Electric pump

Abstract

This invention provides an electric pump that can efficiently dissipate heat from circuit boards and improve heat dissipation capabilities. [Solution] An electric pump 100 comprising: a shaft 2 extending in the axial direction; a rotatable rotor 3 located radially outside the shaft 2; a stator 4 located radially outside the rotor 3 and surrounding the rotor 3; a pump unit 5 connected to one axial side of the rotor 3; a housing 7 housing the rotor 3 and the stator 4; a circuit board 9 positioned on the other axial side of the housing 7; and a cover 13 covering the other axial side of the circuit board 9, wherein the cover 13 comprises a base, a plurality of heat dissipation parts protruding from the base to the other axial side, and a projection that protrudes from the base and the plurality of heat dissipation parts to the other axial side.

Description

Technical Field

[0001] The present invention relates to an electric pump.

Background Art

[0002] Conventionally, a seal-less electric pump that prevents fluid leakage by integrating a pump section and a motor section is known. Patent Document 1 discloses an electric pump having a cup-shaped partition member between a rotor constituting a motor section and a stator surrounding the rotor. In the electric pump of Patent Document 1, the inside of the rotor is sealed by the partition member so that the fluid flowing into the rotor does not leak to the stator side.

[0003] Also, Patent Document 2 discloses an electric pump having a rotor rotatable about a central axis, a stator having a coil and facing the rotor with a gap in the radial direction, a plurality of terminals located on one axial side of the stator, and a substrate located on one axial side of the plurality of terminals. In the electric pump of Patent Document 2, the power of an external power source is supplied to the substrate through a connector section, and the 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.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Documents 1 and 2, there is room for improvement in efficiently dissipating the heat generated from electronic components of the substrate and improving the heat dissipation ability of the pump.

[0006] The object of the present invention is to provide an electric pump that can efficiently dissipate heat from a circuit board and improve its heat dissipation capacity. [Means for solving the problem]

[0007] One embodiment of the electric pump according to the present invention includes an axially extending shaft, a rotatable rotor located radially outward from the shaft, a stator located radially outward from the rotor and surrounding the rotor, a pump unit connected to one axial side of the rotor, a housing housing the rotor and the stator, a circuit board disposed on the other axial side of the housing, and a cover covering the other axial side of the circuit board, wherein the cover has a base, a plurality of heat dissipation parts protruding from the base to the other axial side, and a projection that protrudes from the base and the plurality of heat dissipation parts to the other axial side. According to the electric pump, heat generated from the circuit board is transferred from the base of the cover covering the other axial side of the circuit board to the projection or the plurality of heat dissipation parts, and the heat is dissipated. [Effects of the Invention]

[0008] According to the present invention, heat generated from the circuit board can be efficiently dissipated, thereby improving the heat dissipation capacity of the electric pump. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of an electric pump according to one embodiment. [Figure 2] Figure 2 is a plan view of an electric pump according to one embodiment. [Figure 3] Figure 3 is a cross-sectional view of AA in Figure 2. [Figure 4] Figure 4 is a perspective view of an electric pump according to one embodiment, with the inverter cover and heat sink removed. [Figure 5] Figure 5 is a perspective view of a partition wall member of an electric pump according to one embodiment. [Figure 6]Figure 6 is a bottom view of a partition wall member of an electric pump according to one embodiment. [Figure 7] Figure 7 is a perspective view of the shaft of an electric pump according to one embodiment. [Figure 8] Figure 8 is a perspective view of an electric pump according to one embodiment, with the inverter cover, heat sink, circuit board, and insulating member removed. [Figure 9] Figure 9 is a perspective view of a cross-section of the pump section of an electric pump according to one embodiment. [Figure 10] Figure 10 is a cross-sectional perspective view of the partition member and rotor cover of an electric pump according to one embodiment. [Figure 11] Figure 11 is a cross-sectional view of BB in Figure 3. [Figure 12] Figure 12 is a cross-sectional view of CC in Figure 3. [Figure 13] Figure 13 is a cross-sectional view of the inverter cover and surrounding area of ​​an electric pump according to one embodiment. [Figure 14] Figure 14 is a perspective view of an electric pump according to one embodiment, with the inverter cover removed. [Figure 15] Figure 15 is an enlarged cross-sectional view of the inverter cover and surrounding area of ​​an electric pump according to one embodiment. [Figure 16] Figure 16 is a perspective view of an electric pump according to one embodiment, with the inverter cover, heat sink, circuit board, insulating member, housing, and reinforcing member removed. [Figure 17] Figure 17 is an enlarged perspective view of a portion of the busbar assembly of an electric pump according to one embodiment. [Modes for carrying out the invention]

[0010] Hereinafter, a pump according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments and can be changed within the scope of the technical idea of the present invention. In the following drawings, in order to make each component easier to understand, the scale and number etc. in each structure may be different from those in the actual structure. In the description of the embodiment, expressions such as up, down, left, and right may be used, but such expressions are for facilitating the understanding of the embodiment and do not limit the present invention.

[0011] <Configuration of Electric Pump> The configuration of an electric pump 100 according to an embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 14.

[0012] The electric pump 100 has a shaft 2, a rotor 3, a stator 4, a pump section 5, a partition member 6, a housing 7, an auxiliary member 8, a circuit board 9, an insulating member 10, a bearing member 12, an inverter cover 13, a heat dissipation material 14, a bus bar assembly 15, a rotor cover 16, and a fixing member 17. Note that in FIG. 13, the description of the heat dissipation material 14 is omitted.

[0013] The shaft 2 extends in the axial direction (the vertical direction in FIG. 3). The shaft 2 does not rotate. The shaft 2 has a fastening hole 21 on the lower end surface in the axial direction and an opposing portion 22 on the upper end surface in the axial direction. Also, the shaft 2 has a housing fitting portion 23 on the side surface (circumferential surface) below the opposing portion 22.

[0014] The fastening hole 21 is a hole formed inside the chamber fitting portion 24 and extends from one end in the axial direction (the lower end in FIG. 3) of the shaft 2 toward the other side in the axial direction (the upper side in FIG. 3).

[0015] The opposing portion 22 is provided on the other axial side of the shaft 2 and is exposed on the other axial side of the upper wall portion 71 (Figure 8) of the housing 7, thereby making contact with the insulating member 10. The opposing portion 22 has a larger diameter than the other portion of the shaft 2. The opposing portion 22 may also be called an enlarged diameter portion.

[0016] The housing fitting portion 23 is fitted to the shaft fitting portion 712 of the upper wall portion 71 on the other axial side of the shaft 2.

[0017] The chamber fitting portion 24 is fixed and connected to the shaft fitting portion 513 (Figure 3) of the pump portion 5 at one axial end of the shaft 2.

[0018] The rotor 3 is a cylindrical component located radially outward from the shaft 2. The rotor 3 includes a rotor core, a magnet, a rotor cover 16, and a bearing member 12. The rotor 3 rotates due to the electromagnetic field generated by the stator 4. The rotor 3 has three through holes 31 that extend in the axial direction. The three through holes 31 are spaced 120 degrees apart around the bearing member 12.

[0019] The stator 4 is located radially outward from the rotor 3 and surrounds the rotor 3. The stator 4 has a coil 41 connected to the busbar 151 of the busbar assembly 15. The stator 4 has a mating portion 32 on the other axial side that mates with the busbar assembly 15. The busbar assembly 15 has a smaller diameter than the stator 4. Because the busbar assembly 15 has a smaller diameter than the stator 4, it is possible to suppress radial enlargement, and at the same time, the assembly workability of the stator 4 and housing 7 is excellent. The coil 41 of the stator 4 is powered from a power source (not shown) via a connector 91a and busbar 151 mounted on the circuit board 9, and an electromagnetic field is generated when current flows through the coil 41.

[0020] The pump unit 5 is located on one axial side of the housing 7. The pump unit 5 includes a chamber 51 and an impeller 52.

[0021] The chamber 51 is fixed to one axial side of the housing 7. The chamber 51 has an intake port 511, an outlet port 512, and a shaft fitting portion 513.

[0022] The intake port 511 draws fluid in the direction of F1 into the chamber 51. The fluid flowing into the chamber 51 is water or oil, etc.

[0023] The discharge port 512 directs the fluid, which is drawn in from the intake port 511 and moves in the F2 direction due to the rotation of the impeller 52, towards the F3 direction, thereby discharging it to the outside of the chamber 51.

[0024] The shaft fitting portion 513 extends from one axial side of the chamber 51 to the other axial side, inserted into the through hole 522a of the lower disc portion 522 and the through hole 521a of the upper disc portion 521 of the impeller 52. The chamber fitting portion 24 of the shaft 2 is fixed to the shaft fitting portion 513 by a fixing member 17. The shaft fitting portion 513 extends from one axial side of the chamber 51 to the other axial side. The shaft fitting portion 513 passes inside the through hole 522a of the lower disc portion 522 and the through hole 521a of the upper disc portion 521 of the impeller 52. The shaft fitting portion 513 fits with one axial side of the shaft 2 and is fixed to the shaft 2 by the fixing member 17.

[0025] The impeller 52 is located inside the chamber 51. The impeller 52 is connected to the rotor 3 and is rotatable together with the rotor 3. The impeller 52 has an upper disc portion 521, a lower disc portion 522, and a blade portion 523.

[0026] The upper disc portion 521 is disc-shaped and faces the partition member 6 with a gap in the axial direction. The upper disc portion 521 has a through hole 521a and a cylindrical portion 521b.

[0027] The through-hole 521a is a circular hole centered on the central axis P, which is the rotation center of the rotor 3. The through-hole 521a faces the through-hole 31 of the rotor 3 in the axial direction.

[0028] The cylindrical portion 521b extends axially toward the other side around the through hole 521a. The cylindrical portion 521b fits with the axial end of the rotor 3, allowing the impeller 52 to rotate together with the rotor 3.

[0029] The lower disc portion 522 is disc-shaped and has a circular through hole 522a centered on the central axis P. The lower disc portion 522 faces the upper disc portion 521 with a gap between them in the axial direction. The through hole 522a faces the through hole 521a in the axial direction and communicates with the intake port 511.

[0030] The blade portion 523 is connected to the upper disc portion 521 and the lower disc portion 522.

[0031] The impeller 52 rotates the fluid drawn into the chamber 51 from the intake port 511, thereby applying centrifugal force to the fluid, and the centrifugal force applied to the fluid causes the fluid to be discharged from the discharge port 512.

[0032] The partition member 6 is provided to cover the rotor 3 from the other axial side. The partition member 6 is a hat-shaped member. The partition member 6 is made of a material such as a resin with high thermal conductivity. The partition member 6 is located between the rotor 3 and the pump section 5 and the stator 4. The partition member 6 has a first partition section 61, a second partition section 62, a third partition section 63, a fourth partition section 64, a fifth partition section 65, and ribs 66.

[0033] The first partition wall 61 has an insertion hole 613 through which the shaft 2 passes. The first partition wall 61 is plate-shaped. The first partition wall 61 is located on the other axial side of the rotor 3. The first partition wall 61 extends radially outward from the shaft 2. The first partition wall 61 faces the first wall 161 of the rotor cover 16 with an axial gap between them, and together with the first wall 161, forms a flow path R2 (second flow path) (Figure 10). Fluid drawn in from the suction port 511 of the pump unit 5 that does not go toward the discharge port 512 flows through the flow path R2. The first partition wall 61 has a first surface 611 (Figure 3) and a second surface 612 (Figure 3) opposite the first surface 611. Details of the fluid flow path will be explained later in the description of the operation of the electric pump 100.

[0034] The first surface portion 611 is in contact with the auxiliary member 8.

[0035] The second surface 612 has radial ribs 612a (Figure 6) that extend radially outward from the shaft 2 and faces the flow path R2. As shown in Figure 6, the second surface 612 has radial ribs 612a that extend radially outward from the shaft 2. The second surface 612 has multiple ribs 612a. The multiple ribs 612a are arranged at equal intervals in the circumferential direction. The spacing between the multiple ribs 612a in the circumferential direction becomes narrower from the radially outward to the radially inward direction. The ribs 612a face the flow path R2.

[0036] The second partition wall 62 is cylindrical and extends axially from the radial outer peripheral edge of the first partition wall 61 between the rotor 3 and the stator 4. The second partition wall 62 faces the stator 4 with a gap between them in the radial direction. The second partition wall 62 faces the second wall 162 of the rotor cover 16 (described later) with a gap between them in the radial direction and, together with the second wall 162, forms a flow path R1 (first flow path) and thus faces the flow path R1. Fluid that is not directed toward the discharge port 512 from the inlet 511 of the pump unit 5 flows through the flow path R1.

[0037] The third bulkhead section 63 extends radially outward from one axial end of the second bulkhead section 62 between the stator 4 and the pump section 5.

[0038] The fourth partition wall 64 extends from the radial outer peripheral edge of the third partition wall 63 toward the other axial direction.

[0039] The fifth bulkhead section 65 extends radially outward from the axial end of the fourth bulkhead section 64 between the housing 7 and the pump section 5.

[0040] Multiple ribs 66 are provided at intervals along the circumferential direction of the second partition wall 62 and are connected to the second partition wall 62 and the third partition wall 63.

[0041] The housing 7 houses the rotor 3 and the stator 4. The housing 7 has an upper wall portion 71 located on one axial side of the partition member 6.

[0042] The upper wall portion 71 is in contact with the insulating member 10. The upper wall portion 71 has a recess 711 that is recessed toward one side in the axial direction. The opposing portion 22 of the shaft 2 is exposed in the recess 711. The upper wall portion 71 has a shaft fitting portion 712 that fits into the housing fitting portion 23 of the shaft 2 on the radially outer side of the shaft 2.

[0043] The auxiliary member 8 is provided between the other axial side (first partition portion 61) of the partition member 6 and the upper wall portion 71 of the housing 7. The auxiliary member 8 supports (assists) the first partition portion 61 of the partition member 6 so that it does not bend due to the pressure of the fluid flowing through the flow path R2. The auxiliary member 8 has 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 when viewed in the axial direction.

[0044] The large-diameter portion 81 is provided at one end of the auxiliary member 8 on the axial side and is in contact with the partition member 6.

[0045] The small-diameter portion 82 extends from the large-diameter portion 81 in the opposite direction in the axial direction. The small-diameter portion 82 is provided to reduce the volume and thus the weight of the auxiliary member 8.

[0046] The circuit board 9 is provided on the other axial side of the upper wall portion 71 of the housing 7 via an insulating member 10. The circuit board 9 covers substantially the entire other axial side (second surface) of the upper wall portion 71. Multiple different electronic components 91 are mounted on the other axial side of the circuit board 9. One axial side (first surface) of the circuit board 9 is in contact with the insulating member 10.

[0047] Multiple electronic components 91 mounted on the circuit board 9 include a connector 91a. The electronic components 91 also include ICs (integrated circuits) that constitute the drive circuit and control circuit. A signal cable 91b for receiving a predetermined signal, which is connected to a signal supply source (not shown), and a power cable 91c for receiving power, which is connected to a power supply (not shown), are connected to the connector 91a.

[0048] Each of the signal cable 91b and the power cable 91c is fixed by a fixing member 92 to the other axial side of the protrusion 133 of the inverter cover 13 and pulled out.

[0049] The insulating member 10 is a sheet-like member provided between one axial side of the circuit board 9 and the upper wall portion 71 of the housing 7. The insulating member 10 is made of a thermally conductive material such as silicon. The insulating member 10 is in overall radial contact with the circuit board 9 and the upper wall portion 71.

[0050] The bearing member 12 is provided between the shaft 2 and the rotor 3. The shaft 2 is inserted into the bearing member 12.

[0051] The inverter cover 13 covers the other axial side of the circuit board 9 and the heat dissipation material 14. The inverter cover 13 has a base portion 131, a plurality of heat dissipation portions 132, and a protruding portion 133.

[0052] The base portion 131 is provided on the other axial side of the circuit board 9 and is in contact with the heat dissipation material 14. The base portion 131 is circular when viewed from the axial direction. The length of the wall portion 133a in the first direction (Figure 2) intersecting the axial direction is smaller than the diameter of the base portion 131.

[0053] Multiple heat dissipation sections 132 protrude from the base 131 toward the other axial direction. The multiple heat dissipation sections 132 are positioned between the wall surface 133a and the other end of the second direction (Figure 2) that intersects with the wall surface 133a. Among the multiple heat dissipation sections 132, those adjacent to the wall surface 133a are connected to the wall surface 133a via the base 131. The multiple heat dissipation sections 132 have heat dissipation fins 134 and recesses 132a.

[0054] The heat dissipation fins 134 are plate-shaped and protrude from the base 131 toward the other axial direction. The heat dissipation fins 134 are arranged parallel to each other with spacing between them.

[0055] The recess 132a is recessed on the other side in the axial direction. The recess 132a has a connecting portion 132b and a storage recess 132c. The connecting portion 132b connects adjacent heat dissipation fins 134 and does not house electronic components 91 inside. The storage recess 132c connects adjacent heat dissipation fins 134 and houses electronic components 91 inside.

[0056] The protrusion 133 extends axially to the other side from the multiple heat dissipation sections 132. The protrusion 133 is provided on the radial outer edge of the cover 13. The protrusion 133 has a crescent shape when viewed from the other side in the axial direction. The protrusion 133 covers the connector 91a, which is one of the electronic components 91 mounted on the circuit board 9. The protrusion 133 extends axially to the other side from the multiple heat dissipation sections 132 because it is necessary to provide a certain distance between the connector 91a and the fixing member 92 so as not to put a load on the connection between the connector 91a mounted on the circuit board 9 and the signal cable 91b and the power cable 91c. The protrusion 133 has a curved portion 133b that extends along the outer edge of the base 131. The curved portion 133b is located on one end side of the base 131 in a second direction that intersects with the wall portion 133a. The projection 133 has a wall portion 133a extending in a first direction intersecting the axial direction. When viewed radially, the wall portion 133a is exposed on the other axial side of the ends of the plurality of heat dissipation fins 134 on the other axial side. The projection 133 has a top portion 133c on the other axial side of the connector 91a. The top portion 133c is connected to the wall portion 133a and the curved portion 133b.

[0057] The heat dissipation material 14, acting as a heat conductive member, covers the other axial side of the circuit board 9 where the electronic components 91 are mounted. The heat dissipation material 14 is provided between the circuit board 9 and the base 131 in the axial direction.

[0058] The busbar assembly 15 is located between the circuit board 9 and the stator 4. The busbar assembly 15 is housed in the housing 7 and is fitted into the fitting portion 42 of the stator 4. When viewed from the other axial side, the busbar assembly 15 has a smaller diameter than the stator 4. The busbar assembly 15 includes busbars 151 and busbar support members 152.

[0059] The busbar 151 is formed of a conductive material such as metal. At least a portion of the busbar 151 overlaps with the stator 4 when viewed from the other axial side. At least a portion of the busbar 151 overlaps with the shaft fitting portion 712 when 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 when viewed from the other axial side. At least a portion of the busbar 151 overlaps with the partition member 6 when viewed from the other axial side. The busbar 151 has a coil connection portion 151a, a circuit board connection portion 151b, and a holding portion 151c.

[0060] The coil connection portion 151a extends radially inward from the holding portion 151c and is provided in pairs. The pair of coil connection portions 151a are each connected to the coils 41 of adjacent stators 4 in the circumferential direction with respect to the central axis P. The coil connection portion 151a is U-shaped when viewed from the radial direction. The coil connection portion 151a overlaps with the stator 4 when viewed from the other axial side. The coil connection portion 151a overlaps with the shaft fitting portion 712 when viewed from the radial direction. The coil connection portion 151a overlaps with the large diameter portion 81 of the auxiliary member 8 when viewed from the other axial side. The coil connection portion 151a overlaps with the partition member 6 when viewed from the other axial side.

[0061] The circuit board connection portion 151b is provided in pairs and is pin-shaped, protruding from the holding portion 151c toward the other axial end. The circuit board connection portion 151b is soldered to the other axial side of the circuit board 9 via a through-hole (not shown) of the circuit board 9 and is connected to the electronic component 91 mounted on the other axial side of the circuit board 9.

[0062] The retaining portion 151c is provided between the coil connection portion 151a and the circuit board connection portion 151b, and is held and fixed by the busbar support member 152. The other axial side of the retaining portion 151c protrudes in the other axial direction from the circuit board side projection 152a of the busbar support member 152, which will be described later.

[0063] The busbar support member 152 is made of an insulating material. The busbar support member 152 holds the busbar 151. The busbar support member 152 has a through hole 152b that penetrates radially outward along the axial direction. The coil 41 passes through the through hole 152b. The busbar support member 152 has a substrate-side projection 152a that protrudes radially to the other side in the axial direction on its outer peripheral edge. The substrate-side projection 152a holds the holding portion 151c of the busbar 151.

[0064] The rotor cover 16 completely covers the rotor core. The rotor cover 16 has at least a first wall portion 161 and a second wall portion 162.

[0065] The first wall portion 161 faces the first surface portion 611 of the partition wall member 6 with an axial gap between them. The first wall portion 161 has a surface facing the other side in the axial direction.

[0066] The second wall portion 162 is located between the second partition portion 62 of the partition member 6 and the rotor core. The second wall portion 162 is the outer circumferential surface (outer diameter surface) of the rotor 3. The second wall portion 162 has a surface facing radially outward.

[0067] The fixing member 17 fixes the pump unit 5 to one axial side of the shaft 2. The fixing member 17 has a fastening portion 171 that is fastened to the fastening hole 21 of the shaft 2, and a top portion 172 that is larger in diameter than the fastening portion 171. The top portion 172 faces the flow path of the pump unit 5. The top portion 172 is in contact with the fluid that is drawn in from the suction port 511 and heads toward the discharge port 512.

[0068] <Operation of the electric pump> The operation of the electric pump 100 according to an embodiment of the present invention will be described in detail below with reference to Figures 1 to 14.

[0069] When power is supplied to the stator 4 from a power source (not shown) via the power 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, which is mated with the rotor 3, also rotates.

[0070] Fluid such as water is drawn into the chamber 51 of the pump unit 5 from the suction port 511 in the direction of F1, and flows toward the discharge port 512 in the direction of F2 due to the centrifugal force caused by the rotation of the impeller 52. Subsequently, the fluid flows toward the discharge port 512 in the direction of F3 and is discharged from the discharge port 512.

[0071] In this case, some of the fluid flowing in the F2 direction does not flow in the F3 direction. The fluid that does not flow in the F3 direction flows in the F4 direction in the gap between the upper disc portion 521 of the impeller 52 and the third partition portion 63, and flows into the interior (inside) of the partition member 6 from the gap between the upper disc portion 521 and the third partition portion 63 of the partition member 6. In this embodiment, by providing ribs 66 on the partition member 6, a decrease in the rigidity of the partition member 6 can be suppressed (or prevented). Since a decrease in the rigidity of the partition member 6 is suppressed (or prevented), deformation and damage to the partition member 6 due to pressure from the fluid flowing in the F4 direction can be avoided.

[0072] The fluid that flows into the interior of the partition member 6 flows in the direction F5 axially toward the other side through the flow path R1 in the gap between the second partition portion 62 of the partition member 6 and the second wall portion 162 of the rotor cover 16. Subsequently, the fluid flows radially in the direction F6 through the flow path R2 in the gap between the first partition portion 61 of the partition member 6 and the first wall portion 161 of the rotor cover 16. At this time, the second surface portion 612 of the first partition portion 181 comes into contact with the fluid flowing in the flow path R2 in the direction F6 between the first partition portion 61 and the first wall portion 161. Furthermore, since the first partition portion 61 is supported by the auxiliary member 8 to prevent it from bending, the third partition portion 63 can be supported by the second partition portion 62 and the fourth partition portion 64, thereby suppressing (or preventing) a decrease in the rigidity of the partition member 6. Since the reduction in rigidity of the partition wall member 6 can be suppressed (or prevented), deformation and damage to the partition wall member 6 due to pressure from the fluid flowing in the F6 direction can be avoided.

[0073] The fluid that flows in the direction of F6 through the flow path R2 in the gap between the first partition wall 61 and the first wall 161 reaches the rotor 3 and then flows into the through hole 31 of the rotor 3. The fluid that flows into the through hole 31 flows in the direction of F7 through the flow path R3 of the through hole 31. Subsequently, this fluid flows through the through hole 521a of the upper disc portion 521 of the impeller 52 and merges with the fluid that flows in the gap between the upper disc portion 521 and the lower disc portion 522 and flows in the direction of F2.

[0074] <Regarding heat dissipation of electric pumps> The heat dissipation of the electric pump 100 according to an embodiment of the present invention will be described in detail below with reference to Figures 1 to 14.

[0075] A portion of the heat generated by the electronic components 91 mounted on the circuit board 9 is transferred to the heat dissipation material 14 covering the other axial side of the circuit board 9 where the electronic components 91 are mounted, and then transferred to the base 131 of the inverter cover 13. Therefore, the heat generated from the circuit board 9 can be dissipated to the base 131 via the heat dissipation material 14. The heat transferred to the base 131 is then dissipated from the base 131 to the outside of the electric pump 100, thus allowing the heat generated on the circuit board 9 to be dissipated to the outside of the electric pump 100.

[0076] A portion of the heat transferred to the base 131 is transferred to the heat dissipation section 132 for cooling. Another portion of the heat transferred to the base 131 is transferred to the protruding portion 133 for cooling. Furthermore, a portion of the heat transferred to the base 131 is transferred to the multiple heat dissipation fins 134 of the inverter cover 13 for cooling. This allows the heat generated from the circuit board 9 to be dissipated using the protruding portion 133, which is a component that covers the connector 91a. In addition, the heat generated from the circuit board 9 can be dissipated using the heat dissipation section 132, which is a component that houses the electronic components 91. The heat dissipated to the protruding portion 133 or the heat dissipation section 132 is released to the outside of the electric pump 100, thus allowing the heat generated on the circuit board 9 to be dissipated.

[0077] Thus, according to this embodiment, the inverter cover 13 has a base portion 131, a plurality of heat dissipation portions 132 that protrude axially in the other direction from the base portion 131, and a protruding portion 133 that protrudes axially in the other direction from the base portion 131 and the plurality of heat dissipation portions 132. As a result, the heat generated from the circuit board 9 can be transferred (dissipated) in the order of the base portion 131 and the protruding portion 133, or in the order of the base portion 131 and the plurality of heat dissipation portions 132. With this configuration, heat dissipation from the circuit board 9 can be achieved efficiently, and the heat dissipation capacity of the electric pump 100 can be improved.

[0078] Furthermore, according to this embodiment, the protruding portion 133 has a wall portion 133a extending in a first direction intersecting the axial direction, and the wall portion 133a is exposed on the other axial side than the other axial end of the plurality of heat dissipation portions 132 when viewed from the radial direction, thereby increasing the surface area, which improves heat dissipation and allows for greater heat dissipation to the outside without being obstructed by the plurality of heat dissipation portions 132.

[0079] Furthermore, according to this embodiment, the base portion 131 is circular when viewed from the axial direction, and the length of the wall portion 133a in the first direction is smaller than the diameter of the base portion 131. This suppresses the radial enlargement of the wall portion 133a compared to the base portion 131, while increasing the surface area of ​​the wall portion 133a and improving heat dissipation.

[0080] Furthermore, according to this embodiment, since the protruding portion 133 has a curved portion 133b that extends along the outer peripheral edge of the base portion 131, the surface area facing the outside can be increased compared to when it is composed of a flat surface, thus improving heat dissipation.

[0081] Furthermore, according to this embodiment, the curved portion 133b is located on one end side of the base portion 131 in a second direction intersecting with the wall portion 133a, and the multiple heat dissipation portions 132 are arranged between the wall portion 133a and the other end side of the base portion 131 in the second direction. With this configuration, the inverter cover 13 can arrange multiple heat dissipation portions 132 in areas other than one end side of the base portion 131 by arranging the protruding portion on one end side, thus allowing for the arrangement of more heat dissipation portions 132 and further improving heat dissipation performance.

[0082] Furthermore, according to this embodiment, the protrusion 133 covers the connector 91a mounted on the circuit board 9, thereby allowing heat generated from the circuit board 9 to be dissipated using the protrusion 133, which is a component that covers the connector 91a.

[0083] Furthermore, according to this embodiment, the protruding portion 133 has a top surface portion 133c on the axial side opposite to the connector 91a, which increases the surface area and thus further improves heat dissipation.

[0084] Furthermore, according to this embodiment, since the top surface 133c is connected to the wall surface 133a and the curved surface 133b, heat can be conducted to each of the top surface 133c, wall surface 133a, and curved surface 133b, thus further improving heat dissipation.

[0085] Furthermore, according to this embodiment, the multiple heat dissipation units 132 cover the electronic components 91 mounted on the circuit board 9 and have storage recesses 132a that are recessed on the other side in the axial direction, allowing heat generated from the circuit board 9 to be dissipated using the storage recesses 132a.

[0086] Furthermore, according to this embodiment, the heat dissipation portion 132 adjacent to the wall portion 133a among the multiple heat dissipation portions 132 is connected to the wall portion 133a via the base portion 131, thereby increasing the surface area and further improving heat dissipation performance.

[0087] Furthermore, according to this embodiment, by having a heat dissipation material 14 between the circuit board 9 and the base 131 in the axial direction, heat can be dissipated by the heat dissipation material 14, thus further improving heat dissipation performance.

[0088] The embodiments described above should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and all modifications within the meaning and scope of the claims are intended to be included.

[0089] Specifically, in the above embodiment, the connector 91a is covered by the protrusion 133, but the protrusion 133 may also cover electronic components 91 other than the connector 91a.

[0090] Furthermore, in the above embodiment, the electronic components 91 are housed in multiple heat dissipation sections 132, but other components may be housed in the multiple heat dissipation sections 132, or nothing may be housed in them at all.

[0091] Furthermore, although a heat dissipation material 14 is provided in the above embodiment, the circuit board 9 may be covered with the inverter cover 13 without providing the heat dissipation material 14. [Explanation of Symbols]

[0092] 2 shafts 3 rotors 4 stata 5 Pump section 6. Partition Member 7 Housing 8. Auxiliary members 9 Circuit board 10 Insulating material 13 Inverter cover 14 Heat dissipation material 15 Busbar Assembly 16 Rotor Cover 17 Fixing member 22. Opposing part 23 Housing fitting section 41 coils 52 Impeller 61 1st bulkhead part 62 2nd bulkhead part 71 Upper wall 81 Large diameter section 82 Small diameter section 91 Electronic Components 91a connector 100 Electric Pumps 132 Heat radiation part 132a Storage recess 133 Protrusion 151 Bus Bar 151a Coil connection section 511 Inlet 512 Discharge port

Claims

1. It is an electric pump, A shaft extending in the axial direction, A rotatable rotor located radially outward from the shaft, A stator located radially outward of the rotor and surrounding the rotor, A pump section connected to one axial side of the rotor, A housing that accommodates the rotor and the stator, A circuit board is positioned on the other axial side of the housing, The circuit board has a cover that covers the other axial side, The aforementioned cover is The base and, Multiple heat dissipation parts protruding axially from the base, A protruding portion that protrudes axially in the other direction from the base and the plurality of heat dissipation portions, Having, Electric pump.

2. The aforementioned protrusion is It has a wall portion extending in a first direction intersecting the axial direction, The aforementioned wall portion is Viewed radially, the portion exposed on the other axial side is greater than the end on the other axial side of the plurality of heat dissipation portions. The electric pump according to claim 1.

3. The aforementioned base is circular when viewed from the axial direction. The length of the wall portion in the first direction is smaller than the diameter of the base portion. The electric pump according to claim 2.

4. The aforementioned base is circular when viewed from the axial direction, The protruding portion has a curved portion that extends along the outer peripheral edge of the base. The electric pump according to claim 1.

5. The aforementioned base is circular when viewed from the axial direction. The aforementioned protrusion is The base has a curved portion that extends along the outer peripheral edge, The aforementioned curved portion is, Located on one end side of the base in a second direction intersecting with the aforementioned wall surface, The aforementioned multiple heat dissipation units are In the second direction, the following is arranged between the wall portion and the other end of the base portion: The electric pump according to claim 2.

6. The aforementioned protrusion is Covering the connector mounted on the aforementioned circuit board, The electric pump according to claim 1.

7. The aforementioned protrusion is The top surface portion is located on the other axial side of the connector portion. The electric pump according to claim 6.

8. The aforementioned protrusion is It has a wall portion extending in a first direction intersecting the axial direction, The aforementioned base is circular when viewed from the axial direction, The aforementioned protrusion is The base has a curved portion that extends along the outer peripheral edge, The top portion is The wall portion and the curved portion are connected, The electric pump according to claim 7.

9. The aforementioned multiple heat dissipation units are The circuit board has a housing recess that covers the electronic components mounted on it and is recessed on the other side in the axial direction. The electric pump according to claim 1 or claim 2.

10. The aforementioned multiple heat dissipation units are It has a connecting portion that is recessed on the other side in the axial direction, Of the plurality of heat dissipation sections, the heat dissipation section adjacent to the wall section is, It is connected to the wall surface via the base, The electric pump according to claim 2.

11. A heat conductive member is provided between the circuit board and the base in the axial direction. The electric pump according to claim 1.

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