Motor device and oil pump device

Abstract

To provide a technology for improving exhaust heat efficiency of heat emitted from a control circuit without enlarging a motor device.SOLUTION: A motor device has an electric motor, a control board on which a control circuit controlling the electric motor is mounted, a metal housing supporting a first surface of the control board, a resin cover attached to the housing so as to cover the first surface of the control board, a second surface on an opposite side, and the periphery of the control board, and a heat radiation member radiating heat which a heating element included in the control circuit generates to the housing. The heat radiation member has a heat receiving plate fixed to the cover at a position facing to the heating element, and a heat transmitting plate protruding toward the housing from the heat receiving plate at a position deviated from the control board. The housing has a receiving part receiving a protrusion end of the heat transmitting plate inserted into an extension direction of a rotation axis outside a motor accommodating space, and an exhaust heat wall which extends in the extension direction of the rotation axis and surface-contacts the heat transmitting plate received by the receiving part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a motor device and an oil pump device equipped with the motor device. [Background technology]

[0002] In recent years, efforts have been made to promote the Sustainable Development Goals (2030 Agenda for Sustainable Development, adopted at the United Nations Summit on September 25, 2015, hereafter referred to as "SDGs"). In line with this, technologies that aim to prevent waste generation, reduce waste, and significantly reduce waste generation by recycling and reusing products in order to ensure sustainable production and consumption patterns have become known.

[0003] Conventionally, there has been known a so-called "mechanically and electrically integrated" motor device in which an electric motor and a control board that controls the electric motor are housed and integrated in a housing. In addition, such a motor device is provided with a heat sink that dissipates heat emitted from a control circuit mounted on the control board through the housing.

[0004] For example, Patent Document 1 discloses a motor device in which a heat sink is fixed with bolts to the outside of the motor accommodating space of a housing. More specifically, the heat sink in Patent Document 1 has one surface in the thickness direction in surface contact with a control board, and the other surface in the thickness direction in surface contact with a mounting surface of the housing that is perpendicular to the rotation shaft of the motor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-136825 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since there is little space outside the motor-accommodating space in the housing, it is difficult to ensure a large mounting surface. As a result, the contact area between the heat sink and the housing cannot be increased, making it difficult to improve the heat dissipation efficiency. On the other hand, if one tries to improve the heat dissipation efficiency of the motor device of Patent Document 1, it is necessary to increase the size of the motor device in the radial direction.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a technique for improving the efficiency of dissipating heat emitted from a control circuit without increasing the size of a motor device. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the present invention provides a motor device comprising: an electric motor; a control board on which a control circuit for controlling the electric motor is mounted; a metal housing having a motor accommodating space for accommodating the electric motor and supporting a first surface of the control board at a position offset from the motor accommodating space in the extension direction of the rotating shaft of the electric motor; a resin cover attached to the housing so as to cover a second surface of the control board opposite the first surface and the periphery of the control board; and a heat dissipation member for dissipating heat generated by a heat generating element included in the control circuit to the housing, wherein the heat dissipation member comprises a heat receiving plate fixed to the cover at a position facing the heat generating element, and a heat transfer plate protruding from the heat receiving plate towards the housing at a position offset from the control board, and the housing comprises, outside the motor accommodating space, a receiving portion for receiving the protruding end of the heat transfer plate inserted in the extension direction of the rotating shaft, and a heat exhaust wall extending in the extension direction of the rotating shaft and in face-to-face contact with the heat transfer plate received in the receiving portion. Effect of the Invention

[0009] According to the present invention, it is possible to improve the efficiency of dissipating heat emitted from a control circuit without increasing the size of a motor device. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is an external perspective view of an oil pump device according to an embodiment of the present invention; [Diagram 2] FIG. [Diagram 3] FIG. 2 is a perspective view of the control unit with the cover removed. [Figure 4] FIG. [Diagram 5] FIG. 2 is a perspective view of the cover as seen from the back side. [Figure 6] 4A and 4B are cross-sectional views showing the state before and after a protruding end of a heat transfer plate is inserted into a recessed groove of a heat sink support part. [Figure 7] 4 is a cross-sectional view showing the positional relationship between a heat sink support portion, a control board, and a heat sink. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An oil pump device 1 according to an embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a perspective view of the appearance of the oil pump device 1 according to this embodiment.

[0012] The oil pump device 1 according to this embodiment supplies oil (for example, lubricating oil) to an engine clutch or a transmission clutch mounted on, for example, an automobile, although the use of the oil pump device 1 is not limited thereto.

[0013] 1, the oil pump device 1 is a so-called "electric oil pump" that includes a motor section 2, a control section 3, and a pump section 4. The motor section 2 and the control section 3 configure a so-called "mechanically and electrically integrated" motor device 5 independent of the pump section 4. The motor device 5 is not limited to driving the pump section 4, and may also drive a cooling fan or wipers.

[0014] The motor section 2 includes an electric motor 6 (see FIG. 7) that rotates (generates driving force) by driving power supplied from the control section 3. There is no particular limitation on the specific example of the electric motor 6, but for example, an inner rotor type brushless motor can be adopted. The configuration of the electric motor 6 is already well known, so a detailed description will be omitted. The control section 3 supplies power supplied from an external device (not shown) to the electric motor 6 as driving power. The specific configuration of the control section 3 will be described later with reference to FIG. 2 and subsequent figures. The driving force of the motor section 2 is transmitted to the pump section 4, which pumps oil. The configuration of the pump section 4 is already well known, so a detailed description will be omitted.

[0015] The motor section 2, the control section 3, and the pump section 4 are disposed adjacent to each other in the extending direction of a rotating shaft 7 (see FIG. 7) of an electric motor 6, which will be described later. More specifically, the control section 3 is disposed adjacent to the motor section 2 disposed in the center on one side in the extending direction of the rotating shaft 7, and the pump section 4 is disposed adjacent to the other side in the extending direction of the rotating shaft 7.

[0016] The oil pump device 1 includes a housing 10 that houses a motor section 2, a control section 3, and a pump section 4. The housing 10 is made of a metal material such as aluminum die-cast. Note that the housing 10 is not limited to being an integrated type that houses the motor section 2, the control section 3, and the pump section 4 together, and may be configured with some parts being separate.

[0017] Fig. 2 is an exploded perspective view of the control unit 3. Fig. 3 is a perspective view of the control unit 3 with the cover 60 removed. As shown in Figs. 2 and 3, the control unit 3 mainly includes a housing 10, a control board 20, a connector unit 30, a relay unit 40, a heat sink 50, and a cover 60. Hereinafter, the extension direction of the rotating shaft 7 will be simply referred to as the "axial direction", and the direction perpendicular to the extension direction of the rotating shaft 7 (the radial direction of the rotating shaft 7) will be simply referred to as the "radial direction".

[0018] As shown in FIG. 2, the housing 10 defines a motor accommodating space 11 that accommodates the electric motor 6. The motor accommodating space 11 is a space having a generally cylindrical outer shape. The housing 10 also has a support surface 12 that supports components (20-60) of the control unit 3. The support surface 12 is a surface that expands in the radial direction at a position axially offset from the motor accommodating space 11. The support surface 12 has a generally rectangular outer shape when viewed from the axial direction.

[0019] The support surface 12 is provided with a plurality of (four in this embodiment) support protrusions 13a, 13b, 13c, and 13d, a plurality of (four in this embodiment) screw seats 14a, 14b, 14c, and 14d, and a heat sink support portion 15.

[0020] The support protrusions 13a to 13d protrude in the axial direction from the support surface 12 at different positions on the support surface 12 (typically, positions surrounding the motor accommodating space 11). The support protrusions 13a to 13d support the control board 20 at their tips. Second positioning holes 16a, 16b, 16c, and 16d for receiving positioning pins 64a to 64d (described later) are formed in the support protrusions 13a to 13d. The second positioning holes 16a to 16d extend from the tips of the support protrusions 13a to 13d toward the base ends.

[0021] The screw seats 14a to 14d protrude in the axial direction from the support surface 12 at different positions on the support surface 12 (typically, positions surrounding the motor accommodating space 11). The screw seats 14a to 14d have screw holes 17a, 17b, 17c, and 17d formed therein that communicate with the screw holes 65a to 65d of the cover 60 when the cover 60 is attached to the housing 10. The screws 18a to 18d are screwed into the communicating screw holes 17a to 17d, 65a to 65d, thereby fixing the cover 60 to the housing 10.

[0022] The heat sink support portion 15 supports an end portion of the heat sink 50. The heat sink support portion 15 is provided at a position radially out of the motor accommodating space 11. The heat sink support portion 15 is provided linearly in parallel to one of the four sides constituting the outer edge of the support surface 12 at a position adjacent to the side. A specific configuration of the heat sink support portion 15 will be described later with reference to FIG. 6.

[0023] The control board 20 has a board 21. The board 21 is a flat member having a generally rectangular outer shape. The board 21 has a first surface 21a and a second surface 21b (see FIG. 7). The first surface 21a is a surface on one side of the board 21 in the thickness direction (the side facing the motor accommodating space 11). The second surface 21b is a surface on the other side of the board 21 in the thickness direction (the side opposite to the first surface 21a). As shown in FIG. 6, the board 21 is disposed so as to overlap the motor accommodating space 11 when viewed from the axial direction. The outer edge of the board 21 is located outside the motor accommodating space 11 when viewed from the axial direction.

[0024] The substrate 21 is formed with first positioning holes 22a, 22b, 22c, and 22d penetrating in the thickness direction. The first positioning holes 22a-22d are formed at positions corresponding to the support protrusions 13a-13d on the outer edge of the substrate 21. When the substrate 21 is supported by the tips of the support protrusions 13a-13d, the corresponding first positioning holes 22a-22d and second positioning holes 16a-16d communicate with each other. When the positioning pins 64a-64d are inserted into the corresponding first positioning holes 22a-22d and second positioning holes 16a-16d, the housing 10, the control substrate 20, and the cover 60 are positioned.

[0025] A plurality of circuit elements 23a, 23b constituting a control circuit 23 for controlling the electric motor 6 are mounted on one or both of the first surface 21a and the second surface 21b of the substrate 21. At least a part of the circuit elements 23a, 23b (for example, the circuit element 23b) is a heat generating element that generates a large amount of heat. The circuit element 23b is mounted on the second surface 21b of the substrate 21 in the vicinity of a side (left side in FIG. 3) that is different from the side (right side in FIG. 3) on which the connector unit 30 is arranged and the side (upper side in FIG. 3) on which the relay unit 40 is arranged, among the four sides constituting the outer edge of the substrate 21.

[0026] The connector unit 30 connects the external device and the control circuit 23. The connector unit 30 includes a pair of power lines for supplying the driving power output from the external device to the control circuit 23, and a pair of signal lines for transmitting and receiving control signals between the external device and the control circuit 23. The connector unit 30 is accommodated in a connector holder 63 of the cover 60. The connector unit 30 is, for example, inserted when the cover 60 is injection molded, and is molded as one piece. The relay unit 40 connects the control circuit 23 and the electric motor 6 (more specifically, the coil). The relay unit 40 supplies the driving power output from the control circuit 23 to the coil. This causes the electric motor 6 to rotate.

[0027] Fig. 4 is a perspective view of the heat sink 50. The heat sink 50 is a heat dissipation member that dissipates heat generated by the circuit elements 23b to the housing 10. The heat sink 50 is made of a metal material with high thermal conductivity (e.g., copper). The heat sink 50 is formed into the shape shown in Fig. 4, for example, by pressing a flat plate.

[0028] As shown in Fig. 4, the heat sink 50 is composed of a heat receiving plate 51 and a heat transfer plate 52. The heat sink 50 is bent so that the heat receiving plate 51 and the heat transfer plate 52 intersect (orthogonally). That is, the heat sink 50 has a generally L-shaped outer shape. Furthermore, a protruding end 53 of the heat transfer plate 52 (the end opposite the heat receiving plate 51) is curved in a U-shape (or a J-shape) by folding back the tip of the heat transfer plate 52 toward the heat receiving plate 51. Furthermore, a slit 54 extending from the protruding end 53 toward the heat receiving plate 51 is formed in the heat transfer plate 52.

[0029] Fig. 5 is a perspective view of the cover 60 as viewed from the back side. The cover 60 is integrally molded, for example, by injection molding a resin material. That is, the cover 60 is formed of a material that has a lower thermal conductivity than the housing 10 and is lighter than the housing 10. As shown in Figs. 2 and 5, the cover 60 mainly includes a top wall 61, a side wall 62, a connector holder 63, and a plurality of positioning pins 64a, 64b, 64c, and 64d.

[0030] The top wall 61 is a portion that covers the second surface 21b of the control board 20 (substrate 21). When the cover 60 is attached to the housing 10, the top wall 61 faces the second surface 21b at a predetermined distance from the control board 20 in the axial direction. In addition, the heat receiving plate 51 of the heat sink 50 is attached to the surface (rear surface) of the top wall 61 that faces the second surface 21b. The heat receiving plate 51 may be attached to the top wall 61 by, for example, thermal caulking, or may be inserted when the cover 60 is injection molded. Furthermore, screw holes 65a, 65b, 65c, and 65d that penetrate in the thickness direction are formed at the four corners of the top wall 61.

[0031] The side wall 62 is a frame-shaped portion that covers the periphery of the control board 20. The side wall 62 protrudes from the outer edge of the top wall 61 toward the housing 10 (i.e., in the axial direction). When the housing 10 is attached to the cover 60, the tip of the side wall 62 abuts against the support surface 12 of the housing 10. As a result, a board accommodating space 24 that accommodates the control board 20 is formed between the housing 10 and the cover 60 (more specifically, the support surface 12, the top wall 61, and the side wall 62). The connector holder 63 is provided on the outer side of the side wall 62 and holds the connector unit 30.

[0032] The positioning pins 64a to 64d protrude in the axial direction from the back surface of the top wall 61 inside the side wall 62. When the positioning pins 64a to 64d are inserted into the first positioning holes 22a to 22d, the control board 20 is attached to the cover 60 with the second surface 21b facing the top wall 61. When the positioning pins 64a to 64d are inserted into the second positioning holes 16a to 16d in this state, the screw holes 17a to 17d and 65a to 65d communicate with each other, and the protruding end 53 of the heat transfer plate 52 is inserted in the axial direction into the recessed groove 15d of the heat sink support part 15, as described later. Then, the screws 18a to 18d are screwed into the communicated screw holes 17a to 17d and 65a to 65d, so that the cover 60 is fixed to the housing 10 with the housing 10, the control board 20, the heat sink 50, and the cover 60 positioned.

[0033] Fig. 6 is a cross-sectional view showing before (A) and after (B) the protruding end 53 of the heat transfer plate 52 is inserted into the recessed groove 15d of the heat sink support part 15. Fig. 7 is a cross-sectional view showing the positional relationship between the heat sink support part 15, the control board 20, and the heat sink 50.

[0034] 6 and 7, the heat sink support 15 includes a base 15a, a heat exhaust wall 15b, and an opposing wall 15c. The base 15a is a portion supported by the support surface 12. The heat exhaust wall 15b and the opposing wall 15c are spaced apart from each other by a predetermined distance in the thickness direction of the heat transfer plate 52 and extend from the base 15a in the axial direction (i.e., toward the cover 60). The base 15a, the heat exhaust wall 15b, and the opposing wall 15c are also extended in the width direction of the heat transfer plate 52 along the support surface 12.

[0035] The base 15a, the heat exhaust wall 15b, and the opposing wall 15c define a groove 15d. The groove 15d is an example of a receiving portion that receives the protruding end 53 of the heat transfer plate 52 that is inserted in the axial direction. The groove 15d extends linearly on the support surface 12 in a direction perpendicular to the thickness direction of the heat transfer plate 52. However, the shape of the groove 15d is not limited thereto, and may be curved along the outer periphery of the motor accommodating space 11.

[0036] As shown in FIG. 6(A), the diameter D1 of the curved protruding end 53 in its natural state is larger than the width dimension D2 of the groove 15d. Here, the natural state of the protruding end 53 refers to a state in which no external force other than gravity is applied (typically, the state before being inserted into the groove 15d). The width dimension D2 of the groove 15d corresponds to the distance between the heat exhaust wall 15b and the opposing wall 15c. As shown in FIG. 6(B), the curved protruding end 53 is inserted into the groove 15d in an elastically contracted state. When the protruding end 53 is inserted into the groove 15d, the heat transfer plate 52 and the heat exhaust wall 15b come into surface contact.

[0037] As shown in Fig. 7, the heat receiving plate 51 faces the second surface 21b (more specifically, the circuit element 23b) of the control board 20 at a predetermined interval in the axial direction. In other words, the heat receiving plate 51 and the control board 20 are arranged in parallel at a predetermined interval in the axial direction. In addition, a heat dissipation agent 55 is interposed between the heat receiving plate 51 and the circuit element 23b. In other words, the heat receiving plate 51 is in contact with the circuit element 23b via the heat dissipation agent. The heat dissipation agent 55 is made of, for example, a thermosetting resin with high thermal conductivity.

[0038] 7, the heat transfer plate 52 protrudes from the heat receiving plate 51 toward the housing 10 (more specifically, the heat sink support portion 15) at a position away from the control board 20. More specifically, the heat transfer plate 52 protrudes toward the housing 10, facing the side (the left side in FIG. 2) that is closest to the circuit element 23b among the multiple sides that define the outer edge of the control board 20. Furthermore, the slit 54 extends to a position closer to the heat receiving plate 51 than the heat exhaust wall 15b.

[0039] According to the above embodiment, for example, the following advantageous effects are achieved.

[0040] According to the above embodiment, the heat exhaust wall 15b and the heat transfer plate 52 extending in the axial direction are in surface contact with each other, and the heat generated by the circuit element 23b is dissipated to the housing 10. Here, the axial size of the board accommodating space 24 originally has a margin corresponding to the heights of the circuit elements 23a, 23b mounted on the board 21 and the heights of the support protrusions 13a to 13d, so that it is easy to increase the contact area between the heat exhaust wall 15b and the heat transfer plate 52.

[0041] This improves the efficiency of dissipating heat emitted from the control circuit 23 without increasing the size of the oil pump device 1 (motor device 5) compared to Patent Document 1. As a result, deterioration of the control circuit 23 due to heat is suppressed, which contributes to extending the life of the oil pump device 1 (motor device 5) and preventing the generation of waste. Furthermore, by adopting a resin cover 60, the oil pump device 1 can be made lighter than a metal cover, which contributes to carbon neutrality.

[0042] Furthermore, according to the above embodiment, by making the protruding end 53 of the heat transfer plate 52 curved, it is possible to prevent the heat sink 50 (in other words, the cover 60) from being caught when entering the recessed groove 15d. As a result, it is possible to smoothly attach the heat sink 50 (in other words, the cover 60) to the housing 10. However, the shape of the protruding end 53 is not limited to a curved shape.

[0043] According to the above embodiment, the diameter D1 of the protruding end 53 in its natural state is made larger than the width D2 of the recessed groove 15d, and the protruding end 53 is inserted into the recessed groove 15d while being elastically contracted in diameter. This causes the heat transfer plate 52 to come into close contact with the heat exhaust wall 15b due to the elastic force of the protruding end 53 trying to return to its original position, thereby further improving the heat exhaust efficiency. However, the relationship between D1 and D2 is not limited to the above example.

[0044] According to the above embodiment, the slits 54 are provided in the heat transfer plate 52, thereby improving the elastic deformation of the heat transfer plate 52. As a result, the heat transfer plate 52 supported by the heat sink support 15 in an elastically deformed state is brought into close contact with the heat exhaust wall 15b by the force of elastic recovery, and the heat exhaust efficiency is further improved. In addition, the heat transfer plate 52 can absorb the manufacturing error and assembly error of the heat sink support 15, the heat sink 50, and the cover 60 by elastic deformation. The shape, position, number, and width of the slits 54 are appropriately selected depending on the material and thickness of the heat sink 50. The slits 54 can be omitted.

[0045] Furthermore, according to the above embodiment, the heat sink 50 can be made smaller by providing the heat transfer plate 52 on the side closest to the circuit element 23b that generates a large amount of heat, among the multiple sides that define the outer edge of the control board 20. As a result, the heat transfer path from the circuit element 23b to the heat sink support part 15 is shortened, further improving the heat dissipation efficiency. However, the arrangement of the heat transfer plate 52 is not limited to the above example. As another example, multiple heat transfer plates 52 may be provided that extend in different directions (for example, the left side and the bottom side in FIG. 2) from the heat receiving plate 51.

[0046] Furthermore, according to the above embodiment, by bringing the heat receiving plate 51 into contact with the circuit element 23b mounted on the second surface 21b via the heat dissipation agent 55, the heat dissipation efficiency is further improved compared to interposing a substrate between the heat generating element and the heat sink as in Patent Document 1. However, the positional relationship between the circuit element 23b and the heat receiving plate 51 is not limited to the above example.

[0047] The embodiments of the present invention have been described above. Note that the present invention is not limited to the above-described embodiments, and various modified examples are included. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of this embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of this embodiment with another configuration. [Explanation of symbols]

[0048] 1: Oil pump device 2: Motor section 3: Control section 4: Pump section 5: Motor device 6: Electric motor 7: Rotation axis 10: Housing 11: Motor housing space 12: Support surface 13: Support protrusion 14: Screw seat 15: Heat sink support 15a: base 15b: Heat exhaust wall 15c: Opposing wall 15d: Concave groove 16: Second positioning hole 17: Screw hole 18: Screw 20: Control board 21: Substrate 21a: 1st page 21b: 2nd side 22: First positioning hole 23: Control circuit 24: Substrate storage space 30: Connector unit 40: Relay unit 50: Heat sink 51: Heat receiving plate 52: Heat transfer plate 53:Protruding end 54: Slit 55: Heat dissipation agent 60: Cover 61: Ceiling wall 62: Side wall 64: Positioning pin 65: Screw hole

Claims

1. An electric motor; A control board on which a control circuit for controlling the electric motor is mounted; a metal housing having a motor accommodating space for accommodating the electric motor and supporting a first surface of the control board at a position offset from the motor accommodating space in an extension direction of a rotation shaft of the electric motor; a resin cover attached to the housing so as to cover a second surface of the control board opposite to the first surface and an area around the control board; a heat dissipation member that dissipates heat generated by a heating element included in the control circuit to the housing, The heat dissipation member is a heat receiving plate fixed to the cover at a position facing the heating element; a heat transfer plate protruding from the heat receiving plate toward the housing at a position separated from the control board, The housing is provided, outside the motor accommodating space, a receiving portion for receiving a protruding end of the heat transfer plate inserted in the extending direction of the rotation shaft; a heat exhaust wall extending in the extension direction of the rotation shaft and in surface contact with the heat transfer plate received in the receiving portion.

2. 2. The motor device according to claim 1, The motor device is characterized in that the protruding end is curved such that the tip of the heat transfer plate is folded back toward the heat receiving plate.

3. 3. The motor device according to claim 2, The receiving portion is a recessed groove whose one end in a width direction is defined by the heat exhaust wall, The motor device is characterized in that the curved protruding end has a diameter in its natural state larger than a width dimension of the groove, and is inserted into the groove in an elastically contracted state.

4. 2. The motor device according to claim 1, A motor device, characterized in that a slit is formed in the heat transfer plate, the slit extending from the protruding end to a position closer to the heat receiving plate than the heat exhaust wall.

5. 2. The motor device according to claim 1, A motor device, characterized in that the heat transfer plate protrudes toward the housing, facing the side closest to the heat generating element among a plurality of sides that define the outer edge of the control board.

6. 2. The motor device according to claim 1, the heat generating element is mounted on the second surface of the control board, A motor device, wherein the heat receiving plate is in contact with the heat generating element via a heat dissipation agent.

7. The motor device according to claim 1 ; and a pump unit that pumps oil by the driving force of the electric motor.

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