Motor and pump device

Abstract

To provide a motor in which stress on a circuit board of the motor due to assembly of a heat transfer member is alleviated.SOLUTION: A motor of a pump device includes a housing that seals a stator, a circuit board 19 for supplying a power to a coil of the stator, a cover 9 that is fixed to the housing from one side in an axial direction along a rotation axis of a rotor and accommodates the circuit board 19 between the housing and the motor, and a heat transfer member 10 that is disposed at a position where the cover 9 and a substrate surface of the circuit board 19 face each other and is compressed between the cover 9 and the circuit board 19. The cover 9 is provided with a protruding part 11 protruding toward the heat transfer member 10 at a position overlapping the heat transfer member 10 as viewed in the axial direction. The protruding part 11 includes a distal end surface 12 that contacts the heat transfer member 10. The distal end surface 12 includes a tapered portion T inclined with respect to the substrate surface of the circuit board 19.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a motor and pump device. [Background technology]

[0002] Patent Document 1 describes a pump device in which a motor rotates an impeller located in a pump chamber. The pump device in Patent Document 1 includes a resin housing that houses a rotor and a stator, and a metal cover that is attached to cover the upper end of the housing. A circuit board that mounts a motor drive circuit for supplying power to a coil located in the stator is located inside the cover. An inverter circuit that generates a large amount of heat is mounted on the circuit board, and a heat dissipation material (heat transfer member) is located between the area where the inverter circuit is mounted and the cover. The part of the cover that comes into contact with the heat dissipation material is recessed toward the heat dissipation material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-151925 Summary of the Invention [Problem to be solved by the invention]

[0004] In a motor circuit board structure in which a heat-transfer member such as a heat-dissipating sheet is interposed between the cover and the circuit board to dissipate heat, the heat-transfer member is compressed between the cover and the circuit board to ensure contact with the heat-transfer member. However, in this structure, when the cover and the heat-transfer member are attached, the circuit board is pressed against the heat-transfer member, and stress corresponding to the force required to crush the heat-transfer member is applied to the circuit board. This stress applied to the circuit board can cause defects such as cracks in the solder and components on the circuit board.

[0005] In view of the above problems, an object of the present invention is to alleviate stress on the circuit board of the motor that accompanies the assembly of the heat transfer member. [Means for solving the problem]

[0006] In order to solve the above problem, the motor of the present invention comprises a rotor and a stator surrounding the outer periphery of the rotor, a housing that seals the stator, a circuit board for supplying power to the coils of the stator, a cover that is fixed to the housing from one side in the axial direction along the rotational axis of the rotor and that houses the circuit board between the housing and the cover, and a heat transfer member that is arranged at a location where the cover and a board surface of the circuit board face each other and is compressed between the cover and the circuit board, and is characterized in that the cover has a protrusion that protrudes toward the heat transfer member at a position that overlaps with the heat transfer member when viewed from the axial direction, and the protrusion has a tip that makes surface contact with the heat transfer member, and the tip has a curved portion that is curved in a shape that protrudes toward the heat transfer member or a tapered portion that is inclined with respect to the board surface.

[0007] In order to solve the above problem, the pump device of the present invention is characterized by having the above-mentioned motor, a case fixed to the housing from the other side in the axial direction to form a pump chamber between the case and the housing, and an impeller arranged in the pump chamber and rotating integrally with the rotor. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of the pump device. [Figure 2] FIG. 2 is a cross-sectional view of the pump device (a cross-sectional view taken along the line AA in FIG. 1). [Figure 3] FIG. 3 is an exploded perspective view of the pump device with the cover and the circuit board removed from the housing, as viewed from the other axial side. [Figure 4] FIG. 4 is a cross-sectional view of the pump device (a cross-sectional view taken along the line BB in FIG. 2). [Figure 5] FIG. 5 is a cross-sectional view of the cover, the circuit board, and the heat transfer member taken along a line passing through the center of the tip end surface (line CC in FIG. 2). [Figure 6] FIG. 6 is a plan view of the tip end surface as seen from one side in the axial direction, and a perspective view and a side view that schematically show the shape of the tip end surface. [Figure 7] FIG. 7 is an explanatory view schematically showing the compression step of the heat transfer member. [Figure 8] FIG. 8 is a perspective view and a side view schematically showing the shape of the tip end face of the first modification. [Figure 9] FIG. 9 is a perspective view and a side view schematically showing the shape of the tip end surface of the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the pump device 1 and the motor 2 will be described with reference to the drawings. In the following description, the direction along the rotation axis L of the motor 2 is referred to as the axial direction, one side of the axial direction is referred to as L1, and the other side of the axial direction is referred to as L2.

[0010] (Pumping equipment) FIG. 1 is an external perspective view of a pump device 1. FIG. 2 is a cross-sectional view of the pump device taken along the line AA in FIG. 1. As shown in FIGS. 1 and 2, the pump device 1 includes a motor 2, an impeller 3 that is driven to rotate about a rotation axis L by the motor 2, and a case 4 that covers the motor 2 from one axial side L1. The motor 2 includes a rotor 5, a stator 7 that surrounds the outer periphery of the rotor 5, a housing 8 that covers the stator 7, and a cover 9 that is fixed to the housing 8 from the other axial side L2. The housing 8 is a resin-sealed member that is integrated with the stator 7 by insert molding.

[0011] The impeller 3 is disposed in a pump chamber 20 defined by the housing 8 and the case 4. The impeller 3 and the rotor 5 rotate together about the rotation axis L. The stator 7 includes a coil 6 wound around a stator core 70 with an insulator 71 interposed between them. A circuit board 19 that supplies power to the coil 6 is fixed to the end of the housing 8 on the other axial side L2 and is covered by a cover 9.

[0012] The case 4 has an intake port 21 that opens to one side L1 in the axial direction, and an outlet port 22 that opens in a direction perpendicular to the axial direction. The intake port 21 is provided in the radial center of the pump chamber 20, and the outlet port 22 is provided on the outer periphery of the pump chamber 20. An intake pipe (not shown) can be connected to the intake port 21, and an outlet pipe (not shown) can be connected to the outlet port 22. The housing 8 is provided with a connector portion 80 that holds a plurality of connector terminals for external connection.

[0013] (Circuit board fixing structure) 3 is an exploded perspective view of the pump device 1 with the cover 9 and circuit board 19 removed from the housing 8, viewed from the other axial side L2. As shown in FIGS. 2 and 3, the housing 8 has a body portion 81 that covers the outer periphery of the stator 7. At the end of the other axial side L2 of the body portion 81, there is provided an annular cover fixing surface 82 facing the other axial side L2, and a tubular portion 83 that protrudes from the inner peripheral edge of the cover fixing surface 82 toward the other axial side L2. Inside the tubular portion 83, there are arranged the tip portions of the winding terminals 72 that are connected to the coil 6 of the stator 7 and the tip portion of the connector terminal 73 that is held by the connector portion 80.

[0014] The circuit board 19 is fixed to two bosses 89 that protrude from the inner circumferential surface of the cylindrical portion 83 toward the inner circumferential side by tapping screws 18. The tip portions of the winding terminals 72 and connector terminals 73 are fitted and soldered into terminal holes provided on the outer periphery of the substrate 19 .

[0015] (Cover fixing structure) Fig. 4 is a cross-sectional view of the pump device 1, taken along the line BB in Fig. 2. As shown in Figs. 2, 3, and 4, the cover 9 has a circular bottom 91 facing the circuit board 19 from the other side L2 in the axial direction, an annular wall 92 bent from the outer periphery of the bottom 91 toward the housing 8, and a flange 93 extending outward from the annular wall 92. The annular wall 92 has a step 94 bent from midway in the axial direction toward the outer periphery.

[0016] A recess 84 recessed inward is provided on the outer peripheral surface of the cylindrical portion 83 of the housing 8. A seal member 17 such as an O-ring is disposed in the recess 84. The seal member 17 closely contacts the inner peripheral surface of the annular wall 92 and the step portion 94, and also closely contacts the inner surface of the recess 84. Therefore, the seal member 17 seals the gap between the cover 9 and the housing 8.

[0017] As shown in Figures 2 and 4, when the cover 9 is fixed to the housing 8, the tubular portion 83 is fitted inside the annular wall 92 and the flange portion 93 is brought into contact with the cover fixing surface 82. A boss portion 85 protruding from the cover fixing surface 82 is fitted in some of the multiple through holes 95 that pass through the flange portion 93. The cover 9 is positioned relative to the housing 8 by fitting the boss portion 85 into the through hole 95. A welding cap 86 is fixed to the tip of the boss portion 85 by welding. Furthermore, a fixing screw 16 is passed through some of the multiple through holes 95. The tip of the fixing screw 16 is screwed into a fixing hole 87 provided in the cover fixing surface 82.

[0018] In this way, the cover 9 is fixed to the housing 8 by combining screw fastening with the fixing screws 16 and welding the welding caps 86 to the bosses 85. Note that it is also possible to adopt a configuration in which the tips of the bosses 85 are crushed and crimped without using the welding caps 86. The guide holes 88 opening in the tip surface of each boss 85 are holes into which guide pins are inserted to guide the housing 8 when assembling the cover 9 to the housing 8.

[0019] The flange portion 93 is provided with a plurality of through holes 95 at equal intervals in the circumferential direction. The cover fixing surface 82 is provided with boss portions 85 and fixing holes 87 alternately arranged in the circumferential direction at positions overlapping with the through holes 95 when viewed from the axial direction. In this embodiment, six through holes 95 are provided at equal angular intervals. The cover fixing surface 82 has three boss portions 85 and three fixing holes 87 arranged alternately in the circumferential direction. As shown in FIG. 3 , the number of through holes 95 and their arrangement pitch are determined so that an imaginary line P connecting the centers of adjacent through holes 95 in the circumferential direction is located radially outward of the outer diameter of the seal member 17 disposed inside the annular wall 92. This ensures that the seal member 17 can be crushed reliably.

[0020] (heat transfer material) As shown in Figures 2 and 4, the motor 2 of the pump device 1 includes a heat transfer member 10 disposed between the circuit board 19 and the cover 9. The heat transfer member 10 is a sheet-like elastic member having a predetermined thickness. The heat transfer member 10 contacts the circuit board 19 and the cover 9. Therefore, heat generated from the circuit board 19 is transferred to the cover 9 via the heat transfer member 10, thereby suppressing a temperature rise in the circuit board 19. The cover 9 is made of a material with high heat dissipation properties. For example, the cover 9 is made of a metal such as aluminum, brass, or copper. Therefore, the heat transferred from the heat transfer member 10 to the cover 9 is dissipated to the outside from the surface of the cover 9.

[0021] The bottom 91 of the cover 9 has a flat portion 96 perpendicular to the axial direction, and a protruding portion 11 protruding from the flat portion 96 toward the circuit board 19. The protruding portion 11 has a tip surface 12 facing the board surface S of the circuit board 19, and an edge portion 13 bent from the outer periphery of the tip surface 12 toward the flat portion 96. The protruding dimension of the protruding portion 11 is determined so that the distance between the tip surface 12 and the circuit board 19 is smaller than the thickness of the heat transfer member 10. Therefore, when the cover 9 is fixed to the housing 8, the heat transfer member 10 placed on the board surface S of the circuit board 19 is pressed and compressed by the tip surface 12 of the protruding portion 11. As a result, the heat transfer member 10 is in close contact with the board surface S of the circuit board 19 or with electronic elements, solder, circuit patterns, etc. arranged on the board surface S, and is also in close contact with the tip surface 12 of the protruding portion 11.

[0022] 2 and 4, a heat generating element E, which is an electronic element that generates a large amount of heat, is mounted on circuit board 19 at a position overlapping heat transfer member 10 as viewed from the axial direction. Heat generating element E is, for example, a switching element for generating a drive current to be supplied to coil 6. In this embodiment, a FET (Field Effect Transistor) is disposed on circuit board 19 as the switching element. Furthermore, solder lands (not shown) that function as heat dissipation pads are formed on circuit board 19 at a position overlapping heat transfer member 10 as viewed from the axial direction.

[0023] (Tip surface shape) Fig. 5 is a cross-sectional view of the cover 9, the circuit board 19, and the heat transfer member 10 taken at a position passing through the center of the tip surface 12 (position CC in Fig. 2). Fig. 6 is a plan view of the tip surface 12 as viewed from one side L1 in the axial direction, and a perspective view and a side view schematically showing the shape of the tip surface 12. In the perspective view and side view of Fig. 6, the inclination angle of the tapered portion T provided on the tip surface 12 is exaggerated to make the explanation easier to understand.

[0024] As shown in Fig. 6, the tip surface 12 of the protrusion 11 provided on the cover 9 has an apex portion 120 that protrudes most toward one side L1 in the axial direction. As shown in the upper view of Fig. 6, the planar shape of the tip surface 12 viewed from the axial direction is rectangular. The outer periphery of the tip surface 12 has a first side 121 and a second side 122 that face each other in a first direction X that is perpendicular to the axial direction, and a third side 123 and a fourth side 124 that face each other in a second direction Y that is perpendicular to the axial direction and perpendicular to the first direction X. The planar shape of the tip surface 12 is a rectangle whose dimension in the first direction X is longer than its dimension in the second direction.

[0025] The tip surface 12 has a tapered portion T that is inclined with respect to the board surface S of the circuit board 19. In this embodiment, the board surface S is perpendicular to the axial direction. Therefore, the tapered portion T is an inclined surface that is inclined in a direction that forms an acute angle with respect to a plane perpendicular to the axial direction. The tapered portion T has a first inclined surface T1 extending from the apex portion 120 to the first side 121, a second inclined surface T2 extending from the apex portion 120 to the second side 122, a third inclined surface T3 extending from the apex portion 120 to the third side 123, and a fourth inclined surface T4 extending from the apex portion 120 to the fourth side 124. In this embodiment, the apex portion 120 is located in the center of the tip surface 12, and the tip surface 12 has a quadrangular pyramid shape.

[0026] 7 is an explanatory diagram that schematically shows the compression process of the heat transfer member 10. As shown in the upper diagram of FIG. 7, the apex portion 120 of the tip surface 12 of the protrusion 11 provided on the cover 9 is the first to come into contact with the heat transfer member 10. The entire tip surface 12 except for the apex portion 120 is configured as a tapered portion T. Therefore, as shown in the lower diagram of FIG. 7, the heat transfer member 10 is pressed not by a plane perpendicular to the compression direction (axial direction), but by the tapered portion T that is inclined in a direction that forms an acute angle with respect to a plane perpendicular to the compression direction.

[0027] When the heat transfer member 10 is pressed by the tapered portion T inclined with respect to the compression direction, the pressing force required to compress the heat transfer member 10 is smaller than when the heat transfer member 10 is pressed by a plane perpendicular to the compression direction, and therefore the pressing force received by the circuit board 19 is also smaller. Therefore, the deflection of the circuit board 19 can be reduced, and the stress generated in the circuit board 19 can be reduced. For example, with the shape of the tip end surface 12 of this embodiment, the stress generated in the circuit board 19 can be reduced by about 20% compared to when the heat transfer member 10 is compressed by a plane perpendicular to the axial direction. can be alleviated.

[0028] The portion of the heat transfer member 10 that is pressed by the apex portion 120 of the tip end surface 12 adheres most firmly to the circuit board 19. The shape of the tip end surface 12 is preferably such that the heat transfer member 10 adheres most firmly to the position where the heat generating element E is mounted or the position where a solder land that functions as a heat dissipation pad is formed.

[0029] A plurality of heat-generating elements E are mounted on the circuit board 19. For example, in this embodiment, six heat-generating elements E are mounted. The heat transfer member 10 is preferably attached to the entire area where the plurality of heat-generating elements E are arranged. Alternatively, if the size of the heat transfer member 10 is not large enough to cover the entire area where the heat-generating elements E are arranged, it is preferable to attach the heat transfer member 10 to the center of the area where the heat-generating elements E are arranged.

[0030] (Main effects of this embodiment) As described above, the pump device 1 of this embodiment includes the motor 2, the case 4 fixed to the housing 8 of the motor 2 from the other axial side L2 and forming a pump chamber 20 between the case 4 and the housing 8, and the impeller 3 disposed in the pump chamber 20 and rotating integrally with the rotor 5. The motor 2 also includes the rotor 5, the stator 7 surrounding the rotor 5, the housing 8 sealing the stator 7, a circuit board 19 for supplying power to the coil 6 of the stator 7, a cover 9 fixed to the housing 8 from one axial side L1 along the rotation axis L of the rotor 5 and accommodating the circuit board 19 between the cover 9 and the housing 8, and a heat transfer member 10 disposed at a position where the cover 9 and the board surface S of the circuit board 19 face each other and compressed between the cover 9 and the circuit board 19. The cover 9 has a protrusion 11 that protrudes toward the heat transfer member 10 at a position overlapping the heat transfer member 10 when viewed from the axial direction. The protrusion 11 has a tip surface 12 that contacts the heat transfer member 10. The tip surface 12 has a tapered portion T that is inclined with respect to the board surface S of the circuit board 19 .

[0031] In this embodiment, the heat transfer member 10 is compressed between the cover 9 and the circuit board 19, and the heat transfer member 10 is in close contact with the cover 9 and the circuit board 19. This allows heat generated in the circuit board 19 to be transferred to the cover 9 via the heat transfer member 10 and dissipated. This prevents the temperature of the circuit board 19 from rising. Furthermore, the leading end surface 12 that presses the heat transfer member 10 toward the circuit board 19 includes a tapered portion T that is inclined relative to the board surface S of the circuit board 19. By pressing the heat transfer member 10 with an inclined surface rather than a flat surface perpendicular to the pressing direction, the pressing force applied to the circuit board 19 can be reduced. This reduces the deflection of the circuit board 19 and reduces stress, thereby alleviating stress applied to the solder on the circuit board 19 and preventing cracks. Furthermore, stress applied to electronic elements mounted on the circuit board 19 can be alleviated. Furthermore, providing the tapered portion T on the leading end surface 12 increases the contact area of ​​the heat transfer member 10 with the leading end surface 12, thereby enhancing the heat dissipation effect.

[0032] In this embodiment, the planar shape of the tip surface 12 as viewed from the axial direction is a rectangle having a first side 121 and a second side 122 that face each other in a first direction X that is perpendicular to the axial direction, and a third side 123 and a fourth side 124 that face each other in a second direction Y that is perpendicular to the axial direction and perpendicular to the first direction X. The tip surface 12 has an apex portion 120 that protrudes most toward the heat transfer member 10, and a tapered portion T. The tapered portion T has a first inclined surface T1 extending from the apex portion 120 toward the first side 121 and a second inclined surface T2 extending from the apex portion 120 toward the second side 122. By making the apex portion 120 protrude most and providing inclined surfaces that slope in opposite directions on both sides of the apex portion 120 in this way, when the heat transfer member 10 is compressed and crushed, a pressing force is concentrated at one point, and both side surfaces in the first direction X expand evenly. Therefore, since the heat transfer member 10 is easily crushed, the pressure applied to the circuit board 19 via the heat transfer member 10 can be reduced.

[0033] In this embodiment, the tapered portion T provided on the tip surface 12 includes a third inclined surface T3 extending from the apex 120 toward the third side 123 and a fourth inclined surface T4 extending from the apex 120 toward the fourth side 124. When the tip surface 12 is formed into a quadrangular pyramid shape, the pressure is concentrated at one point, and the entire outer circumferential surface expands evenly. Therefore, the heat transfer member 10 is easily crushed, and the pressure applied to the circuit board 19 via the heat transfer member 10 can be reduced.

[0034] In this embodiment, the apex portion 120 of the tip surface 12 overlaps the heat generating element E mounted on the circuit board 19 or the solder land formed on the circuit board 19 when viewed from the axial direction. This allows the heat transfer member 10 to be most firmly attached to the position where the heat generating element E is mounted or the position where the solder land is formed. It also minimizes the distance between the heat generating element E or the solder land and the tip surface 12. Therefore, heat generated in the heat generating element E or heat transferred via the solder land can be efficiently transferred to the cover 9, thereby improving the heat dissipation effect.

[0035] In this embodiment, the housing 8 has a cover fixing surface 82 perpendicular to the axial direction, which is provided on the outer periphery of the circuit board 19. The cover fixing surface 82 is formed with bosses 85 that protrude in the axial direction and fixing holes 87 that are recessed in the axial direction. The bosses 85 and fixing holes 87 are arranged alternately in the circumferential direction on the outer periphery of the circuit board 19. The cover 9 has a bottom 91 provided with protrusions 11, and a flange 93 that is provided on the outer periphery of the bottom 91 and abuts against the cover fixing surface 82 from one axial side L1. The flange 93 has through holes 95 formed in positions that axially overlap the bosses 85 and fixing holes 87. The tips of fixing screws 16 that pass through the through holes 95 are fastened to the fixing holes 87. The tips of the bosses 85 are provided with crimped or welded portions that overlap the edges of the through holes 95.

[0036] By providing the positioning bosses 85 on the cover fixing surface 82, the cover 9 can be positioned relative to the housing 8. This improves assembly workability. Furthermore, since the positioning accuracy of the cover 9 can be improved, the positioning accuracy of the apex portion 120 of the tip surface 12 relative to the heating element E and solder lands mounted on the circuit board 19 can also be improved. Therefore, the heat transfer member 10 can be tightly attached to the high-temperature area, thereby improving the heat dissipation effect. Furthermore, since positioning is performed using a portion of the fixing through-holes 95, there is no need to provide the cover 9 and housing 8 with a separate positioning shape (e.g., a D-cut or a spigot structure). Therefore, the structures of the cover 9 and housing 8 can be simplified. Furthermore, by welding some of the fixing locations, the number of fixing screws 16 can be reduced, resulting in weight and cost savings.

[0037] (Variation 1) FIG. 8 is a perspective view and a side view schematically illustrating the shape of the tip surface 12A of Modification 1. The tip surface 12A of Modification 1 includes a vertex portion 120A that extends linearly in the second direction Y at the center of the tip surface 12A in the first direction X and a tapered portion TA that is inclined relative to the substrate surface S. The tapered portion TA includes a first inclined surface T5 extending from the vertex portion 120A toward the first side 121 and a second inclined surface T6 extending from the vertex portion 120A toward the second side 122. When the tip surface 12A presses the heat transfer member 10, the heat transfer member 10 is compressed and crushed. The pressing force is concentrated at the vertex portion 120A in the center in the first direction X, and both side surfaces in the first direction X expand evenly. Therefore, the heat transfer member 10 is easily crushed, and the pressing force applied to the circuit board 19 via the heat transfer member 10 can be reduced.

[0038] In the tip surface 12A of the first modification, the most protruding apex portion 120A extends linearly, so it is preferable to arrange the plurality of heating elements E at positions that overlap with the apex portion 120A when viewed from the axial direction. For example, six FETs are arranged in three rows of two each, and the heating elements E are arranged in the central row. The two FETs placed on the cover 9 are configured to overlap with the apex portion 120A when viewed from the axial direction. This allows the heat generated from the plurality of heat generating elements E to be efficiently transferred to the cover 9.

[0039] (Variation 2) FIG. 9 is a perspective view and a side view schematically illustrating the shape of the tip surface 12B of Modification 2. The tip surface 12B of Modification 2 is a curved surface that protrudes toward one side L1 in the axial direction. The tip surface 12B is a curved surface with its apex at the center in the first direction X. When the heat transfer member 10 is pressed by the curved surface, the heat transfer member 10 is compressed and crushed, and the pressing force is concentrated in the center in the first direction X, and both side surfaces in the first direction X expand evenly. Therefore, because the heat transfer member 10 is easily crushed, the pressing force applied to the circuit board 19 via the heat transfer member 10 can be reduced.

[0040] (Other variations) The shape of the surface that presses and compresses the heat transfer member 10 is not limited to the above-described form and its modifications. That is, the surface that presses the heat transfer member 10 may have a vertex that protrudes most from the substrate surface S, and a surface that has a shape in which the distance from the substrate surface S increases with increasing distance from the vertex.

[0041] (Other embodiments) The above embodiment is the configuration of the motor 2 that rotates the impeller 3 of the pump device 1, but this configuration may also be applied to motors for other uses.

[0042] (summary) A summary of this disclosure is provided below. (1) a rotor and a stator surrounding the outer periphery of the rotor; a housing that seals the stator; a circuit board for supplying power to the coils of the stator; a cover fixed to the housing from one side in the axial direction along the rotation axis of the rotor, and accommodating the circuit board between the cover and the housing; a heat transfer member that is disposed at a position where the cover and a board surface of the circuit board face each other and is compressed between the cover and the circuit board, the cover is provided with a protruding portion that protrudes toward the heat transfer member at a position that overlaps the heat transfer member when viewed from the axial direction, the protruding portion having a tip surface that contacts the heat transfer member, The motor is characterized in that the tip surface has a curved portion that is curved in a shape that protrudes toward the heat transfer member, or a tapered portion that is inclined with respect to the substrate surface.

[0043] (2) a planar shape of the tip surface as viewed from the axial direction is a rectangle having a first side and a second side that face each other in a first direction that is perpendicular to the axial direction, and a third side and a fourth side that face each other in a second direction that is perpendicular to the axial direction and perpendicular to the first direction, the tip surface includes a vertex portion that protrudes most toward the heat transfer member, and the tapered portion; The tapered portion is a first inclined surface extending from the vertex portion toward the first side; The motor according to (1) above, further comprising a second inclined surface extending from the vertex portion toward the second side.

[0044] (3) The motor according to (2) above, wherein the vertex portion extends linearly in the second direction.

[0045] (4) The tapered portion is a third inclined surface extending from the vertex portion toward the third side; The motor according to (2) or (3) above, further comprising a fourth inclined surface extending from the vertex portion toward the fourth side.

[0046] (5) A motor as described in any one of (2) to (4) above, characterized in that the vertex portion overlaps with a heat generating element mounted on the circuit board or a solder land formed on the circuit board when viewed from the axial direction.

[0047] (6) The housing has a cover fixing surface that is perpendicular to the axial direction and is provided on the outer periphery of the circuit board, The cover fixing surface is formed with boss portions that protrude in the axial direction and fixing holes that are recessed in the axial direction, and the boss portions and the fixing holes are alternately arranged in the circumferential direction on the outer periphery of the circuit board, the cover includes a bottom portion on which the protrusion is provided, and a flange portion provided on the outer periphery of the bottom portion and abutting against the cover fixing surface from one side in the axial direction, the flange portion having a through hole formed at a position overlapping with each of the boss portion and the fixing hole in the axial direction, The tip of a screw passed through the through hole is screwed into the fixing hole, The motor according to any one of (1) to (5) above, wherein a crimped portion or a welded portion that overlaps the edge of the through hole is provided at the tip of the boss portion.

[0048] (7) The motor according to any one of (1) to (6) above; a case fixed to the housing from the other side in the axial direction to form a pump chamber between the housing and the case; an impeller disposed in the pump chamber and rotating integrally with the rotor. [Explanation of symbols]

[0049] 1...pump device, 2...motor, 3...impeller, 4...case, 5...rotor, 6...coil, 7...stator, 8...housing, 9...cover, 10...heat transfer member, 11...protrusion, 12, 12A, 12B...tip surface, 13...edge, 16...fixing screw, 17...sealing member, 18...tapping screw, 19...circuit board, 20...pump chamber, 21...suction port, 22...discharge port, 70...stator core, 71...insulator, 72...winding terminal, 73...connector terminal, 80...connector portion, 81...body portion, 82...cover fixing surface, 83...cylindrical portion, 84...recess, 85...boss portion, 86...welding Cap, 87...fixing hole, 88...guide hole, 89...boss portion, 91...bottom portion, 92...annular wall, 93...flange portion, 94...step portion, 95...through hole, 96...flat portion, 120, 120A...vertex portion, 121...first edge, 122...second edge, 123...third edge, 124...fourth edge, E...heating element, L...rotation axis, L1...one side in the axial direction, L2...other side in the axial direction, P...imaginary line, S...substrate surface, T, TA...tapered portion, T1...first inclined surface, T2...second inclined surface, T3...third inclined surface, T4...fourth inclined surface, T5...first inclined surface, T6...second inclined surface, X...first direction, Y...second direction

Claims

1. a rotor and a stator surrounding the outer periphery of the rotor; a housing that seals the stator; a circuit board for supplying power to the coils of the stator; a cover fixed to the housing from one side in the axial direction along the rotation axis of the rotor, and accommodating the circuit board between the cover and the housing; a heat transfer member that is disposed at a position where the cover and a board surface of the circuit board face each other and is compressed between the cover and the circuit board, the cover is provided with a protruding portion that protrudes toward the heat transfer member at a position that overlaps the heat transfer member when viewed from the axial direction, the protruding portion having a tip surface that contacts the heat transfer member, The motor is characterized in that the tip surface has a curved portion that is curved in a shape that protrudes toward the heat transfer member, or a tapered portion that is inclined with respect to the substrate surface.

2. a planar shape of the tip surface as viewed from the axial direction is a rectangle including a first side and a second side that face each other in a first direction that is perpendicular to the axial direction, and a third side and a fourth side that face each other in a second direction that is perpendicular to the axial direction and perpendicular to the first direction, the tip surface includes a vertex portion that protrudes most toward the heat transfer member, and the tapered portion; The tapered portion is a first inclined surface extending from the vertex portion toward the first side; 2. The motor according to claim 1, further comprising: a second inclined surface extending from the vertex portion toward the second side.

3. The motor according to claim 2 , wherein the vertex portion extends linearly in the second direction.

4. The tapered portion is a third inclined surface extending from the vertex portion toward the third side; 3. The motor according to claim 2, further comprising: a fourth inclined surface extending from the vertex portion toward the fourth side.

5. 3. The motor according to claim 2, wherein the vertex portion overlaps a heat generating element mounted on the circuit board or a solder land formed on the circuit board when viewed from the axial direction.

6. The housing has a cover fixing surface that is perpendicular to the axial direction and is provided on the outer periphery of the circuit board, The cover fixing surface is formed with boss portions that protrude in the axial direction and fixing holes that are recessed in the axial direction, and the boss portions and the fixing holes are alternately arranged in the circumferential direction on the outer periphery of the circuit board, the cover includes a bottom portion on which the protrusion is provided, and a flange portion provided on the outer periphery of the bottom portion and abutting against the cover fixing surface from one side in the axial direction, the flange portion having a through hole formed at a position overlapping with each of the boss portion and the fixing hole in the axial direction, The tip of a screw passed through the through hole is screwed into the fixing hole, 2. The motor according to claim 1, wherein a tip of the boss portion is provided with a crimped portion or a welded portion that overlaps the edge of the through hole.

7. A motor according to any one of claims 1 to 6; a case fixed to the housing from the other side in the axial direction to form a pump chamber between the housing and the case; an impeller disposed in the pump chamber and rotating integrally with the rotor.

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