阅读说明：本技术 马达 (Motor ) 是由 服部隆志 斋藤裕也 二之宫优太 石田尚 藤原英雄 于 2020-09-30 设计创作，主要内容包括：本发明提供马达,该马达具有马达主体部、控制基板、导通部件。马达主体部具有静止部和旋转部。静止部具有定子。旋转部包含与定子对置地配置的转子,该旋转部以沿着中心轴线延伸的轴为中心经由轴承部而旋转。控制基板与中心轴线垂直地扩展,与定子电连接。导通部件是沿轴向延伸的金属制的部件。并且,静止部具有壳体。壳体是从径向外侧包围定子的至少一部分和导通部件的一部分的树脂制的部件。导通部件的轴向一侧的端部与控制基板直接或间接接触,导通部件的轴向另一侧的端部与金属制的分体部件直接或间接接触。(The invention provides a motor, which comprises a motor main body part, a control substrate and a conducting component. The motor main body has a stationary portion and a rotating portion. The stationary portion has a stator. The rotating portion includes a rotor disposed to face the stator, and rotates about a shaft extending along a central axis via a bearing portion. The control board extends perpendicularly to the central axis and is electrically connected to the stator. The conductive member is a metal member extending in the axial direction. The stationary portion has a housing. The housing is a resin member that surrounds at least a part of the stator and a part of the conducting member from the outside in the radial direction. One end of the conductive member in the axial direction is in direct or indirect contact with the control board, and the other end of the conductive member in the axial direction is in direct or indirect contact with the metallic separate member.)

1. A motor, comprising:

a motor main body having a stationary portion including a stator, and a rotating portion including a rotor disposed to face the stator, the rotating portion rotating about a shaft extending along a central axis via a bearing portion;

a control board extending perpendicular to the central axis and electrically connected to the stator; and

a conductive member made of a metal, and a conductive layer,

the stationary portion has a resin case surrounding at least a part of the stator and a part of the conducting member from a radially outer side,

the end portion of one axial side of the conducting member is in direct or indirect contact with the control board, and the end portion of the other axial side of the conducting member is in direct or indirect contact with a metal split member.

2. The motor of claim 1,

the conducting member is a metal member extending in the axial direction,

the housing covers at least a portion of the stator and a portion of the conducting member,

an end portion of the conducting member on one side in the axial direction protrudes from the housing on one side in the axial direction and is in direct or indirect contact with the control board,

the end portion of the other axial side of the conducting member protrudes from the housing to the other axial side and is in direct or indirect contact with a separate member made of metal.

3. The motor of claim 2,

the stator has:

a stator core as a magnetic body annularly surrounding the central axis and having a plurality of teeth extending in a radial direction;

a resin insulator covering at least a part of the stator core; and

a coil formed of a wire wound around the teeth with the insulator interposed therebetween,

the case covers the stator core, the insulator, and at least a portion of the coil and a portion of the conducting member.

4. The motor of claim 3,

the stator core is formed of a plurality of core pieces arranged in a circumferential direction.

5. The motor of claim 4,

the core member has:

an iron core back portion having an arc shape with the central axis as a center; and

the teeth extending radially inward from the core back,

the core back has a groove recessed radially inward from the outer peripheral surface,

at least a part of the conducting member is located inside the groove.

6. The motor of claim 5,

the groove portion has a depth in the radial direction larger than an outer diameter of the conducting member.

7. The motor according to any one of claims 1 to 6,

a part of the housing is sandwiched between the conducting member and the stator.

8. The motor according to any one of claims 1 to 7,

the stationary portion further includes a cover fixed to the housing and extending in a radial direction on one axial side of the control board.

9. The motor according to any one of claims 1 to 8,

the stationary portion further includes a metallic heat sink fixed to the housing, contacting or approaching the control board and extending radially around the central axis,

the control board has a heat generating element, which is an electronic component for driving the motor main body.

10. The motor according to any one of claims 1 to 8,

the stationary portion further includes a metallic heat sink fixed to the control board, contacting the control board and extending radially around the central axis,

the control board has a heat generating element, which is an electronic component for driving the motor main body.

11. The motor according to claim 9 or 10,

the heat sink is in contact with or close to the other axial surface of the control board and is fixed to the control board via a 1 st metal fastening member,

the end portion of the conducting member on one side in the axial direction is in contact with the heat sink, and the 1 st fastening member is in contact with the control board.

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

an end portion of the conducting member on one side in the axial direction is in direct contact with the control substrate.

13. The motor according to any one of claims 9 to 11,

the bearing portion includes a 1 st bearing portion, an outer ring of the 1 st bearing portion is fixed to an inner peripheral surface of the radiator, and an inner ring is fixed to an outer peripheral surface of the shaft.

14. The motor according to any one of claims 1 to 12,

the stationary portion further includes a metal bearing holding portion that is fixed to the housing or the stator and radially extends around the center axis on the other axial side of the stator,

the bearing portion includes a 2 nd bearing portion, an outer ring of the 2 nd bearing portion is fixed to an inner peripheral surface of the bearing holding portion, and an inner ring is fixed to an outer peripheral surface of the shaft.

15. The motor of claim 14,

the bearing holding portion includes:

a flange portion that extends radially outward from the housing; and

a mounting hole which is a through hole axially penetrating the flange portion,

the other axial end of the conductive member is in contact with the bearing holding portion, and the bearing holding portion is fixed to the separate member in the mounting hole via a 2 nd fastening member made of metal.

16. The motor according to any one of claims 1 to 14,

the end portion of the other axial side of the conducting member is in direct contact with the split member.

17. The motor of claim 1,

the conducting member is constituted by the bearing portion and the shaft.

18. The motor according to any one of claims 1 to 17,

the motor has at least two of the conducting members.

Technical Field

The present invention relates to a motor.

Background

Conventionally, an electromechanical motor in which a main body portion of a motor having a stator and a rotor and a control board for controlling the main body portion are integrated has been widely used. The structure of an electromechanical motor is described in, for example, japanese patent laid-open No. 2016 and 34203. Japanese patent application laid-open No. 2016-. The base plate is disposed perpendicularly to the axial direction of the motor and fixed to the bottom of the motor case by screws. The motor case is formed in a bottomed cylindrical shape from metal such as aluminum. Thus, when the motor is mounted on a target device (for example, an electric power steering device), a ground path of the substrate is ensured through the metal motor case.

Patent document 1: japanese patent laid-open publication No. 2016-34203

In recent years, resin cases have been used for the purpose of reducing the weight of motors, improving dust-proof performance, and improving manufacturing efficiency. However, in the electromechanical integrated motor, when the housing is made of resin, it may be difficult to secure a ground path for the substrate.

Disclosure of Invention

An object of the present invention is to provide a structure capable of easily securing a ground path of a substrate in an electromechanical integrated motor having a resin case.

An exemplary 1 st invention of the present application is a motor including: a motor main body having a stationary portion including a stator, and a rotating portion including a rotor disposed to face the stator, the rotating portion rotating about a shaft extending along a central axis via a bearing portion; a control board extending perpendicular to the central axis and electrically connected to the stator; and a metallic conduction member, wherein the stationary portion has a resin case surrounding at least a part of the stator and a part of the conduction member from the outside in the radial direction, one end portion of the conduction member in the axial direction is in direct or indirect contact with the control board, and the other end portion of the conduction member in the axial direction is in direct or indirect contact with a separate member made of metal.

According to exemplary 1 st aspect of the present application, a motor having a control board is provided with a metallic conductive member extending in an axial direction. One axial end of the conducting member protrudes from the resin case toward one axial side to be in contact with the control board, and the other axial end of the conducting member protrudes from the case toward the other axial side to be in direct or indirect contact with the metal separate member. This makes it possible to easily secure a ground path of the control board.

Drawings

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

Fig. 2 is a partial plan view of the stator core according to embodiment 1.

Fig. 3 is a longitudinal sectional view of the motor of embodiment 2.

Fig. 4 is a longitudinal sectional view of a motor according to a modification.

Fig. 5 is a partial schematic view of a conduction member according to a modification.

Description of the reference symbols

1. 1B: a motor; 2. 2B: a stationary portion; 3. 3B: a rotating part; 5. 5B: a bearing portion; 9. 9B: a central axis; 10. 10B: a motor main body portion; 21. 21B: a stator; 22. 22B: a housing; 23. 23B: a cover; 24. 24B, 24C: a heat sink; 25. 25B, 25C: a bearing holding portion; 31: a shaft; 32: a rotor; 40: a core member; 41: the back of the iron core; 42: teeth; 43. 43B: a wire; 51: a 1 st bearing portion; 52: a 2 nd bearing portion; 81. 81B: a main body portion; 82. 82B: an inner protrusion; 83. 83B: an annular plate portion; 90. 90B: a control substrate; 91. 91B: a connector; 92B: a 2 nd mounting hole; 93B: a fastening member; 100. 100B, 100C: a conducting member; 101C: a bending section; 200. 200B, 200C: a separate component; 201B: a recess; 210. 210B: a fastening member; 211: a stator core; 212: an insulating member; 213. 213B: a coil; 214: an insulating tube; 221: a cylindrical portion; 222: a flange portion; 242B: a convex portion; 243: a through hole; 245: a through hole; 246B: a fastening hole; 247B, 247C: a recess; 250. 250B: a through hole; 256: 1 st mounting hole; 321: a rotor core; 322: a magnet; 410: a groove part; 500: and a conducting component.

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 portions will be described with the axial direction as the vertical direction and the control substrate 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 and modifications, "upper side (upper end portion)" is replaced with "one axial side (end portion on one axial side)", and "lower side (lower end portion)" is replaced with "the other axial side (end portion on the other axial side)".

The "parallel direction" also includes a substantially parallel direction. The "vertical direction" also includes a substantially vertical direction.

< 1. embodiment 1 >

Fig. 1 is a longitudinal sectional view of a motor 1 according to an embodiment of the present invention. The motor 1 of the present embodiment is mounted on, for example, an automobile, and is used as a drive source for generating a drive force of an electric power steering apparatus. However, the motor of the present invention may be used for applications other than power steering. For example, the motor of the present invention may be used as a drive source for other parts of an automobile, such as an engine cooling fan or an oil pump. The motor of the present invention may be mounted on a home appliance, an OA equipment, a medical equipment, or the like, and generates various driving forces.

As shown in fig. 1, the motor 1 includes a motor main body 10, a control board 90, and a conduction member 100.

The motor main body 10 includes a stationary portion 2, a rotating portion 3, and a bearing portion 5. The stationary portion 2 is fixed to a separate member 200 located outside the motor 1. The separate member 200 is, for example, a housing of a device to be driven by the motor 1. The rotating portion 3 is supported via a bearing portion 5 so as to be rotatable about a central axis 9 extending vertically with respect to the stationary portion 2.

The stationary portion 2 of the present embodiment includes a stator 21, a housing 22, a cover 23, a heat sink 24, and a bearing holding portion 25.

The stator 21 is an armature that generates magnetic flux in response to a drive current. The stator 21 is disposed radially outward of the rotor 32 described later. The stator 21 includes a stator core 211, a plurality of insulators 212, a plurality of coils 213, and an insulating tube 214.

Fig. 2 is a partial plan view of the stator core 211. In fig. 2, the housing 22 and the conducting member 100 are also shown in phantom. As shown in fig. 2, the stator core 211 is composed of a plurality of core pieces 40. The core member 40 is made of, for example, a laminated steel plate in which electromagnetic steel plates as magnetic bodies are laminated in the axial direction. The plurality of core pieces 40 are arranged in the circumferential direction. Each core member 40 has a core back 41 and teeth 42. Each core back 41 has an arc shape centered on the central axis 9. The plurality of core backs 41 are in contact with each other and surround the central axis 9 in an annular shape as a whole. In addition, each core back 41 is provided with a groove 410. The groove 410 is recessed radially inward from the outer peripheral surface. This can reduce the weight of the stator core 211 including the plurality of core backs 41. The teeth 42 extend from the core back 41 toward the radially inner side.

The insulating member 212 is made of resin as an insulator. In the stator 21 of the present embodiment, an insulator 212 is provided for each tooth 42. The upper surface, the lower surface, and both circumferential end surfaces of each tooth 42 in the surface of each core member 40 constituting the stator core 211 are covered with an insulator 212. However, the stator core 211 may be configured such that at least a part thereof is covered with the insulator 212.

The coil 213 is formed of the conductive wire 43 wound around the insulator 212. That is, in the present embodiment, the lead wire 43 is wound around the teeth 42 as the magnetic core via the insulator 212. The insulator 212 prevents the teeth 42 and the coils 213 from being electrically short-circuited by being sandwiched between the teeth 42 and the coils 213

The insulating tube 214 is a cylindrical member made of resin as an insulator. The insulating tube 214 extends in the axial direction. The upper portion of the insulating tube 214 passes through a through hole 243 of the radiator 24 described later. The lower portion of the insulating tube 214 is fitted in the case 22 to be described later. A part of the lead wire 43 constituting the coil 213 is drawn upward, passes through the space inside the insulating tube 214, and is electrically connected to the control board 90. Since the lead wires 43 are covered with the insulating tube 214, the lead wires 43 are prevented from being scattered or bent during resin molding of the housing 22 described later. This makes it possible to easily connect the lead wire 43 to the control board 90 after the resin molding of the case 22. In addition, the insulating tube 214 suppresses contact of the lead 43 with the heat sink 24. This ensures conduction between the control board 90 and the coil 213.

The housing 22 is a resin member that covers the stator 21 and a part of the conduction member 100 in the axial direction. That is, the housing 22 surrounds the stator 21 and a part of the conducting member 100 in the axial direction from the radially outer side. Here, "a part of the conducting member 100 in the axial direction" means "a part located at the middle in the axial direction" of the conducting member 100 excluding the upper end portion and the lower end portion. In the present embodiment, the surface of the stator 21 except the end surfaces of the teeth 42 on the inner side in the radial direction is covered with the resin forming the housing 22. The material of the housing 22 is, for example, thermosetting unsaturated polyester resin. The case 22 is obtained by pouring and curing a resin into a cavity in a mold in which the stator 21 and the conducting member 100 are housed. This enables the housing 22 to be easily formed. Further, by forming the case 22 made of resin, the entire motor 1 including the case 22 can be reduced in weight. 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 22 has a cylindrical portion 221, a flange portion 222, and a connecting portion 223. The cylindrical portion 221 extends in a substantially cylindrical shape in the axial direction. The stator core 211, the insulator 212, the coil 213, and the insulating tube 214 are covered with resin constituting the cylindrical portion 221. The flange portion 222 extends radially outward from the upper end of the cylindrical portion 221. The connecting portion 223 extends in the axial direction from the radially outer end of the flange portion 222. The lower end of the connecting portion 223 protrudes downward from the lower surface of the flange portion 222. Further, the connection portion 223 is fitted with a portion of the connector 91 other than the upper end portion. The upper end of the connector 91 protrudes upward from the housing 22. The lower end of the connector 91 of the present embodiment is exposed to the outside of the motor 1. The motor 1 is connected to a connection portion of an electric power steering apparatus, not shown, at a connection portion 223. Thereby, the control board 90 and the electric circuit of the electric power steering apparatus are electrically connected via the connector 91. In addition, a part of the connector 91 may also extend in the radial direction.

The cover 23 is radially expanded on the upper side of the stator 21, the housing 22, and the control substrate 90. For example, a thin plate made of metal such as aluminum or stainless steel is used as the material of the cover 23. The cover 23 has a cover fixing portion 231. The cover fixing portion 231 extends in the axial direction at the outer peripheral portion of the cover 23. The lower end of the cover fixing portion 231 is fixed to the upper surface of the connecting portion 223 of the housing 22. The control board 90 is housed in a space formed by the housing 22, the cover 23, and the bearing holding portion 25. This can prevent the control board 90 from being contaminated or damaged. As a result, the control reliability of the motor main body 10 is improved.

The heat sink 24 is disposed close to the control board 90. The radiator 24 of the present embodiment extends radially in an annular shape around the center axis 9. The heat sink 24 is made of a metal having excellent thermal conductivity. The heat sink 24 may be disposed in contact with the control board 90.

In the present embodiment, the heat sink 24 includes a main body portion 81, an inner protruding portion 82, and an annular plate portion 83. The body 81 extends in the radial direction above the stator 21 and a rotor 32 described later. The inner projecting portion 82 projects further radially inward from a portion above the radially inner end of the body 81. The annular plate portion 83 extends further radially outward from a portion above the radially outer end of the body portion 81. The outer peripheral surface of the body 81 and the outer peripheral surface of the annular plate 83 of the radiator 24 contact the inner peripheral surface of the case 22. The lower surface of the body 81 and the lower surface of the annular plate 83 of the heat sink 24 contact the upper surface of the case 22. The outer peripheral surface and the lower surface of the body portion 81 and the outer peripheral surface and the lower surface of the annular plate portion 83 of the heat sink 24 are fixed to the inner peripheral surface and the upper surface of the case 22 by, for example, adhesion. However, only a part of these portions may be fixed to the case 22 by adhesion. The heat sink 24 may be fixed to the case 22 by a method other than adhesion. In addition, the shape of the heat sink 24 is not limited to the above shape. For example, the heat sink 24 may be extended in a flat plate shape in the radial direction without a step. The heat sink 24 may have a rectangular shape in a plan view. The radiator 24 may have a cylindrical inner peripheral surface.

The heat sink 24 has a plurality of (3 in the present embodiment) convex portions 242. The three convex portions 242B protrude upward from a part of the upper surface of the heat sink 24. The upper surface of each convex portion 242 is in contact with the lower surface of the control board 90. In addition, a fastening hole 246 is provided in the convex portion 242. The fastening hole 246 is a threaded hole formed from the upper surface of the boss 242 toward the lower side. However, the number of the convex portions 242 provided on the heat sink 24 is not limited thereto. The heat sink 24 may not necessarily have the convex portion 242. In the case where the protruding portion 242 is not provided, the fastening hole 246 may be provided in the main body 81 or the annular plate portion 83.

In addition, a plurality of through holes 243 are formed in the body 81 of the heat sink 24. Each through hole 243 axially penetrates the body 81. As described above, the insulating tube 214 is disposed in the through hole 243.

The inner protruding portion 82 of the heat sink 24 is located radially inward of the body 81. An outer ring of the 1 st bearing portion 51 described later is fixed to the lower surface of the inner protrusion 82 and the inner circumferential surface of the body 81. That is, the heat sink 24 also functions as a bearing holding portion that holds the 1 st bearing portion 51. This can suppress the number of components of the entire motor 1. Further, since the first bearing portion 51 can be stably held by the metal heat sink 24, the rotation accuracy of the rotating portion 3 is improved.

A through hole 245 is provided at one circumferential portion of the annular plate portion 83 of the heat sink 24. The through hole 245 penetrates the annular plate 83 in the axial direction. The through hole 245 axially faces the groove 410.

The bearing holder 25 is radially expanded annularly around the center axis 9 below the stator 21. The bearing holding portion 25 of the present embodiment is formed of a metal member. The bearing holding portion 25 includes a flat plate portion 251, an inner protruding portion 252, an outer protruding portion 253, and a flange portion 254. The flat plate portion 251, the inner protruding portion 252, the outer protruding portion 253, and the flange portion 254 of the present embodiment are integrally connected.

The flat plate portion 251 extends in a disc shape around the center axis 9. Through-hole 250 is provided near the outer periphery of flat plate 251. The through hole 250 axially penetrates the flat plate portion 251. However, instead of through-hole 250, a recess may be provided that is recessed downward from a portion of the upper surface of flat plate portion 251.

The inner protruding portion 252 protrudes upward from the inner peripheral portion of the flat plate portion 251. However, the radially inner end 255 of the flat plate portion 251 is located radially inward of the inner protruding portion 252. An outer ring of the 2 nd bearing portion 52, which will be described later, is fixed to an upper surface of the radially inner end 255 of the flat plate portion 251 and an inner peripheral surface of the inner protruding portion 252.

The outer protruding portion 253 protrudes upward from the outer peripheral portion of the flat plate portion 251. The flange 254 is expanded radially outward from the upper end of the outer protrusion 253. The flange 254 is radially outwardly expanded from the cylindrical portion 221 of the housing 22. Further, the flange 254 is provided with a 1 st mounting hole 256. The 1 st mounting hole 256 is a through hole that penetrates the flange 254 in the axial direction. The bearing holding portion 25 is fixed to the separate member 200 by screw fastening with the metal fastening member 210 inserted through the 1 st mounting hole 256. The fastening part 210 is in contact with the metal part of the separate body part 200. Thereby, the bearing holding portion 25 is electrically connected to the separate member 200.

The lower end of the housing 22 is disposed at a corner formed by the upper surface of the flat plate portion 251 and the inner peripheral surface of the outer projecting portion 253. The bearing holding portion 25 is fixed to the housing 22 by, for example, adhesion. However, the bearing holding portion 25 may be fixed to the stator 21.

The rotating portion 3 of the present embodiment includes a shaft 31 and a rotor 32.

The shaft 31 is a columnar member extending along the center axis 9. The shaft 31 is made of a metal such as stainless steel. The shaft 31 rotates about the center axis 9 while being supported by a 1 st bearing portion 51 and a 2 nd bearing portion 52, which will be described later. The lower end of the shaft 31 projects downward from the bearing holder 25. A device to be driven is connected to a lower end portion of the shaft 31 via a power transmission mechanism such as a gear. However, the upper end of the shaft 31 may be connected to a device to be driven. The shaft 31 may be a hollow member. The shaft 31 also functions as a conducting member 500 together with the 1 st bearing part 51 and the 2 nd bearing part 52. The conducting member 500 is surrounded by the housing 22 from the radially outer side.

The rotor 32 has a rotor core 321 and a plurality of magnets 322. The rotor core 321 extends annularly around the shaft 31 around the central axis 9. The rotor core 321 is fixed to the outer peripheral surface of the shaft 31 and rotates together with the shaft 31. 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 fixed to the inner circumferential surface of the rotor core 321 by press fitting. However, the shaft 31 may be fixed to the rotor core 321 by bonding instead of or in addition to press fitting. Further, a member such as a bushing may be disposed between the inner surface of the rotor core 321 and the outer surface of the shaft 31. The rotor 32 is disposed radially inward of the stator 21.

The plurality of magnets 322 are fixed to the outer peripheral surface of the rotor core 321 with an adhesive, for example. The plurality of magnets 322 are disposed radially inward of the cylindrical portion 221 of the housing 22. The radially outer surface of each magnet 322 is a magnetic pole surface facing radially inward end surfaces of the teeth 42 of the stator 21 with a slight gap therebetween. The plurality of magnets 322 are arranged in the circumferential direction such that N poles and S poles are alternately arranged. However, instead of the plurality of magnets 322, one annular magnet may be used in which N-poles and S-poles are alternately magnetized in the circumferential direction. The plurality of magnets 322 may be embedded in the rotor core 321.

The bearing portion 5 includes a 1 st bearing portion 51 and a 2 nd bearing portion 52. In the first bearing unit 51 and the second bearing unit 52 of the present embodiment, ball bearings are used to rotate the outer ring and the inner ring via rolling elements, respectively. The outer race of the 1 st bearing portion 51 is fixed to the inner peripheral surface of the body 81 of the radiator 24 and the lower surface of the inner protrusion 82. The inner ring of the 1 st bearing portion 51 is fixed to the outer circumferential surface of the shaft 31. Thus, the 1 st bearing portion 51 rotatably supports the shaft 31 on the upper side of the rotor 32 with respect to the radiator 24 and the housing 22 to which the radiator 24 is fixed. Further, the outer ring of the 2 nd bearing portion 52 is fixed to the inner peripheral surface of the inner protruding portion 252 of the bearing holding portion 25 and the upper surface of the end portion 255 of the flat plate portion 251. The inner ring of the 2 nd bearing portion 52 is fixed to the outer peripheral surface of the shaft 31. Thus, the 2 nd bearing portion 52 supports the shaft 31 at a position lower than the rotor 32 so as to be rotatable with respect to the bearing holding portion 25 and the housing 22 to which the bearing holding portion 25 is fixed. However, the 1 st bearing part 51 and the 2 nd bearing part 52 may be bearings of other types such as slide bearings or fluid bearings instead of the ball bearings. The bearing 5, more specifically, the 1 st bearing 51 and the 2 nd bearing 52 also function as the conducting member 500 together with the shaft 31.

The control board 90 is a member for driving the motor main body 10. The control board 90 extends in a plate shape perpendicular to the center axis 9. The control board 90 is provided with a plurality of (3 in the present embodiment) 2 nd mounting holes 92. The 3 nd mounting holes 92 are through holes that penetrate the control board 90 in the axial direction. The control board 90 is fixed to the fastening hole 246 of the metallic heat sink 24 by a metallic fastening member 93 that penetrates the 2 nd mounting hole 92. However, the control board 90 may be fixed to the upper surface of the housing 22. In addition, the number of the 2 nd mounting holes 92 provided on the control substrate 90 is not limited thereto. In the present embodiment, the fastening member 93 may not be made of metal.

A pattern including a ground line is formed on the control substrate 90. On the control board 90, heat generating elements such as transistors are mounted as electronic components for driving the motor main body 10. The control board 90 is electrically connected to the coil 213 via the lead 43. Further, a lead (not shown) extending from an external power supply is electrically connected to the control board 90 via a connector 91. That is, the coil 213 and the external power supply are electrically connected via the control board 90.

When the motor 1 is driven, a drive current is supplied from the electric circuit of the electric power steering apparatus to the coil 213 via the connector 91, the control board 90, and the lead 43. This generates magnetic flux in the plurality of teeth 42 of the stator core 211. 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 mounted on the shaft 31 rotates together with the rotating portion 3.

Heat generated from the heat generating elements mounted on the control board 90 is dissipated via the heat sink 24 disposed in proximity to the control board 90. This suppresses the temperature rise of the heat generating element when the motor 1 is driven.

The conductive member 100 is a metal member extending in a columnar shape in the axial direction. As described above, a part including the upper end portion of the conducting member 100 and a part including the lower end portion of the conducting member 100 are not covered with the resin forming the case 22. In the present embodiment, the upper end of the conductive member 100 protrudes upward from the case 22, and penetrates the through hole 245 of the heat sink 24 to be in direct contact with the ground line of the control board 90. The lower end of the conductive member 100 protrudes downward from the housing 22, and is inserted into the through hole 250 of the bearing holder 25 to contact the bearing holder 25. As described above, the bearing holding portion 25 is fixed to the separate member 200 by screw fastening with the metal fastening member 210 inserted through the 1 st mounting hole 256. The fastening part 210 is in contact with the metal part of the separate body part 200. That is, the lower end of the conducting member 100 protrudes downward from the housing 22, and indirectly contacts the separate member 200 via the bearing holding portion 25 and the fastening member 210. Thus, the control board 90 secures a ground path via the conduction member 100, the bearing holding portion 25, and the fastening member 210, and the electric charges of the control board 90 are grounded. As a result, a structure in which static electricity generated in the control board 90 is removed can be formed, and the control reliability of the motor main body 10 can be improved. However, the shape of the conductive member 100 is not limited to the cylindrical shape. The conducting member 100 may be, for example, extended in a plate shape in the axial direction.

As shown in fig. 2, a part of the conducting member 100 of the present embodiment is located inside the groove 410 of the stator 21. This suppresses the conductive member 100 from protruding radially outward beyond the outer peripheral surface of the stator core 211. Therefore, the amount of resin of the case 22 covering the stator 21 and a part of the conducting member 100 is reduced. As a result, the manufacturing cost of the motor 1 can be reduced, and the entire motor 1 including the housing 22 can be downsized in the radial direction. Further, by disposing the conduction member 100 inside the groove portion 410, positional displacement of the conduction member 100 is suppressed when the case 22 is molded. However, the depth of the groove 410 in the radial direction may be larger than the outer diameter of the conductive member 100. The entire conductive member 100 may be disposed inside the groove 410. That is, at least a part of the conducting member 100 may be located inside the groove 410 of the stator 21. The conductive member 100 may be disposed at a position different from the groove 410.

As shown in fig. 2, a part of the resin forming the case 22 is sandwiched between the conductive member 100 and the core back 41 in the present embodiment. That is, the conducting member 100 of the present embodiment does not contact the stator 21. However, the conducting member 100 may be in contact with the stator 21.

As shown in fig. 1, in the present embodiment, the bearing 5 and the shaft 31 also function as a conducting member. That is, the motor 1 includes at least two conducting members, i.e., a conducting member 500 including the bearing portion 5 and the shaft 31 and a conducting member 100 extending in the axial direction. The conductive member 500 ensures a ground path for the control board 90 via the conductive member 500, the bearing holding portion 25, and the fastening member 210, and grounds the electric charge of the control board 90. As a result, a structure in which static electricity generated in the control board 90 is removed can be formed, and the control reliability of the motor main body 10 can be improved.

Further, since the motor 1 includes the two conductive members 100 and 500, two ground paths are provided from the control board 90 to the bearing holding portion 25. That is, an annular ground path is formed. Therefore, a potential difference is less likely to occur between the control board 90 and the bearing holding portion 25, and thus electric corrosion is less likely to occur at each contact portion between the conducting member 100 and the control board 90, between the conducting members 100 and 500 and the heat sink 24, and between the conducting members 100 and 500 and the bearing holding portion 25. Further, the control reliability of the motor main body 10 is improved.

< 2 > embodiment 2

Next, embodiment 2 of the present invention will be explained. Fig. 3 is a longitudinal sectional view of the motor 1B of embodiment 2. In the following description, differences from embodiment 1 will be mainly described, and portions that are the same as those in embodiment 1 are denoted by "B" and redundant description thereof will be omitted.

In the present embodiment, a recess 247B is provided at one circumferential position on the lower surface of the annular plate portion 83B. The recess 247B is recessed upward from a part of the lower surface of the annular plate portion 83B. The recess 247B axially faces the groove 410B.

In the present embodiment, the upper end of the conducting member 100B protrudes upward from the case 22B, and is inserted into the recess 247B of the heat sink 24B to contact the heat sink 24B. The heat sink 24B is electrically connected to the control board 90B via a metal fastening member 93B. That is, the upper end portion of the conducting member 100B protrudes upward from the case 22B, and indirectly contacts the ground line of the control board 90B via the heat sink 24B and the fastening member 93B. In addition, as in embodiment 1, the lower end portion of the conducting member 100B protrudes downward from the housing 22B, and indirectly contacts the metal portion of the separate member 200B via the metal bearing holding portion 25B and the metal fastening member 210B. Thus, the control board 90B secures a ground path via the fastening member 93B, the heat sink 24B, the conduction member 100B, the bearing holding portion 25B, and the fastening member 210B, and grounds the electric charge of the control board 90B. As a result, a structure in which static electricity generated in the control board 90B is removed can be formed, and the control reliability of the motor main body portion 10B is improved.

As shown in the modification of fig. 4, the lower end of the conductive member 100B may protrude downward from the housing 22B, penetrate through the through hole 250B of the bearing holding portion 25B, and directly contact the metal portion of the separate member 200B. In the example of fig. 4, a recess 201B is provided in the separate member 200B. The recess 201B is recessed from the upper surface of the separate member 200B to the lower side. The lower end of the conducting member 100B is inserted into the recess 201B and contacts the separate member 200B. Thus, the control board 90B secures a ground path via the conductive member 100B, and charges of the control board 90B are grounded. As a result, a structure in which static electricity generated in the control board 90B is removed can be formed, and the control reliability of the motor main body portion 10B is improved. However, the recess 201B may not be provided.

< 3. 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.

Fig. 5 is a partial schematic view of a conduction member 100C according to a modification. In embodiment 2 described above, the upper end portion of the conducting member 100B is inserted in the recess 247B provided in the heat sink 24B in the axial direction and contacts the heat sink 24B. In contrast, in the modification of fig. 5, the upper end portion of the conducting member 100C is thinner than the lower portion of the conducting member 100C. The upper end of the conducting member 100C is folded back to form a bent portion 101C. Further, the bent portion 101C is inserted into a recess 247C provided in the heat sink 24C. Accordingly, the conductive member 100C can be more reliably brought into contact with the heat sink 24C by the elasticity of the bent portion 101C. However, the upper end of the conductive member may be in contact with the through hole of the control board, and may have the same structure as the bent portion 101C. In addition, the lower end portion of the conductive member may be brought into contact with at least one of the through hole of the bearing holding portion and the recess of the separate member, and may have the same structure as the bent portion 101C.

In the above-described embodiment and modification, the contact portion between at least one of the upper end portion and the lower end portion of the conducting member and at least one of the heat sink, the bearing holding portion, and the separate member may be further filled with a conductive adhesive. This makes it possible to more reliably bring the conducting member into contact with at least one of the heat sink, the bearing holding portion, and the separate member. Further, at least one of the upper end portion and the lower end portion of the conducting member and at least one of the heat sink, the bearing holding portion, and the separate member may be fixed by another method such as welding.

In the above-described embodiment and modification, the outer ring of the bearing portion is fixed to the radiator and the bearing holding portion, but either one of them is preferably supported to be displaceable in the axial direction. Further, it is preferable that an elastic member such as a wave washer is interposed between the radiator or the bearing holding portion, which supports the outer ring to be displaceable in the axial direction, and the outer ring.

Further, a sensor magnet may be provided at the distal end portion of the shaft 31, and a magnetic sensor that detects a change in magnetic flux caused by rotation of the sensor magnet may be provided on the lower surface of the control board 90. The control board 90 may control the electric power supplied to the coil 213 according to the rotational position of the rotor 3, which is the shaft 31 obtained from the detection result of the magnetic sensor.

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-described embodiment and modification may be appropriately combined within a range in which no contradiction occurs.

Industrial applicability

The present invention can be applied to a motor.