Motor device

Abstract

The purpose of the present disclosure is to provide a motor device with improved heat dissipation. This motor device (1) comprises a motor (2) and a second housing (30). The motor (2) has a first housing (20) that accommodates a rotor (23) and a stator (21). The second housing (30) accommodates a drive circuit (50) for driving the motor (2), and is attached to the first housing (20). A plurality of heat dissipation fins (42) are provided on a surface of the second housing (30), the surface facing the first housing (20). The plurality of heat dissipation fins (42) are interposed between the second housing (30) and the first housing (20).

Description

Motor device

[0001] The present disclosure relates to a motor device, and more particularly to a motor device in which a drive circuit for driving the motor is integrated with the motor.

[0002] Patent Document 1 discloses a power converter including a semiconductor power module, a finned heat dissipation member that receives heat from the semiconductor power module on one side thereof, a cooling body joined to the finned heat dissipation member, and a heat transfer support member. The heat transfer support member transfers heat from a mounting board on which circuit components, including heat-generating circuit components that drive the semiconductor power module, are mounted to the cooling body. The heat transfer support member supports the mounting board while maintaining a predetermined distance from the semiconductor power module. This power converter is applied to a motor drive circuit that drives a vehicle's traction motor.

[0003] In a motor device in which a drive circuit for driving a motor is integrated with the motor, there is a possibility that the temperature of the drive circuit will rise due to the influence of heat generated by the motor.

[0004] International Publication No. 2013 / 31147

[0005] An object of the present disclosure is to provide a motor device that can reduce the temperature rise in a drive circuit.

[0006] A motor device according to one aspect of the present disclosure includes a motor and a second housing. The motor has a first housing that houses a rotor and a stator. The second housing houses a drive circuit that drives the motor and is attached to the first housing. A plurality of heat dissipation fins are provided on the surface of the second housing that faces the first housing. The plurality of heat dissipation fins are interposed between the second housing and the first housing.

[0007] FIG. 1 is a cross-sectional view of a motor device according to an embodiment of the present disclosure. FIG. 2 is an external perspective view of the motor device attached to a base plate. FIG. 3 is a partial cross-sectional view of the motor device according to Modification 1. FIG. 4 is an external perspective view of the motor device attached to a base plate. FIG. 5 is a partial cross-sectional view of the motor device according to Modification 2. FIG. 6 is a partial cross-sectional view of the motor device according to Modification 2. FIG. 7 is a partial cross-sectional view of the motor device according to Modification 3. FIG. 8 is a partial cross-sectional view of the motor device according to Modification 3. FIG. 9 is a partial cross-sectional view of the motor device according to Modification 4. FIG. 10 is a Y-Z cross-sectional view of a heat sink provided in a motor device according to Modification 5. FIG. 11 is a Y-Z cross-sectional view of a heat sink provided in a motor device according to Modification 5. FIG. 12 is a cross-sectional view of a motor device according to Modification 6. FIG. 13 is an A1-A1 cross-sectional view of FIG. 12. FIG. 14 is a perspective view of a heat sink provided in a motor device according to Modification 6. FIG. 15 is a plan view of a heat sink of a comparative example. FIG. 16 is a Y-Z cross-sectional view of a heat sink provided in a motor device according to Modification 6. Fig. 17 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 7. Fig. 18 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 7. Fig. 19 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 8. Fig. 20 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 8. Fig. 21 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 9. Fig. 22 is a YZ cross-sectional view of a heat sink provided in a motor device according to Modification 9. Fig. 23 is a perspective view of a second heat sink provided in a motor device according to Modification 10.

[0008] Hereinafter, motor devices according to embodiments will be described in detail with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the dimensional ratios of the sizes of the components do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0009] (Embodiment) (1) Overview As shown in Figures 1 and 2, a motor device 1 according to this embodiment includes a motor 2 and a second housing 30. The motor 2 has a first housing 20 that houses a rotor 23 and a stator 21. The second housing 30 houses a drive circuit 50 that drives the motor 2 and is attached to the first housing 20. A plurality of heat dissipation fins 42 are provided on the surface of the second housing 30 that faces the first housing 20. The plurality of heat dissipation fins 42 are interposed between the second housing 30 and the first housing 20.

[0010] In the motor device 1 of this embodiment, a plurality of heat dissipation fins 42 are interposed between the second housing 30 that houses the drive circuit 50 and the first housing 20 of the motor 2. Therefore, heat from the first housing 20 is less likely to be transferred to the second housing 30 than when the opposing surface of the second housing 30 is in direct contact with the first housing 20.

[0011] Furthermore, the first housing 20 and the second housing 30 are connected via a plurality of heat dissipation fins 42, and a space SP1 through which air flows is formed between the first housing 20 and the second housing 30, so that the chimney effect makes it easier for cold air from outside to enter the space SP1. This increases the efficiency of heat exchange in the plurality of heat dissipation fins 42, and makes it possible to reduce the temperature rise of the drive circuit 50 housed in the second housing 30.

[0012] (2) Details The motor device 1 according to the embodiment will be described in detail below with reference to FIGS. 1 and 2. In the following description, as shown in FIG. 2, the X-axis direction, which is the arrangement direction of the first housing 20 and the second housing 30, is defined as the front-to-rear direction, the Y-axis direction as the left-to-right direction, and the Z-axis direction as the up-to-down direction. Furthermore, the positive direction in the X-axis direction is defined as the front side, the positive direction in the Y-axis direction as the right side, and the positive direction in the Z-axis direction as the top side. However, these directions are merely examples and are not intended to limit the directions in which the motor device 1 is used. Furthermore, the arrows indicating the various directions in the drawings are merely shown for explanatory purposes and do not have any physical substance.

[0013] The motor device 1 is an electromechanical integrated motor in which a motor 2 and a control unit 3 having a drive circuit 50 for controlling the motor 2 are integrated together.

[0014] As described above, the motor device 1 includes the motor 2 and the control unit 3 .

[0015] The motor 2 includes a first housing 20 that houses a rotor 23, a stator 21, and the like.

[0016] The first housing 20 includes a cylindrical member 200 and cover members 201 and 202 .

[0017] The cylindrical member 200 is made of, for example, a metal material or a synthetic resin material, and is formed in a rectangular cylindrical shape with both ends in the front-rear direction being open.

[0018] The cover member 201 is formed in a flat plate shape from, for example, a metal material or a synthetic resin material, and is attached to the cylindrical member 200 with bolts or the like so as to close the opening on the rear side of the cylindrical member 200.

[0019] The cover member 202 is formed in a flat plate shape from, for example, a metal material or a synthetic resin material. The cover member 202 is attached to the cylindrical member 200 with bolts or the like so as to close the front opening of the cylindrical member 200. The cover member 202 has a through hole through which the shaft 24 of the motor 2 is inserted.

[0020] A stator 21 and a rotor 23 are housed inside the first housing 20. A coil 22 is provided on the stator 21. The rotor 23 is integral with a shaft 24, and the shaft 24 is rotatably supported on the first housing 20 via bearings 25 and 26. The front end portion of the shaft 24 is inserted into a through-hole provided in the cover member 202 and is exposed to the outside of the first housing 20. The bearing 26 is fixed to the cylindrical member 200 or the cover member 201 via an appropriate member. The bearing 25 is fixed to the cover member 202, for example, but may also be fixed to the cylindrical member 200 via an appropriate member.

[0021] The control unit 3 includes a drive circuit 50 that drives the motor 2 and a second housing 30 that houses the drive circuit 50 .

[0022] The second housing 30 includes a cylindrical member 31 , a heat sink 40 , and a cover 32 .

[0023] The cylindrical member 31 is made of, for example, a metal material or a synthetic resin material and is formed in a rectangular cylindrical shape with both ends in the front-rear direction being open.

[0024] The cover 32 is formed into a flat plate shape from, for example, a synthetic resin material, and is attached to the cylindrical member 31 using bolts or the like so as to close the opening on the rear side of the cylindrical member 31.

[0025] The heat sink 40 is made of a metal material such as aluminum having good thermal conductivity, or a ceramic material, and includes a flat base member 41 and a plurality of heat dissipation fins 42 provided on one surface of the base member 41.

[0026] The base material 41 is attached to the cylindrical member 31 using bolts or the like so as to close the front opening of the cylindrical member 31. When the heat sink 40 is attached to the cylindrical member 31, the front surface 41A of the base material 41 becomes the front surface of the second housing 30.

[0027] The plurality of heat dissipation fins 42 are integrally provided on the front surface 41A of the base material 41 (i.e., the front surface of the second housing 30). Each of the plurality of heat dissipation fins 42 is formed in an elongated cylindrical shape (round pin shape). The plurality of heat dissipation fins 42 are arranged, for example, at regular intervals in the Y-axis direction and the Z-axis direction. First ends (rear ends in this embodiment) of the plurality of heat dissipation fins 42 in the axial direction are connected to the base material 41. Second ends (front ends in this embodiment) of the plurality of heat dissipation fins 42 in the axial direction are in contact with the rear surface of the cover member 201 of the first housing 20, and the second housing 30 is fixed to the first housing 20 in an appropriate manner. In other words, the plurality of heat dissipation fins 42 are interposed between the first housing 20 and the second housing 30.

[0028] The second housing 30 accommodates a drive circuit 50 therein.

[0029] The drive circuit 50 includes a circuit board 51 on which are mounted circuit components such as a plurality of switching elements 52 that constitute an inverter circuit and a driver IC 53 that controls the plurality of switching elements 52. The circuit board 51 is a double-sided board. For example, the plurality of switching elements 52 are mounted on the rear mounting surface of the circuit board 51, and the plurality of driver ICs 53 are mounted on the front mounting surface of the circuit board 51.

[0030] The circuit board 51 is fixed to the base material 41 of the heat sink 40 via a plurality of metal spacers 54. A heat sink 61 made of, for example, a metal or ceramic material is fixed to the rear surface of the base material 41. In addition, a heat sink sheet 62 made of insulating synthetic resin is interposed between the driver IC 53 mounted on the front mounting surface of the circuit board 51 and the heat sink 61. Therefore, heat generated by the driver IC 53 is conducted to the base material 41 of the heat sink 40 via the heat sink sheet 62 and the heat sink 61, and is dissipated from the base material 41 and the plurality of heat sink fins 42, etc.

[0031] A heat sink 63 made of, for example, a metal or ceramic material is disposed between the circuit board 51 and the cover 32. A plurality of metal spacers 55 are disposed between the circuit board 51 and the heat sink 63, and the heat sink 63 is fixed to the base material 41 of the heat sink 40 via a plurality of metal spacers 55 and 54. A heat dissipation sheet 64 made of insulating synthetic resin is disposed between the heat sink 63 and the switching elements 52 mounted on the rear mounting surface of the circuit board 51. Heat generated by the switching elements 52 is conducted to the heat sink 63 via the heat dissipation sheet 64, and further conducted to the base material 41 of the heat sink 40 via the metal spacers 55 and 54, and is dissipated from the base material 41 and the plurality of heat dissipation fins 42, etc.

[0032] 2, the motor device 1 is attached to a base plate 110 via the L-shaped flange 100 by fixing a cover member 202 to the flange portion 101 of the L-shaped flange 100. A through-hole is provided in the flange portion 101, into which the shaft 24 of the motor 2 is inserted, and the shaft 24 is connected to a load device via a coupling.

[0033] The configuration of the motor device 1 described above is an example, and the configuration of the motor device 1 can be changed as appropriate.

[0034] In the motor device 1 of this embodiment, the second housing 30 housing the drive circuit 50 is provided with multiple heat dissipation fins 42 on the surface (front surface 41A of the base material 41) facing the first housing 20 of the motor 2. The second housing 30 is attached to the first housing 20 via the multiple heat dissipation fins 42. Therefore, compared to when the facing surface of the second housing 30 is in direct contact with the first housing 20, heat generated by the motor 2 is less likely to be transferred to the second housing 30, thereby reducing the temperature rise of the drive circuit 50. Furthermore, since the first housing 20 and the second housing 30 are connected via the multiple heat dissipation fins 42, a space SP1 through which air flows is formed between the first housing 20 and the second housing 30. This facilitates the chimney effect, allowing cold air from outside to enter the space SP1. This increases the efficiency of heat exchange at the multiple heat dissipation fins 42, thereby reducing the temperature rise of the drive circuit 50 housed in the second housing 30.

[0035] In addition, heat from the drive circuit 50 is dissipated from surfaces of the second housing 30 other than the front surface 30A on which the heat dissipation fins 42 are provided. In this embodiment, the cover 32, which forms the rear surface of the second housing 30, is made of a synthetic resin material, but the cover 32 may also be made of a metal material. By making the cover 32 out of metal, heat from the drive circuit 50 is more easily dissipated from the cover 32 than when the cover 32 is made of a synthetic resin material, and the temperature rise of the drive circuit 50 can be further reduced.

[0036] (3) Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved.

[0037] Modifications of the above embodiment are listed below. The modifications described below can be applied in appropriate combinations. Note that, hereinafter, the above embodiment may also be referred to as the basic configuration.

[0038] (3.1) Modification 1 A motor device 1 according to modification 1 will be described with reference to FIGS. 3 and 4. FIG.

[0039] The motor device 1 according to Modification 1 differs from the basic configuration in that the second housing 30 has a plurality of second heat dissipation fins 72 on the surface opposite to the surface facing the first housing 20 (the front surface 41A of the base material 41). Components common to the basic configuration are denoted by the same reference numerals, and illustrations and descriptions thereof are omitted. In the following, the plurality of heat dissipation fins 42 described in the basic configuration may be referred to as a plurality of first heat dissipation fins, and the heat sink 40 may be referred to as a first heat sink 40. The surface of the second housing 30 facing the first housing 20 (the front surface 41A of the base material 41) may be referred to as a first surface 30A, and the surface of the second housing 30 opposite the first surface 30A may be referred to as a second surface 30B.

[0040] The motor device 1 according to the first modification includes a second heat sink 70 having a plurality of second heat dissipation fins 72 in addition to the first heat sink 40 described above.

[0041] The second heat sink 70 is made of a metal material such as aluminum having good thermal conductivity, or a ceramic material, and includes a flat base member 71 and a plurality of second heat dissipation fins 72 provided on a rear surface 71A of the base member 71.

[0042] The base material 71 is attached to the cylindrical member 31 using bolts or the like so as to close the rear opening of the cylindrical member 31. When the second heat sink 70 is attached to the cylindrical member 31, the rear surface 71A of the base material 71 becomes the second surface 30B of the second housing 30.

[0043] The second heat dissipation fins 72 are integrally provided on the rear surface 71A of the base material 71 (i.e., the second surface 30B of the second housing 30). Each of the second heat dissipation fins 72 is formed in an elongated cylindrical shape (round pin shape). The second heat dissipation fins 72 are arranged, for example, at regular intervals in the Y-axis direction and the Z-axis direction. The front ends of the second heat dissipation fins 72 are each connected to the base material 71, and the second heat dissipation fins 72 each protrude rearward from the rear surface 71A of the base material 71 (the second surface 30B of the second housing 30).

[0044] Furthermore, in the motor device 1 of Modification 1, the rear surface of the heat dissipation plate 63 is in contact with the front surface of the base material 71 of the second heat sink 70. A heat dissipation sheet 64 made of insulating synthetic resin is interposed between the heat dissipation plate 63 and the switching elements 52 mounted on the rear mounting surface of the circuit board 51. Therefore, heat generated by the switching elements 52 and the like is transferred to the base material 71 of the second heat sink 70 via the heat dissipation sheet 64 and the heat dissipation plate 63, and is then dissipated from the base material 71 and the plurality of second heat dissipation fins 72 and the like.

[0045] In the motor device 1 of Modification 1, heat generated by the driver IC 53 and other components mounted on the front mounting surface of the circuit board 51 is dissipated from the first heat sink 40 via the heat dissipation sheet 62 and the heat dissipation plate 61. Heat generated by the switching elements 52 and other components mounted on the rear mounting surface of the circuit board 51 is dissipated from the second heat sink 70 via the heat dissipation sheet 64 and the heat dissipation plate 63. In this way, heat generated in the drive circuit 50 is dissipated from both the first heat sink 40 and the second heat sink 70, thereby improving heat dissipation performance compared to the basic configuration and further reducing the temperature rise in the drive circuit 50.

[0046] (3.2) Modification 2 A motor device 1 according to modification 2 will be described with reference to FIGS. 5 and 6. FIG.

[0047] The motor device 1 according to the second modification differs from the first modification in that the arrangement interval D1 of the first heat dissipation fins 42 is different from the arrangement interval D2 of the second heat dissipation fins 72. Components that are common to the first modification are given the same reference numerals, and illustrations and descriptions thereof are omitted.

[0048] The arrangement interval D1 of the multiple first heat dissipation fins 42 can be changed as appropriate depending on the total heat generation amount of at least one heat-generating component (hereinafter referred to as the first heat-generating component) thermally coupled to the first heat sink 40 among the circuit components that make up the drive circuit 50. The arrangement interval D2 of the multiple second heat dissipation fins 72 can be changed as appropriate depending on the heat generation amount of at least one heat-generating component (hereinafter referred to as the second heat-generating component) thermally coupled to the second heat sink 70 among the circuit components that make up the drive circuit 50.

[0049] 5 , when the total heat generation amount of the first heat-generating components is greater than the total heat generation amount of the second heat-generating components, it is preferable to set the arrangement interval D1 of the multiple first heat-generating fins 42 narrower than the arrangement interval D2 of the multiple second heat-generating fins 72. If the surface areas of the first heat-generating fins 42 and the second heat-generating fins 72 are approximately the same, the surface area of ​​the first heat-generating fins 42 can be made larger than the surface area of ​​the second heat-generating fins 70 by setting the arrangement density of the multiple first heat-generating fins 42 higher than the arrangement density of the multiple second heat-generating fins 72. As a result, the heat-generating performance of the first heat-generating component 40 can be improved compared to the heat-generating performance of the second heat-generating component 70, and the temperature rise of the first heat-generating component, which has a larger total heat generation amount than the second heat-generating component, can be reduced, thereby reducing the temperature rise of the drive circuit 50.

[0050] 6 , when the total heat generation amount of the second heat-generating components is greater than the total heat generation amount of the first heat-generating components, it is preferable to set the arrangement interval D2 of the second heat-generating fins 72 narrower than the arrangement interval D1 of the first heat-generating fins 42. If the surface area per fin of the first heat-generating fins 42 and the surface area per fin of the second heat-generating fins 72 are approximately the same, the surface area of ​​the second heat-generating fins 72 can be made larger than the surface area of ​​the first heat-generating fins 40 by setting the arrangement density of the second heat-generating fins 72 higher than the arrangement density of the first heat-generating fins 42. As a result, the heat-generating performance of the second heat-generating component 70 can be improved compared to the first heat-generating component 40, and the temperature rise of the second heat-generating component, which has a larger total heat generation amount than the first heat-generating component, can be reduced, thereby reducing the temperature rise of the drive circuit 50.

[0051] (3.3) Modification 3 A motor device 1 according to modification 3 will be described with reference to FIGS. 7 and 8. FIG.

[0052] The motor device 1 according to the third modification differs from the first modification in that the length L1 of the first heat dissipation fins 42 and the length L2 of the second heat dissipation fins 72 are different from each other in the arrangement direction of the first housing 20 and the second housing 30. Note that components common to the first modification are denoted by the same reference numerals, and illustrations and descriptions thereof will be omitted.

[0053] In Modification 3, the length L1 of the multiple first heat dissipation fins 42 in the arrangement direction is set to be the same. The lengths of the multiple first heat dissipation fins 42 may vary within the range of manufacturing tolerance, and the length L1 of the multiple first heat dissipation fins 42 in the arrangement direction is the average length of the multiple first heat dissipation fins 42. The length L1 of the multiple first heat dissipation fins 42 can be changed as appropriate depending on the total amount of heat generated by the first heat-generating components thermally coupled to the first heat sink 40.

[0054] In addition, in Modification 3, the length L2 of the multiple second heat dissipation fins 72 in the arrangement direction is set to be the same. The lengths of the multiple second heat dissipation fins 72 may vary within the range of manufacturing tolerance, and the length L2 of the multiple second heat dissipation fins 72 in the arrangement direction is the average length of the multiple second heat dissipation fins 72. The length L2 of the multiple second heat dissipation fins 72 can be changed as appropriate depending on the amount of heat generated by the second heat-generating component thermally coupled to the second heat sink 70.

[0055] When the total heat generation amount of the first heat-generating components is greater than the total heat generation amount of the second heat-generating components, it is preferable to make the length L1 of the multiple first heat-generating fins 42 longer than the length L2 of the multiple second heat-generating fins 72 in the arrangement direction, as shown in Fig. 7. This allows the surface area of ​​each first heat-generating fin 42 to be greater than the surface area of ​​each second heat-generating fin 72. If the arrangement spacing between the first heat-generating fins 42 and the second heat-generating fins 72 is approximately the same, the surface area of ​​the first heat sink 40 can be greater than the surface area of ​​the second heat sink 70. As a result, the heat dissipation performance of the first heat sink 40 can be improved compared to the heat dissipation performance of the second heat sink 70, and the temperature rise of the first heat-generating components, which have a greater total heat generation amount than the second heat-generating components, can be reduced, thereby reducing the temperature rise of the drive circuit 50.

[0056] 8 , when the total heat generation amount of the second heat-generating components is greater than the total heat generation amount of the first heat-generating components, it is preferable to make the length L2 of the multiple second heat-generating fins 72 longer than the length L1 of the multiple first heat-generating fins 42 in the arrangement direction. This allows the surface area of ​​each second heat-generating fin 72 to be larger than the surface area of ​​each first heat-generating fin 42, and if the arrangement spacing between the first heat-generating fins 42 and the second heat-generating fins 72 is approximately the same, the surface area of ​​the second heat sink 70 can be larger than the surface area of ​​the first heat sink 40. As a result, the heat-generating performance of the second heat sink 70 can be improved compared to the heat-generating performance of the first heat sink 40, and the temperature rise of the second heat-generating components, which have a larger total heat generation amount than the first heat-generating components, can be reduced, thereby reducing the temperature rise of the drive circuit 50.

[0057] In addition, in variant example 3, as in variant example 2, the arrangement spacing D1 of the multiple first heat dissipation fins 42 and the arrangement spacing D2 of the multiple second heat dissipation fins 72 may be different from each other, thereby adjusting the heat dissipation performance of the first heat sink 40 and the second heat sink 70.

[0058] (3.4) Modification 4 A motor device 1 according to modification 4 will be described with reference to FIG.

[0059] The motor device 1 of Modification 4 differs from Modification 1 in that, of the multiple driver ICs 53 (53A, 53B) mounted on the front mounting surface of the circuit board 51, at least one driver IC (for example, driver IC 53A) is thermally coupled to the first heat sink 40, and at least one driver IC (for example, driver IC 53B) is thermally coupled to the second heat sink 70. Note that components common to Modification 1 are given the same reference numerals, and illustrations and descriptions thereof will be omitted.

[0060] The circuit board 51 is attached to the base material 41 of the first heat sink 40 via a metal spacer 54. A heat sink 61 made of, for example, a metal or ceramic material is fixed to the rear surface of the base material 41 in an area in front of the driver IC 53A. A heat sink sheet 62 made of insulating synthetic resin is interposed between the driver IC 53A and the heat sink 61. Heat generated by the driver IC 53A is conducted to the base material 41 of the heat sink 40 via the heat sink sheet 62 and the heat sink 61, and is then dissipated from the base material 41, the heat sink fins 42, etc.

[0061] A heat sink 63 made of, for example, a metal or ceramic material is disposed between the circuit board 51 and the base 71 of the second heat sink 70, with the rear surface of the heat sink 63 in contact with the base 71 of the second heat sink 70. A plurality of metal spacers 55 are disposed between the circuit board 51 and the heat sink 63, and the heat sink 63 is connected to the circuit board 51 via the plurality of metal spacers 55. A heat dissipation sheet 64 made of insulating synthetic resin is disposed between the heat sink 63 and the switching elements 52 mounted on the rear mounting surface of the circuit board 51. Heat generated by the switching elements 52 is conducted to the base 71 of the second heat sink 70 via the heat dissipation sheet 64 and the heat sink 63, and is dissipated from the base 71 and the plurality of second heat dissipation fins 72, etc.

[0062] A heat sink 65 made of, for example, a metal or ceramic material is disposed between the driver IC 53B mounted on the front mounting surface of the circuit board 51 and the base 41 of the first heat sink 40. A heat dissipation sheet 66 made of insulating synthetic resin is interposed between the driver IC 53B and the heat dissipation sheet 65. The heat dissipation sheet 65 is not in contact with the base 41 and is fixed to the circuit board 51 via a metal spacer 56. The heat dissipation sheet 65 is thermally coupled to the base 71 of the second heat sink 70 via the metal spacers 56 and 55 and the heat dissipation sheet 63. Therefore, heat generated by the driver IC 53B is conducted to the heat dissipation sheet 66 to the heat dissipation sheet 63, and then conducted to the base 71 of the second heat sink 70 via the metal spacers 56 and 55 and the heat dissipation sheet 63, and is dissipated from the base 71 and the plurality of second heat dissipation fins 72.

[0063] In this way, the second housing 30 accommodates a plurality of heat-generating components that constitute the drive circuit 50. The plurality of heat-generating components include at least one first heat-generating component thermally connected to the plurality of first heat-dissipating fins 42 and at least one second heat-generating component thermally connected to the plurality of second heat-dissipating fins 72.

[0064] In other words, the multiple heat-generating components include at least one first heat-generating component thermally connected to the first heat sink 40 and at least one second heat-generating component thermally connected to the second heat sink 70.

[0065] 9 , the driver IC 53A is thermally coupled to the first heat sink 40, and the driver IC 53B and the switching element 52 are thermally coupled to the second heat sink 70, but it is possible to change whether each of the plurality of heat-generating components is connected to the first heat sink 40 or the second heat sink 70 as appropriate. The decision of whether each of the plurality of heat-generating components is connected to the first heat sink 40 or the second heat sink 70 is preferably based on the heat generation amount of the plurality of heat-generating components and the heat dissipation performance of the first heat sink 40 and the second heat sink 70. For example, the decision of whether each of the plurality of heat-generating components is connected to the first heat sink 40 or the second heat sink 70 may be made so that the amount of heat transferred from the heat-generating component to the first heat sink 40 and the amount of heat transferred from the heat-generating component to the second heat sink 70 are equal. By evenly distributing the heat from multiple heat-generating components to the first heat sink 40 and the second heat sink 70, the heat from multiple heat-generating components can be dissipated from both the first heat sink 40 and the second heat sink 70, thereby reducing the temperature rise of the drive circuit 50.

[0066] If the heat dissipation performance of the first heat sink 40 is higher than that of the second heat sink 70, the heat from the multiple heat-generating components can be allocated to the first heat sink 40 and the second heat sink 70 so that the amount of heat transferred from the drive circuit 50 to the first heat sink 40 is greater than the amount of heat transferred from the drive circuit 50 to the second heat sink 70. If the heat dissipation performance of the second heat sink 70 is higher than that of the first heat sink 40, the heat from the multiple heat-generating components can be allocated to the first heat sink 40 and the second heat sink 70 so that the amount of heat transferred from the drive circuit 50 to the second heat sink 70 is greater than the amount of heat transferred from the drive circuit 50 to the first heat sink 40.

[0067] (3.5) Modification 5 A motor device 1 according to modification 5 will be described with reference to FIG. 10 and other figures.

[0068] 10, the motor device 1 according to the fifth modification differs from the basic configuration in that the plurality of heat dissipation fins 42 provided on the front surface 41A of the base material 41 of the heat sink 40 are arranged in a staggered pattern. Note that, other than the arrangement of the plurality of heat dissipation fins 42, the motor device 1 according to the fifth modification is the same as the basic configuration, and therefore, the same components as those in the basic configuration are denoted by the same reference numerals and will not be illustrated or described again.

[0069] On the front surface 41A of the base material 41, a plurality of heat dissipation fins 42 are arranged in a staggered pattern, with a first row in which the plurality of heat dissipation fins 42 are arranged at equal pitch along the Y-axis direction alternating with a second row in which the plurality of heat dissipation fins 42 are arranged at the same pitch as the first row but shifted in position by (1 / 2) pitch along the Y-axis direction.

[0070] The arrangement pattern of the plurality of heat dissipation fins 42 arranged on the front surface 41A of the base material 41 can be changed as appropriate. For example, as shown in Fig. 11 , the plurality of heat dissipation fins 42 may be arranged in multiple rows on the front surface 41A of the base material 41, with the rows arranged at equal pitches along the Y-axis direction, so that the positions of the heat dissipation fins 42 are the same in the Y-axis direction. Here, the arrangement pattern of the plurality of heat dissipation fins 42 as shown in Fig. 11 is sometimes referred to as a lattice arrangement.

[0071] When multiple heat dissipation fins 42 are arranged in a staggered pattern on the front surface 41A of the base material 41, the distance to the four surrounding heat dissipation fins 42 can be set equal for each of the multiple heat dissipation fins 42, compared to when the multiple heat dissipation fins 42 are arranged in a grid pattern, and the heat dissipation performance of each of the multiple heat dissipation fins 42 can be made uniform.

[0072] In the second heat sink 70 described in Modifications 2 to 4, the arrangement pattern of the second heat dissipation fins 72 arranged on the rear surface 71A of the base material 71 can be changed as appropriate. The arrangement pattern of the second heat dissipation fins 72 may be a staggered arrangement, a lattice arrangement, or any other arrangement pattern.

[0073] (3.6) Modification 6 A motor device 1 according to modification 6 will be described with reference to FIGS.

[0074] The motor device 1 of the sixth modification differs from the basic configuration in that a plurality of flat heat dissipation fins 42A are provided on the front surface 41A of the base material 41 of the heat sink 40. Since the motor device 1 of the sixth modification is the same as the basic configuration except for the plurality of heat dissipation fins 42A, the same components as the basic configuration are denoted by the same reference numerals and will not be illustrated or described again.

[0075] 12 is a ZX cross-sectional view of the motor device 1, FIG. 13 is a cross-sectional view taken along the line A1-A1 in FIG. 12, and FIG. 14 is a perspective view of the heat sink 40 as seen from the front.

[0076] In the base material 41 of the heat sink 40, an air passage 43 is provided along the up-down direction on the surface (front surface 41A) facing the first housing 20. No heat dissipation fins 42A are provided in the center in the left-right direction of the front surface 41A of the base material 41, and the area where no heat dissipation fins 42A are provided becomes the air passage 43 (see FIG. 13 ).

[0077] A plurality of heat dissipation fins 42A are provided on both the left and right sides of the ventilation passage 43 on the front surface 41A of the base material 41. In other words, the plurality of heat dissipation fins 42A include a plurality of first fins 421 provided in a region on the right side of the ventilation passage 43 on the opposing surface, and a plurality of second fins 422 provided in a region on the left side of the ventilation passage 43 on the opposing surface.

[0078] The multiple first fins 421 are formed in the shape of plates extending along the first direction DR1. The angle θ1 that the first direction DR1, which is parallel to the longitudinal direction of the first fins 421, makes with the up-down direction (Z-axis direction) is preferably, for example, 40 to 70 degrees. The multiple first fins 421 are arranged on opposing surfaces of the base material 41 so as to be aligned at regular intervals in directions perpendicular to the first direction DR1 and the X-axis direction.

[0079] The second fins 422 are formed in the shape of plates extending along the second direction DR2. The angle θ2 between the second direction DR2, which is parallel to the longitudinal direction of the second fins 422, and the up-down direction (Z-axis direction) is preferably 40 to 70 degrees, for example. The second fins 422 are arranged on the opposing surfaces of the base material 41 so as to be aligned at regular intervals in directions perpendicular to the second direction DR2 and the X-axis direction.

[0080] 13, arrows indicate a first direction DR1, which is the longitudinal direction of the first fin 421, and a second direction DR2, which is the longitudinal direction of the second fin 422. When the opposing surface (front surface 41A) is viewed in plan, each of the first direction DR1 and the second direction DR2 is inclined obliquely with respect to the up-down direction (Z-axis direction).

[0081] In this way, on the opposing surface of the base material 41 of the heat sink 40, a plurality of first fins 421 each formed in a plate shape are arranged on the right side of the ventilation passage 43, and a plurality of second fins 422 each formed in a plate shape are arranged on the left side of the ventilation passage 43.

[0082] Here, each of the plurality of first fins 421 and the plurality of second fins 422 is formed in a shape that, the further upward, the farther it is from the ventilation passage 43. In other words, each of the plurality of first fins 421 and the plurality of second fins 422 is inclined obliquely so that a first end on the side closer to the ventilation passage 43 is positioned lower than a second end on the opposite side.

[0083] The first fins 421 and the second fins 422 are symmetrical with respect to the ventilation passage 43 .

[0084] As a result, air rising in ventilation passage 43 flows from ventilation passage 43 to flow passage 431 between the plurality of first fins 421 or flow passage 432 between the plurality of second fins 422, and moves upward through flow passage 431 or 432. Here, since the plurality of first fins 421 and the plurality of second fins 422 are formed symmetrically with respect to ventilation passage 43, air can flow evenly from ventilation passage 43 to flow passages 431 and 432. Then, as the air flows through flow passages 431 and 432, heat exchange occurs between the air passing through flow passage 431 and the first fins 421, and between the air passing through flow passage 432 and the second fins 422, respectively, and the temperature rise of drive circuit 50 can be reduced.

[0085] Fig. 15 is a plan view of a heat sink 40C of the comparative example. In the heat sink 40C of the comparative example, a plurality of heat dissipation fins 42 extending in the up-down direction are arranged in a row in the left-right direction on the front surface 41A of the base material 41, and a flow path 44 through which air passes is provided between two adjacent heat dissipation fins 42. Note that the dotted arrows in Fig. 15 indicate the air flow.

[0086] Here, inside the second housing 30, air heated by the heat-generating components moves upward, so the temperature of the upper region B1 becomes higher than the temperature of the lower region on the front surface 41A of the base material 41, which is the opposing surface 30A of the second housing 30. In the comparative example, when air that flows into the flow path 44 from below the heat sink 40C rises within the flow path 44, thermal interference occurs with the warm air present in the upper part of the flow path 44, which can impair the air flow and reduce the heat dissipation performance of the heat sink 40C.

[0087] In contrast, in the motor device 1 of Modification 6, the first fins 421 and the second fins 422 are inclined so that their first ends, which are closer to the ventilation passage 43, are positioned lower than their opposite second ends, causing air to move outward through the flow passages 431 and 432. As a result, the air flowing from the ventilation passage 43 into the flow passages 431 and 432 avoids the upper center of the opposing surface, preventing the air flow from being obstructed by thermal interference. Therefore, by smoothing the movement of air within the flow passages 431 and 432, the heat dissipation performance of the heat sink 40 can be improved, which has the advantage of suppressing temperature increases in the drive circuit 50.

[0088] The shapes of the first fin 421 and the second fin 422 shown in FIG. 13 are merely examples and can be changed as appropriate.

[0089] 16 , each of the plurality of first fins 421 and the plurality of second fins 422 may be formed in a shape that approaches the ventilation passage 43 as it goes upward. In other words, each of the plurality of first fins 421 and the plurality of second fins 422 may be inclined obliquely so that a first end closer to the ventilation passage 43 is positioned higher than a second end on the opposite side. In this case, air that flows from outside the heat sink 40 into a flow path 431 between the plurality of first fins 421 or a flow path 432 between the plurality of second fins 422 moves upward within the flow path 431 or 432 and exits outside the heat sink 40 directly or through the ventilation passage 43. The air flowing through some of the flow paths 431, 432 merges with the ventilation path 43 and exits from the ventilation path 43 to the outside of the heat sink 40, so that the chimney effect makes the air flowing through the flow paths 431, 432 smoother, improving the heat dissipation performance of the plurality of first fins 421 and the plurality of second fins 422. This improves the heat dissipation performance of the heat sink 40 and makes it possible to suppress a temperature rise in the drive circuit 50.

[0090] The shapes of the first fins 421 and the second fins 422 are not limited to the above shapes and can be changed as appropriate. The first fins 421 and the second fins 422 are formed in a flat plate shape, but may be curved so that their shape when viewed from the front is an arc. Furthermore, the first fins 421 and the second fins 422 are formed in a symmetrical shape with respect to the ventilation passage 43, but may be formed in an asymmetrical shape with respect to the ventilation passage 43.

[0091] Furthermore, the ventilation passage 43 is provided in the center in the left-right direction on the opposing surface of the base material 41 of the heat sink 40, but may be provided in an area shifted to the right or left from the center.

[0092] (3.7) Modification 7 The heat sink 40 provided in the motor device 1 of modification 7 will be described with reference to FIGS. 17 and 18. FIG.

[0093] In the heat sink 40 included in the motor device 1 of Modification 6, the passage width of the ventilation passage 43 is constant (see FIG. 13 ). However, in Modification 7, as shown in FIG. 17 , the passage width D3 of the lower portion of the ventilation passage 43 is wider than the passage width D4 of the upper portion of the ventilation passage 43. Here, the passage width of the ventilation passage 43 refers to the width of the ventilation passage 43 in the left-right direction, and is the width of the space between a line LN1 connecting the left ends of the first fins 421 and a line LN2 connecting the right ends of the second fins 422. Therefore, the passage width D3 of the lower portion of the ventilation passage 43 is the distance between the lines LN1 and LN2 at the lower end of the ventilation passage 43, and the passage width D4 of the upper portion of the ventilation passage 43 is the distance between the lines LN1 and LN2 at the upper end of the ventilation passage 43. Since the configuration is the same as that of Modification 6 except for the passage width of the ventilation passage 43, the same components as those of Modification 6 are given the same reference numerals and are not illustrated or described again.

[0094] In the heat sink 40 shown in Figure 17, the passage width of the ventilation passage 43 becomes wider as it goes downward, which has the advantage that air can more easily flow from the ventilation passage 43 into the flow path 431 between adjacent first fins 421 and the flow path 432 between adjacent second fins 422, compared to when the passage width of the ventilation passage 43 is constant.

[0095] 17, the passage width of the ventilation passage 43 changes linearly so as to become wider toward the bottom (in other words, so as to become narrower toward the top), but it may also change nonlinearly. Also, the passage width of the ventilation passage 43 may change in stages so that the lower part is wider than the upper part of the ventilation passage 43.

[0096] In addition, in the heat sink 40 shown in Figure 17, each of the multiple first fins 421 and multiple second fins 422 is inclined so that the first end closer to the ventilation passage 43 is positioned lower than the second end on the opposite side, but the shapes of the first fins 421 and second fins 422 can be changed as appropriate.

[0097] As shown in Figure 18, in a heat sink 40 in which each of the multiple first fins 421 and multiple second fins 422 is inclined so that the first end closer to the ventilation passage is positioned higher than the second end on the opposite side, the passage width at the bottom of the ventilation passage 43 may be wider than the passage width at the top of the ventilation passage 43.

[0098] Even in this case, compared to when the passage width of the ventilation passage 43 is constant, there is an advantage that the air flowing in the flow path 431 between two adjacent first fins 421 and the flow path 432 between two adjacent second fins 422 can more easily flow into the ventilation passage 43.

[0099] (3.8) Modification 8 The heat sink 40 provided in the motor device 1 of modification 8 will be described with reference to FIGS. 19 and 20. FIG.

[0100] FIG. 19 is a YZ cross-sectional view of the heat sink 40 provided in the motor device 1 of the eighth modified example.

[0101] The heat sink 40 included in the motor device 1 of Modification 8 differs from Modification 6 in that the spacing D11 between the multiple first fins 421 is wider at the bottom of the base material 41 than at the top of the base material 41, and the spacing D12 between the multiple second fins 422 is wider at the bottom of the base material 41 than at the top of the base material 41. Here, the spacing D11 between the multiple first fins 421 refers to the spacing between two adjacent first fins 421 among the multiple first fins 421. Furthermore, the spacing D12 between the multiple second fins 422 refers to the spacing between two adjacent second fins 422 among the multiple second fins 422. Note that Modification 8 is similar to Modification 6 except that the spacing D11 between the multiple first fins 421 and the spacing D12 between the multiple second fins 422 change in the up-down direction. Therefore, components common to Modification 6 are denoted by the same reference numerals, and illustrations and descriptions thereof are omitted.

[0102] 19 , the spacing D11 between the first fins 421 increases toward the bottom, which has the advantage that air can more easily flow from the ventilation passages 43 into the flow paths 431 between adjacent first fins 421 than when the spacing D11 between the first fins 421 is constant. Similarly, the spacing D12 between the second fins 422 increases toward the bottom, which has the advantage that air can more easily flow from the ventilation passages 43 into the flow paths 432 between adjacent second fins 422 than when the spacing D12 between the second fins 422 is constant.

[0103] 19, the spacing D11 between the first fins 421 and the spacing D12 between the second fins 422 increase by a constant increment so as to become wider toward the bottom of the base material 41, but they may also change nonlinearly. Alternatively, the spacing D11 between the first fins 421 and the spacing D12 between the second fins 422 may change in stages so as to be wider at the bottom of the base material 41 than at the top.

[0104] In addition, in the heat sink 40 shown in Figure 19, each of the multiple first fins 421 and multiple second fins 422 is inclined so that the first end closer to the ventilation passage 43 is positioned lower than the second end on the opposite side, but the shapes of the first fins 421 and second fins 422 can be changed as appropriate.

[0105] As shown in Figure 20, in a heat sink 40 in which each of the multiple first fins 421 and multiple second fins 422 is inclined so that the first end closer to the ventilation passage 43 is positioned higher than the second end on the opposite side, the spacing D11 between the first fins 421 and the spacing D12 between the second fins 422 may be wider at the bottom of the base material 41 than at the top of the base material 41.

[0106] Even in this case, there is an advantage that the air flowing through the flow path 431 between adjacent first fins 421 and the flow path 432 between adjacent second fins 422 can more easily flow into the ventilation passage 43, compared to when the spacing D11 between the first fins 421 and the spacing D12 between the second fins 422 are constant.

[0107] (3.9) Modification 9 The heat sink 40 provided in the motor device 1 of modification 9 will be described with reference to FIGS. 21 and 22. FIG.

[0108] FIG. 21 is a YZ cross-sectional view of the heat sink 40 provided in the motor device 1 of the ninth modification.

[0109] The heat sink 40 included in the motor device 1 of Modification 9 differs from Modification 6 in that the inclination of the first direction DR1, along which the first fins 421 extend, with respect to the up-down direction is greater at the bottom of the base material 41 than at the top of the base material 41, and the inclination of the second direction DR2, along which the second fins 422 extend, with respect to the up-down direction is greater at the bottom of the base material 41 than at the top of the base material 41. Note that, apart from the first fins 421 and second fins 422, the heat sink 40 is the same as Modification 6, and therefore components common to Modification 9 are denoted by the same reference numerals and will not be illustrated or described again.

[0110] 21 , the inclination of the first direction DR1 (i.e., the longitudinal direction of the first fins 421) with respect to the up-down direction differs among the multiple first fins 421. Furthermore, the inclination of the second direction DR2 (i.e., the longitudinal direction of the second fins 422) with respect to the up-down direction differs among the multiple second fins 422.

[0111] More specifically, the inclination of the first direction DR1 with respect to the up-down direction between the multiple first fins 421 gradually increases from the top to the bottom of the base material 41. As a result, the flow paths 431 between adjacent first fins 421 are wider at the bottom than at the top of the base material 41, which makes it easier for air to flow through the flow paths 431, which has the advantage of improving heat dissipation performance.

[0112] Similarly, the inclination of the second direction DR2 with respect to the up-down direction between the multiple second fins 422 gradually increases from the top to the bottom of the base material 41. As a result, the flow paths 432 between adjacent second fins 422 are wider at the bottom than at the top of the base material 41, making it easier for air to flow through the flow paths 432, which has the advantage of improving heat dissipation performance.

[0113] 21, the inclination of the first direction DR1 with respect to the vertical direction and the inclination of the second direction DR2 with respect to the vertical direction each gradually increase by a constant increment from the top to the bottom of the base material 41, but the increment does not necessarily have to be constant. The inclination of the first direction DR1 with respect to the vertical direction and the inclination of the second direction DR2 with respect to the vertical direction each may increase nonlinearly from the top to the bottom of the base material 41.

[0114] In addition, in the heat sink 40 shown in Figure 21, each of the multiple first fins 421 and multiple second fins 422 is inclined so that the first end closer to the ventilation passage 43 is positioned lower than the second end on the opposite side, but the shapes of the first fins 421 and second fins 422 can be changed as appropriate.

[0115] As shown in Figure 22, in a heat sink 40 in which each of the multiple first fins 421 and multiple second fins 422 is inclined diagonally so that the first end closer to the ventilation passage 43 is positioned higher than the second end on the opposite side, the inclination of the first direction DR1 relative to the vertical direction and the inclination of the second direction DR2 relative to the vertical direction may each be configured to be greater at the bottom than at the top of the base material 41.

[0116] In this case, the width of the portion where the flow path 431 between adjacent first fins 421 connects to the ventilation passage 43 and the width of the portion where the flow path 432 between adjacent second fins 422 connects to the ventilation passage 43 are both wider than when the inclination of the first direction DR1 with respect to the up-down direction and the inclination of the second direction DR2 with respect to the up-down direction are both constant. This makes it easier for the air flowing through the flow paths 431 and 432 to flow into the ventilation passage 43, improving the heat dissipation performance of the first fins 421 and the second fins 422 and reducing the temperature rise of the drive circuit 50.

[0117] (3.10) Modification 10 A motor device 1 according to modification 10 will be described with reference to FIG.

[0118] The motor device 1 of Modification 10 differs from Modification 2 in that, as in Modification 6, flat heat dissipation fins 42A are provided on the front surface 41A of the base material 41 of the first heat sink 40, and flat second heat dissipation fins 72A are provided on the rear surface 71A of the base material 71 of the second heat sink 70. Note that, since the components other than the first heat sink 40 and the second heat sink 70 are the same as those of Modification 2, the same reference numerals are used for the components common to Modification 2, and illustrations and descriptions thereof will be omitted.

[0119] The first heat sink 40 provided in the motor device 1 of Modification 10 has a structure similar to that of the heat sink 40 described in Modification 6, and therefore a description thereof will be omitted. Note that the ventilation passage 43 provided on the front surface 41A of the base material 41 of the first heat sink 40 serves as the first ventilation passage 43.

[0120] 23 is a perspective view of the second heat sink 70 included in the motor device 1 of Modification 10, and a second ventilation passage 73 is provided along the up-down direction on the rear surface 71A (second surface 30B opposite to the first surface) of the base material 71 of the second heat sink 70. The second heat dissipation fins 72A are not provided in the center in the left-right direction of the rear surface 71A of the base material 71, and the region where the second heat dissipation fins 72A are not provided becomes the second ventilation passage 73.

[0121] A plurality of second heat dissipation fins 72A are provided on both the left and right sides of the second ventilation passage 73 on the rear surface 71A of the base material 71. In other words, the plurality of second heat dissipation fins 72A include a plurality of third fins 721 provided in a region on the second surface 30B to the right of the second ventilation passage 73 and a plurality of fourth fins 722 provided in a region on the second surface 30B to the left of the second ventilation passage 73.

[0122] The multiple third fins 721 are formed in plate shapes extending along the third direction DR3. The multiple third fins 721 are arranged on the rear surface 71A (second surface 30B) of the base material 71 so as to be aligned at regular intervals in directions perpendicular to the third direction DR3 and the X-axis direction. The multiple fourth fins 722 are formed in plate shapes extending along the fourth direction DR4. The multiple fourth fins 722 are arranged on the rear surface 71A (second surface 30B) of the base material 71 so as to be aligned at regular intervals in directions perpendicular to the fourth direction DR4 and the X-axis direction. When the second surface 30B is viewed in plan, the third direction DR3 and the fourth direction DR4 are each inclined obliquely with respect to the up-down direction (Z-axis direction). In FIG. 23 , the third direction DR3, which is the longitudinal direction of the third fins 721, and the fourth direction DR4, which is the longitudinal direction of the fourth fins 722, are indicated by arrows.

[0123] In this way, on the second surface 30B of the base material 71 of the second heat sink 70, a plurality of third fins 721 each formed in a plate shape are arranged on the right side of the second ventilation passage 73, and a plurality of fourth fins 722 each formed in a plate shape are arranged on the left side of the second ventilation passage 73.

[0124] Here, the plurality of third fins 721 and the plurality of fourth fins 722 are formed in a symmetrical shape with respect to the second ventilation passage 73 .

[0125] Each of the plurality of third fins 721 and the plurality of fourth fins 722 is inclined obliquely so that a first end closer to the second ventilation passage 73 is positioned lower than a second end on the opposite side.

[0126] As a result, air rising through the second ventilation passage 73 flows from the second ventilation passage 73 into a flow path 731 between two adjacent third fins 721 or a flow path 732 between two adjacent fourth fins 722, and moves upward through the flow path 731 or 732. Here, the third fins 721 and the fourth fins 722 are inclined so that their first ends, which are closer to the second ventilation passage 73, are positioned lower than their opposite second ends. This allows the air to move outward through the flow paths 731 and 732 and avoid the upper center of the base material 71, thereby preventing the air flow from being obstructed by thermal interference. Therefore, by smoothing the movement of air through the flow paths 731 and 732, the heat dissipation performance of the second heat sink 70 can be improved, and the temperature rise of the drive circuit 50 can be suppressed.

[0127] 23 is merely an example and can be modified as appropriate. For example, each of the third fins 721 and the fourth fins 722 may be inclined so that a first end closer to the second ventilation passage 73 is positioned higher than a second end on the opposite side. In this case, air flowing into the flow passages 731 and 732 from outside the second heat sink 70 moves upward within the flow passages 731 and 732 and exits the second heat sink 70 directly or through the second ventilation passage 73. Because air moves inward through the flow passages 731 between the third fins 721 and the flow passages 732 between the fourth fins 722, a chimney effect ensures smooth airflow through the flow passages 731 and 732, improving the heat dissipation performance of the second heat sink 70.

[0128] In addition, the shape and arrangement of the multiple third fins 721 and multiple fourth fins 722 provided on the second heat sink 70 can be changed as appropriate, and may be formed in the same shape and arrangement as the multiple first fins 421 and multiple second fins 422 described in variant examples 7 to 9.

[0129] (3.11) Other Modifications The configurations of the motor 2 exemplified in the basic configuration and modifications 1 to 10 are merely examples and can be modified as appropriate.

[0130] In the basic configuration and variants 1 to 10, multiple heat dissipation fins 42, 42A are in contact with the cover member 201 of the motor 2, but a plate-shaped insulating member may be attached to the outer surface of the cover member 201 and multiple heat dissipation fins 42 may be in contact with the insulating member.

[0131] (Summary) The above-described embodiments and the like disclose the following aspects.

[0132] The motor device (1) of the first aspect includes a motor (2) and a second housing (30). The motor (2) has a first housing (20) that houses a rotor (23) and a stator (21). The second housing (30) houses a drive circuit (50) that drives the motor (2) and is attached to the first housing (20). A plurality of heat dissipation fins (42) are provided on the surface of the second housing (30) that faces the first housing (20). The plurality of heat dissipation fins (42) are interposed between the second housing (30) and the first housing (20).

[0133] According to this aspect, heat from the first housing (20) is less likely to be transferred to the second housing (30) than when the opposing surface of the second housing (30) is in direct contact with the first housing (20). Furthermore, by providing multiple heat dissipation fins (42) between the first housing (20) and the second housing (30), a space through which air can flow is formed between the first housing (20) and the second housing (30), which facilitates cold air from the outside to enter the space between the first housing (20) and the second housing (30) due to a chimney effect. This increases the efficiency of heat exchange in the multiple heat dissipation fins (42), thereby reducing the temperature rise of the drive circuit (50) housed in the second housing (30).

[0134] In the motor device (1) of the second aspect, in the first aspect, the plurality of heat dissipation fins (42) are a plurality of first heat dissipation fins (42), and a plurality of second heat dissipation fins (72) are provided on the surface opposite to the opposing surface of the second housing (30).

[0135] According to this aspect, heat can be dissipated from a plurality of heat dissipation fins (42) provided on the opposing surface of the second housing (30) and a plurality of second heat dissipation fins (72) provided on the surface opposite the opposing surface, thereby further reducing the temperature rise of the drive circuit (50).

[0136] In the motor device (1) of the third aspect, the arrangement intervals of the plurality of first heat dissipation fins (42) and the arrangement intervals of the plurality of second heat dissipation fins (72) are different from each other in the second aspect.

[0137] According to this aspect, by setting the spacing between the multiple first heat dissipation fins (42) and the multiple second heat dissipation fins (72), it is possible to change the heat dissipation area of ​​the multiple first heat dissipation fins (42) and the heat dissipation area of ​​the multiple second heat dissipation fins (72).

[0138] In the motor device (1) of the fourth aspect, in the third aspect, the arrangement intervals of the plurality of first heat dissipation fins (42) are narrower than the arrangement intervals of the plurality of second heat dissipation fins (72).

[0139] According to this aspect, if the surface area per first heat dissipation fin (42) and per second heat dissipation fin (72) is the same, the heat dissipation area of ​​the multiple first heat dissipation fins (42) can be made larger than the heat dissipation area of ​​the multiple second heat dissipation fins (72).

[0140] In the motor device (1) of the fifth aspect, in any of the second to fourth aspects, the lengths of the plurality of first heat dissipation fins (42) and the lengths of the plurality of second heat dissipation fins (72) are different from each other in the arrangement direction in which the first housing (20) and the second housing (30) are aligned.

[0141] According to this aspect, by setting the lengths of the plurality of first heat dissipation fins (42) and the plurality of second heat dissipation fins (72), it is possible to change the heat dissipation area of ​​the plurality of first heat dissipation fins (42) and the heat dissipation area of ​​the plurality of second heat dissipation fins (72).

[0142] In the motor device (1) of the sixth aspect, in the fifth aspect, the length of the plurality of first heat dissipating fins (42) is longer than the length of the plurality of second heat dissipating fins (72) in the arrangement direction.

[0143] According to this aspect, if the number of first heat dissipation fins (42) and second heat dissipation fins (72) is the same, the heat dissipation area of ​​the multiple first heat dissipation fins (42) can be made larger than the heat dissipation area of ​​the multiple second heat dissipation fins (72).

[0144] In the motor device (1) of a seventh aspect, in any one of the second to sixth aspects, the second housing (30) accommodates a plurality of heat-generating components (52, 53) that constitute the drive circuit (50). The plurality of heat-generating components (52, 53) include at least one first heat-generating component thermally connected to a plurality of first heat-dissipating fins (42) and at least one second heat-generating component thermally connected to a plurality of second heat-dissipating fins (72).

[0145] According to this aspect, it is possible to set whether the multiple heat-generating components (52, 53) are first heat-generating components or second heat-generating components depending on the heat dissipation capacity of the multiple first heat dissipation fins (42) and the heat dissipation capacity of the multiple second heat dissipation fins (72).

[0146] In the motor device (1) of an eighth aspect, in any one of the first to seventh aspects, an air passage (43) is provided on the opposing surface along the vertical direction. The plurality of heat dissipation fins (42) include a plurality of first fins (421) provided in a region on the opposing surface to the right of the air passage (43) and a plurality of second fins (422) provided in a region on the opposing surface to the left of the air passage (43). The plurality of first fins (421) are formed in a plate shape extending along a first direction (DR1), and the plurality of second fins (422) are formed in a plate shape extending along a second direction (DR2). When the opposing surface is viewed in a plane, the first direction (DR1) and the second direction (DR2) are each obliquely inclined with respect to the vertical direction.

[0147] According to this aspect, since the first direction (DR1) and the second direction (DR2) are each inclined obliquely with respect to the up-down direction, when air moves through the flow paths between the plurality of first fins (421) and the flow paths between the plurality of second fins (422), it is possible to suppress thermal interference between the air and warm air present in the upper part of the flow paths. Therefore, the heat dissipation performance of the plurality of first fins (421) and the plurality of second fins (422) is improved, and it is possible to reduce the temperature rise of the drive circuit (50).

[0148] In the motor device (1) of the ninth aspect, in the eighth aspect, the plurality of first fins (421) and the plurality of second fins (422) are formed in a symmetrical shape with respect to the ventilation passage (43).

[0149] According to this aspect, the air flow in the flow passages between the plurality of first fins (421) and the air flow in the flow passages between the plurality of second fins (422) can be made uniform.

[0150] In the motor device (1) of the 10th aspect, in the 8th or 9th aspect, each of the plurality of first fins (421) and the plurality of second fins (422) is inclined obliquely so that the first end closer to the ventilation passage (43) is positioned lower than the second end on the opposite side.

[0151] According to this aspect, air moves outward through the flow paths between the multiple first fins (421) and the flow paths between the multiple second fins (422), thereby smoothing the flow of air in the flow paths and improving the heat dissipation performance of the multiple first fins (421) and the multiple second fins (422).

[0152] In the motor device (1) of the eleventh aspect, in any of the eighth to tenth aspects, each of the plurality of first fins (421) and the plurality of second fins (422) is inclined obliquely so that the first end close to the ventilation passage (43) is positioned higher than the second end on the opposite side.

[0153] According to this aspect, air flows from the flow paths between the plurality of first fins (421) and the flow paths between the plurality of second fins (422) to merge into the ventilation passage (43), so that the chimney effect makes the air flow in the flow paths smoother, thereby improving the heat dissipation performance of the plurality of first fins (421) and the plurality of second fins (422).

[0154] In the motor device (1) of a twelfth aspect, in any of the second to seventh aspects, a first ventilation passage (43) is provided along the vertical direction on the first surface, which is the opposing surface. The multiple first heat dissipation fins (42) include multiple first fins (421) provided in a region on the first surface to the right of the first ventilation passage (43) and multiple second fins (422) provided in a region on the opposing surface to the left of the first ventilation passage (43). The multiple first fins (421) are formed in a plate shape extending along the first direction (DR1), and the multiple second fins (422) are formed in a plate shape extending along the second direction (DR2). When the first surface is viewed in a plane, the first direction (DR1) and the second direction (DR2) are each obliquely inclined with respect to the vertical direction. In the second housing (30), a second ventilation passage (73) is provided along the vertical direction on the second surface opposite the first surface. The second heat dissipation fins (72) include a plurality of third fins (721) provided in a region on the second surface to the right of the second ventilation passage (73) and a plurality of fourth fins (722) provided in a region on the second surface to the left of the second ventilation passage (73). The third fins (721) are formed in plate shapes extending along a third direction (DR3), and the fourth fins (722) are formed in plate shapes extending along a fourth direction (DR4). When the second surface is viewed in a plane, the third direction (DR3) and the fourth direction (DR4) are each inclined obliquely with respect to the up-down direction.

[0155] According to this aspect, since the first direction (DR1) and the second direction (DR2) are each inclined obliquely with respect to the vertical direction, when air moves through the flow paths between the plurality of first fins (421) and the flow paths between the plurality of second fins (422), thermal interference between the air and the warm air present at the upper part of the flow paths can be suppressed. Therefore, the heat dissipation performance of the plurality of first fins (421) and the plurality of second fins (422) is improved, and the temperature rise of the drive circuit (50) can be reduced. Furthermore, since the third direction (DR3) and the fourth direction (DR4) are each inclined obliquely with respect to the vertical direction, when air moves through the flow paths between the plurality of third fins (721) and the flow paths between the plurality of fourth fins (722), thermal interference between the air and the warm air present at the upper part of the flow paths can be suppressed. Therefore, the heat dissipation performance of the plurality of third fins (721) and the plurality of fourth fins (722) is improved, and the temperature rise of the drive circuit (50) can be reduced.

[0156] In the motor device (1) of the thirteenth aspect, in the twelfth aspect, the plurality of third fins (721) and the plurality of fourth fins (722) are formed in a shape symmetrical with respect to the second ventilation passage (73).

[0157] According to this aspect, the air flow in the flow passages between the plurality of third fins (721) and the air flow in the flow passages between the plurality of fourth fins (722) can be made uniform.

[0158] In the motor device (1) of the 14th aspect, in the 12th or 13th aspect, each of the plurality of third fins (721) and the plurality of fourth fins (722) is inclined obliquely so that the first end close to the second ventilation passage (73) is positioned lower than the second end on the opposite side.

[0159] According to this aspect, air moves outward through the flow paths between the multiple third fins (721) and the flow paths between the multiple fourth fins (722), thereby smoothing the flow of air in the flow paths and improving the heat dissipation performance of the multiple third fins (721) and the multiple fourth fins (722).

[0160] In the motor device (1) of the 15th aspect, in any of the 12th to 14th aspects, each of the plurality of third fins (721) and the plurality of fourth fins (722) is inclined obliquely so that the first end close to the second ventilation passage (73) is positioned higher than the second end on the opposite side.

[0161] According to this aspect, air moves inward through the flow paths between the multiple third fins (721) and the flow paths between the multiple fourth fins (722), so that the chimney effect makes the air flow in the flow paths smoother, thereby improving the heat dissipation performance of the multiple third fins (721) and the multiple fourth fins (722).

[0162] The configurations according to the second to fifteenth aspects are not essential for the motor device (1) and can be omitted as appropriate.

[0163] REFERENCE SIGNS LIST 1 motor device 2 motor 20 first housing 21 stator 23 rotor 30 second housing 42 heat dissipation fin (first heat dissipation fin) 43 ventilation path (first ventilation path) 50 drive circuit 52 switching element (heat generating component) 53 driver IC (heat generating component) 72 second heat dissipation fin 73 second ventilation path 421 first fin 422 second fin 721 third fin 722 fourth fin DR1 first direction DR2 second direction

Claims

1. A motor having a first housing that accommodates a rotor and a stator, The system comprises a second housing that houses a drive circuit for driving the motor and is attached to the first housing, Multiple heat dissipation fins are provided on the surface of the second housing facing the first housing. The plurality of heat dissipation fins are interposed between the second housing and the first housing. Motor device.

2. The aforementioned plurality of heat dissipation fins are a plurality of first heat dissipation fins, Multiple second heat dissipation fins are provided on the surface of the second housing opposite to the opposing surface. The motor device according to claim 1.

3. The spacing between the plurality of first heat dissipation fins and the spacing between the plurality of second heat dissipation fins are different from each other. The motor device according to claim 2.

4. The spacing between the plurality of first heat dissipation fins is narrower than the spacing between the plurality of second heat dissipation fins. The motor device according to claim 3.

5. In the arrangement direction in which the first housing and the second housing are aligned, the lengths of the plurality of first heat dissipation fins and the lengths of the plurality of second heat dissipation fins are different from each other. A motor device according to any one of claims 2 to 4.

6. In the aforementioned arrangement direction, the length of the plurality of first heat dissipation fins is longer than the length of the plurality of second heat dissipation fins. The motor device according to claim 5.

7. The second housing contains a plurality of heat-generating components that constitute the drive circuit. The plurality of heat-generating components include at least one first heat-generating component thermally connected to the plurality of first heat-dissipating fins, and at least one second heat-generating component thermally connected to the plurality of second heat-dissipating fins. A motor device according to any one of claims 2 to 4.

8. A ventilation passage is provided on the aforementioned opposing surface, running vertically. The plurality of heat dissipation fins include a plurality of first fins provided in the region to the right of the air passage on the opposing surface, and a plurality of second fins provided in the region to the left of the air passage on the opposing surface. The plurality of first fins are formed in a plate shape extending along a first direction, and the plurality of second fins are formed in a plate shape extending along a second direction. When the opposing surfaces are viewed from above, the first and second directions are each inclined diagonally with respect to the vertical direction. A motor device according to any one of claims 1 to 4.

9. The plurality of first fins and the plurality of second fins are formed in a shape symmetrical with respect to the air passage. The motor device according to claim 8.

10. Each of the plurality of first fins and the plurality of second fins is inclined diagonally such that the first end closest to the air passage is located lower than the second end on the opposite side. The motor device according to claim 8.

11. Each of the plurality of first fins and the plurality of second fins is inclined diagonally such that the first end closest to the air passage is located above the second end on the opposite side. The motor device according to claim 8.

12. The first surface, which is the opposing surface, is provided with a first ventilation passage running vertically. The plurality of first heat dissipation fins include a plurality of first fins provided in the region to the right of the first air passage on the first surface, and a plurality of second fins provided in the region to the left of the first air passage on the opposing surface. The plurality of first fins are formed in a plate shape extending along a first direction, and the plurality of second fins are formed in a plate shape extending along a second direction. When the first surface is viewed from above, the first direction and the second direction are each inclined diagonally with respect to the vertical direction. In the second housing, a second ventilation passage is provided on the second surface opposite to the first surface, oriented vertically. The plurality of second heat dissipation fins include a plurality of third fins provided in the region to the right of the second air passage on the second surface, and a plurality of fourth fins provided in the region to the left of the second air passage on the second surface. The plurality of third fins are formed in a plate shape extending along the third direction, and the plurality of fourth fins are formed in a plate shape extending along the fourth direction. When the second surface is viewed from above, the third and fourth directions are each inclined diagonally with respect to the vertical direction. A motor device according to any one of claims 2 to 4.

13. The plurality of third fins and the plurality of fourth fins are formed in a shape symmetrical with respect to the second air passage. The motor device according to claim 12.

14. Each of the plurality of third fins and the plurality of fourth fins is inclined diagonally such that the first end closest to the second air passage is located lower than the second end on the opposite side. The motor device according to claim 12.

15. Each of the plurality of third fins and the plurality of fourth fins is inclined diagonally such that the first end closest to the second air passage is located above the second end on the opposite side. The motor device according to claim 12.