed on Apr. 4, 2025; and No. 2025-062801 filed on Apr. 4, 2025; and U.S. Provisional Patent Application No. 63 / 720,904 filed on Nov. 15, 2024, the entire contents of which are hereby incorporated herein by reference.1. FIELD OF THE INVENTION

[0002] The present disclosure relates to an electric pump.2. BACKGROUND

[0003] Conventionally, a seal-less electric pump is known in which a pump portion and a motor portion have an integrated structure to prevent a fluid from leaking. An electric pump is disclosed including a cup-shaped partition wall portion provided between a rotor constituting a motor portion and a stator surrounding the rotor. In this electric pump, an inside of the rotor is sealed by the partition wall portion to prevent a fluid flowing into the rotor from leaking toward the stator side.

[0004] In addition, an electric pump is disclosed including: a rotor that is rotatable about a center axis; a coil; a stator opposed to the rotor via a gap provided therebetween in a radial direction; a plurality of terminals disposed at one side of the stator in an axial direction; and a substrate disposed at one side of the plurality of terminals in the axial direction. In this electric pump, electrical power from an external power source is supplied to the substrate via a connector portion, and the electrical power supplied to the substrate is supplied from the substrate to the coil of the stator through a first terminal, a second terminal, and a third terminal.

[0005] However, in the electric pump described above, there is room for improvement in terms of efficiently dissipating heat generated from electronic components or the like of the substrate to enhance the thermal dissipation performance of the pump.SUMMARY

[0006] An electric pump according to an example embodiment of the present disclosure includes a shaft extending in an axial direction, a rotatable rotor located at an outer side of the shaft in a radial direction, a stator located at an outer side of the rotor in a radial direction and surrounding the rotor, a pump portion coupled to the rotor at one side in an axial direction, a housing to accommodate the rotor and the stator, a circuit board located at another side of the housing in an axial direction, and a cover to cover another side of the circuit board in an axial direction. The cover includes a base portion, a plurality of heat dissipation portions protruding more toward another side in an axial direction than the base portion, and a raised portion protruding more toward another side in an axial direction than the base portion and the plurality of heat dissipation portions. According to the electric pump, the heat generated from the circuit board is transferred to the raised portion or the plurality of heat dissipation portions from the base portion of the cover configured to cover another side of the circuit board in the axial direction, and this heat is dissipated.

[0007] The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a perspective view illustrating an electric pump according to an example embodiment.

[0009] FIG. 2 is a plan view illustrating the electric pump according to the example embodiment.

[0010] FIG. 3 is a cross-sectional view along A-A in FIG. 2.

[0011] FIG. 4 is a perspective view illustrating a state where an inverter cover and a thermal dissipation section of the electric pump according to the example embodiment have been removed.

[0012] FIG. 5 is a perspective view illustrating a partition wall portion of the electric pump according to the example embodiment.

[0013] FIG. 6 is a bottom view illustrating the partition wall portion of the electric pump according to the example embodiment.

[0014] FIG. 7 is a perspective view illustrating a shaft of the electric pump according to the example embodiment.

[0015] FIG. 8 is a perspective view illustrating a state where an inverter cover, a thermal dissipation section, a circuit board, and an insulation member of the electric pump according to the example embodiment have been removed.

[0016] FIG. 9 is a perspective view illustrating a cross-section of a pump portion of the electric pump according to the example embodiment.

[0017] FIG. 10 is a cross-sectional perspective view illustrating the partition wall portion and a rotor cover of the electric pump according to the example embodiment.

[0018] FIG. 11 is a cross-sectional view along B-B in FIG. 3.

[0019] FIG. 12 is a cross-sectional view along C-C in FIG. 3.

[0020] FIG. 13 is a cross-sectional view illustrating an inverter cover of the electric pump and a surrounding area thereof according to the example embodiment.

[0021] FIG. 14 is a perspective view illustrating a state where the inverter cover of the electric pump according to the example embodiment have been removed.

[0022] FIG. 15 is an enlarged cross-sectional view illustrating the inverter cover of the electric pump and the surrounding area thereof according to the example embodiment.

[0023] FIG. 16 is a perspective view illustrating a state where the inverter cover, the thermal dissipation section, the circuit board, the insulation member, a housing, and an auxiliary member of the electric pump according to the example embodiment have been removed.

[0024] FIG. 17 is an enlarged perspective view illustrating a portion of a busbar assembly of the electric pump according to the example embodiment.DETAILED DESCRIPTION

[0025] Below, a pump according to the example embodiment of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the example embodiment described below, and modification is possible within the technical spirit of the present disclosure. In addition, the scale, the number, and the like of individual structures may differ from the scale, the number, and the like of actual structures in order to facilitate understanding of each configuration in the following drawings. In the description of the example embodiment, the expressions “up”, “down”, “left”, “right”, and the like may be used. However, these expressions of “up”, “down”, “left”, “right”, and the like may be used to facilitate understanding of the example embodiment, and are not intended to limit the present disclosure.Configuration of Electric Pump

[0026] A configuration of an electric pump 100 according to the example embodiment of the present disclosure will be described in detail below with reference to FIGS. 1 to 14.

[0027] The electric pump 100 includes a shaft 2, a rotor 3, a stator 4, a pump portion 5, a partition wall portion 6, a housing 7, an auxiliary member 8, a circuit board 9, an insulation member 10, a bearing member 12, an inverter cover 13, a thermal dissipation section 14, a busbar assembly 15, a rotor cover 16, and a fixing portion 17. Note that, in FIG. 13, description of the thermal dissipation section 14 is omitted.

[0028] The shaft 2 extends in an axial direction (in an up-down direction in FIG. 3). The shaft 2 does not rotate. The shaft 2 includes a fastening hole 21 at a lower end surface in the axial direction, and an opposing portion 22 at an upper end surface in the axial direction. In addition, the shaft 2 includes a housing engagement portion 23 at a side surface (circumferential surface) below the opposing portion 22.

[0029] The fastening hole 21 is a hole formed inside of a chamber engagement portion 24, and extends from an end portion (lower end in FIG. 3) of the shaft 2 at one side in the axial direction toward the other side in the axial direction (upper side in FIG. 3).

[0030] The opposing portion 22 is provided at another portion of the shaft 2 at another side in the axial direction, and is exposed to an upper wall portion 71 (FIG. 8) of the housing 7 at the other side in the axial direction, thereby being opposed to and in contact with the insulation member 10. The opposing portion 22 has a larger diameter than portions of the shaft 2 other than the opposing portion 22. The opposing portion 22 may be referred to as a diameter-increased portion. The opposing portion 22 faces the other side in the axial direction and is provided along a first surface of the circuit board 9 at the one side in the axial direction.

[0031] The housing engagement portion 23 engages with a shaft engagement portion 712 of the upper wall portion 71 at the other side of the shaft 2 in the axial direction.

[0032] The chamber engagement portion 24 is fixed to and coupled to a shaft engagement portion 513 (FIG. 3) of the pump portion 5 at the end portion of the shaft 2 at the one side in the axial direction. The chamber engagement portion 24 is a shaft heat dissipation portion disposed at the pump portion 5 more toward the one side in the axial direction than the housing fixing section 23.

[0033] The rotor 3 is a tubular-shaped member disposed at an outer side of the shaft 2 in the radial direction. The rotor 3 includes a rotor core, a magnet, the rotor cover 16, and the bearing member 12. The rotor 3 rotates through an electromagnetic field generated by the stator 4. The rotor 3 includes three through-holes 31 extending in the axial direction. The three through-holes 31 are disposed at intervals of 120 degrees around the bearing member 12.

[0034] The stator 4 is disposed at an outer side of the rotor 3 in the radial direction, and surrounds the rotor 3. The stator 4 includes a coil 41 coupled to a busbar 151 of the busbar assembly 15. The stator 4 includes an engagement portion 32 disposed at the other side in the axial direction that engages with the busbar assembly 15. The busbar assembly 15 has a smaller diameter than the stator 4. Since the busbar assembly 15 has a smaller diameter than the stator 4, it is possible to suppress an increase in the size in the radial direction, and also to exhibit excellent assembling workability of the stator 4 and the housing 7. The coil 41 of the stator 4 is supplied with electricity from a power supply (not illustrated) via a connector 91a mounted on the circuit board 9 and the busbar 151, and an electric current flows through the coil 41 to generate an electromagnetic field.

[0035] The pump portion 5 is provided at the housing 7 at the one side in the axial direction. The pump portion 5 includes a chamber 51 and an impeller 52.

[0036] The chamber 51 is fixed to of the housing 7 at the one side in the axial direction. The chamber 51 includes an inlet port 511, an ejection port 512, and a shaft engagement portion 513.

[0037] The inlet port 511 draws a fluid flowing in an F1 direction into the chamber 51. The fluid flowing into the chamber 51 is water, oil, or the like.

[0038] The ejection port 512 causes the fluid drawn from the inlet port 511 and flowing in an F2 direction due to rotation of the impeller 52 to move in an F3 direction, thereby discharging the fluid to the outside of the chamber 51.

[0039] The shaft engagement portion 513 is inserted into a through-hole 522a of a lower-side disk portion 522 of the impeller 52 and a through-hole 521a of an upper-side disk portion 521 from the one side of the chamber 51 in the axial direction toward the other side in the axial direction, and extends. The chamber engagement portion 24 of the shaft 2 is fixed to the shaft engagement portion 513 with the fixing portion 17. The shaft engagement portion 513 extends from the chamber 51 at the one side in the axial direction toward the other side in the axial direction. The shaft engagement portion 513 passes through a through-hole 522a of a lower-side disk portion 522 of the impeller 52 and a through-hole 521a of an upper-side disk portion 521. The shaft engagement portion 513 engages with the shaft 2 at the one side in the axial direction, and is fixed to the shaft 2 with the fixing portion 17.

[0040] The impeller 52 is provided inside of the chamber 51. The impeller 52 is coupled to the rotor 3 and is capable of rotating together with the rotor 3. The impeller 52 includes the upper-side disk portion 521, the lower-side disk portion 522, and a vane portion 523.

[0041] The upper-side disk portion 521 has a disk shape, and is opposed to the partition wall portion 6 with a gap being provided in the axial direction therebetween. The upper-side disk portion 521 includes the through-hole 521a and a tubular portion 521b.

[0042] The through-hole 521a is a circular hole with the center being a center axis P serving as the center of rotation of the rotor 3. The through-hole 521a is opposed to the through-hole 31 of the rotor 3 in the axial direction.

[0043] The tubular portion 521b extends around the through-hole 521a toward the other side in the axial direction. The tubular portion 521b engages with an end portion of the rotor 3 at the one side in the axial direction and enables the impeller 52 to rotate together with the rotor 3.

[0044] The lower-side disk portion 522 has a disk shape, and includes the through-hole 522a having a circular shape with the center axis P being the center. The lower-side disk portion 522 is opposed to the upper-side disk portion 521 in the axial direction with a space being provided therebetween. The through-hole 522a is opposed to the through-hole 521a in the axial direction, and communicates with the inlet port 511.

[0045] The vane portion 523 is coupled to the upper-side disk portion 521 and the lower-side disk portion 522.

[0046] The impeller 52 rotates to cause the fluid drawn into the chamber 51 from the inlet port 511 to rotate to give centrifugal force to the fluid, and also cause the fluid to be discharged from the ejection port 512 through the centrifugal force given to the fluid.

[0047] The partition wall portion 6 is provided so as to cover the rotor 3 from the other side in the axial direction. The partition wall portion 6 is a member having a hat shape (hat with an edge). The partition wall portion 6 is made of a material such as resin being highly thermally conductive. The partition wall portion 6 is disposed between the stator 4 and the rotor 3 and between the stator 4 and the pump portion 5. The partition wall portion 6 includes a first partition wall portion 61, a second partition wall portion 62, a third partition wall portion 63, a fourth partition wall portion 64, a fifth partition wall portion 65, and a rib 66.

[0048] The first partition wall portion 61 includes an insertion hole 613 through which the shaft 2 passes. A seal member is provided between the insertion hole 613 and the shaft 2. The seal member makes it possible to prevent a fluid from leaking to the outside of the partition wall portion 6. The first partition wall portion 61 has a plate shape. The first partition wall portion 61 is disposed more toward the other side in the axial direction than the rotor 3. The first partition wall portion 61 extends from the shaft 2 toward the outer side in the radial direction. The first partition wall portion 61 is opposed to a first wall portion 161 of the rotor cover 16 with a space being provided therebetween in the axial direction to form a flow path R2 (second flow path) (FIG. 10) together with the first wall portion 161. Among the fluid drawn from the inlet port 511 of the pump portion 5, the fluid that does not go toward the ejection port 512 flows through the flow path R2. The first partition wall portion 61 includes a first surface portion 611 (FIG. 3), and a second surface portion 612 (FIG. 3) at a side opposite from the first surface portion 611. Note that the flow path of the fluid will be described in detail in the description of operation of the electric pump 100 that will be described later.

[0049] The first surface portion 611 is in contact with the auxiliary member 8.

[0050] The second surface portion 612 includes a radial shape rib 612a (FIG. 6) directed to the outside in the radial direction with the shaft 2 being the center, and faces the flow path R2. The second surface portion 612 includes the radial shape rib 612a directed to the outside in the radial direction with the shaft 2 being the center, as illustrated in FIG. 6. The second surface portion 612 includes a plurality of the ribs 612a. The plurality of the ribs 612a are disposed at equal intervals in the circumferential direction. The intervals between the plurality of the ribs 612a in the circumferential direction become narrower from the outer side in the radial direction toward the inner side in the radial direction. The ribs 612a face the flow path R2.

[0051] The second partition wall portion 62 has a tubular shape, and extends from an outer circumferential edge portion of the first partition wall portion 61 in the radial direction toward the one side in the axial direction between the rotor 3 and the stator 4. The second partition wall portion 62 is opposed to the stator 4 in the radial direction with a space being provided therebetween. The second partition wall portion 62 is opposed to a second wall portion 162, which will be described later, of the rotor cover 16 in the radial direction with a space being provided therebetween to form a flow path R1 (first flow path) together with the second wall portion 162, thereby facing the flow path R1. Among the fluid drawn from the inlet port 511 of the pump portion 5, the fluid that does not go toward the ejection port 512 flows through the flow path R1.

[0052] The third partition wall portion 63 extends from an end portion of the second partition wall portion 62 at the one side in the axial direction toward the outer side in the radial direction between the stator 4 and the pump portion 5.

[0053] The fourth partition wall portion 64 extends from an outer circumferential edge portion of the third partition wall portion 63 in the radial direction toward the other side in the axial direction.

[0054] The fifth partition wall portion 65 extends from an end portion of the fourth partition wall portion 64 at the other side in the axial direction toward the outer side in the radial direction between the housing 7 and the pump portion 5.

[0055] A plurality of the ribs 66 are provided along the circumferential direction of the second partition wall portion 62 with a space being provided between individual ribs, and are coupled to the second partition wall portion 62 and the third partition wall portion 63.

[0056] The housing 7 accommodates the rotor 3 and the stator 4. The housing 7 includes the upper wall portion 71 disposed more toward the other side in the axial direction than the partition wall portion 6.

[0057] The upper wall portion 71 is in contact with the insulation member 10. The upper wall portion 71 includes a recessed portion 711 that is recessed toward the one side in the axial direction. The opposing portion 22 of the shaft 2 is exposed at the recessed portion 711. The upper wall portion 71 includes the shaft engagement portion 712 that engages with the housing engagement portion 23 of the shaft 2 at the outer side of the shaft 2 in the radial direction. A surface 71a of the upper wall portion 71 at the other side in the axial direction and the opposing portion 22 of the shaft 2 constitute a heat transfer plane extending along the first surface 9a, which faces the circuit board 9 at the one side in the axial direction, the heat transfer plane facing another side in the axial direction.

[0058] The auxiliary member 8 is provided between another side (first partition wall portion 61) of the partition wall portion 6 and the upper wall portion 71 of the housing 7 in the axial direction. The auxiliary member 8 supports (assists) the first partition wall portion 61 such that the first partition wall portion 61 of the partition wall portion 6 does not bend due to pressure of the fluid flowing through the flow path R2. The auxiliary member 8 includes a large diameter portion 81 and a small diameter portion 82. The small diameter portion 82 has a smaller diameter than the large diameter portion 81 as viewed in the axial direction.

[0059] The large diameter portion 81 is provided at an end portion of the auxiliary member 8 at the one side in the axial direction, and is in contact with the partition wall portion 6.

[0060] The small diameter portion 82 extends from the large diameter portion 81 toward the other side in the axial direction. The small diameter portion 82 is provided to reduce the volume of and the weight of the auxiliary member 8.

[0061] The circuit board 9 is provided at the upper wall portion 71 of the housing 7 at the other side in the axial direction via the insulation member 10. The circuit board 9 covers substantially the entire surface of the upper wall portion 71 at the other side (second surface) in the axial direction. A plurality of different electronic components 91 are mounted on the circuit board 9 at the other side in the axial direction. The one side (first surface) of the circuit board 9 in the axial direction is in contact with the insulation member 10.

[0062] The plurality of different electronic components 91 mounted on the circuit board 9 include a connector 91a. In addition, the electronic components 91 include a driving circuit, an integrated circuit (IC) constituting a control circuit, and the like. The connector 91a is coupled to a signal cable 91b coupled to a signal supplying source (not illustrated) and used to receive a predetermined signal, and also to a power supply cable 91c coupled to a power supply (not illustrated) and used to receive electrical power.

[0063] Each of the signal cable 91b and the power supply cable 91c is fixed at another side of the raised portion 133 of the inverter cover 13 in the axial direction by the fixing portion 92, and is led out.

[0064] The insulation member 10 is a sheet-shaped member provided between the circuit board 9 at the one side in the axial direction and the upper wall portion 71 of the housing 7. The insulation member 10 is provided to insulate the circuit board 9 and the upper wall portion 71 from each other. The insulation member 10 is also a thermally conductive portion made of a material such as silicon being thermally conductive. The insulation member 10 is entirely in contact with the circuit board 9 and the upper wall portion 71 in the radial direction.

[0065] The bearing member 12 is provided between the shaft 2 and the rotor 3. The shaft 2 is inserted into the bearing member 12.

[0066] The inverter cover 13 covers the other side of the circuit board 9 and the thermal dissipation section 14 in the axial direction. The inverter cover 13 includes a base portion 131, a plurality of heat dissipation portions 132, and the raised portion 133.

[0067] The base portion 131 is provided at the circuit board 9 at the other side in the axial direction, and is in contact with the thermal dissipation section 14. The base portion 131 has a circular shape as viewed from the axial direction. A length of a wall surface portion 133a in a first direction (FIG. 2) intersecting the axial direction is smaller than a diameter of the base portion 131.

[0068] The plurality of heat dissipation portions 132 protrude from the base portion 131 toward the other side in the axial direction. In a second direction (FIG. 2) intersecting the wall surface portion 133a, the plurality of heat dissipation portions 132 are disposed between the wall surface portion 133a and another end side in the second direction. Among the plurality of heat dissipation portions 132, a heat dissipation portion 132 adjacent to the wall surface portion 133a is coupled to the wall surface portion 133a via the base portion 131. The plurality of heat dissipation portions 132 include a radiating fin 134 and a recessed portion 132a.

[0069] The radiating fin 134 has a plate shape, and protrudes from the base portion 131 toward the other side in the axial direction. The radiating fins 134 are provided so as to be parallel to each other with a space being provided therebetween.

[0070] The recessed portion 132a recesses toward the other side in the axial direction. The recessed portion 132a includes a connecting portion 132b and an accommodation recessed portion 132c. The connecting portion 132b couples adjacent radiating fins 134 to each other, and does not accommodate the electronic component 91 in an interior thereof. The accommodation recessed portion 132c couples adjacent radiating fins 134 to each other, and accommodates the electronic component 91 in an interior thereof.

[0071] The raised portion 133 protrudes more toward the other side in the axial direction than the plurality of heat dissipation portions 132. The raised portion 133 is provided at an outer circumferential edge portion of the inverter cover 13 in the radial direction. The raised portion 133 has a half-moon shape as viewed from the other side in the axial direction. The raised portion 133 covers the connector 91a that is one of the electronic components 91 mounted on the circuit board 9. The raised portion 133 protrudes more toward the other side in the axial direction than the plurality of heat dissipation portions 132 because a certain distance needs to be provided between the connector 91a and the fixing portion 92 so that a load does not act on the connecting portions between the connector 91a mounted on the circuit board 9 and the signal cable 91b as well as between the connector 91a and the power supply cable 91c. The raised portion 133 includes a curved surface portion 133b extending along an outer circumferential edge portion of the base portion 131. The curved surface portion 133b is disposed at one end side of the base portion 131 in the second direction intersecting the wall surface portion 133a. The raised portion 133 includes the wall surface portion 133a extending in the first direction intersecting the axial direction. The wall surface portion 133a is exposed to another side in the axial direction more than end portions of the plurality of radiating fins 134 at the other side in the axial direction, as viewed from the radial direction. The raised portion 133 includes a top surface portion 133c disposed more toward the other side in the axial direction than the connector 91a. The top surface portion 133c is coupled to the wall surface portion 133a and the curved surface portion 133b.

[0072] The thermal dissipation section 14 serving as a thermally conductive portion covers the other side in the axial direction where the electronic components 91 of the circuit board 9 are mounted. The thermal dissipation section 14 is provided between the circuit board 9 and the base portion 131 in the axial direction.

[0073] The busbar assembly 15 is provided between the circuit board 9 and the stator 4. The busbar assembly 15 is accommodated in the housing 7, and engages with the engagement portion 42 of the stator 4. The busbar assembly 15 has a smaller diameter than the stator 4 as viewed from the other side in the axial direction. The busbar assembly 15 includes the busbar 151 and a busbar support member 152.

[0074] The busbar 151 is made of a material such as a metal being electrically conductive. At least a portion of the busbar 151 overlaps with the stator 4 as viewed from the other side in the axial direction. At least a portion of the busbar 151 overlaps with the shaft engagement portion 712 as viewed from the radial direction. At least a portion of the busbar 151 overlaps with the large diameter portion 81 of the auxiliary member 8 as viewed from the other side in the axial direction. At least a portion of the busbar 151 overlaps with the partition wall portion 6 as viewed from the other side in the axial direction. The busbar 151 includes a coil connecting portion 151a, a circuit-board connecting portion 151b, and a holding portion 151c.

[0075] The coil connecting portion 151a extends from the holding portion 151c toward the inner side in the radial direction, and is provided as a pair. The pair of coil connecting portions 151a are coupled to individual coils 41 of stators 4 adjacent in the circumferential direction with the center axis P being the center. The coil connecting portion 151a U-shaped as viewed from the radial direction. The coil connecting portion 151a overlaps with the stator 4 as viewed from the other side in the axial direction. The coil connecting portion 151a overlaps with the shaft engagement portion 712 as viewed from the radial direction. The coil connecting portion 151a overlaps with the large diameter portion 81 of the auxiliary member 8 as viewed from the other side in the axial direction. The coil connecting portion 151a overlaps with the partition wall portion 6 as viewed from the other side in the axial direction.

[0076] A pair of the circuit-board connecting portions 151b are provided, and have a pin shape so as to protrude from the holding portion 151c toward the other end portion side in the axial direction. The circuit-board connecting portion 151b is soldered to a surface of the circuit board 9 at the other side in the axial direction via a through-hole (not illustrated) of the circuit board 9, and is coupled to the electronic component 91 mounted on the circuit board 9 at the other side in the axial direction.

[0077] The holding portion 151c is provided between the coil connecting portion 151a and the circuit-board connecting portion 151b, and is held at and fixed to the busbar support member 152. The other side of the holding portion 151c in the axial direction protrudes toward the other side in the axial direction from a substrate-side protruding portion 152a (which will be described later) of the busbar support member 152.

[0078] The busbar support member 152 is made of a material being insulating. The busbar support member 152 holds the busbar 151. The busbar support member 152 includes a through-hole 152b penetrating along the axial direction at an outer side in the radial direction. The coil 41 is inserted into the through-hole 152b. The busbar support member 152 includes the substrate-side protruding portion 152a protruding toward the other side in the axial direction at an outer circumferential edge portion in the radial direction. The substrate-side protruding portion 152a holds the holding portion 151c of the busbar 151.

[0079] The rotor cover 16 entirely covers the rotor core. The rotor cover 16 includes at least the first wall portion 161 and the second wall portion 162.

[0080] The first wall portion 161 is opposed to the first surface portion 611 of the partition wall portion 6 with a space being provided therebetween in the axial direction. The first wall portion 161 includes a surface facing the other side in the axial direction.

[0081] The second wall portion 162 is disposed between the second partition wall portion 62 of the partition wall portion 6 and the rotor core. The second wall portion 162 is an outer circumferential surface (outer diameter surface) of the rotor 3. The second wall portion 162 includes a surface facing the outer side in the radial direction.

[0082] The fixing portion 17 fixes the pump portion 5 and the shaft 2 at the one side in the axial direction. The fixing portion 17 includes a fastening portion 171 fastened in the fastening hole 21 of the shaft 2 and a top portion 172 having a larger diameter than the fastening portion 171. The top portion 172 faces a flow path of the pump portion 5. The top portion 172 is in contact with a fluid drawn from the inlet port 511 and flowing toward the ejection port 512.Operation of Electric Pump

[0083] Operation of the electric pump 100 according to the example embodiment of the present disclosure will be described in detail below with reference to FIGS. 1 to 14.

[0084] When electrical power is supplied from a power supply (not illustrated) to the stator 4 via the power supply cable 91c, the connector 91a mounted on the circuit board 9, and the busbar 151, the stator 4 forms an electromagnetic field. This electromagnetic field causes the rotor 3 to rotate. As the rotor 3 rotates, the impeller 52 engaging with the rotor 3 also rotates.

[0085] A fluid such as water drawn into the inside of the chamber 51 from the inlet port 511 of the chamber 51 of the pump portion 5 toward the F1 direction flows toward the ejection port 512 in the F2 direction by centrifugal force due to the rotation of the impeller 52. Subsequently, this fluid flows in the F3 direction, which is a direction toward the ejection port 512, and is discharged from the ejection port 512.

[0086] At this time, among the fluid flowing in the F2 direction, a fluid is present that does not flow in the F3 direction. The fluid that does not flow in the F3 direction flows in the F4 direction through a gap between the upper-side disk portion 521 of the impeller 52 and the third partition wall portion 63, thereby flowing into the inside (inner side) of the partition wall portion 6 through the gap between the upper-side disk portion 521 and the third partition wall portion 63 of the partition wall portion 6. In the present example embodiment, with the partition wall portion 6 being provided with the ribs 66, it is possible to suppress (or prevent) a reduction in the rigidity of the partition wall portion 6. Since the reduction in the rigidity of the partition wall portion 6 is suppressed (or prevented), it is possible to avoid deformation or breakage of the partition wall portion 6 due to a pressure from the fluid flowing in the F4 direction.

[0087] The fluid flowing into the inside of the partition wall portion 6 flows in the F5 direction in the flow path R1 of a gap between the second partition wall portion 62 of the partition wall portion 6 and the second wall portion 162 of the rotor cover 16 toward the other side in the axial direction. Subsequently, this fluid flows toward the F6 direction, which is the radial direction, in the flow path R2 of a gap between the first partition wall portion 61 of the partition wall portion 6 and the first wall portion 161 of the rotor cover 16. At this time, the second surface portion 612 of the first partition wall portion 61 comes into contact with the fluid flowing in the F6 direction in the flow path R2 of the gap between the first partition wall portion 61 and the first wall portion 161. In addition, since the first partition wall portion 61 is supported by the auxiliary member 8 so that the first partition wall portion 61 does not bend, it is possible to support the third partition wall portion 63 by the second partition wall portion 62 and the fourth partition wall portion 64, which makes it possible to suppress (or prevent) a reduction in the rigidity of the partition wall portion 6. Since it is possible to suppress (or prevent) a reduction in the rigidity of the partition wall portion 6, it is possible to avoid deformation or breakage of the partition wall portion 6 due to pressure from the fluid flowing in the F6 direction.

[0088] The fluid flowing toward the F6 direction in the flow path R2 of the gap between the first partition wall portion 61 and the first wall portion 161 reaches the rotor 3, and then flows into the through-hole 31 of the rotor 3. The fluid flowing into the through-hole 31 flows in the F7 direction through a flow path R3 of the through-hole 31. Subsequently, this fluid flows via into a gap between the upper-side disk portion 521 and the lower-side disk portion 522 via a through-hole 521a of the upper-side disk portion 521 of the impeller 52, and merges with the fluid flowing in the F2 direction.Regarding Heat Dissipation of Electric Pump

[0089] Heat dissipation of the electric pump 100 according to the example embodiment of the present disclosure will be described in detail below with reference to FIGS. 1 to 14.

[0090] Part of the heat generated as a result of heat generation of the electronic components 91 mounted at the circuit board 9 is transferred to the thermal dissipation section 14 that covers the circuit board 9 at the other side in the axial direction where the electronic components 91 are mounted, and is transferred to the base portion 131 of the inverter cover 13. Thus, the heat generated from the circuit board 9 can be dissipated to the base portion 131 via the thermal dissipation section 14. Since the heat transferred to the base portion 131 is dissipated from the base portion 131 to the outside of the electric pump 100, it is possible to dissipate the heat generated in the circuit board 9 to the outside of the electric pump 100.

[0091] Part of the heat transferred to the base portion 131 is transferred to the heat dissipation portion 132, and is dissipated. In addition, part of the heat transferred to the base portion 131 is transferred to the raised portion 133, and is dissipated. Furthermore, part of the heat transferred to the base portion 131 is transferred to the plurality of radiating fins 134 of the inverter cover 13, and is dissipated. This makes it possible to dissipate the heat generated from the circuit board 9 by using the raised portion 133 that is a member covering the connector 91a. In addition, it is possible to dissipate the heat generated from the circuit board 9, by using the heat dissipation portion 132 that is a member accommodating the electronic components 91. Since the heat dissipated to the raised portion 133 or the heat dissipation portion 132 is discharged to the outside of the electric pump 100, it is possible to dissipate the heat generated in the circuit board 9.

[0092] Part of heat generated through heat generation of the electronic component 91 mounted on the circuit board 9 is transferred to the insulation member 10 via a surface of the circuit board 9 at the one side in the axial direction, which is at the opposite side from the mounting surface on which the electronic component 91 is mounted.

[0093] The heat transferred to the insulation member 10 is transferred from the insulation member 10 to the upper wall portion 71 of the housing 7, and then, is further transferred to the reinforcing portion 8. At this time, by transferring the heat generated in the circuit board 9 via the insulation member 10 to the reinforcing portion 8, it is possible to dissipate, at the insulation member 10 and the reinforcing portion 8, the heat generated in the circuit board 9. That is, the insulation member 10 functions as a heat dissipation member (thermally conductive portion) that dissipates the heat generated in the circuit board 9. According to this configuration, it is possible to dissipate the heat generated in the circuit board 9, by using the reinforcing portion 8 that reinforces the first partition wall portion 61 so that the first partition wall portion 61 does not bend. Furthermore, since the insulation member 10 (thermally conductive portion) is entirely in contact with the circuit board 9 and the upper wall portion 71 entirely in the radial direction, it is possible to transfer, to the insulation member 10, the heat generated from the entirety of the radial direction of the circuit board 9, and also possible to transfer the heat to the entirety the upper wall portion 71 in the radial direction.

[0094] The heat transferred to the insulation member 10 is transferred from the insulation member 10 to the upper wall portion 71 of the housing 7. The heat transferred to the upper wall portion 71 is partially dissipated, and is also partially transferred from the shaft engagement portion 712 to the housing fixing section 23 of the shaft 2, thereby being transferred to the shaft 2. This enables the heat transferred to the upper wall portion 71 of the housing 7 to be further transferred to the shaft 2 and be dissipated. In addition, the heat transferred to the insulation member 10 is transferred from the insulation member 10 to the opposing portion 22 that is in contact with the insulation member 10, thereby being transferred to the shaft 2. This enables the heat generated from the circuit board 9 to be transferred to the shaft 2 and be dissipated. At this time, by setting the opposing portion 22 so as to have a larger diameter than a portion of the shaft 2 except for the opposing potion 22, it is possible to increase the contact surface with the insulation member 10, which makes it possible to efficiently transfer the heat to the shaft 2.

[0095] Part of the heat transferred to the shaft 2 is transferred to the fixing portion 17. As for the heat transferred to the fixing portion 17, since the top portion 172 of the fixing portion 17 faces the flow path for a fluid of the pump portion 5 drawn from the inlet port 511 and flowing toward the ejection port 512, it is possible to dissipate, to the fluid, the heat transferred from the shaft 2 to the fixing portion 17. At this time, since the top portion 172 of the fixing portion 17 has a larger diameter than the fastening portion 171, it is possible to efficiently dissipate the heat transferred to the fixing portion 17, by using the fluid coming into contact with the top portion 172.

[0096] The heat transferred to the reinforcing portion 8 is transferred from the reinforcing portion 8 to the first partition wall portion 61 of the partition wall portion 6. The heat transferred to the first partition wall portion 61 is dissipated to the fluid in contact with the second surface portion 612 of the first partition wall portion 61.

[0097] The second partition wall portion 62 of the partition wall portion 6 is opposed to the stator 4 with a space being provided therebetween in the radial direction, and hence, does not directly receive any influence of the heat generated in the stator 4. Since the second partition wall portion 62 (partition wall portion 6) does not directly receive any influence of heat generated in the stator 4, it is possible to effectively dissipate the heat generated in the circuit board 9.

[0098] In addition, the partition wall portion 6 includes the ribs 612a at the inner side of the partition wall portion 6. More specifically, the second surface portion 612 of the first partition wall portion 61 that the partition wall portion 6 includes the ribs 612a. As the second surface portion 612 includes the ribs 612a having a radial shape directed from the shaft 2 to the outside in the radial direction, it is possible to increase the surface area of the second surface portion 612 to increase a contact surface between the second surface portion 612 of the first partition wall portion 61 and the fluid coming in contact with the second surface portion 612, which makes it possible to further improve the dissipating property for heat generated from the circuit board 9. In particular, it is possible to effectively dissipate the heat generated in the circuit board 9 while reducing the blockage of the flow of a fluid flowing through the gap between the first partition wall portion 61 and the first wall portion 161 in the radial direction toward the center axis P.

[0099] Furthermore, as the second surface portion 612 includes the ribs 612a having a radial shape directed from the shaft 2 to the outside in the radial direction, it is possible to increase the surface area of the second surface portion 612. With the ribs 612a, it is possible to increase the surface area of the second surface portion 612. This makes it possible to increase the contact area at which it comes into contact with the fluid flowing into the inside of the partition wall portion 6. Since the partition wall portion 6 including the ribs 612a is able to increase the contact area with the fluid, it is possible to further improve the dissipating property for heat generated from the circuit board 9. In particular, the partition wall portion 6 includes the ribs 612a disposed in a radial manner, thereby being able to effectively dissipate the heat generated in the circuit board 9 while reducing the blockage of the flow of a fluid flowing through the gap between the first partition wall portion 61 and the first wall portion 161 in the radial direction toward the center axis P (through-hole 31). In addition, the intervals between the plurality of the ribs 612a in the circumferential direction become narrower from the outer side in the radial direction toward the inner side in the radial direction. This makes it possible to guide the fluid flowing into a portion between adjacent ribs 612a (flow path R2) so as to facilitate flow from the outer side in the radial direction toward the inner side in the radial direction. Since the plurality of ribs 612a are able to guide the fluid so as to facilitate flow toward the inner side in the radial direction, it is possible to cause the fluid to efficiently (effectively) flow into the through-hole 31. Thus, the heat generated in the circuit board 9 can be dissipated to the fluid via the insulation member 10 (thermally conductive portion 10), the upper wall portion 71 of the housing 7, the reinforcing portion 8, and the partition wall portion 6 (the first partition wall portion 61 and the second surface portion 612).

[0100] In this manner, according to the present example embodiment, the partition wall member 6 faces the flow path R1 and the flow path R2 through which, among the fluid drawn from the inlet port 511, the fluid that does not go toward the ejection port 512 flows, and heat generated from the circuit board 9 is transferred sequentially to the upper wall portion 71 and the partition wall portion 6 in this order, whereby the heat generated from the circuit board 9 can be dissipated from the upper wall portion 71 of the housing 7 via the partition wall portion 6 to the fluid flowing through the flow paths R1 and R2 that the partition wall portion 6 faces. This makes it possible to efficiently achieve the dissipation of heat of the circuit board 9, which makes it possible to improve the thermal dissipation performance.

[0101] Furthermore, with the present example embodiment, the outer diameter of the opposing portion 22 is larger than the outer diameter of the housing fixing section 23. This makes it possible to efficiently transfer the heat generated from the circuit board 9 to the shaft 2.

[0102] According to the present example embodiment, the partition wall portion 6 is provided at the other side of the rotor 3 in the axial direction, and includes: the sheet-shape first partition wall portion 61 through which the shaft 2 passes and that extends from the shaft 2 toward the outer side in the radial direction; and the tubular-shape second partition wall portion 62 extending between the rotor 3 and the stator 4 from the outer circumferential edge portion, in the radial direction, of the first partition wall portion 61. Furthermore, the second partition wall portion 62 is opposed to the stator 4 in the radial direction with a space being provided therebetween. This makes it possible to dissipate the heat generated in the circuit board 9 without directly receiving any influence of heat generated in the stator 4.

[0103] According to the present example embodiment, the partition wall portion 6 includes: the first surface portion 611 at the other side in the axial direction; and the second surface portion 612 facing the flow path R2 at an opposite side from the first surface portion 611. The second surface portion 612 includes the ribs 612a having a radial shape directed from the shaft 2 to the outside in the radial direction. This makes it possible to increase the surface area of the second surface portion 612, which makes it possible to increase the contact area between the second surface portion 612 of the first partition wall portion 61 and the fluid coming into contact with the second surface portion 612. Thus, it is possible to further improve the dissipating property for heat generated from the circuit board 9.

[0104] According to the present example embodiment, the second surface portion 612 includes the ribs 612a having a radial shape directed from the shaft 2 to the outside in the radial direction. This makes it possible to effectively dissipate the heat generated in the circuit board 9 while reducing the blockage of the flow of a fluid flowing through the gap between the first partition wall portion 61 and the first wall portion 161 toward the center axis P in the radial direction.

[0105] According to the present example embodiment, the reinforcing portion 8 is provided between the partition wall portion 6 and the upper wall portion 71 to support the partition wall portion 6. The heat generated from the circuit board 9 is transferred sequentially to the upper wall portion 71, the reinforcing portion 8, and the partition wall portion 6 in this order. Thus, the heat generated in the circuit board 9 can be dissipated through the reinforcing portion 8 configured to support the first partition wall portion 61 so that the first partition wall portion 61 does not bend.

[0106] According to the present example embodiment, the insulation member 10 is further provided between the circuit board 9 and the upper wall portion 71 so as to be entirely in contact with the circuit board 9 and the upper wall portion 71 throughout the radial direction. The heat generated from the circuit board 9 is transferred sequentially to the insulation member 10, the upper wall portion 71, and the partition wall portion 6 in this order. Thus, it is possible to transfer, to the insulation member 10, the heat generated from the entirety of the radial direction of the circuit board 9, and also possible to transfer it to the entirety of the radial direction of the upper wall portion 71.

[0107] In addition, in the present example embodiment, the opposing portion 22 of the shaft 2 has a larger diameter than a portion of the shaft 2 except for the opposing portion 22. However, the opposing portion 22 may have a diameter equal to that of a portion of the shaft 2 except for the opposing portion 22 in the radial direction, or the opposing portion 22 may have a smaller diameter in the radial direction than a portion of the shaft 2 except for the opposing portion 22.

[0108] In addition, in the example embodiment described above, a space is provided between the stator 4 and the partition wall portion 6 in the radial direction. However, the stator 4 and the partition wall portion 6 may engage with each other in the radial direction.

[0109] In addition, in the example embodiment described above, the ribs 612a or grooves 612a of the second surface portion 612 are configured as protruding portions or recessed portions having a radial shape directed toward the outside in the radial direction with the shaft 2 being the center. However, the ribs 612a or grooves 612a of the second surface portion 612 may be configured as protruding portions or recessed portions along the circumferences of plural circles having different diameters with the center axis P being the center.

[0110] Furthermore, in the example embodiment described above, the second surface portion 612 is provided with ribs 612a that are protruding portions, but may be recessed portions. It is possible to provide the second surface portion 612 with grooves recessed toward the first surface portion 611 side from the second surface portion 612, rather than the ribs that are protruding portions. As the second surface portion 612 includes the grooves having a radial shape directed toward the outside in the radial direction with the shaft 2 being the center, it is possible to obtain the same effects as the case where the ribs 612a are provided.

[0111] In addition, in the example embodiment described above, the insulation member 10 is provided. However, it may be possible to employ a configuration in which the insulation member 10 is not provided, and the circuit board 9 and the upper wall portion 71 are in direct contact with each other.

[0112] In this manner, according to the present example embodiment, the inverter cover 13 includes: the base portion 131; the plurality of heat dissipation portions 132 protruding more toward another side in an axial direction than the base portion 131; and the raised portion 133 protruding more toward another side in the axial direction than the base portion 131 and the plurality of heat dissipation portions 132. This makes it possible to transfer (dissipate) the heat generated from the circuit board 9 sequentially to the base portion 131 and the raised portion 133 in this order, or to transfer (dissipate) the heat to the base portion 131 and the plurality of heat dissipation portions 132 in this order. According to this configuration, it is possible to efficiently achieve the dissipation of the heat of the circuit board 9, thereby enhancing the thermal dissipation performance of the electric pump 100.

[0113] According to the present example embodiment, the raised portion 133 includes the wall surface portion 133a extending in the first direction intersecting the axial direction, and the wall surface portion 133a is exposed to another side in the axial direction more than the end portions of the plurality of heat dissipation portions 132 at the other side in the axial direction as viewed from the radial direction. This makes it possible to increase the surface area. Thus, it is possible to improve thermal dissipation, and also possible to dissipate the heat more to the outside without being blocked by the plurality of heat dissipation portions 132.

[0114] According to the present example embodiment, the base portion 131 has a round shape as viewed from an axial direction, and a length of the wall surface portion 133a in the first direction is smaller than a diameter of the base portion 131. This makes it possible to increase the surface area of the wall surface portion 133a to improve thermal dissipation while suppressing an increase in the size of the wall surface portion 133a to be larger than the base portion 131 in a radial direction.

[0115] According to the present example embodiment, the raised portion 133 includes the curved surface portion 133b extending along an outer circumferential edge portion of the base portion 131. Thus, as compared with a case of being configured as a flat surface, it is possible to increase the area of the surface that is in contact with the outside, which makes it possible to improve thermal dissipation.

[0116] According to the present example embodiment, the curved surface portion 133b is disposed at one end side of the base portion 131 in the second direction intersecting the wall surface portion 133a, and the plurality of heat dissipation portions 132 are disposed between the wall surface portion 133a and another end side of the base portion 131 in the second direction. According to this configuration, as for the inverter cover 13, by disposing the raised portion at one end side, it is possible to dispose the plurality of heat dissipation portions 132 at other regions of the base portion 131 other than one end side. This makes it possible to dispose a large number of heat dissipation portions 132, which makes it possible to further improve thermal dissipation.

[0117] According to the present example embodiment, the raised portion 133 covers the connector 91a mounted at the circuit board 9. This makes it possible to dissipate the heat generated from the circuit board 9, by using the raised portion 133 that is a member covering the connector 91a.

[0118] According to the present example embodiment, the raised portion 133 includes the top surface portion 133c disposed more toward another side in an axial direction than the connector 91a. This makes it possible to increase the surface area, thereby further improving thermal dissipation.

[0119] According to the present example embodiment, the top surface portion 133c is coupled to the wall surface portion 133a and the curved surface portion 133b. This enables the top surface portion 133c, the wall surface portion 133a, and the curved surface portion 133b to transfer heat to each other, thereby being able to further improve thermal dissipation.

[0120] According to the present example embodiment, the plurality of heat dissipation portions 132 cover the electronic component 91 mounted on the circuit board 9, and include the accommodation recessed portion 132c recessed toward another side in an axial direction. This makes it possible to dissipate the heat generated from the circuit board 9, by using the accommodation recessed portion 132c.

[0121] According to the present example embodiment, of the plurality of heat dissipation portions 132, a heat dissipation portion 132 adjacent to the wall surface portion 133a is coupled to the wall surface portion 133a through the base portion 131. This makes it possible to increase the surface area, which makes it possible to further improve thermal dissipation.

[0122] The present example embodiment includes the thermal dissipation section 14 between the circuit board 9 and the base portion 131 in an axial direction. This makes it possible to dissipate the heat using the thermal dissipation section 14, which makes it possible to further improve thermal dissipation.

[0123] It should be considered that the example embodiment described above is given as an example in term of all aspects, and is not given for the purpose of limitation. The scope of the present disclosure is given in the scope of claims, rather than the example embodiment described above, and it is intended that all modifications are included within the meaning and scope equivalent to the scope of claims.

[0124] Specifically, in the example embodiment described above, the connector 91a is covered with the raised portion 133. However, the electronic component 91 other than the connector 91a may be covered with the raised portion 133.

[0125] In addition, in the example embodiment described above, the electronic component 91 is accommodated in the plurality of heat dissipation portions 132. However, items other than the electronic component 91 may be accommodated in the plurality of heat dissipation portions 132, or nothing may be accommodated therein.

[0126] Furthermore, in the example embodiment described above, the thermal dissipation section 14. However, the circuit board 9 may be covered with the inverter cover 13 without providing the thermal dissipation section 14.

[0127] Features of the above-described example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

[0128] While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Claims

1. An electric pump comprising:a shaft extending in an axial direction;a rotatable rotor located at an outer side of the shaft in a radial direction;a stator located at an outer side of the rotor in a radial direction and surrounding the rotor;a pump portion coupled to the rotor at one side in an axial direction;a housing configured to accommodate the rotor and the stator;a circuit board located at another side of the housing in an axial direction; anda cover configured to cover another side of the circuit board in an axial direction; whereinthe cover includes:a base portion;a plurality of heat dissipation portions protruding more toward another side in an axial direction than the base portion; anda raised portion protruding more toward another side in an axial direction than the base portion and the plurality of heat dissipation portions.

2. The electric pump according to claim 1, whereinthe raised portion includes a wall surface portion extending in a first direction intersecting an axial direction; andthe wall surface portion is exposed to another side in an axial direction more than end portions of the plurality of heat dissipation portions at another side in an axial direction, as viewed from a radial direction.

3. The electric pump according to claim 2, whereinthe base portion has a round shape as viewed from an axial direction; anda length of the wall surface portion in the first direction is smaller than a diameter of the base portion.

4. The electric pump according to claim 1, whereinthe base portion has a round shape as viewed from an axial direction; andthe raised portion includes a curved surface portion extending along an outer circumferential edge portion of the base portion.

5. The electric pump according to claim 2, whereinthe base portion has a round shape as viewed from an axial direction;the raised portion includes a curved surface portion extending along an outer circumferential edge portion of the base portion;the curved surface portion is located at one end side of the base portion in a second direction intersecting the wall surface portion; andthe plurality of heat dissipation portions are located between the wall surface portion and another end side of the base portion in the second direction.

6. The electric pump according to claim 1, whereinthe plurality of heat dissipation portions cover an electronic component mounted on the circuit board, and include an accommodation recessed portion recessed toward another side in an axial direction.

7. The electric pump according to claim 2, whereinthe plurality of heat dissipation portions include a connecting portion recessed toward another side in an axial direction; andamong the plurality of heat dissipation portions, a heat dissipation portion adjacent to the wall surface portion is coupled to the wall surface portion via the base portion.

8. The electric pump according to claim 1, further comprising a thermal dissipation section between the circuit board and the base portion in an axial direction.

9. An electric pump comprising:a shaft extending in an axial direction;a rotatable rotor located at an outer side of the shaft in a radial direction;a stator located at an outer side of the rotor in the radial direction and surrounding the rotor;a housing to accommodate the rotor and the stator;a pump portion coupled to the rotor at one side in an axial direction; anda circuit board located at the housing at another side in an axial direction; whereinthe housing includes an upper wall portion located more toward another side in an axial direction than the rotor and the stator;the circuit board is located more toward another side in an axial direction than the upper wall portion; andthe upper wall portion includes a heat transfer plane extending along a first surface opposing one side of the circuit board in the axial direction, the heat transfer plane opposing another side in an axial direction.

10. The electric pump according to claim 9, whereinthe shaft includes a shaft end surface which opposes another side in an axial direction and extends along the first surface; andthe heat transfer plane includes the shaft end surface.

11. The electric pump according to claim 9, whereinthe shaft includes a housing fixing section fixed to the upper wall portion at another side in an axial direction; andthe shaft end surface has an outer diameter larger than an outer diameter of the housing fixing section.

12. The electric pump according to claim 9, further comprising:a fixing portion configured to fix an end portion of the shaft at one side in an axial direction and the pump portion; whereinthe fixing portion is exposed to an inside of the pump portion.

13. The electric pump according to claim 9, further comprising:a thermally conductive portion between the circuit board and the upper wall portion.

14. An electric pump comprising:a shaft extending in an axial direction;a rotatable rotor located at the shaft at an outer side in a radial direction;a stator located at the rotor at an outside in a radial direction and surrounding the rotor;a housing to accommodate the rotor and the stator;a circuit board located at the housing at another side in an axial direction;a pump portion coupled to the rotor at one side in an axial direction; anda partition wall portion provided to cover the rotor from another side in an axial direction, and located between the rotor and the pump portion, and the stator; whereinthe housing includes an upper wall portion located at the partition wall portion at the other side in the axial direction;the circuit board is provided at the upper wall portion at another side in an axial direction; andthe electric pump includes a reinforcing portion provided between the partition wall portion and the upper wall portion, to transfer or dissipate heat generated from the circuit board, and configured to reinforce the partition wall portion.

15. The electric pump according to claim 14, whereinthe partition wall portion includes:a sheet-shaped first partition wall portion located at the rotor at another side in an axial direction and extending in a direction intersecting the axial direction; anda tubular-shape second partition wall portion extending between the rotor and the stator from an outer circumferential edge portion of the first partition wall portion; andthe second partition wall portion is opposed to the stator in a radial direction with a space being provided between the second partition wall portion and the stator.

16. The electric pump according to claim 15, whereinthe partition wall portion defines a flow path between the partition wall portion and the rotor, the flow path being a path through which, among a fluid drawn by the pump portion, a fluid flows that does not go toward a discharging side.

17. The electric pump according to claim 16, whereinthe rotor includes:a first wall portion including a surface opposing another side in an axial direction; anda second wall portion including a surface opposing an outer side in a radial direction;the flow path includes a first flow path and a second flow path;the first flow path is defined by the second partition wall portion and the second wall portion; andthe second flow path is defined by the first partition wall portion and the first wall portion.

18. The electric pump according to claim 16, whereinthe first partition wall portion includes:a first surface portion at another side in the axial direction; anda second surface portion disposed at an opposite side from the first surface portion and facing the flow path; andthe second surface portion includes a protruding portion or a recessed portion.

19. The electric pump according to claim 18, wherein the protruding portion is a rib extending in a radial direction.

20. The electric pump according to claim 14, whereinthe electric pump includes a thermally conductive portion between the circuit board and the upper wall portion; andthe thermally conductive portion is entirely in contact with the circuit board and the upper wall portion in a radial direction.

Images