Pump device

Abstract

A pump device (1) comprises: a casing (2) having an inflow port (32) through which a fluid flows in and an outflow port (33) through which the fluid flows out; a shaft (48) supported by the casing (2); a rotor (6) rotatably supported by the shaft (48); a stator (7) opposing the rotor (6) in the radial direction; and a substrate (8) electrically connected to the stator (7). The substrate (8) includes a heat-generating component (82), and the heat of the heat-generating component (82) is transmitted to the shaft (48) via a heat conductor (84).

Description

Pump device

[0001] The present invention relates to a pump device.

[0002] For example, Patent Document 1 discloses a fluid pump for conveying a coolant to a stack of fuel cells. A cooling fluid jacket for cooling a motor that generates heat and a control board is incorporated in this fluid pump.

[0003] For example, Patent Document 2 discloses a water pump for pumping a coolant to an air conditioner heater or the like of a vehicle. In this water pump, when an electric current is supplied to a coil, an impeller rotates due to a magnetic interaction generated between the coil and a magnet.

[0004] For example, Patent Document 3 discloses an electric pump provided with a circuit board for controlling the rotation of a motor. In order to dissipate the heat of a heating element mounted on the circuit board, the heating element is in contact with a rib of a housing forming a flow path of a coolant via a thermally conductive adhesive.

[0005] Japanese Patent Application Laid-Open No. 2024-512, Japanese Patent Application Laid-Open No. 2015-117580, Japanese Patent Application Laid-Open No. 2015-104168

[0006] In the cooling fluid jacket of Patent Document 1, a guide flow path for conveying a coolant is formed. This guide flow path is formed in a complicated shape inside the housing of the motor. Therefore, the manufacturing cost of the fluid pump increases.

[0007] In Patent Document 2, the coil generates heat as an electric current is supplied to the coil. In increasing the output of the water pump, an increase in the amount of heat generated due to an increase in the diameter of the copper wire forming the coil is expected. Therefore, further cooling measures are required for the water pump.

[0008] In Patent Document 3, in increasing the output of the electric pump, an increase in the heat generation of the heating element is expected. Since a highly heat-resistant heating element that can withstand such an increase in heat generation is expensive, the manufacturing cost of the circuit board, that is, the electric pump increases.

[0009] The present invention has been made in view of the above problems, and one of its objectives is to provide a pump device that can cool heat-generating components with a simple structure.

[0010] Furthermore, the present invention has been made in view of the above problems, and one of its objectives is to provide a pump device that can efficiently cool a coil.

[0011] Furthermore, the present invention has been made in view of the above problems, and one of its objectives is to provide a low-cost pump device.

[0012] A pump device according to a first aspect of the present invention comprises a casing having an inlet for fluid to flow in and an outlet for the fluid to flow out; a shaft supported by the casing; a rotor rotatably supported by the shaft; a stator facing the rotor in the radial direction; and a substrate electrically connected to the stator, wherein the substrate includes a heat-generating component, and the heat from the heat-generating component is transmitted to the shaft via a heat conductor.

[0013] A pump device according to a second aspect of the present invention comprises a shaft, a rotor rotatably supported on the shaft, a stator facing the rotor, coils wound around a plurality of teeth of the stator, and a casing forming a housing portion in which the rotor is housed, wherein the stator is fixed to the casing, and in the circumferential direction, a cylinder extending in the axial direction is provided between the plurality of coils, and a liquid is housed in the cylinder.

[0014] A pump device according to a third aspect of the present invention comprises a shaft extending in the direction of rotation axis, a rotor rotatably supported on the shaft, a stator facing the rotor, a casing housing the rotor, and a plurality of circuit boards, wherein the plurality of circuit boards are arranged in the direction of rotation axis, and a heat-generating component is connected to the circuit board located on the rotor side of the plurality of circuit boards.

[0015] This is a schematic perspective view showing the structure of a pump device 1 according to one embodiment of the present invention. This is a schematic perspective view showing the structure of a pump device 1 according to one embodiment of the present invention. This is a cross-sectional view along line 3-3 in Figure 1. This is a cross-sectional view along line 4-4 in Figure 3. This is a partially enlarged perspective view showing an enlarged portion of the surface of the circuit board 8. This is a partially enlarged cross-sectional view showing an enlarged portion of the cross-section of Figure 3. This is a partially enlarged cross-sectional view showing the structure of a pump device 1A according to one modified example, corresponding to the cross-section of Figure 3. This is a partially enlarged cross-sectional view showing the structure of a pump device 1B according to yet another modified example, corresponding to the cross-section of Figure 3. This is a cross-sectional view showing the structure of a pump device 1C according to yet another modified example of the present invention, corresponding to the cross-section of Figure 3. This is a cross-sectional view along line 10-10 in Figure 9. This is a partially enlarged perspective cross-sectional view showing an enlarged portion of the upper end portion 49a of the cylinder 49, corresponding to the cross-section of Figure 9. This is a schematic cross-sectional view showing the structure of a pump device 1D according to yet another modified example of the present invention. This is a partially enlarged perspective cross-sectional view showing a portion of the cross-section of Figure 12. This is a cross-sectional view along line 14-14 in Figure 12. This is a partially enlarged perspective cross-sectional view showing the structure of a pump device 1E according to yet another modified example of the present invention, corresponding to Figure 13. This is a schematic perspective view showing the structure of a pump device 1F according to yet another modification of the present invention. This is a schematic perspective view showing the structure of a pump device 1F according to yet another modification of the present invention. This is a cross-sectional view along line 18-18 in Figure 16. This is a schematic cross-sectional view showing the structure of a pump device 1G according to yet another modification of the present invention. This is a schematic cross-sectional view showing the structure of a pump device 1H according to yet another modification of the present invention. This is a perspective view along line 21-21 in Figure 20. This is a schematic cross-sectional view showing the structure of a pump device 1I according to yet another modification of the present invention. This is a schematic perspective view showing the structure of a heat dissipation member 96 according to one specific example.

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Figures 1 and 2 are schematic perspective views showing the structure of a pump device 1 according to an embodiment of the present invention. This pump device 1 is, for example, a water pump. A water pump is a centrifugal pump for transferring (pressurizing) a fluid, i.e., a coolant (liquid). The pump device 1 is installed, for example, in the engine room or motor room of a vehicle. The pump device 1 is used, for example, to cool a drive source such as the engine or motor of a vehicle by transferring coolant to the drive source.

[0017] In pump device 1, the direction along axis x is defined as the axial direction (also called the "rotation axis direction"). In this axial direction, one side is defined as the upper side and the other side as the lower side. The upper and lower sides do not necessarily coincide with the upper and lower sides in the direction of gravity. Furthermore, the direction perpendicular to axis x is defined as the radial direction. In the radial direction, the direction approaching axis x is defined as the inner circumference side, and the direction moving away from axis x is defined as the outer circumference side. In addition, a circumferential direction is defined around axis x. The clockwise and counterclockwise directions in the circumferential direction are defined as the direction when viewed from the upper side in the axial direction.

[0018] Figure 1 is a perspective view of the pump device 1 from above. Figure 2 is a perspective view of the pump device 1 from below. The pump device 1 includes a casing 2 that is formed in a generally cylindrical shape with axis x as the center. The casing 2 has a case 3, a can section 4, and a cover 5 arranged in order from top to bottom along axis x. The case 3 and the can section 4 are formed by injection molding from a thermoplastic resin material, such as PPS (polyphenylene sulfide). The cover 5 is formed from a metal material, such as aluminum. The internal space of the casing 2 is defined by the case 3 and the can section 4.

[0019] Case 3 comprises a main body 31 and an inlet 32 ​​and an outlet 33 integrally formed on the main body 31. The main body 31 is formed, for example, as a flat cylindrical shape with the top closed. The inlet 32 ​​protrudes upward from the top surface of the main body 31 along the axis x. The inlet 32 ​​is formed, for example, as a cylindrical shape centered on the axis x. Fluid flows into the internal space of the casing 2 from the inlet 32. The outlet 33 protrudes outward from the main body 31 along the tangent to a virtual circle centered on the axis x. The outlet 33 is formed, for example, as a cylindrical shape centered on the tangent. Fluid flows out from the internal space of the casing 2 through the outlet 33.

[0020] The can portion 4 is formed as a whole, for example, in a cylindrical shape. A case 3 is attached to the upper end of the can portion 4, while a cover 5 is attached to the lower end of the can portion 4. The cover 5 has a body 51 and a plurality of fins 52. The body 51 is formed, for example, in a flat cylindrical shape with the lower end closed. The plurality of fins 52 protrude downward in the axial direction from the lower surface of the body 51. In this example, the plurality of fins 52 are arranged parallel to each other. The body 51 and the plurality of fins 52 form the heat sink 53 according to the present invention. The body 51 and the plurality of fins 52 are integrally formed from a thermally conductive metal material, for example, aluminum.

[0021] A connector housing (not shown) is further formed on the main body 51. One or more connector pins are housed within the connector housing. The connector pins protrude downward from the main body 51 within the connector housing. Connectors of external devices are connected to the connector pins. Power and signals are supplied from the external device to the pump device 1 via the connector pins. The connector housing may be formed separately from the main body 51, for example, from an insulating resin material. Alternatively, the main body 51, heat sink 53, and connector housing may be integrally formed from a thermally conductive metal or resin material.

[0022] Figure 3 is a cross-sectional view along line 3-3 in Figure 1. As shown in Figure 3, the can portion 4 has a bottom wall 41, an inner wall 42, a top wall 43, and an outer wall 44. The bottom wall 41 is formed, for example, in the shape of a flat disc perpendicular to the axis x. The inner wall 42 extends upward from the outer edge of the bottom wall 41. The inner wall 42 is formed in the shape of a cylinder centered on the axis x. The top wall 43 extends outward from the upper edge of the inner wall 42. The top wall 43 is formed in the shape of an annular ring centered on the axis x. The outer wall 44 extends downward from the outer edge of the top wall 43. The outer wall 44 is formed in the shape of a cylinder centered on the axis x.

[0023] The can section 4 further has a flange 45 that extends radially outward in an annular shape adjacent to the upper end of the outer wall 44. An annular groove 46 is formed on the upper surface of the flange 45. An elastic member such as an annular O-ring, i.e., a gasket 47, is placed in this groove 46. The annular lower surface of the main body 31 of the case 3 is received by the upper surface of the flange 45 of the can section 4. As the lower surface of the main body 31 is pressed against the upper surface of the flange 45, the gasket 47 is compressed in the groove 46. As a result, the space between the main body 31 and the flange 45 is sealed, preventing fluid from leaking out of the pump device 1.

[0024] An internal space S is formed within the casing 2 by the case 3 and the can section 4. The internal space S is formed from a first space S1 and a second space S2. The first space S1 is formed by the main body 31 of the case 3 and the top wall 43 of the can section 4. The second space S2 is formed by the bottom wall 41 and the inner wall 42 of the can section 4. Both the first space S1 and the second space S2 are generally cylindrical spaces centered, for example, on an axis x. The first space S1 and the second space S2 are in communication with each other. In the radial direction, the diameter of the first space S1 is larger than the diameter of the second space S2. On the other hand, in the axial direction, the height of the first space S1 is smaller than the height of the second space S2.

[0025] Case 3 has a support portion 34 positioned adjacent to the lower end of the inlet portion 32 within the main body 31, and a plurality of spokes 35 supporting the support portion 34. In this example, the support portion 34 is positioned to enter the first space S1 from the lower end of the inlet portion 32 along the axis x. The plurality of spokes 35 connect the outer surface of the support portion 34 and the inner surface of the inlet portion 32 to each other. In this example, three spokes 35 are arranged at predetermined intervals in the circumferential direction. Each spoke 35 is formed in a flat plate shape, for example, extending along a virtual plane containing the axis x.

[0026] A shaft 48 is positioned in the internal space S of the casing 2. The shaft 48 is formed in a cylindrical shape, for example, with an axis x as its center. The upper end of the shaft 48 is fixed to a recess 34a formed on the lower surface of the support portion 34 of the case 3. On the other hand, the lower end of the shaft 48 is fixed to a through hole 41a that penetrates the bottom wall 41 along the axis x. For fixing, the lower end of the shaft 48 is, for example, press-fitted into the through hole 41a. The shaft 48 is formed from a metal material with high thermal conductivity, such as stainless steel. In this way, the shaft 48 is supported and fixed to the casing 2.

[0027] The pump device 1 includes a rotor 6 rotatably supported on a shaft 48 about an axis x. The rotor 6 is housed in the internal space S of the casing 2. The rotor 6 has a bearing 61 supported on the shaft 48, a rotor body 62 fixed to the bearing 61, and a magnet 63 fixed to the rotor body 62. The bearing 61 is formed in a cylindrical shape along the axis x. The inner circumferential surface of the bearing 61 faces the outer circumferential surface of the shaft 48 with a predetermined gap between them. In this way, the bearing 61, and thus the rotor 6, is configured to be rotatable about the axis x and movable in the vertical direction along the axis x. The bearing 61 is a so-called sliding bearing.

[0028] The rotor body 62 has a cylindrical portion 64, a flange 65, and a plurality of blades 66. The rotor body 62 is integrally formed by injection molding from a thermoplastic resin material, such as PPS (polyphenylene sulfide). The cylindrical portion 64 is formed in a generally cylindrical shape with axis x as the center. A bearing 61 is fixed inside the cylindrical portion 64. The flange 65 extends radially in an annular shape from the upper end of the cylindrical portion 64 in the axial direction. That is, the flange 65 is formed in a disc shape with axis x as the center.

[0029] Multiple blades 66 rise upward from the top surface of the flange 65. The multiple blades 66 are arranged circumferentially. In this example, all blades 66 have the same shape and dimensions. Each blade 66 extends in a curved manner from the inner circumferential end of the flange 65 to the outer circumferential end of the flange 65. In this example, when viewed from above, each blade 66 extends obliquely in a clockwise direction with respect to the radial direction from the inner circumferential end to the outer circumferential end. The height of each blade 66 from the top surface of the flange 65 decreases, for example, from the inner circumferential end to the outer circumferential end of the blade 66. In other words, the height of each blade 66 may differ between the inner and outer circumferential ends, and more preferably, the height of the inner circumferential end of each blade 66 may be greater than the height of the outer circumferential end.

[0030] The magnet 63 is fixed to the cylindrical portion 64 below the flange 65. In this example, the magnet 63 is formed in a cylindrical shape with axis x as its center. The magnet 63 is divided into two cylindrical parts in the axial direction, for example, but is not limited to this, and may be composed of a single magnet. The magnet 63 is, for example, a permanent magnet. The magnet 63 has, for example, alternating regions magnetized as south poles and regions magnetized as north poles in the circumferential direction. In this case, the division position or magnetic center of the magnet 63 coincides with the magnetic center position of the stator 7 in the axial direction, but is not limited to this, and may be shifted upward in the axial direction. In this case, the magnetic force acts to pull the magnet 63 downward in the axial direction, so that the rotor 6 does not float upward.

[0031] In the axial direction, a predetermined gap is secured between the upper end of the bearing 61 and the lower surface of the support portion 34, and between the lower ends of the bearing 61 and the rotor body 62 and the bottom wall 41. The flange 65 and blades 66 of the rotor body 62 are housed in the first space S1, while the magnet 63 is housed in the second space S2. In the axial and radial directions, the blades 66 face the inner surface of the body 31 of the case 3 with a predetermined gap between them. In the radial direction, the outer circumferential surface of the magnet 63 faces the inner circumferential surface of the inner wall 42 with a predetermined gap between them. Also, in the axial direction, the lower surface of the magnet 63 faces the bottom wall 41 with a predetermined gap between them.

[0032] Figure 4 is a cross-sectional view along line 4-4 in Figure 3. Referring to both Figures 3 and 4, the pump device 1 includes a stator 7 incorporated into the can section 4. Specifically, the stator 7 is positioned in an annular space between the inner wall 42 and the outer wall 44 and fixed to the outer circumferential surface of the inner wall 42 and the inner circumferential surface of the outer wall 44. The stator 7 includes a stator core 71, a plurality of coils 72, and an insulator 73. The stator core 71 is formed from a laminate of a plurality of thin plates stacked in the axial direction. The laminate is made of a magnetic material. The coils 72 have windings, for example, made of copper wire. The insulator 73 electrically insulates the stator core 71 from the plurality of coils 72. The insulator 73 is made of an insulating material, for example, a resin material. The stator 7 may be fixed to either the outer circumferential surface of the inner wall 42 or the inner circumferential surface of the outer wall 44.

[0033] The stator core 71 comprises an annular portion 74 and a plurality of teeth 75. The annular portion 74 is fixed to the inner circumferential surface of the outer wall 44 of the can portion 4. The annular portion 74 is defined in an annular shape around the axis x. Each tooth 75 protrudes inward from the inner circumferential surface of the annular portion 74. Each tooth 75 faces the outer circumferential surface of the magnet 63 with a predetermined magnetic gap, sandwiching the inner wall 42 of the can portion 4. In this way, the stator 7 faces the rotor 6 in the radial direction. The windings of the coil 72 are wound around the insulator 73 that covers each tooth 75. In this example, there are six teeth 75, but the number of teeth 75 can be any number, such as 12 or 18. The number of poles of the rotor 6 can also be changed in accordance with the change in the number of teeth 75.

[0034] In the pump device 1, when current is supplied to the coil 72, the rotor body 62, i.e., the rotor 6, rotates counterclockwise around the axis x due to the magnetic interaction between the coil 72 and the magnet 63. This rotation generates a flow of coolant from the inlet 32 ​​into the first space S1 via multiple blades 66. The coolant flows outwards through the multiple blades 66 and then flows out from the outlet 33. In this way, the coolant is pumped to, for example, a drive source. The coolant may include, for example, water. Other liquids may be included in the water. Other liquids may include, for example, antifreeze such as propylene glycol or ethylene glycol, or rust inhibitors. Furthermore, the coolant and other liquids may have insulating properties.

[0035] Returning to Figure 3, the pump device 1 includes a circuit board (substrate) 8 incorporated between the can section 4 and the cover 5. In this example, the circuit board 8 has a substrate body 81 formed, for example, in a circular shape along a plane perpendicular to the axis x. One or more electronic components 82 are mounted on the front and back surfaces of the substrate body 81. These electronic components 82 include, for example, field-effect transistors (FETs) and capacitors. Connector pins (not shown) are also mounted on the circuit board 8. In this example, the upper surface of the cover body 51 faces the back surface of the circuit board 8.

[0036] The circuit board 8 is electrically connected to the coil 72, i.e., the stator 7, by terminals (not shown). On the other hand, connectors from external devices are connected to connector pins mounted on the circuit board 8. Power and signals are supplied from the external device to the electronic components 82 and coil 72 on the circuit board 8 via these connector pins and terminals. For example, the supply of power causes the electronic components 82 and coil 72 on the circuit board 8 to generate heat. The electronic component 82 constitutes a heat-generating component. In one example, the temperature generated by the electronic component 82 tends to be higher than the temperature generated by the coil 72.

[0037] Figure 5 is a partially enlarged perspective view of a portion of the surface of the circuit board 8. Figure 6 is a partially enlarged cross-sectional view of a portion of the cross-section of Figure 3. Referring to Figures 5 and 6 together, the circuit board 8 has a through hole 83 that penetrates the board body 81 in the axial direction. The through hole 83 is formed, for example, in a cylindrical shape centered on axis x. The shaft 48 can extend below the circuit board 8 by being inserted into the through hole 83. The lower end of the shaft 48 is in contact with the upper surface of the cover body 51, i.e., the heat sink 53. A thermally conductive grease or the like may be sandwiched between the lower end of the shaft 48 and the upper surface of the cover body 51.

[0038] The circuit board 8 has a heat conductor 84 that connects each electronic component 82 and the shaft 48 to each other. In this example, the heat conductor 84 has a first portion 85 and a second portion 86. The first portion 85 is formed, for example, in a cylindrical shape. The first portion 85 is placed in the through hole 83 and contacts the outer surface of the shaft 48. The second portion 86 extends from each electronic component 82 to the first portion 85 along the front and back surfaces of the circuit board body 81. In this way, the second portion 86 connects the electronic components 82 and the first portion 85 to each other. The heat conductor 84 is formed from a metal material with high thermal conductivity, such as copper foil. Note that the heat conductor 84 is not electrically connected to the electronic components 82.

[0039] In the pump device 1, when power is supplied to the coil 72 from an external device via the circuit board 8, heat is generated in the electronic component 82. The heat from the electronic component 82 is transmitted to the shaft 48, for example, via the second portion 86 and the first portion 85 of the heat conductor 84. Meanwhile, the shaft 48 is in contact with the coolant in the first space S1 and the second space S2 within the casing 2. Therefore, the heat transmitted from the electronic component 82 to the shaft 48 via the heat conductor 84 is transferred to the coolant from the outer surface of the shaft 48. As a result, the electronic component 82 can be cooled. For this cooling to occur, it is sufficient for the shaft 48 and the electronic component 82 to be connected to each other by the heat conductor 84, so the electronic component 82 can be cooled with a simple structure.

[0040] Furthermore, the heat from the electronic component 82 is transmitted to the shaft 48, for example, via the second portion 86 and the first portion 85 of the heat conductor 84, and then from the shaft 48 to the heat sink 53. In the heat sink 53, heat is released from the surface of the multiple fins 52 toward the space outside the pump device 1. As a result, the electronic component 82 can be cooled. In this way, the pump device 1 can conduct heat through two paths: a first path through which heat is transferred from the electronic component 82 to the coolant via the heat conductor 84 and the shaft 48, and a second path through which heat is transferred from the electronic component 82 to the heat sink 53 via the heat conductor 84 and the shaft 48. As a result, the cooling efficiency of the electronic component 82 can be further improved.

[0041] Figure 7 is a partially enlarged cross-sectional view corresponding to the cross-section of Figure 3, schematically showing the structure of a modified pump device 1A. In this pump device 1A, the shaft 48 has a cylindrical shaft body 48a and a plate 48b extending radially from the shaft body 48a. In this example, the plate 48b is formed in the shape of a disc centered on axis x. In the radial direction, the dimensions of the plate 48b are smaller than, for example, the dimensions of the bottom wall 41. However, in the radial direction, the dimensions of the plate 48b may be larger than, for example, the dimensions of the bottom wall 41. The shaft body 48a and the plate 48b are integrally formed from a metal material such as stainless steel by casting or the like. The plate 48b may be formed separately from the shaft body 48a from a metal material such as aluminum.

[0042] The plate 48b is positioned, for example, between the bottom wall 41 and the circuit board 8 in the axial direction. The plate 48b has an upper surface 48c facing upwards in the axial direction and a lower surface 48d facing downwards in the axial direction. The upper surface 48c of the plate 48b is in contact with the lower surface of the bottom wall 41, while the lower surface 48d of the plate 48b is in contact with the upper surface of the electronic component 82. Other components similar to those in the pump device 1 of the previously described embodiment are given the same reference numerals, and redundant explanations are omitted here. With this pump device 1A, the heat from the electronic component 82 is transferred from the plate 48b to the coolant via the shaft body 48a and the bottom wall 41. As a result, the cooling efficiency of the electronic component 82 can be further improved.

[0043] FIG. 8 is a partially enlarged cross-sectional view schematically showing the structure of a pump device 1B according to yet another modification corresponding to the cross-section of FIG. 3. In this pump device 1B, the configuration of the pump device 1A is such that a plurality of, in this example, six convex portions 48e protruding upward in the axial direction are formed on the upper surface 48c of the plate 48b of the shaft 48. Each convex portion 48e is formed in an annular shape around the axis x. In this example, the plurality of convex portions 48e are formed in concentric circles centered on the axis x. An annular groove portion 48f is formed between the adjacent convex portions 48e, 48e in the radial direction. The plurality of groove portions 48f are formed in concentric circles centered on the axis x. The shaft body 48a, the plate 48b, and the convex portions 48e are integrally formed based on casting or the like from a metal material such as stainless steel, for example.

[0044] The upper surface 48c of the plate 48b is in contact with the lower surface of the bottom wall 41. Further, the convex portions 48e are embedded in the bottom wall 41. That is, a plurality of concave portions 41b for receiving the plurality of convex portions 48e are formed on the lower surface of the bottom wall 41. The bottom wall 41 enters into the groove portion 48f between the convex portions 48e, 48e. As a result, the convex portions 48e are in contact with the bottom wall 41. In this example, the height of the convex portions 48e from the upper surface 48c is set to be equal for all the convex portions 48e. When the shaft 48 is attached to the can portion 4, insert molding is performed in a state where the shaft 48 is previously arranged in a mold. On the other hand, as described above, the lower surface 48d of the plate 48b is in contact with the electronic component 82. In addition, the same components as those of the pump devices 1 and 1A of the above-described embodiment are denoted by the same reference numerals, and redundant descriptions here are omitted.

[0045] In this pump device 1B, heat from the electronic components 82 is transferred from the plate 48b and the multiple protrusions 48e to the coolant via the shaft body 48a and the bottom wall 41. By forming the multiple protrusions 48e on the shaft 48, the contact area with the bottom wall 41 can be increased, so that heat can be efficiently transferred from the plate 48b and protrusions 48e on the shaft 48 to the bottom wall 41. As a result, the cooling efficiency of the electronic components 82 can be further improved. In addition, by forming the protrusions 48e and grooves 48f, a large distance is secured between the shaft 48 and the bottom wall 41 from the internal space S to the external space of the can section 4. As a result, even if a gap is formed between the bottom wall 41 and the shaft 48 due to the difference in the coefficient of linear expansion caused by the difference in materials between the bottom wall 41 and the shaft 48, leakage of the coolant from the internal space S to the external space can be prevented.

[0046] In the pump devices 1, 1A, and 1B described above, the formation of the first portion 85 of the heat conductor 84 may be omitted. That is, the second portion 86 of the heat conductor 84 may directly connect the electronic component 82 and the shaft 48. Also, the shape of the plate 48b extending radially from the shaft body 48a may be formed into various shapes other than a disc. The shape and radial dimensions of this plate 48b are preferably set to correspond to the arrangement of the electronic component 82 on the substrate body 81 of the circuit board 8, for example. Also, the shape of the protrusion 48e formed on the upper surface 48c of the plate 48b may be formed into various shapes other than annular.

[0047] FIG. 9 is a cross-sectional view schematically showing the structure of a pump device 1C according to yet another modified example of the present invention, corresponding to the cross section of FIG. 3. FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9. Referring to FIGS. 9 and 10 together, the can portion 4 further has one or more cylinders 49 provided so as to extend axially from the top wall 43. In this example, six cylinders 49 are arranged in the circumferential direction. The cylinder 49 is disposed in an annular space between the inner wall 42 and the outer wall 44 in the can portion 4. Each cylinder 49 is formed, for example, in a cylindrical shape centered on an axis parallel to the axis x. One end, i.e., the upper end portion 49a of the cylinder 49 is open, while the other end, i.e., the lower end portion 49b of the cylinder 49 is closed. In this example, the lower end portion 49b of the cylinder 49 extends axially below the bottom wall 41.

[0048] In this pump device 1C, a third space S3 is formed in each cylinder 49. The third space S3 communicates with the first space S1. The first space S1 and the second space S2 constitute the housing portion according to the present invention. Also, in the pump device 1C, the shaft 48 does not extend axially up to the substrate body 81 of the circuit board 8. In this example, the lower end of the shaft 48 is supported by the through hole 41a of the bottom wall 41. Further, no through hole 83 is formed in the substrate body 81. Note that the lower end of the shaft 48 may be fixed to a bottomed hole formed in the bottom wall 41 instead of the through hole 41a. Furthermore, some of the respective coils 72 are electrically connected to the substrate body 81 by terminals 87. The terminal 87 is formed, for example, from a metal material having high thermal conductivity. In this example, the terminal 87 extends, for example, from the upper surface of the electronic component 82 toward the coil 72.

[0049] As shown in Figure 10, each cylinder 49 is positioned between coils 72, 72 that are adjacent to each other in the circumferential direction. In this example, the outer surface of each cylinder 49 may be in contact with the coils 72. In the annular space between the inner wall 42 and the outer wall 44, a heat dissipation member 76 is interposed between the cylinder 49 and the coils 72. The heat dissipation member 76 is filled, for example, around the cylinder 49 between the circumferentially opposing coils 72, 72, and between the radially opposing annular portion 74 and teeth 75. As shown in Figure 9, the heat dissipation member 76 is positioned over the entire region in the axial direction where the coils 72 are arranged. In this example, the heat dissipation member 76 is positioned over the entire region in the axial direction where the insulator 73 is arranged.

[0050] The heat dissipation member 76 is formed, for example, from a resin material, i.e., varnish, that has insulating properties and high thermal conductivity. Resin materials include, for example, polyamide-imide, polyimide, epoxy, etc. In addition, to improve thermal conductivity, a filler with high thermal conductivity may be added to the resin material. In forming such a heat dissipation member 76, for example, after the stator 7 is fixed between the inner wall 42 and the outer wall 44 of the can portion 4, a varnish that has not yet cured is applied between the cylinder 49 and the coil 72. Subsequently, the heat dissipation member 76 is formed between the cylinder 49 and the coil 72 by, for example, heat curing of the varnish.

[0051] Figure 11 is a partially enlarged perspective cross-sectional view corresponding to the cross-section in Figure 9, showing an enlarged portion of the upper end 49a of the cylinder 49. Referring to both Figure 9 and Figure 11, a portion of the upper end 49a of the cylinder 49 faces, for example, the lower surface of the flange 65 of the rotor body 62 of the rotor 6, in the axial direction. In the axial direction, most of the upper end 49a faces the lower surface of the flange 65, and a portion of the outer circumference of the upper end 49a is located further outward than the outer circumference end of the flange 65. In this example, the upper end 49a of each cylinder 49 is formed on an inclined surface of the top wall 43 that is directed upward in the axial direction from the inner circumference to the outer circumference. Thus, the third space S3 of each cylinder 49 is in communication with the first space S1.

[0052] In the pump device 1C, when power is supplied to the coil 72 from an external device via the circuit board 8 and terminals 87, heat is generated in the coil 72. Meanwhile, in the internal space S, the coolant that flows in from the inlet 32 ​​circulates between the first space S1, the second space S2, and the third space S3. In particular, the coolant is agitated in the third space S3. In this way, the coolant is contained within the cylinder 49. The heat generated in the coil 72 is conducted directly to the cylinder 49, or indirectly to the cylinder 49 via the heat dissipation member 76. Subsequently, the heat is transferred from the cylinder 49 to the coolant. Since the coolant circulates within the internal space S, the heat is released from the pump device 1C along with the coolant. As a result, the coil 72 can be cooled efficiently.

[0053] Furthermore, heat is also generated in the electronic components 82 mounted on the main board 81 due to the power supplied from an external device. The temperature generated by the electronic components 82 tends to be higher than the temperature generated by the coil 72. Since heat moves from a hot object to a cold object, the heat from the electronic components 82 is conducted to the coil 72, for example, via the terminal 87. This heat generated by the electronic components 82, along with the heat generated by the coil 72, is also transferred to the coolant via the cylinder 49. As a result, not only the coil 72 but also the electronic components 82 can be cooled simultaneously. In this way, the electronic components 82 can also be cooled efficiently.

[0054] Figure 12 is a schematic cross-sectional view showing the structure of a pump device 1D according to yet another modification of the present invention. The cross-section in Figure 12 corresponds to the cross-section in Figure 3. Figure 13 is a partially enlarged perspective cross-sectional view of a part of the cross-section in Figure 12. Referring together to Figures 12 and 13, in this example, the lower end portion 49b of the cylinder 49 of the can portion 4 extends further down compared to the other modification described above with reference to Figures 9 to 11, and contacts the surface of the substrate body 81 of the circuit board 8. Since both the lower end portion 49b of the cylinder 49 and the surface of the substrate body 81 extend along a plane perpendicular to the axis x, the lower end portion 49b is in contact with the surface of the substrate body 81 over its entire surface. In this example, the lower end portions 49b of all six cylinders 49 are in contact with the surface of the substrate body 81.

[0055] Figure 14 is a cross-sectional view along line 14-14 in Figure 12. Referring together to Figures 13 and 14, a conductor 88 is formed on the surface of the substrate body 81 along the surface of the substrate body 81. In this example, the conductor 88 has, for example, a first portion 88a that extends in an annular shape around axis x, and a second portion 88b that extends from the first portion 88a. The first portion 88a is in contact with the lower ends 49b of all six cylinders 49. The second portion 88b connects the first portion 88a to each electronic component 82, respectively. However, the conductor 88 is not electrically connected to the electronic components 82. The conductor 88 is formed from a metallic material with high thermal conductivity, such as copper foil. In this example, as is clear from Figure 13, the conductor 88 is embedded in the surface of the substrate body 81.

[0056] With this pump device 1D, the heat generated by the electronic component 82 is transferred from the cylinder 49 to the coolant via the aforementioned terminal 87, coil 72, and heat dissipation member 76. Furthermore, the heat generated by the electronic component 82 is transferred from the lower end 49b of the cylinder 49 to the coolant via the conductor 88. In this way, two heat conduction paths are formed from the electronic component 82 to the coolant. As a result, the pump device 1D can transfer the heat generated by the electronic component 82 to the coolant through two heat conduction paths, thereby further improving the heat dissipation efficiency. Note that in the pump device 1D, components similar to those in the pump device 1 are given the same reference numerals, and redundant explanations are omitted here.

[0057] Figure 15 is a partially enlarged perspective cross-sectional view schematically showing the structure of a pump device 1E corresponding to another modification, which is the same as Figure 13. As shown in Figure 15, in this pump device 1E, the cylinder 49 extends further downward through a through hole 89 that penetrates from the front to the back surface of the substrate body 81. In this case, the first portion 88a of the conductor 88 of the substrate body 81 is in contact with the outer circumferential surface of the cylinder 49. Also, the lower end portion 49b of the cylinder 49 is in contact with the upper surface of the body 51 of the cover 5. With this configuration, the heat generated by the electronic component 82 is transferred to the body 51 of the cover 5 via the conductor 88 and the cylinder 49. The heat is released from the fins 52 of the body 51 toward the outside space. As a result, the heat dissipation efficiency of the pump device 1E can be further improved.

[0058] In the pump devices 1C, 1D, and 1E described above, the heat dissipation member 76 may be omitted as long as the cylinder 49 and the coil 72 are in contact. Furthermore, the shape of the cylinder 49 is not limited to a cylindrical shape, and in a cross-section along a plane perpendicular to the axis x, it may have other polygonal shapes such as a triangle, square, or trapezoid that are suitable for the shape of the space between the coils 72, 72. Furthermore, multiple cylinders 49 may be arranged in the space between the coils 72, 72. Also, cylinders 49 do not have to be arranged in all the spaces between the multiple coils 72, 72, and cylinders 49 may be arranged in some of the spaces between the multiple coils 72, 72. In addition, adjacent cylinders 49, 48 in the circumferential direction may be in communication with each other to enable the flow of coolant. Furthermore, the lower end 49b of the cylinder 49 may be in direct contact with the upper surface of the electronic component 82. In addition, the heat dissipation member 76 may be formed to extend to a region that contacts the surface of the substrate body 81.

[0059] Figures 16 and 17 correspond to Figures 1 and 2, respectively, and are perspective views schematically showing the structure of a pump device 1F according to yet another modification of the present invention. Referring together to Figures 16 and 17, in this pump device 1F, the cover 5 further has a connector housing 54 attached to the lower surface of the main body 51. The connector housing 54 is attached to the lower surface of the main body 51 by fixing members 55, such as screws. The connector housing 54 is formed in a cylindrical shape, for example, extending downward parallel to the direction of rotation axis. One or more connector pins (not shown) are housed inside the connector housing 54. The connector housing 54 is formed from, for example, an insulating resin material. In the following description, the same reference numerals are used for components similar to those in the pump device 1 described above, and redundant explanations are omitted.

[0060] Figure 18 is a cross-sectional view along line 18-18 in Figure 16. The pump device 1F incorporates multiple circuit boards, in this example two first circuit boards 91 and second circuit boards 92, instead of the aforementioned circuit board 8. Both the first circuit board 91 and the second circuit board 92 are formed in a flat plate shape that extends along a plane perpendicular to the axis x. The first circuit board 91 and the second circuit board 92 are arranged side by side in the direction of the rotation axis. In this example, the first circuit board 91 is positioned above the second circuit board 92. That is, the first circuit board 91 is positioned closer to the rotor 6 than the second circuit board 92. The first circuit board 91 and the second circuit board 92 are spaced apart from each other in the direction of the rotation axis. Both the first circuit board 91 and the second circuit board 92 are attached, for example, to the can section 4.

[0061] The first circuit board 91 and the second circuit board 92 are formed in a disc shape, for example, with axis x as the center. In this example, the dimensions of the first circuit board 91 are set to be smaller than the dimensions of the second circuit board 92 in the radial direction perpendicular to axis x. In this example, the dimensions of the first circuit board 91 in the radial direction are set to be about half the dimensions of the second circuit board 92 in the radial direction. Also, the outer edge of the first circuit board 91 is positioned on the inner side of the outer edge of the bottom wall 41 in the radial direction. Note that the first circuit board 91 and the second circuit board 92 may have different shapes and dimensions than those in the above example.

[0062] One or more first electronic components 93 are mounted on the upper surface of the first circuit board 91. In this example, for example, six first electronic components 93 are mounted. The first electronic components 93 are connected to the first circuit board 91. The first electronic components 93 may also be mounted on the lower surface of the first circuit board 91. One or more second electronic components 94 are mounted on the upper and lower surfaces of the second circuit board 92. The second electronic components 94 are connected to the second circuit board 92. In a projected view along the rotation axis, it is preferable that the second electronic components 94 are offset from the first electronic components 93. That is, in a projected view, it is preferable that the first electronic components 93 and the second electronic components 94 do not overlap each other.

[0063] The first electronic component 93 includes, for example, an electronic component that heats up to a relatively high temperature (has a relatively high heat resistance temperature) due to heat generation, such as a field-effect transistor (FET), a shunt resistor, or an IC chip. On the other hand, the second electronic component 94 includes an electronic component that heats up to a relatively lower temperature than the first electronic component 93 (has a relatively low heat resistance temperature), such as an electrolytic capacitor or a chip inductor. In other words, the first electronic component 93 generates heat to a higher temperature than the second electronic component 94. The first electronic component 93 constitutes the heat-generating component according to the present invention. Connector pins (not shown) are connected to the first circuit board 91 and the second circuit board 92.

[0064] In this example, all first electronic components 93 mounted on the upper surface of the first circuit board 91 are in contact with the lower surface of the bottom wall 41 of the casing 2 and the lower end of the shaft 48. The first circuit board 91 and the second circuit board 92 are electrically connected to each other, for example, by wiring or terminals. In addition, some of the coils 72 are electrically connected to the first circuit board 91 and the second circuit board 92. Furthermore, power and signals are supplied to the first electronic components 93, the second electronic components 94, and the coils 72 from an external device via connector pins or terminals. For example, the supply of power causes the first electronic components 93, the second electronic components 94, and the coils 72 to generate heat.

[0065] In the pump device 1F described above, the first electronic component 93 on the first circuit board 91 generates heat to a higher temperature than the second electronic component 94 on the second circuit board 92. Since the first circuit board 91 and the second circuit board 92 are arranged side by side in the direction of the rotation axis and spaced apart, the heat from the first electronic component 93 can be prevented from reaching the second electronic component 94 compared to when they are mounted on the same circuit board. Therefore, the second circuit board 92 can use low-cost electronic components with a low heat resistance temperature (rated temperature). As a result, a low-cost pump device 1F can be provided. Furthermore, if the first electronic component 93 is an FET, a larger current can be passed through the first electronic component 93 than before, thereby improving the performance of the pump device 1F. Also, if the second electronic component 94 is, for example, an electrolytic capacitor that is vulnerable to heat, the lifespan of the second electronic component 94 can be extended.

[0066] Furthermore, in the pump device 1F, the first electronic component 93 mounted on the first circuit board 91 is in contact with the bottom wall 41 and shaft 48 of the casing 2. As a result, the heat generated by the first electronic component 93 is transferred to the coolant in the internal space S via the bottom wall 41 and shaft 48. Since the coolant is discharged from the internal space S through the outlet 33, the heat from the first electronic component 93 is released from the pump device 1F. In this way, the first electronic component 93 can be cooled efficiently. In addition, the two first circuit boards 91 and second circuit boards 92 increase the area on which electronic components can be mounted, thereby increasing the degree of freedom in the design of the placement of electronic components.

[0067] Furthermore, it is assumed that heat from the first electronic component 93 is released into the space between the bottom wall 41 of the can section 4 and the cover 5, for example, from the lower surface of the first circuit board 91. In the direction of rotation, the first circuit board 91 is spaced apart from the second circuit board 92, so the effect of heat released from these first electronic components 93 on the second electronic component 94 can be reduced. Also, in a projected view in the direction of rotation, the first electronic component 93 and the second electronic component 94 are offset from each other, so the effect of heat released from the first electronic component 93, for example, in the direction of rotation, on the second electronic component 94 can be suppressed.

[0068] Figure 19 is a schematic cross-sectional view showing the structure of a pump device 1G according to yet another modification of the present invention. The cross-section in Figure 19 corresponds to the cross-section in Figure 18. In this pump device 1G, a heat dissipation member 95 is further incorporated into the pump device 1F described above. The heat dissipation member 95 is sandwiched between the first circuit board 91 and the bottom wall 41. In this example, the heat dissipation member 95 extends radially beyond the outer periphery of the bottom wall 41. Similarly, the first circuit board 91 also extends radially beyond the outer periphery of the bottom wall 41, just like the heat dissipation member 95. Other components similar to those in the pump device 1F described above are given the same reference numerals, and redundant explanations are omitted here.

[0069] The heat dissipation member 95 is formed from a metal material with high thermal conductivity, such as aluminum. In this example, the heat dissipation member 95 is formed in the form of a sheet, for example. The heat dissipation member 95 is formed in the form of a disc perpendicular to the axis x, for example. The upper surface of the heat dissipation member 95 is in contact with the lower surface of the bottom wall 41 and the lower end of the shaft 48. The lower surface of the heat dissipation member 95 is in contact with the upper surface of the first electronic component 93. With this configuration, heat from the first electronic component 93 can be efficiently conducted to the bottom wall 41 and the shaft 48 via the heat dissipation member 95. Although the first circuit board 91 and the heat dissipation member 95 extend radially beyond the outer edge of the bottom wall 41, they may have the same dimensions as the outer edge of the bottom wall 41, as described above.

[0070] Figure 20 is a schematic cross-sectional view showing the structure of a pump device 1H according to yet another modification of the present invention. Figure 21 is a perspective cross-sectional view along the line 21-21 in Figure 20. Referring together to Figures 20 and 21, in this pump device 1H, one or more recesses 41c are formed in the bottom wall 41, which are recessed downwards from the upper surface of the bottom wall 41, as in the pump device 1G described above. In this example, a plurality of arc-shaped recesses 41c are formed concentrically around the shaft 48. That is, the diameter of the plurality of recesses 41c increases from the inner circumference to the outer circumference. An arc-shaped protrusion 41d is formed by radially adjacent recesses 41c, 41c. Other components similar to those in the pump devices 1F and 1G described above are given the same reference numerals, and redundant explanations are omitted here.

[0071] In this pump device 1H, a plurality of recesses 41c and a plurality of protrusions 41d are formed in the bottom wall 41. As a result, the surface area of ​​the upper surface of the bottom wall 41 can be increased compared to the case where the upper surface of the bottom wall 41 is defined as a flat surface. That is, the contact area between the bottom wall 41 and the coolant can be increased. As a result, the heat of the first electronic component 93 is transferred to the coolant more efficiently through the bottom wall 41. On the other hand, the thickness of the bottom wall 41 can be maintained as before, so a decrease in the rigidity (strength) of the bottom wall 41 can be suppressed. The aforementioned heat dissipation member 95 may be sandwiched between the lower surface of the bottom wall 41 and the first electronic component 93.

[0072] Figure 22 is a schematic cross-sectional view showing the structure of a pump device 1I according to yet another modification of the present invention. The cross-section in Figure 22 corresponds to the cross-section in Figure 19. In this pump device 1I, a second heat dissipation member 96 is further incorporated into the pump device 1G described above. In this example, the heat dissipation member 96 is incorporated into the bottom wall 41 of the can portion 4. The heat dissipation member 96 is embedded in the bottom wall 41 by insert molding into the can portion 4, for example, while supporting the shaft 48. In this example, the heat dissipation member 96 has dimensions smaller than the dimensions of the bottom wall 41 in the radial direction. In one example, the heat dissipation member 96 is formed of a metal material with high thermal conductivity, such as aluminum. Other components similar to those in the pump device 1G described above are given the same reference numerals, and redundant explanations are omitted here.

[0073] Figure 23 is a schematic perspective view showing the structure of a heat dissipation member 96 according to one specific example. Figure 23 is a perspective view of the heat dissipation member 96 viewed from below in the direction of rotation. Referring together to Figures 22 and 23, the heat dissipation member 96 according to one specific example has an annular body 97 around an axis x. In this example, the body 97 is formed in a disc shape extending along a plane perpendicular to the axis x. The body 97 defines a flat upper surface 97a and a lower surface 97b along the plane perpendicular to the axis x. The body 97 has a through hole 98 that penetrates from the upper surface 97a to the lower surface 97b. A shaft 48 is supported within this through hole 98. Specifically, the shaft 48 is fixed to the body 97, i.e., the heat dissipation member 96, by, for example, press-fitting it into the through hole 98 of the body 97. In the direction of rotation, the through hole 41a of the bottom wall 41 is continuous with the through hole 98 of the heat dissipation member 96.

[0074] In this example, the lower surface 97b has a plurality of ribs 99 that extend downward parallel to the axis x. In one example, the plurality of ribs 99 include an annular first rib 99A formed concentrically around the axis x, and one or more second ribs 99B that extend intermittently in the circumferential direction around the axis x. In this example, four arc-shaped second ribs 99B are formed in a circumferential direction centered on the axis x, three first ribs 99A are formed on the inner circumference side of these four second ribs 99B, and three first ribs 99A are formed on the outer circumference side of the four second ribs 99B. In this example, the innermost first rib 99A is formed along the through hole 98, and the outermost first rib 99A is formed along the outer circumference end of the main body 97. In one example, the first rib 99A is a cylindrical rib centered on the axis x.

[0075] In the direction of rotation, the height of the first rib 99A from the lower surface 97b of the main body 97 is set to be constant. Similarly, the height of the second rib 99B from the lower surface 97b in the direction of rotation is set to be constant. Furthermore, the height of the second rib 99B in the direction of rotation is set to be greater than that of the first rib 99A. With these settings, the first rib 99A is embedded in the bottom wall 41. That is, the resin material of the bottom wall 41 flows between the first ribs 99A in the radial direction. Thus, the bottom wall 41 has an annular rib 41e that extends upward in the direction of rotation between the first ribs 99A on the lower surface 97b side of the main body 97 of the heat dissipation member 96.

[0076] On the other hand, the lower end surface of the second rib 99B is exposed to the lower surface of the bottom wall 41. In this example, the lower end surface of the second rib 99B is set flush with the lower surface of the bottom wall 41. That is, the lower end surface of the second rib 99B is defined on the same plane as the lower surface of the bottom wall 41. In this example, since the upper surface of the heat dissipation member 95 is in contact with the lower surface of the bottom wall 41, the lower end surface of the second rib 99B is also in contact with the upper surface of the heat dissipation member 95. In this example, the dimensions (thickness) of the ribs 99 defined in the circumferential direction are set to be larger for the second rib 99B than for the first rib 99A. In this example, four second ribs 99B are arranged in a line in the circumferential direction, but a number other than four, i.e., two, three, or five second ribs 99B may be arranged in the circumferential direction.

[0077] In this pump device 1I, the shaft 48 and the heat dissipation member 96 are integrally formed in the can portion 4 by insert molding. As a result, resin material flows between radially adjacent first ribs 99A. In this way, the first ribs 99A and ribs 41b can increase the surface area of ​​the interface between the bottom wall 41 and the heat dissipation member 96, thereby ensuring high airtightness between the bottom wall 41 and the heat dissipation member 96. As a result, leakage of coolant from the inside to the outside of the can portion 4 can be prevented. The surface of the heat dissipation member 96 may be roughened. This roughening process improves the strength of the bond between the resin material of the bottom wall 41 and the metal material of the heat dissipation member 96, thereby further improving airtightness.

[0078] Furthermore, for example, heat from the first electronic component 93 is transferred to the coolant via the heat dissipation member 95, the bottom wall 41, the heat dissipation member 96, and the shaft 48. In particular, since the heat dissipation member 95 and the heat dissipation member 96, which have high thermal conductivity, are directly connected to each other through the second rib 99B, heat from the first electronic component 93 is efficiently transferred from the heat dissipation member 95 to the coolant via the heat dissipation member 96 and the shaft 48. In this way, the first electronic component 93 can be efficiently cooled. In this example, the lower end of the shaft 48 is in contact with the heat dissipation member 95, but the lower end of the shaft 48 may be embedded in the bottom wall 41. That is, the bottom wall 41 may have a hole with a bottom, i.e., a recess, instead of a through hole 41a. With this configuration, leakage of coolant from the interface between the bottom wall 41 and the shaft 48 can be further suppressed.

[0079] Although the present invention has been described above through the embodiments described above, the technical scope of the present invention is not limited to the scope described in the embodiments above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0080] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit its interpretation. Furthermore, the embodiments described above do not limit the scope of application of the present invention, and the present invention may encompass anything as its target application. The components of the above embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0081] For example, the present invention includes differences that arise in the implementation of manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined to the extent that they do not conflict with the technical requirements. In addition, each component can be selectively combined as appropriate to achieve at least some of the above-mentioned problems and effects.

[0082] 1-1I Pump device, 2 Casing, 3 Case, 31 Main body, 32 Inlet, 33 Outlet, 34 Support part, 34a Recess, 35 Spoke, 4 Can part, 41 Bottom wall, 41a Through hole, 41b Recess, 41c Recess, 41d Protrusion, 41e Rib, 42 Inner wall, 43 Top wall, 44 Outer wall, 45 Flange, 46 Groove, 47 Gasket, 48 Shaft, 48a Shaft body, 48b Plate, 48c Top surface (side facing one direction), 48d Bottom surface (side facing the other direction), 48e Protrusion, 48f Groove, 49 Cylinder, 49a Upper end (end), 49b Lower end (end), 5 Cover, 51 Main body, 52 Fin, 53 Heat sink, 54 Connector housing, 55 Fixing member, 6 Rotor, 61 Bearing, 62 Rotor body, 63 Magnet, 64 Cylinder section, 65 Flange, 66 Blades, 7 Stator, 71 Stator core, 72 Coil, 73 Insulator, 74 Annular section, 75 Teeth, 76 Heat dissipation member, 8 Circuit board (board), 81 Board body, 82 Electronic component (heat-generating component), 83 Through hole, 84 Thermal conductor, 85 First part, 86 Second part, 87 Terminal, 88 Conductor, 88a First part, 88b Second part, 89 Through hole, 91 First circuit board (circuit board), 92 Second circuit board (circuit board), 93 First electronic component (heat-generating component), 94 Second electronic component, 95 Heat dissipation member, 96 (Second) heat dissipation member, 97 Body, 97a Top surface, 97b Bottom surface, 98 Through hole, 99, 99A, 99B Ribs (first rib, second rib), S internal space, S1 first space, S2 second space, S3 third space, x axis

Claims

1. A pump device comprising: a casing having an inlet for fluid to flow in and an outlet for the fluid to flow out; a shaft supported by the casing; a rotor rotatably supported by the shaft; a stator facing the rotor in the radial direction; and a substrate electrically connected to the stator, wherein the substrate includes a heat-generating component, and the heat from the heat-generating component is transmitted to the shaft via a heat conductor.

2. The pump device according to claim 1, wherein the shaft is in contact with the fluid.

3. The pump device according to claim 1 or 2, wherein the substrate has a through hole that penetrates in the axial direction, and the shaft is inserted into the through hole.

4. The pump device according to any one of claims 1 to 3, wherein the casing comprises a heat sink, and the shaft is in contact with the heat sink.

5. The pump device according to any one of claims 1 to 4, wherein the shaft comprises a plate extending in the radial direction, and the plate and the heat-generating component are in contact in the axial direction.

6. The pump device according to claim 5, wherein the plate comprises a surface facing one direction in the axial direction and a surface facing the other direction, the surface facing one direction having a plurality of protrusions projecting in the axial direction, the plurality of protrusions in contact with the casing, and the other surface in contact with the heat-generating component.

7. The pump device according to claim 6, wherein the plurality of protrusions are arranged radially.

8. A pump device comprising: a shaft; a rotor rotatably supported on the shaft; a stator facing the rotor; coils wound around a plurality of teeth of the stator; and a casing forming a housing portion in which the rotor is housed, wherein the stator is fixed to the casing, and in the circumferential direction, a cylinder extending in the axial direction is provided between the plurality of coils, and a liquid is housed in the cylinder.

9. The pump device according to claim 8, wherein one end of the cylinder in the axial direction is in communication with the housing, and the liquid circulates between the housing and the cylinder.

10. The pump device according to claim 8 or 9, wherein a heat dissipation member is interposed between the cylinder and the coil.

11. The pump device according to claim 8 or 9, wherein the casing comprises a circuit board electrically connected to the stator, and the other end of the cylinder in the axial direction is in contact with the circuit board or in contact with a heat-generating component connected to the circuit board.

12. A pump device comprising: a shaft extending in the direction of the rotation axis; a rotor rotatably supported on the shaft; a stator facing the rotor; a casing housing the rotor; and a plurality of circuit boards, wherein the plurality of circuit boards are arranged in the direction of the rotation axis, and a heat-generating component is connected to the circuit board on the rotor side of the plurality of circuit boards.

13. The pump device according to claim 12, wherein the heat-generating component is in contact with the casing.

14. The pump device according to claim 12 or 13, wherein the heat-generating component is in contact with the casing via a heat-dissipating member.

15. The pump device according to claim 14, wherein the bottom wall of the casing is provided with a plurality of ribs between it and the heat dissipation member.

16. The pump device according to claim 15, wherein the plurality of ribs are formed by a second heat dissipation member incorporated into the bottom wall.

17. The pump device according to claim 16, wherein at least a portion of the plurality of ribs is in contact with the heat dissipation member.

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