CN112615458A

CN112615458A - Motor

Info

Publication number: CN112615458A
Application number: CN202011030389.6A
Authority: CN
Inventors: 鹤壮马; 石川将之; 柳乐一辉
Original assignee: Nidec Techno Motor Corp
Current assignee: Nidec Techno Motor Corp
Priority date: 2019-10-03
Filing date: 2020-09-27
Publication date: 2021-04-06
Anticipated expiration: 2040-09-27
Also published as: CN117748799A; CN112615458B

Abstract

The invention provides a motor, which is provided with a static part and a rotating part rotating through a bearing part. The stationary portion includes a stator, a housing, a cover holding the bearing portion, and a circuit board electrically connected to the stator. The rotating part has a rotor and a shaft. The circuit board has electronic components for driving the motor. The housing is opened at a housing opening portion, and accommodates the electronic component in the internal space. The cover covers the housing opening from one axial side of the circuit board. The cover has a resin cover body and a heat dissipation member attached to the cover body and having a higher thermal conductivity than the cover body. The end portion of the other axial side of the heat dissipation member is in contact with the electronic component directly or indirectly via another member. The cover body is interposed at least in the radial direction between the bearing part and the heat radiating part. This can sufficiently ensure the insulating performance between the electronic component and the heat dissipating member and the bearing portion of the support shaft.

Description

Motor

Technical Field

The present invention relates to a motor.

Background

In the past, there are molded motors as follows: the stator of the motor is molded with resin to form a housing, and the rotor is supported via a bearing in the housing. Such a motor is excellent in waterproof property of the stator, vibration damping property against vibration of the stator when the motor is driven, and sound insulation property. A conventional molded motor is described in, for example, japanese patent application laid-open No. 2007-6603.

Patent document 1: japanese patent laid-open No. 2007-6603

The brushless DC motor disclosed in jp 2007-6603 a has a stator completed body (6) in which a rotor completed body and a stator are integrally molded. A bearing (5) on the reverse output shaft side is supported by a bracket (10) and fixed to a stator completed body (6). A printed board (8) on which a drive IC (7) is mounted on the stator completed body (6). Heat dissipation silicon (11) is applied to the bracket (10) and the drive IC (7). Further, a heat sink (12) made of aluminum is attached to the bracket (10). Thus, heat generated in the driver IC (7) can be dissipated through the carrier (10) and the heat dissipating plate (12) via the heat dissipating silicon (11) (except for paragraph 0016, paragraph 0017, and paragraph 0020).

A shaft (3) is fixed to the inner ring of the bearing (5). The shaft (3) is connected to a rotating part, a speed reduction mechanism, and the like of equipment for maintenance and the like by a worker. However, as described above, the bearing (5) is supported by the bracket (10), but only the heat dissipation silicon (11) is applied between the bracket (10) and the drive IC (7). Therefore, the insulation performance between the drive IC (7) and the shaft (3) cannot be sufficiently ensured.

Disclosure of Invention

An object of the present invention is to provide a structure capable of ensuring insulation performance between a heat dissipation member for promoting heat dissipation from electronic components housed inside and a shaft for connecting a rotating portion, a speed reduction mechanism, or the like of a device to be driven, in a molded motor having a housing in which a stator is integrally molded. In addition, a structure capable of preventing the electric corrosion of the bearing is provided.

An exemplary 1 st invention of the present application is a motor having a stationary portion; and a rotating portion that rotates about the central axis via the bearing portion. The stationary portion includes: a stator; a housing that houses at least a portion of the stator; a cover fixed to the housing and directly or indirectly holding the bearing portion; and a circuit board extending in a radial direction and electrically connected to the stator. The rotating part has: a rotor; and a shaft mounted to the rotor and extending along the central axis. The circuit board has an electronic component for driving the motor, and the housing has an inner space that is open at least at a housing opening portion formed at one side in the axial direction and is continuous from the housing opening portion to the other side in the axial direction. The electronic component is located in the interior space. The cover covers the housing opening from a position closer to one side of the circuit board in the axial direction, and the cover includes: a cover main body portion made of resin; and a heat dissipation member attached to the cover body and having a higher thermal conductivity than the cover body. The end portion of the other axial side of the heat dissipation member is in contact with the electronic component directly or indirectly via another member. The cover body is interposed at least in the radial direction between the bearing part and the heat radiating part.

An exemplary 2 nd invention of the present application is a motor having a stationary portion; and a rotating portion that rotates about the central axis via the bearing portion. The stationary portion includes: a stator that surrounds a central axis in an annular shape and includes a stator core as a magnetic body, the stator core having a plurality of teeth extending in a radial direction; a housing that houses at least a portion of the stator; and a cover fixed to the housing. The bearing portion includes one side bearing and the other side bearing disposed apart from each other in the axial direction around the center axis. The housing has: a housing opening portion formed on one side in the axial direction; a housing cylindrical portion extending cylindrically from the housing opening portion toward the other axial side; a bottom plate portion that extends radially inward from the other axial end of the housing cylindrical portion and directly or indirectly fixes the other bearing; and a metal housing-side conductive member extending in the axial direction and electrically connected to the other bearing or the stator core. The housing cylindrical portion and the bottom plate portion are one member made of resin. The stator is accommodated in at least one of the housing cylindrical portion and the bottom plate portion. The cover has: a cover main body part made of resin and covering the shell opening part; a metal one-side bearing housing part fixed to the center of the cover main body part and holding one-side bearing; and a metal cover-side conduction member extending in the radial direction, one end of which is electrically connected to the one-side bearing housing portion and the other end of which is electrically connected to the case-side conduction member.

According to exemplary invention 1 of the present application, a resin cover body portion as an insulator is interposed between a heat radiating member for promoting heat radiation from an electronic component and a bearing portion for rotatably supporting a shaft. This can sufficiently ensure the insulating performance between the electronic component and the heat dissipating member and the bearing portion of the support shaft. As a result, the transmission of electricity flowing through the circuit board to the shaft via the heat radiating member and the bearing portion can be suppressed.

According to the exemplary 2 nd invention of the present application, in the molded motor having the resin case in which the stator is integrally molded, the cover main body portion covering the case opening portion can be easily manufactured by resin molding. Further, a metallic cover-side conduction member and a metallic housing-side conduction member are provided. One end of the cover-side conductive member is electrically connected to the metal bearing holder portion holding the one-side bearing, and the other end of the cover-side conductive member is electrically connected to the case-side conductive member. One end of the housing-side conductive member is electrically connected to the cover-side conductive member, and the other end of the housing-side conductive member is electrically connected to the other bearing or the stator core. This can prevent galvanic corrosion of the one-side bearing and the other-side bearing.

Drawings

Fig. 1 is a longitudinal sectional view of a motor of embodiment 1.

Fig. 2 is a perspective view of the cover and the upper bearing housing portion of embodiment 1.

Fig. 3 is a perspective view of the cover main body and the upper bearing housing in embodiment 1.

Fig. 4 is a perspective view of the heat sink member of embodiment 1.

Fig. 5 is a perspective view of the cover and the upper bearing housing portion of embodiment 1.

Fig. 6 is a partial longitudinal sectional view of the motor of embodiment 1.

Fig. 7 is a perspective view of a cover and an upper bearing housing part according to a modification.

Fig. 8 is a partial longitudinal cross-sectional view of a motor according to a modification.

Fig. 9 is a partial longitudinal cross-sectional view of a motor according to a modification.

Fig. 10 is a partial longitudinal sectional view of the motor of embodiment 2.

Fig. 11 is a perspective view of the cover-side conduction member according to embodiment 2.

Fig. 12 is a perspective view of the cover of embodiment 2.

Fig. 13 is a perspective view of the housing of embodiment 2.

Fig. 14 is a partial bottom view of the motor of embodiment 2.

Fig. 15 is a partial vertical cross-sectional view of a motor according to a modification of embodiment 2.

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the central axis of the motor is referred to as an "axial direction", a direction perpendicular to the central axis of the motor is referred to as a "radial direction", and a direction along an arc centered on the central axis of the motor is referred to as a "circumferential direction". In the present application, the shapes and positional relationships of the respective parts will be described with the axial direction as the vertical direction and the circuit board side as the upper side with respect to the stator. However, the orientation of the motor of the present invention when it is manufactured and when it is used is not intended to be limited by the definition of the up-down direction. That is, in the following embodiments or modifications, "upper side (upper end portion)" may be read as "one axial side (end portion on one axial side)", and "lower side (lower end portion)" may be read as "the other axial side (end portion on the other axial side)". In the present application, the "parallel direction" also includes a substantially parallel direction. In the present application, the "vertical direction" also includes a substantially vertical direction.

< 1. embodiment 1 >

< 1-1. Structure of motor

Fig. 1 is a longitudinal sectional view of the motor 1. The motor 1 is used for home electric appliances such as indoor units and outdoor units of air conditioners, for example. However, the motor of the present invention may be used for applications other than home electric appliances. For example, the motor of the present invention may be mounted on a transportation device such as an automobile or a railway, an OA device, a medical device, a tool, a large industrial device, or the like, and generate various driving forces.

As shown in fig. 1, the motor 1 includes a stationary portion 2 and a rotating portion 3. The stationary unit 2 is fixed to a housing of a device to be driven. The rotating portion 3 is supported rotatably about a vertically extending center axis 9 with respect to the stationary portion 2 via a bearing portion 60 described later. A rotation portion of a device to be driven, a speed reduction mechanism, and the like are fixed to a shaft 31 of the rotation portion 3, which will be described later.

The stationary portion 2 of the present embodiment includes a stator 21, a housing 22, a cover 23, a circuit board 24, and a bearing housing portion 25. The bearing housing 25 includes an upper bearing housing 251 and a lower bearing housing 252. The upper bearing housing 251 forms a part of the cover 23. The lower bearing receiving portion 252 forms a part of the housing 22. However, for easy understanding, the following description will be made by dividing the cover 23 and the upper bearing housing 251, and dividing the housing 22 and the lower bearing housing 252.

The motor 1 of the present embodiment drives the switching elements of the inverter by high-frequency Pulse Width Modulation (PWM) control. In a motor controlled by a pulse width modulation method, an electric corrosion phenomenon of a bearing is easily generated. Therefore, the technique of the present invention is particularly useful for motors that perform pulse width modulation control. In addition, although the motor 1 in the present embodiment performs the pulse width modulation control, the present invention is not limited thereto. The motor may be driven by another control method as long as it is a motor that may cause an electrolytic corrosion phenomenon of the bearing.

The stator 21 is an armature that generates magnetic flux in response to a drive current supplied from an external power supply via the circuit board 24. The stator 21 annularly surrounds a radially outer side of a rotor 32 described later. The stator 21 has a stator core 211, an insulator 212, and a plurality of coils 213. The stator core 221 is a magnetic body made of laminated steel plates in which electromagnetic steel plates are laminated in the axial direction. The stator core 211 is fixed to the housing 22. The stator core 211 has an annular core back 41 and a plurality of teeth 42 projecting radially inward from the core back 41. The core back 41 is disposed substantially coaxially with the central axis 9. The plurality of teeth 42 are arranged at substantially equal intervals in the circumferential direction.

The insulating member 212 is made of resin as an insulator. The insulator 212 is mounted to the stator core 211. The upper surface, the lower surface, and both circumferential side surfaces of each tooth 42 are covered with an insulator 212. The coil 213 is formed of a conductive wire wound around the teeth 42 with the insulator 212 interposed therebetween. The insulator 212 is interposed between the stator core 211 and the coil 213, whereby the stator core 211 and the coil 213 can be prevented from being electrically short-circuited.

The housing 22 is a resin member that holds the stator 21 and a lower bearing portion 62 described later. The housing 22 of the present embodiment is an insert molded product obtained by flowing resin into the inside of a mold holding the stator 21 and the lower bearing housing 252. The housing 22 includes a housing cylindrical portion 221, a bottom plate portion 222, a housing-side communication member 225, and a lower bearing housing portion 252.

The housing cylindrical portion 221 extends in a substantially cylindrical shape in the axial direction. Further, the rotor 32 is disposed radially inward of the housing cylindrical portion 221. In the present embodiment, the surface of the stator 21 other than the end surface on the radially inner side of the teeth 42 is covered with the resin forming the housing 22. This can suppress the stator 21 from being immersed in water. Further, the coil 213 of the stator 21 and the stator core 211 can be electrically insulated. However, the entire stator 21 including the radially inner end surfaces of the teeth 42 may be covered with the resin forming the housing 22. That is, the housing 22 may house at least a part of the stator 21. The housing cylindrical portion 221 of the present embodiment includes a housing body portion 43 and an end wall portion 44. The housing body 43 is a lower portion of the housing cylindrical portion 221. The end wall portion 44 is a portion including an upper end portion of the housing cylindrical portion 221. The end wall portion 44 protrudes upward from the housing main body portion 43. The case body portion 43 and the end wall portion 44 each have a cylindrical shape. However, the radial thickness of the end wall portion 44 is smaller than that of the case body portion 43.

The bottom plate portion 222 extends annularly from the lower end of the housing cylindrical portion 221 radially inward. The bottom plate portion 222 is located below the stator 21 and the rotor 32. Further, the bottom plate portion 222 covers a part of the outer peripheral surface and the lower surface of the lower bearing housing portion 252, and holds the lower bearing housing portion 252.

In addition, the housing 22 also has an inner space 220 that is open at a housing opening portion 223 at an upper end portion of the housing cylindrical portion 221 and is continuous downward from the housing opening portion 223. The rotor 32 and a part of the shaft 31 of the stationary portion 2, which will be described later, including the circuit board 24 of the electronic component 26, which will be described later, and the rotating portion 3 are located in the internal space 220. This makes it possible to reduce the size of the entire motor 1 in the axial direction. However, the position where the housing opening 223 is formed is not limited thereto. The housing opening 223 may be formed on at least one of the upper side and the lower side of the housing 22.

The cover 23 is a substantially plate-shaped member that is arranged above the housing 22 and radially extends in an annular shape around the upper bearing housing 251. The cover 23 includes a cover body 231, a heat radiating member 232, a cover-side conduction member 236, and an upper bearing housing 251. The cover 23 of the present embodiment is an insert-molded product obtained by flowing a resin into the inside of a mold holding a heat radiating member 232, an upper bearing housing 251, and a cover-side conducting member 236, which will be described later. The cover main body 231 is formed by curing the resin. The cover body 231 covers a part of the outer peripheral surface and the lower surface of the upper bearing housing 251 and holds the upper bearing housing 251. By providing the cover main body 231 made of resin in this way, the work is easier than in the case of manufacturing a conventional cover made of metal by press molding, and the manufacturing equipment and the mold can be made inexpensive and compact. Further, as compared with the case of using a metal cover, it is possible to suppress the echo (noise) of the cover main body 231 generated by the vibration from the motor 1 to a low level.

The cover body 231 extends in an annular shape radially outward of the upper bearing housing 251. The upper bearing housing 251 and the cover-side conduction member 236 are fixed to the cover main body 231 by being covered with a resin forming the cover main body 231. More specifically, the cover body 231 covers a part of the outer peripheral surface and the lower surface of the upper bearing housing 251 and holds the upper bearing housing 251. The cover body 231 covers an extension 83 of the cover-side conduction member 236, which will be described later, and holds the cover-side conduction member 236. This eliminates the need to fix the cover-side conducting member 236 and the upper bearing housing 251 to the cover main body 231 with screws, adhesive, or the like. As a result, the number of components of the motor 1 can be reduced.

An annular groove 230 is formed in the lower surface of the cover body 231. The groove 230 is recessed upward from the lower surface of the peripheral edge of the cover body 231. The upper end portion of the end wall portion 44 of the housing 22 is fitted into the groove portion 230. In addition, the cover 23 and the housing 22 are firmly fixed to each other by press-fitting. The cover body 231 covers the housing opening 223 from above the circuit board 24. This suppresses the intrusion of water or foreign matter into the interior of the housing 22.

The circuit board 24 is radially expanded on the upper side of the stator 21 and the rotor 32 and on the lower side of the cover 23. An electronic circuit including electronic components 26 for driving the motor 1 is mounted on the surface of the circuit board 24. An end of a lead wire (not shown) constituting the coil 213 is drawn upward and electrically connected to the electronic circuit. That is, the circuit board 24A is electrically connected to the stator 21A. Further, a lead (not shown) extending from an external power supply is electrically connected to the circuit board 24. That is, the coil 213 and the external power supply are electrically connected via the circuit board 24. The current supplied from the external power supply flows to the coil 213 via the circuit board 24A. The circuit board 24 may be electrically connected to a control circuit mounted on a device to be driven, or may receive a signal line from the control circuit.

In addition, the electronic component 26 is classified into a 1 st electronic component 261 and a 2 nd electronic component 262. The 1 st electronic component 261 is an electronic component that generates heat relatively easily among electronic components mounted on the circuit board 24. The 1 st electronic component 261 includes a switching element such as an FET or an IGBT, for example. In addition, the 1 st electronic component 261 further includes a power semiconductor in which a plurality of switching elements are housed in one package. The 2 nd electronic component 262 is an electronic component that generates heat relatively less easily among the electronic components mounted on the circuit board 24. In the present embodiment, a thermally conductive sheet 240 (other member) in contact with the 1 st electronic component 261 is disposed on the upper side of the circuit board 24. As a material of the thermally conductive sheet 240, for example, an elastic sheet having high thermal conductivity including silicone rubber is used.

The upper bearing housing 251 has a substantially cylindrical shape with a closed upper side. As described above, the cover 23 is an insert-molded article obtained by allowing resin to flow into the interior of a mold holding the heat-radiating member 232 and the upper bearing housing 251, which will be described later. That is, the upper bearing housing 251 is fixed to the cover main body 231 of the cover 23 by molding resin. The upper bearing housing 251 is fixed to the center of the cover main body 231. Further, an upper end portion of the shaft 31 and an upper bearing portion 61, which will be described later, are housed inside the upper bearing housing 251. The upper bearing housing 251 is made of a conductive metal such as iron or aluminum.

The lower bearing housing 252 has a substantially annular shape. As described above, the housing 22 is an insert molded product obtained by flowing resin into the inside of the mold holding the stator 21 and the lower bearing housing 252. That is, the lower bearing housing 252 is fixed to the bottom plate 222 of the housing 22 by molding resin. In the lower bearing housing 252, a lower bearing 62 is housed to rotatably support a shaft 31 described later. The material of the lower bearing housing 252 is a conductive metal such as iron or aluminum.

The rotating portion 3 has a shaft 31 and a rotor 32.

The shaft 31 is a columnar member extending in the vertical direction along the center axis 9. The shaft 31 is supported to be rotatable about the central axis 9. The lower end of the shaft 31 protrudes downward from the lower end of the housing 22. A fan for an air conditioner, which is a rotating part of a device to be driven, is attached to a lower end of the shaft 31, for example. The upper end of the shaft 31 may be coupled to a driving unit other than the fan via a power transmission mechanism such as a gear.

In the present embodiment, the shaft 31 protrudes downward, but the present invention is not limited to this. The shaft 31 may protrude upward from the cover 23, and its upper end may be coupled to the driving unit. The shaft 31 may protrude both below the housing 22 and above the cover 23, and both the lower end and the upper end thereof may be coupled to the driving unit.

The rotor 32 is an annular member disposed radially inward of the stator 21 and around the shaft 31, and rotates together with the shaft 31. The rotor 32 has a rotor core 321 and a plurality of magnets 322.

The rotor core 321 is formed of a laminated steel sheet in which electromagnetic steel sheets are laminated in the axial direction. A rotor through hole 320 is provided radially inside the rotor core 321. The rotor through hole 320 axially penetrates the rotor 32 along the center axis 9. The shaft 31 is inserted into the rotor through hole 320 and is press-fitted to the inner circumferential surface of the rotor core 321. However, the shaft 31 may be attached to the rotor core 321 by bonding instead of or in addition to press fitting.

The plurality of magnets 322 are disposed around the rotor core 321. The radially outer surface of each magnet 322 is a magnetic pole surface facing the radially inner end surface of the tooth 42 of the stator 21. The plurality of magnets 322 are arranged at equal intervals in the circumferential direction such that the magnetic pole surfaces of the N poles and the magnetic pole surfaces of the S poles are alternately arranged.

Instead of the plurality of magnets 322, an annular magnet may be used. When an annular magnet is used, N-poles and S-poles may be alternately magnetized on the outer circumferential surface of the magnet in the circumferential direction. The plurality of magnets 322 may be disposed around the rotor core 321 as in the present embodiment, or may be disposed in a state of being embedded in the rotor core 321.

The bearing portion 60 includes an upper bearing portion 61 and a lower bearing portion 62. The upper bearing portion 61 rotatably supports the shaft 31 above the rotor 32. The lower bearing portion 62 rotatably supports the shaft 31 below the rotor 32. Each of the upper bearing portion 61 and the lower bearing portion 62 of the present embodiment is a ball bearing including a sphere 601, an outer race 602, and an inner race 603. In the ball bearing, an outer race 602 and an inner race 603 relatively rotate via a ball 601. The material of the ball 601, the outer race 602, and the inner race 603 is a conductive metal such as iron. That is, the outer circumferential surfaces and the inner circumferential surfaces of the upper bearing portion 61 and the lower bearing portion 62 are connected to each other by a conductive member.

In the present embodiment, the ball 601, the outer race 602, and the inner race 603 are all made of a conductive material, but the present invention is not limited thereto. For example, even if an insulating material is used for a part of the upper bearing portion 61 and the lower bearing portion 62, the outer circumferential surfaces and the inner circumferential surfaces of the upper bearing portion 61 and the lower bearing portion 62 may be connected to each other by a conductive member. In the present embodiment, the ball bearing is used as the bearing, but a bearing of another type such as a sleeve bearing may be used as long as the outer circumferential surface and the inner circumferential surface of the bearing have conductivity.

The outer ring of the upper bearing portion 61 is fixed to the upper bearing housing portion 251. Thereby, the outer ring of the upper bearing portion 61 is electrically connected to the upper bearing housing 251. The outer race of the lower bearing portion 62 is fixed to the lower bearing housing portion 252. Thereby, the outer ring of the lower bearing portion 62 is electrically connected to the lower bearing housing portion 252. Further, the inner rings of the upper bearing portion 61 and the lower bearing portion 62 are fixed to the shaft 31.

When the motor 1 is driven, electricity is supplied from an external power supply to the 1 st electronic component 261 and the 2 nd electronic component 262 on the circuit board 24. The 1 st electronic component 261 and the 2 nd electronic component 262 generate a drive current for energizing the coil 213 and control energization. By supplying a drive current to the coil 213, a magnetic flux is generated at the plurality of teeth 42 of the stator core 211. Then, a circumferential torque is generated by an action of magnetic flux between the teeth 42 and the magnet 322 mounted on the rotor 32. As a result, the rotating portion 3 rotates about the central axis 9. In addition, the device directly or indirectly mounted on the shaft 31 rotates together with the rotating portion 3.

As described above, the upper bearing portion 61 is supported by the upper bearing housing 251 made of metal. The lower bearing portion 62 is supported by a lower bearing housing 252 made of metal. Accordingly, even when the temperature of each part increases when the motor 1 is driven, the relative dimensional change and deformation between the upper bearing 61 and the upper bearing housing 251 and between the lower bearing 62 and the lower bearing housing 252 can be suppressed. Therefore, the rotating portion 3 is prevented from idling, and high rotation accuracy is maintained.

< 1-2. detailed construction of cover >

Next, a more detailed structure of the cover 23 will be described.

Fig. 2 is a perspective view of the cover 23 and the upper bearing housing 251. As shown in fig. 2, the cover 23 includes the cover body 231 and the heat dissipation member 232. The cover main body 231 is made of resin. On the other hand, a metal such as aluminum is used as the material of the heat dissipation member 232. Therefore, the heat dissipation member 232 has higher thermal conductivity than the cover main body 231.

Fig. 3 is a perspective view of the cover main body 231 and the upper bearing housing 251 viewed from above. Fig. 4 is a perspective view of the heat dissipation member 232. Fig. 5 is a perspective view of cover 23 and upper bearing housing 251 viewed from below. As shown in fig. 3, the cover main body 231 formed by injection molding of resin has a plate-like portion 51 and a hole portion 52. The plate-like portion 51 extends in a plate-like shape in the horizontal direction. The hole 52 is a trace of the placement of the heat dissipation member 232 at the time of injection molding of resin, and penetrates the plate-like portion 51 in the axial direction. That is, as shown in fig. 2 to 4, in the cover 23 formed by injection molding of resin, the heat dissipation member 232 is disposed in the hole 52 and attached to the cover main body 231. As shown in fig. 5, the heat dissipation member 232 is exposed below the cover 23.

As shown in fig. 1, the lower end of the heat dissipation member 232 is indirectly in contact with the 1 st electronic component 261 via a thermally conductive sheet 240 having high thermal conductivity. As shown in fig. 2 and 4, a plurality of fins 71 exposed to the outside of the motor 1 are provided on the upper surface of the heat dissipation member 232. Each fin 71 is a protrusion protruding upward. This allows heat generated in the 1 st electronic component 261 to be dissipated from the heat dissipating member 232 to the outside of the motor 1 via the heat conductive sheet 240. In particular, in the present embodiment, the heat dissipation member 232 is exposed below the cover 23 and directly contacts the heat conductive sheet 240 without an air layer, and therefore the heat dissipation performance is further improved. The thermally conductive sheet 240 may not be provided. That is, the lower end of the heat dissipation member 232 may be in direct contact with the 1 st electronic component 261 without the heat conductive sheet 240.

Further, the 2 nd electronic component 262, which generates relatively little heat, is axially separated from the plate-like portion 51 of the cover 23. The 2 nd electronic component 262 includes, for example, an IC component and the like. The lower end of the heat dissipation member 232 of the present embodiment is located below the plate-like portion 51. Thus, the 1 st electronic component 261 and the heat dissipation member 232 can be brought into contact without bringing the 2 nd electronic component 262 into contact with the cover body 231.

As shown in fig. 4, in the heat dissipation member 232, fixing portions 72 are provided on the outer sides of the plurality of fins 71 in the horizontal direction. The fixing portion 72 extends substantially perpendicularly with respect to the axial direction. However, the fixing portion 72 may be slightly inclined from a direction substantially perpendicular to the axial direction. When the cover 23 is resin-molded, the side surface 721 of the fixing portion 72 and the end surface 722 below the fixing portion 72 are covered with the resin forming the cover body 231, and the heat radiating member 232 is fixed. This prevents the heat dissipation member 232 from coming off the cover main body 231 in the axial direction. Further, since the heat dissipation member 232 can be attached to the cover main body 231 without using screws, an adhesive material, or the like, the gap between the heat dissipation member 232 and the cover main body 231 is almost eliminated. Therefore, even if water splashes onto the cover 23 from the outside of the motor 1, the water can be inhibited from entering the inside of the motor 1. However, the side surface 721 of the fixing portion 72 of the heat radiating member 232 and the upper end surface 723 of the fixing portion 72 may be covered with a resin forming the cover body 231. That is, the heat radiating member 232 may be fixed by covering at least a part of the side surface 721 of the fixing portion 72, the upper end surface 723, and the lower end surface 722 of the fixing portion 72 with the resin forming the cover body 231.

As shown in fig. 4, the heat dissipation member 232 further has an axially extending portion 73 extending in the axial direction on the lower side of the plurality of fins 71. As shown in fig. 5, the cover main body 231 has the 1 st projecting portion 53. The 1 st projecting portion 53 projects downward from the plate portion 51 at the peripheral edge portion of the hole portion 52. In the present embodiment, the entire side surface of the axially extending portion 73 of the heat dissipation member 232 is covered with the resin forming the 1 st protruding portion 53. This increases the area of the resin-coated heat dissipation member 232 forming the cover main body 231. As a result, even when external force is applied to the heat dissipation member 232, tilting or falling can be suppressed. However, at least a part of the side surface of the axially extending portion 73 of the heat radiating member 232 may be covered with the resin forming the cover main body 231.

As shown in fig. 3, a stepped portion 521 is formed in the peripheral edge portion of the hole 52 at the upper end of the cover main body 231. The stepped portion 521 is recessed downward from the upper surface of the plate-shaped portion 51. The stepped portion 521 is expanded in a direction perpendicular to the axial direction compared with the other portions of the hole 52. A part of the lower side of the plurality of fins 71 of the heat radiating member 232 and the fixing portion 72 are disposed on the step portion 521. That is, a part of the heat dissipation member 232 below the plurality of fins 71 is located in the hole 52, and is smaller than the part of the cover body 231 protruding upward. This can suppress the height of the motor 1 in the axial direction. However, the stepped portion 521 may be formed deeper, so that all of the plurality of fins 71 of the heat radiating member 232 may be disposed in the hole 52.

Fig. 6 is a partial longitudinal sectional view of the motor 1. As shown in fig. 6, the upper bearing housing 251 has a cylindrical portion 91 and a flange portion 92. The cylindrical portion 91 extends cylindrically along the center axis 9. Further, an upper bearing portion 61 is disposed inside the cylindrical portion 91. The flange 92 extends radially outward from the lower end of the cylindrical portion 91. The cap body 231 has an annular 2 nd projecting portion 54. The 2 nd projecting portion 54 projects downward from the radially inner end of the plate portion 51. A part of the 2 nd projection 54 in the circumferential direction constitutes a part of the 1 st projection 53. The flange portion 92 of the upper bearing housing 251 is covered with the resin forming the 2 nd projecting portion 54.

Thereby, a structure is formed in which a part of the resin cover body 231, which is an insulator, is interposed between the upper bearing housing portion 251 and the upper bearing portion 61, and the heat dissipation member 232 and the electronic component 26. As a result, the electrical insulation performance between the upper bearing housing 251 and the upper bearing 61, and the heat dissipation member 232 and the electronic component 26 can be sufficiently ensured. Further, it is possible to suppress the transmission of electricity flowing through the circuit board 24 on which the 1 st electronic component 261 and the 2 nd electronic component 262 are mounted to the shaft 31 via the heat dissipation member 232, the upper bearing housing 251, and the upper bearing 61. In particular, in the present embodiment, the insulation distance can be ensured to be longer by interposing the 2 nd projecting portion 54 extending in the axial direction between the upper bearing housing portion 251 and the electronic component 26 and between the upper bearing portion 61 and the electronic component 26.

By resin-molding the cover 23 having such a structure, it is possible to simultaneously form a structure capable of insulating the heat dissipation member 232 and the electronic component 26 from the upper bearing portion 61 and the upper bearing housing portion 251 for holding the upper bearing portion 61. This can shorten the manufacturing process. In the present embodiment, the cylindrical portion 91 of the upper bearing housing 251 is located below the upper end of the motor 1. This suppresses the height of the motor 1 in the axial direction while maintaining the fixing strength of the upper bearing housing 251 to the cover main body 231.

As shown in fig. 4, the fixing portion 72 of the heat dissipation member 232 has a mesa shape extending perpendicularly to the axial direction from the plurality of fins 71. As shown in fig. 2, the upper end surface of the mesa shape is an exposed surface 724 exposed from the cover body 231 to the outside of the motor 1. In resin molding of the cover 23, the peripheral edges of the plurality of fins 71 are pressed from above by a mold in order to prevent the heat dissipation member 232 fitted into the cover 23 from floating. As a result, after the resin molding, the peripheral edge portions of the plurality of fins 71 become exposed surfaces 724 exposed to the outside. When water splashes on the cover 23 from the outside of the motor 1, the water is likely to accumulate on the exposed surface 724.

Therefore, the cover main body 231 of the present embodiment is further formed with a groove 55. The groove 55 is recessed downward from a part of the upper end surface of the cover body 231, and connects the outer peripheral surface of the cover body 231 with the hole 52. The groove 55 is continuous with the exposed surface 724. Accordingly, even if water splashes onto the cover 23 from the outside of the motor 1, the exposed surface 724 does not accumulate and water can be drained through the groove portion 55.

< 2. modification example >

Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments

The upper bearing housing 251 and the lower bearing housing 252 may not be provided. For example, the upper bearing portion 61 may be directly fixed to the cover main body 231 of the cover 23 without the upper bearing housing portion 251. That is, the cover 23 may be configured to directly or indirectly hold the upper bearing portion 61. Further, at least a part of the cover body 231 made of resin as an insulator may be interposed in the radial direction between the upper bearing portion 61 and the heat radiating member 232. This can sufficiently ensure the electrical insulation performance between the upper bearing 61, the heat dissipation member 232, and the electronic component 26. The lower bearing portion 62 may be directly fixed to the bottom plate portion 222 of the housing 22 without the lower bearing housing portion 252. That is, the housing 22 may have a structure that directly or indirectly holds the lower bearing portion 62.

Fig. 7 is a perspective view of the cover 23B and the upper bearing housing portion of a modification example viewed from above. In the example of fig. 7, the surface 234B constituting the hole 52B in the cover main body 231B is inclined in a direction away from the center of the hole 52B in the radial direction as it goes upward. That is, the radial width of the hole 52B increases toward the upper side. This allows air to flow smoothly from the outside of motor 1 into hole 52B and further from hole 52B to the outside of motor 1. As a result, the heat dissipation performance of the heat dissipation member 232B is further improved.

Fig. 8 is a partial longitudinal sectional view of a motor 1C according to another modification. As shown in the example of fig. 8, the fixing portion 72C of the heat dissipation member 232C may be slightly inclined with respect to the horizontal direction. In this case, at least a part of the side surface 721C of the fixing portion 72C, the upper end surface 723C, and the lower end surface 722C of the fixing portion 72C of the heat radiating member 232C is also covered with the resin forming the cover main body 231C, whereby the heat radiating member 232C is firmly fixed.

Fig. 9 is a partial longitudinal sectional view of a motor 1D according to another modification. In the example of fig. 9, the heat dissipation member 232D includes a plurality of fins 71D, fixing portions 72D, and axial extension portions 73D. The axially extending portion 73D extends axially below the plurality of fins 71D. The fixing portion 72D extends substantially perpendicularly to the axial direction outside the lower end portion of the axially extending portion 73D. The side surface 721D of the fixing portion 72D and the upper end surface 723D of the fixing portion 72D are covered with a resin forming the cover body 231D, whereby the heat dissipation member 232D is firmly fixed. In addition, by the heat-radiating member 232D having such a configuration, falling off and dropping from the cover 23D are prevented.

< 1-2. detailed construction of case-side conducting part and cover-side conducting part

Next, a more detailed configuration of the casing-side communication member 225 and the casing-side communication member 236 will be described. As the material of the case-side conductive member 225 and the cover-side conductive member 236, a metal having conductivity such as iron (for example, SPCC), brass, or copper is used.

Fig. 11 is a perspective view of the shroud-side conducting member 236. As shown in fig. 11, the cover-side conduction member 236 is a thin plate-like member. The cover-side conduction member 236 is manufactured by, for example, cutting and punching a sheet of metal thin plate material. In addition, the cover-side conducting member 236 is buried in the resin forming the cover main body portion 231 and extends in the radial direction. The cover-side conduction member 236 includes a contact portion 81, a mounting portion 82, and an extension portion 83. The contact portion 81 is located at the radially outer end portion in the shroud-side conducting member 236. The mounting portion 82 is located at a radially inner end portion in the shroud-side conducting member 236. The extension 83 connects the contact 81 and the mounting 82.

Fig. 12 is a perspective view of the cover 23. As an early stage of the resin molding of the housing 23, the mounting portion 82 of the housing-side conducting member 236 is mounted to the flange portion 92 of the upper bearing housing 251. Then, the resin is flowed into the inside of the mold holding the cover-side conducting member 236 and the upper bearing housing 251. In addition, in order to prevent the cover-side conducting member 236 and the upper bearing housing 251 from floating or warping due to the flow of resin, the cover-side conducting member 236 and the upper bearing housing 251 are pressed at a plurality of locations (two locations in the present embodiment) using pins or the like. Thereby, the two 1

st hole portions

64 and 2 nd hole portions 65, which are traces of the pin and the like, are formed in the molded cover main body portion 231. The 1 st hole portion 64 and the 2 nd hole portion 65 are recessed upward from the lower surface of the cover main body portion 231. In the 1 st hole portion 64, a part of the mounting portion 82 of the cover-side conductive member 236 is exposed to the outside of the cover main body portion 231. In the 2 nd hole 65, a part of the extension portion 83 of the cover-side conduction member 236 is exposed to the outside of the cover main body portion 231.

The mounting portion 82 of the cover-side conducting member 236 is mounted to the flange portion 92 of the upper bearing housing 251 by thermocompression bonding. Thereby, the cover-side conducting member 236 is electrically conducted to the upper bearing housing 251. However, the mounting portion 82 of the cover-side conducting member 236 may be mounted to the flange portion 92 of the upper bearing housing 251 by screwing, welding, soldering, pressure welding, or adhesion.

As described above, at least a part of the extension 83 of the cover-side conduction member 236 is embedded in the resin forming the cover main body 231. Accordingly, even when the electronic component 26 and the like are disposed below the extension portion 83, the insulation between the electronic component 26 and the cover-side conductive member 236 can be improved.

In the motor 1 of the present embodiment, the upper bearing housing 251 and a part of the upper bearing 61 are disposed below the upper end of the housing 22 in order to further reduce the size of the entire motor 1 in the axial direction. Thus, the upper end of the end wall portion 44 is positioned above the lower surface of the flange portion 92 of the upper bearing housing 251.

Therefore, in the cover-side conduction member 236 of the present embodiment, a step portion 84 extending in the axial direction is provided between the contact portion 81 and the attachment portion 82. Thus, the axial position of the contact portion 81 is located above the axial position of the mounting portion 82. As shown in fig. 12, the cover main body 231 further includes a protrusion 237. The protruding portion 237 protrudes further downward from the lower surface of the cover body 231. A portion of the extension 83 of the cover-side conduction member 236 radially inward of the step portion 84 is covered with resin forming the protrusion 237. A portion of the extension portion 83 of the cover-side conduction member 236 radially outward of the step portion 84 is covered with a resin forming a portion of the cover body portion 231 radially outward of the protrusion portion 237. In this way, by forming the cover-side conducting member 236 and the cover main body 231 in a shape that takes into account the difference in height between the upper end portion of the end wall portion 44 of the housing 22 and the lower surface of the flange portion 92 of the upper bearing housing portion 251, the amount of resin used for molding the cover main body 231 can be reduced. Further, since the cover-side conducting member 236 is in the form of a thin plate as described above, the stepped portion 84 can be easily formed by pressing or the like. However, instead of providing the step portion 84, the extension portion 83 may be formed in a shape in which at least a portion between the contact portion 81 and the attachment portion 82 is inclined at a constant inclination angle. That is, the axial position of the contact portion 81 may be located above (on one axial side) the axial position of the mounting portion 82.

As shown in fig. 12, the cover main body 231 includes a 1 st protruding portion 233 and a 2 nd protruding portion 234. The 1 st protruding portion 233 protrudes radially outward from the groove portion 230, i.e., protrudes downward from the outer peripheral portion of the cover body 231. The 2 nd projecting portion 234 projects downward from the cover main body 231 at a position radially inward of the 1 st projecting portion 233 and the groove portion 230. Further, the contact portion 81 of the cover-side conductive member 236 is positioned in the groove portion 230. In the present embodiment, the entire contact portion 81 is exposed to the outside of the cover body 231. However, at least a part of the contact portion 81 may be exposed to the outside of the cover main body portion 231.

Fig. 13 is a perspective view of the housing 22. As shown in fig. 10 and 13, the case-side conducting member 225 extends in the substantially axial direction along the outer peripheral surface of the case 22. The housing-side via 225 has a 1 st terminal 2251, a 2 nd terminal 2252, and a wire part 2253. The 1 st terminal 2251 is located at an upper end of the housing-side lead-through component 225. The 2 nd terminal 2252 is located at the lower end portion in the housing-side lead-through component 225. The wire part 2253 connects the 1 st terminal 2251 and the 2 nd terminal 2252. An upper end of the wire 2253 is connected to the 1 st terminal 2251 for electrical conduction. The lower end of the wire 2253 is connected to the 2 nd terminal 2252 and electrically connected thereto.

As shown in fig. 10, the 1 st terminal 2251 of the present embodiment includes a base end portion 511, a bent portion 512, and an extended portion 513. The base end portion 511 extends upward from the upper end portion of the wire portion 2253 in the substantially axial direction. The bent portion 512 extends radially inward from the upper end of the base end portion 511. The extension portion 513 is located at the tip of the 1 st terminal 2251, and extends substantially in the axial direction downward from the radially inner end of the bent portion 512. The base end portion 511 is disposed on the outer peripheral surface of the end wall portion 44 of the housing 22, the bent portion 512 is disposed on the upper end surface of the end wall portion 44, and the extended portion 513 is disposed on the inner peripheral surface of the end wall portion 44. However, the shape of the upper end of the case-side conducting member 225 is not limited to this. At least a part of the housing-side conductive member 225 may be located on the upper end surface of the end wall portion 44.

As described above, the end wall portion 44 is press-fitted into the cover 23 at the groove portion 230 provided between the 1 st protruding portion 233 and the 2 nd protruding portion 234 of the cover main body portion 231 in the radial direction. At this time, the contact portion 81 of the cover-side conductive member 236 and the bent portion 512 of the case-side conductive member 225 positioned on the upper end surface of the end wall portion 44 are sandwiched between the end wall portion 44 and the cover main body portion 231 and are brought into contact with each other. Thereby, the cover-side conducting member 236 is electrically conducted to the case-side conducting member 225.

Bottom surface 235 (see fig. 13) of groove 230 is located above end wall 44 and extends in a substantially annular shape along the upper end surface of end wall 44. The 1 st projecting portion 233 of the cover main body portion 231 projects downward from the radially outer end of the bottom surface 235 and extends in a substantially arc shape in a bottom view. The 2 nd projecting portion 234 projects downward in a substantially cylindrical shape from the radially inner end of the bottom surface 235. A part of the base end portion 511 of the 1 st terminal 2251 is disposed between the outer peripheral surface of the end wall portion 44 and the 1 st protruding portion 233. The bent portion 512 is disposed between the upper end surface of the end wall portion 44 and the bottom surface 235 of the groove portion 230. Further, the extension 513 is disposed between the inner peripheral surface of the end wall portion 44 and the 2 nd projecting portion 234.

That is, in the present embodiment, the 1 st terminal 2251 having a hook shape is hooked to the upper end portion of the end wall portion 44. In the groove 230, the cover main body 231 covers the 1 st terminal 2251, thereby holding the 1 st terminal 2251. This more reliably fixes the 1 st terminal 2251. In addition, the 1 st terminal 2251 is more reliably in contact with the contact portion 81 of the cover-side conduction member 236.

As described above, the end wall portion 44 and the cover body portion 231 are firmly fixed to each other by press fitting in the groove portion 230. This suppresses separation of the cover-side passage member 236 and the case-side passage member 225 caused by the floating of the cover 23. Further, the contact portion 81 of the cover-side conductive member 236 is positioned in the groove portion 230. Therefore, the contact portion 81 can be prevented from interfering with the fitting of the housing 22 and the cover 23.

In the present embodiment, the cover-side conductive member 236 is in contact with the housing-side conductive member 225 on the lower surface of the cover body 231. This allows the housing-side conductive member 225 and the cover-side conductive member 236 to be electrically connected while further shortening the axial length of the housing-side conductive member 225.

Next, the lead part 2253 of the housing-side conduction member 225 extends downward from the 1 st terminal 2251 along the outer peripheral surface of the housing cylindrical part 221. The lead 2253 is coated with, for example, a resin. The housing 22 has two wall portions 224 on the outer peripheral surface of the housing cylindrical portion 221. The two wall portions 224 extend in a substantially axial direction. The wire part 2253 is disposed between the two wall parts 224 at the outer peripheral surface of the housing cylindrical part 221. This can prevent the housing-side conduction member 225 from being damaged or caught. The housing 22 may have three or more wall portions 224.

Fig. 14 is a partial bottom view of the motor 1. As shown in fig. 14, the wire 2253 extends radially inward from the lower end of the outer peripheral surface of the housing cylindrical portion 221 along the lower surface of the bottom plate portion 222. As described above, the 2 nd terminal 2252, which is a circular terminal, is fixed to the end of the wire 2253 opposite to the 1 st terminal 2251 by, for example, crimping.

The lower bearing housing portion 252 has a housing cylindrical portion and a flange portion 92, similarly to the upper bearing housing portion 251. The flange portion 92 is provided with a screw hole 250. The 2 nd terminal 2252 is screwed into the screw hole 250 of the lower bearing housing 252 by a metal screw 900. Thus, the 2 nd terminal 2252 is electrically connected to the lower bearing receiving portion 252.

As described above, the outer race 602 of the upper bearing 61 is electrically connected to the upper bearing housing portion 251, and the upper bearing housing portion 251 is electrically connected to one end of the cover-side conductive member 236. In addition, the other end of the cover-side conduction member 236 is electrically conducted to the 1 st terminal 2251 of the housing-side conduction member 225. Further, the 2 nd terminal 2252 of the housing-side conductive member 225 is electrically connected to the lower bearing housing 252, and the lower bearing housing 252 is electrically connected to the outer race 602 of the lower bearing 62. That is, the upper bearing 61 and the lower bearing 62 are electrically connected by the cover-side conductive member 236 and the case-side conductive member 225. This allows the upper bearing 61 and the lower bearing 62 to have the same potential, thereby suppressing the potential difference. As a result, the current that tends to flow between the upper and

lower bearings

61 and 62 and the shaft 31 is reduced, and the electric corrosion phenomenon in the upper and

lower bearings

61 and 62 is suppressed.

In particular, in the present embodiment, by using the metal cover-side conducting member 236 and the metal housing-side conducting member 225, a structure for preventing the electric corrosion of the upper bearing 61 and the lower bearing 62 can be easily formed even if the cover main body 231 is made of resin. As a result, the manufacturing operation of the motor 1 is facilitated, and the manufacturing equipment and the die can be made inexpensive and compact, as compared with the conventional case where the cover made of metal is manufactured by press-forming. As a result, the manufacturing cost of the motor 1 can be reduced.

In the above embodiment, the hook-shaped direction of the case-side communication member 225 hooked on the upper end portion of the end wall portion 44 of the case 22 may be reversed. Fig. 7 is a partial longitudinal sectional view of a modified motor 1B. In the modification of fig. 7, the lead part 2253B of the housing-side conduction member 225B extends along the inner peripheral surface of the end wall part 44B of the housing 22B. The 1 st terminal 2251B of the housing-side lead-through member 225B extends radially outward from the lead 2253B through the upper end surface of the end wall portion 44B. Even with such a configuration, the 1 st terminal 2251B can be electrically conducted to the contact portion 71B of the cover-side conducting member 236B. Further, by disposing the wire part 2253B inside the end wall part 44B as in the present modification, it is possible to prevent the wire part 2253B from being damaged or coming off by coming into contact with an operator or an object outside the motor 1B.

The detailed shapes of the respective members may be different from those shown in the drawings of the present application. In addition, the respective elements appearing in the above embodiment and the modified examples may be appropriately combined within a range in which no contradiction occurs.

The present invention can be applied to a motor.

Claims

1. A motor, comprising:

a stationary portion; and

a rotating portion that rotates about a central axis via a bearing portion,

the stationary portion includes:

a stator;

a housing that receives at least a portion of the stator;

a cover fixed to the housing and directly or indirectly holding the bearing portion; and

a circuit board extending in a radial direction and electrically connected to the stator,

the rotating portion includes:

a rotor; and

a shaft mounted to the rotor, extending along the central axis,

the circuit board has electronic components for driving the motor,

the housing has an inner space that is open at least at a housing opening portion formed at one side in the axial direction and is continuous from the housing opening portion to the other side in the axial direction,

the electronic component is located in the interior space,

it is characterized in that the preparation method is characterized in that,

the cover covers the housing opening from a position on one side of the circuit board in the axial direction,

and the cover has:

a cover main body portion made of resin; and

a heat dissipating member attached to the cover main body and having a higher thermal conductivity than the cover main body,

the end portion of the other axial side of the heat dissipation member is in contact with the electronic component directly or indirectly via another member,

the cover body is interposed at least in a radial direction between the bearing part and the heat radiating part.

2. The motor of claim 1,

the cover further includes a metal bearing housing portion fixed to the cover main body portion and having the bearing portion disposed therein,

the cover body is interposed between the bearing housing and the heat radiating member.

3. The motor of claim 2,

the cover main body portion includes:

a plate-shaped portion which is expanded in a plate shape; and

a hole portion axially penetrating the plate-like portion,

the heat radiating member is disposed in the hole, and an end portion of the heat radiating member on the other axial side is located on the other axial side of the plate-shaped portion,

the electronic component has a 1 st electronic component and a 2 nd electronic component,

the 1 st electronic part is in contact with the heat dissipating part directly or indirectly via another part,

the 2 nd electronic component is apart from the plate-like portion.

4. The motor of claim 3,

the heat radiating member has a fixing portion extending perpendicularly to the axial direction,

the heat radiating member is fixed by covering at least a part of a side surface of the fixing portion and end surfaces of one side and the other side in the axial direction of the fixing portion with a resin forming the cover main body portion.

5. The motor of claim 3,

the heat dissipation member further has a plurality of fins exposed to the outside of the motor,

a part or all of the other axial side of the plurality of fins is located in the hole.

6. The motor of claim 3,

the cover main body portion further has a 1 st projecting portion projecting from the plate-shaped portion to the other side in the axial direction at a peripheral edge portion of the hole portion,

at least a part of the side surface of the heat dissipation member is covered with the resin forming the 1 st protruding part.

7. The motor of claim 3,

the bearing housing section includes:

a cylindrical portion in which the bearing portion is disposed, the cylindrical portion extending cylindrically along the central axis; and

a flange portion extending radially outward from an end portion on the other axial side of the cylindrical portion,

the cover body further includes a 2 nd projecting portion projecting from an end portion on the radially inner side of the plate-shaped portion toward the other side in the axial direction,

the flange portion is covered with a resin forming the 2 nd projecting portion,

the cylindrical portion is located on the other axial side than an axial end of the motor.

8. The motor of claim 5,

the heat radiating member has a terrace portion extending perpendicularly to the axial direction from the plurality of fins,

an end surface of the table portion on one axial side has an exposed surface exposed to the outside from the cover main body portion,

the cover main body further includes a groove portion recessed from a part of an end surface on one axial side to the other axial side to connect an outer peripheral surface of the cover main body with the hole portion,

the groove portion is continuous with the exposed surface.

9. The motor of claim 5,

the surface of the cover main body portion constituting the hole portion is inclined in a direction away from a center portion in a radial direction of the hole portion as the surface faces one axial direction side.

10. The motor according to any one of claims 1 to 9,

the heat dissipation member is made of metal.

11. A motor, comprising:

a stationary portion; and

a rotating portion that rotates about a central axis via a bearing portion,

the stationary portion includes:

a stator that surrounds the central axis in an annular shape and includes a stator core as a magnetic body having a plurality of teeth extending in a radial direction;

a housing that receives at least a portion of the stator; and

a cover fixed to the housing,

the bearing portion includes a one-side bearing and another-side bearing disposed axially apart from each other around the central axis,

it is characterized in that the preparation method is characterized in that,

the housing has:

a housing opening portion formed on one side in the axial direction;

a housing cylindrical portion extending cylindrically from the housing opening portion toward the other axial side;

a bottom plate portion that extends radially inward from an end portion on the other axial side of the housing cylindrical portion and directly or indirectly fixes the other bearing; and

a metal housing-side conductive member extending in an axial direction and electrically connected to the other side bearing or the stator core,

the housing cylindrical portion and the bottom plate portion are one member made of resin,

the stator is accommodated in at least one of the housing cylindrical portion and the bottom plate portion,

the cover has:

a cover main body portion made of resin and covering the housing opening portion;

a metal one-side bearing housing portion that is fixed to a center of the cover main body portion and that holds the one-side bearing; and

and a metal cover-side conduction member extending in the radial direction, one end of which is electrically connected to the one-side bearing housing portion and the other end of which is electrically connected to the case-side conduction member.

12. The motor of claim 11,

the cover side conducting member has:

a contact portion that contacts the case-side conducting member at a radially outer end portion,

a mounting portion mounted to the one-side bearing housing portion at a radially inner end portion; and

an extension portion connecting the contact portion and the mounting portion.

13. The motor of claim 11,

the cover-side conductive member is in contact with the housing-side conductive member at a surface of the cover main body portion on the other side in the axial direction.

14. The motor of claim 11,

at least a part of the housing-side conduction member is located on an inner circumferential surface, an outer circumferential surface, or an end surface on one axial side of the housing cylindrical portion,

the housing-side conductive member and the cover-side conductive member are held between the cover body and one axial end of the housing cylindrical portion, and are in contact with each other.

15. The motor of claim 12,

the housing cylindrical portion has:

a housing main body portion that covers the stator; and

a cylindrical end wall portion projecting from the housing body portion toward one axial side,

the cover further has:

a 1 st projecting portion projecting from an outer peripheral portion of the cover main body portion to the other side in the axial direction; and

a 2 nd projecting portion projecting from the cover body portion to the other side in the axial direction at a position radially inward of the 1 st projecting portion,

the end wall portion is press-fitted to the cover at a groove portion provided between the 1 st protruding portion and the 2 nd protruding portion in a radial direction,

at least a part of the housing-side conduction member is located on an end surface on one axial side of the end wall portion,

the contact portion is exposed to the outside of the cover main body portion at the groove portion,

the case-side conductive member and the cover-side conductive member are sandwiched between the end wall portion and the cover body portion and are in contact with each other.

16. The motor according to claim 12 or 15,

at least a part of the extension is embedded in the cover main body,

the contact portion is exposed to the outside of the cover main body portion.