Rotary electric machine and vehicle

Abstract

One aspect of a rotary electric machine according to the present disclosure comprises: a motor body having a rotor and a stator; a housing having an accommodation part that accommodates the motor body; a lid body that is fixed to the housing and closes an opening of the accommodation part; and a control board that faces the opposite side to the accommodation part, is provided to an outward-facing surface of the lid body, and is electrically connected to the motor body. The housing has a step part that protrudes inward from an inner wall surface of the opening. The lid body has a press-fitting part that is provided to protrude on an inward-facing surface that faces the accommodation part, and press-fitted into the opening. The outer wall surface of the press-fitting part comes into pressure contact with the inner wall surface of the opening and forms a pressure contact part. The tip surface of the press-fitting part abuts the step part and forms an abutting part. A closed space surrounded by the housing and the lid body is formed between the pressure contact part and the abutting part.

Description

Rotating electric machines and vehicles

[0001] The present disclosure relates to a rotating electric machine and a vehicle.

[0002] For example, Patent Document 1 describes an electric power steering device in which a control unit is housed in a motor case and is integrated with the motor.

[0003] Patent No. 6771655

[0004] The electric power steering device of Patent Document 1 includes a frame that separates the space inside the case into one that houses the motor and one that houses the control unit. The frame acts as a lid that closes the space that houses the motor. In an electric power steering device, the intrusion of foreign matter into the space that houses the motor can cause wear and damage to rotating parts and bearings, potentially affecting steering operation. For this reason, measures are needed to prevent foreign matter, such as shavings generated when fixing the frame to the case, from entering the motor side.

[0005] In view of the above circumstances, the present disclosure aims to provide a rotating electric machine and a vehicle that can prevent foreign matter, such as shavings, generated when closing a housing that houses a motor body from entering the housing.

[0006] One aspect of a rotating electric machine according to the present disclosure comprises a motor body having a rotor and a stator, a housing having a storage section that houses the motor body, a lid fixed to the housing and closing an opening of the storage section, and a control board provided on the outward surface of the lid facing away from the storage section and electrically connected to the motor body, wherein the housing has a step portion that protrudes inward from the inner wall surface of the opening, the lid body protrudes on its inward surface facing the storage section and has a press-fit portion that is press-fit into the opening, the outer wall surface of the press-fit portion presses against the inner wall surface of the opening to form a press-fit portion, and the tip surface of the press-fit portion abuts against the step portion to form an abutment portion, and a closed space surrounded by the housing and the lid body is formed between the press-fit portion and the abutment portion.

[0007] One aspect of a vehicle according to the present disclosure includes a wheel and an electric power steering device having the above-described rotating electric machine.

[0008] According to the present disclosure, foreign matter such as shavings generated when closing the housing that houses the motor body can be prevented from entering the housing.

[0009] Fig. 1 is a cross-sectional view of a rotating electric machine according to embodiment 1. Fig. 2 is an enlarged cross-sectional view of a main part of the rotating electric machine according to embodiment 1. Fig. 3 is a plan view of the outward surface side of a lid body according to embodiment 2. Fig. 4 is a schematic view of a lid body according to embodiment 2 in which a press-fit portion inner region and a press-fit portion outer region are painted differently. Fig. 5 is a schematic view showing a first modified example of the lid body according to embodiment 2. Fig. 6 is a schematic view showing a second modified example of the lid body according to embodiment 2. Fig. 7 is a schematic view showing a vehicle according to embodiment 3.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments and can be modified as desired within the scope of the technical concept of the present disclosure.

[0011] Embodiment 1. Figure 1 is a cross-sectional view of a rotating electric machine 1 according to embodiment 1. The rotating electric machine 1 shown in Figure 1 includes a rotating shaft 2, a motor body 10, a housing 20, a lid 30, a control board 40, and a cover 50. The housing 20 and the lid 30 are formed from a metal material (such as aluminum) that has excellent heat dissipation properties.

[0012] In the following description, the direction in which the central axis O of the rotating shaft 2 extends will be referred to as the axial direction. Also, the direction intersecting the central axis O of the rotating shaft 2 will be referred to as the radial direction. Also, the direction going around the central axis O of the rotating shaft 2 will be referred to as the circumferential direction.

[0013] The motor body 10 includes a rotor 11 fixed to the rotating shaft 2 and a stator 12 that rotates the rotor 11. The rotor 11 is formed in a cylindrical shape extending in the axial direction and is fixed to the outer circumferential surface of the rotating shaft 2. The rotor 11 includes, for example, a rotor core and a permanent magnet.

[0014] The stator 12 is formed in a cylindrical shape extending in the axial direction and is disposed radially outside the rotor 11. The stator 12 includes a stator core around which coils 13 of each layer (U-phase, V-phase, W-phase) are wound via insulators 14. The stator 12 is fixed to the housing 20 by shrink fitting, press fitting, or the like.

[0015] The housing 20 includes a housing portion 21 that houses the motor main body 10. The housing portion 21 is formed in a cylindrical shape with a bottom and an opening 22 formed on one axial side. A step portion 23 that protrudes radially inward is formed on the inner wall surface of the opening 22. The step portion 23 is formed in an annular shape along the circumferential direction.

[0016] A through-hole 24 is formed in the bottom of the accommodation portion 21, and one end (output end) of the rotary shaft 2 passes through it. A first bearing 25 that rotatably supports the one end of the rotary shaft 2 is provided in the through-hole 24. An extension portion 26 that extends radially outward is provided on the periphery of the opening 22 of the accommodation portion 21.

[0017] The lid 30 is fixed to the housing 20 and closes the storage section 21. The lid 30 has an outward surface 30A facing away from the storage section 21 and an inward surface 30B facing the storage section 21. The lid 30 has a through hole 31 formed therein, through which the other end of the rotating shaft 2 passes. A second bearing 32 is provided in the through hole 31 to rotatably support the other end of the rotating shaft 2.

[0018] A press-fit portion 33 projects from the inward surface 30B of the lid 30 and is fixed by press-fitting into the opening 22 of the accommodation portion 21. The radially facing outer wall surface of the press-fit portion 33 is in pressure contact with the inner wall surface of the opening 22. The axially facing tip surface of the press-fit portion 33 abuts against the step portion 23. The press-fit portion 33 has the above-mentioned through hole 31 formed in its center.

[0019] A control board 40 is attached to the outward surface 30A of the lid 30. A heat dissipation material (not shown), such as heat dissipation grease, is interposed between the control board 40 and the lid 30 to satisfy the heat dissipation requirements of electronic components 41 mounted on the control board 40. A component groove 34 for accommodating the electronic components 41 is formed in the outward surface 30A of the lid 30.

[0020] The control board 40 is electrically connected to the coil 13 of the stator 12 via terminals and wiring (not shown), and controls the rotation of the rotor 11. For example, electronic components for control, power semiconductor components forming an inverter circuit, and electrolytic capacitors are mounted on the outward surface 30A and the inward surface 30B of the control board 40.

[0021] The control board 40 also has a rotation sensor 42 at a portion facing the through-hole 31 of the cover 30. A sensor magnet 3 for transmitting magnetism to the rotation sensor 42 is attached to the end of the rotating shaft 2 facing the rotation sensor 42.

[0022] A connector 43, which transmits and receives signals to and from an external device (not shown), is electrically connected to the control board 40 via a connector terminal 44. The connector 43 receives power from an external device (e.g., a vehicle) and signals from a torque sensor, etc. The connector 43 is attached to the extension 26 of the housing 20, but may also be attached to the cover 50 side.

[0023] The cover 50 is formed in a cylindrical shape with a top that covers the outside of the control board 40. The peripheral edge of the cover 50 is mechanically fixed to the housing 20 by, for example, a snap fit. The cover 50 may be fixed to the housing 20 by an adhesive, or may be fixed to the housing 20 mechanically and with an adhesive in combination.

[0024] 2 is an enlarged cross-sectional view of a main portion of the rotating electric machine 1 according to the first embodiment. As shown in FIG. 2, the outer wall surface of the press-fit portion 33 is in pressure contact with the inner wall surface of the opening 22 in the radial direction to form a press-contact portion 71. In addition, the tip end surface of the press-fit portion 33 is in contact with the step portion 23 in the axial direction to form an abutment portion 70.

[0025] A closed space 60A surrounded by the housing 20 and the cover 30 is formed between the pressure-contact portion 71 and the abutment portion 70. Specifically, the press-fit portion 33 has an inclined portion 33a whose outer shape becomes smaller toward the tip end surface. The inclined portion 33a also functions as a guide when the press-fit portion 33 is press-fitted into the opening 22.

[0026] The closed space 60A is an annular space enclosed by the inclined portion 33a, the step portion 23, and the inner wall surface of the opening 22. The closed space 60A is large enough to accommodate foreign matter such as shavings generated during press-fitting. In addition to providing the inclined portion 33a in the press-fit portion 33, or instead of providing the inclined portion 33a, a groove or the like that forms the closed space 60A may be provided on the housing 20 side.

[0027] A groove 33b is formed in an annular shape along the circumferential direction on the outer wall surface of the press-fit portion 33. The groove 33b forms a gap 60B adjacent to the side opposite the closed space 60A of the press-contact portion 71. The groove 33b opens in an annular shape toward the control board 40. In addition, a protrusion 38 is formed on the outer wall surface of the press-fit portion 33 to narrow the width of the opening of the groove 33b facing the control board 40.

[0028] The protrusion 38 is formed in a ring shape along the circumferential direction on the outer wall surface of the press-fit portion 33. The protrusion 38 forms a gap 72 that prevents foreign objects larger than the size allowable on the control board 40 side from passing through. As a result, foreign objects too large for the control board 40 side cannot pass through the gap 72 and are instead accommodated in the gap 60B within the groove 33b. Note that in addition to providing the groove 33b and the protrusion 38 on the press-fit portion 33, or instead of providing the groove 33b and the protrusion 38, a groove or a protrusion may be provided on the housing 20 side. Furthermore, the protrusion 38 may be formed in an area that includes the outward surface 30A of the lid 30.

[0029] As described above, in the rotating electrical machine 1, the lid 30 is fixed to the housing 20 by press-fitting. When the press-fit portion 33 of the lid 30 is press-fitted into the opening 22 of the accommodation portion 21 of the housing 20, foreign matter such as shavings is generated. If the hardness of the housing 20 is lower than that of the lid 30 or is the same as that of the lid 30, the housing 20 side is scraped during press-fitting, generating foreign matter.

[0030] Such foreign matter is generated toward the housing portion 21. Here, at least a portion of the foreign matter generated toward the housing portion 21 is captured in the closed space 60A and prevented from entering the motor main body 10. In this way, by providing the closed space 60A and confining the foreign matter, it is possible to prevent foreign matter, such as shavings generated during press-fitting, from entering the housing portion 21. Therefore, it is possible to prevent the foreign matter from causing wear or damage to the rotating parts of the motor main body 10, the first bearing 25, etc.

[0031] Furthermore, if the hardness of the housing 20 is greater than or equal to that of the lid 30, the lid 30 side will be scraped off during press-fitting, generating foreign matter. Such foreign matter will be generated toward the control board 40 side. Here, at least a portion of the foreign matter generated toward the control board 40 side is captured in the gap 60B, preventing it from entering the control board 40 side.

[0032] In this way, by providing gap 60B and trapping foreign matter larger than the size that cannot be tolerated on the control board 40 side, it is possible to prevent foreign matter such as shavings generated during press-fitting from entering the control board 40. Therefore, it is possible to prevent the foreign matter from becoming a conductive foreign matter factor on the control board 40 and causing a breakdown of the control board 40.

[0033] As described above, by confining foreign matter generated during press-fitting in the closed space 60A and the gap 60B, the lid 30 can be fixed to the housing 20 by press-fitting alone. As a result, it is possible to eliminate the need for fixing parts such as screws and O-rings, adhesives, caulking, and other processes. Reducing the number of parts and simplifying the process in this way reduces the manufacturing cost of the rotating electrical machine 1.

[0034] As described above, the rotating electric machine 1 of this embodiment includes a motor body 10 having a rotor 11 and a stator 12, a housing 20 having a housing portion 21 that houses the motor body 10, a cover 30 that is fixed to the housing 20 and closes the opening 22 of the housing portion 21, and a control board 40 that is provided on an outward surface 30A of the cover 30 facing away from the housing portion 21 and is electrically connected to the motor body 10. The housing 20 has an inner wall 30A of the opening 22. The lid 30 has a step 23 protruding inward from its inner surface 30B facing the housing 21, and a press-fit portion 33 protruding from an inward surface 30B facing the housing 21 and press-fitted into the opening 22, the outer wall surface of the press-fit portion 33 presses against the inner wall surface of the opening 22 to form a press-fit portion 71, and the tip surface of the press-fit portion 33 abuts against the step 23 to form an abutment portion 70, and a closed space 60A surrounded by the housing 20 and the lid 30 is formed between the press-fit portion 71 and the abutment portion 70. This configuration makes it possible to prevent foreign matter such as shavings generated when the housing 21 that houses the motor main body 10 is closed from entering the housing 21.

[0035] In this embodiment, at least one of the outer wall surface of the press-fit portion 33 and the inner wall surface of the opening 22 is provided with a groove 33b that forms a gap 60B adjacent to the closed space 60A side of the press-fit portion 71, and a protrusion 38 that narrows the width of the opening of the groove 33b facing away from the press-fit portion 71. This configuration prevents foreign matter such as shavings generated when closing the housing 21 that houses the motor main body 10 from entering the control board 40. Furthermore, because the protrusion 38 is not in pressure contact with the inner wall surface of the opening 22, foreign matter such as shavings is not generated at the protrusion 38.

[0036] In this embodiment, the press-fit portion 33 has an inclined portion 33a whose outer shape becomes smaller toward the tip end surface. With this configuration, the inclined portion 33a acts as a guide, making it easier for the press-fit portion 33 to be press-fitted into the opening 22, and a closed space 60A can be formed at the corner between the inner wall surface of the opening 22 and the step portion 23.

[0037] Embodiment 2. Fig. 3 is a plan view of the outward surface 30A of the lid 30 in embodiment 2. Fig. 4 is a schematic diagram of the lid 30 in embodiment 2, in which the press-fit portion inner region 90A and the press-fit portion outer region 90B are painted differently. In the following description, the same components as those in the above-described embodiment may be denoted by the same reference numerals as appropriate, and the description thereof may be omitted.

[0038] As shown in FIG. 3 , the outward surface 30A of the lid 30 is formed with a plurality of component grooves 34. The outward surface 30A of the lid 30 is also provided with a plurality of screw holes 35 for fastening a control board 40 (not shown). The component grooves 34 and screw holes 35 can be appropriately modified to match the layout of the control board 40. The outward surface 30A of the lid 30 serves as a heat dissipation surface 37. Specifically, the lid 30 has approximately the same size as the control board 40 in a plan view, and is designed so that the heat dissipation surface 37 is close to the control board 40 in accordance with the layout of the locations (components and patterns) on the control board 40 that require heat dissipation. The lid 30 receives heat from the control board 40 via a heat dissipation material (not shown), and dissipates (transfers) the heat to the lid 30. In other words, the heat dissipation surface 37 is provided in the press-fit portion inner region 90A and the press-fit portion outer region 90B shown in FIG. 4 , within the ranges where heat dissipation from the control board 40 is required.

[0039] As shown in Fig. 4, the lid 30 has a press-fit portion inner region 90A located inside the press-fit portion 33 when viewed from the press-fit direction (axial direction), and a press-fit portion outer region 90B located outside the press-fit portion 33. Note that in Fig. 4, a dot pattern is applied to the press-fit portion inner region 90A to improve visibility of the press-fit portion inner region 90A. The press-fit portion outer region 90B is a region other than the press-fit portion inner region 90A.

[0040] 3, the outward surface 30A of the lid 30 is formed with processed portions 36, which are pressed surfaces (flat surfaces) to which force is applied when the press-fit portion 33 is press-fitted into the opening 22. The processed portions 36 are provided in the press-fit portion inner region 90A. Specifically, four processed portions 36 are provided at equal intervals of 90 degrees on the same radius from the center of the through hole 31.

[0041] By providing these processed portions 36 in the press-fit portion inner region 90A shown in Fig. 4, the external shape of the lid body 30 can be simplified and made smaller, and the precision with which the press-fit portion 33 is press-fitted into the opening 22 can be improved. The processed portions 36 may be provided across the boundary line between the press-fit portion inner region 90A and the press-fit portion outer region 90B. In this case, the external shape of the lid body 30 becomes slightly larger, but compared to when the processed portions 36 are provided in the press-fit portion outer region 90B, the external shape of the lid body 30 can be simplified and made smaller.

[0042] The pressing surface of processed portion 36 may be formed on the same plane as heat dissipation surface 37. In this way, when the pressing surface of processed portion 36 and heat dissipation surface 37 are shared, a wide range of heat dissipation surface 37 can be ensured, enabling heat dissipation over a wide area. In addition, when the pressing surface of processed portion 36 and heat dissipation surface 37 are shared, a wide range of the pressing surface can be ensured, making it easier to apply a press-fit load uniformly to lid body 30.

[0043] 3, the lid 30 is provided with a rotation restricting portion 81 that restricts rotation of the lid 30 and the housing 20 along the circumferential direction of the opening 22. The rotation restricting portion 81 may be a through hole or a non-through groove. Note that by providing a positioning pin or protrusion on the housing 20 at the same position as the rotation restricting portion 81 on the lid 30, highly accurate positioning can be achieved.

[0044] The rotation restricting portion 81 is provided in the press-fit portion outer region 90B shown in Fig. 4. If the rotation restricting portion 81 is a through-hole, providing it in the press-fit portion inner region 90A creates a path through which foreign matter outside the lid 30 can move toward the housing portion 21. In this case, foreign matter that has entered the housing portion 21 may cause the motor main body 10 to lock or short-circuit.

[0045] If the rotation restricting portion 81 does not penetrate the press-fit portion, it can be provided in the press-fit portion inner region 90A. However, providing the rotation restricting portion 81 in the press-fit portion inner region 90A requires processing other than the component groove 34 on the heat dissipation surface 37, and the area available for heat dissipation is reduced. For this reason, it is preferable to provide the rotation restricting portion 81 in the press-fit portion outer region 90B, even if it does not penetrate the press-fit portion.

[0046] As described above, in the second embodiment, the cover 30 has a press-fit portion inner region 90A located inside the press-fit portion 33 when viewed from the press-fitting direction, and a press-fit portion outer region 90B located outside the press-fit portion 33. The press-fit portion inner region 90A forms part of the heat dissipation surface 37, and also has the component groove 34 formed therein. The press-fit portion outer region 90B forms part of the heat dissipation surface 37, but because it is located away from the motor body 10, it is less affected by heat generated in the motor body 10 than the press-fit portion inner region 90A, allowing for accurate assembly of the connector 43 and the like.

[0047] In the second embodiment, there is provided a rotation restricting portion 81 that restricts rotation of the housing 20 and the lid 30 along the circumferential direction of the opening 22, and the rotation restricting portion 81 is provided in the press-fit portion outer region 90B. With this configuration, the rotation restricting portion 81 is provided in the press-fit portion outer region 90B, which is less affected by heat, so that the rotation of the housing 20 and the lid 30 can be accurately positioned. Furthermore, if the rotation restricting portion 81 is a through-hole, there is no need to form a path that communicates with the accommodation portion 21.

[0048] In the second embodiment, the outward surface 30A of the lid 30 is formed with a processed portion 36, which is a pressing surface that applies force when the press-fit portion 33 is press-fitted into the opening 22, and the processed portion 36 is provided in the press-fit portion inner region 90A or across the boundary between the press-fit portion inner region 90A and the press-fit portion outer region 90B. This configuration makes it possible to simplify and miniaturize the external shape of the lid 30, and also to increase the accuracy with which the press-fit portion 33 is press-fitted into the opening 22.

[0049] In the second embodiment, the cover 30 has a through hole 31 through which the rotating shaft 2 fixed to the rotor 11 passes, and the processed portions 36 are provided at equal intervals around the periphery of the through hole 31. This configuration makes it easier to apply a press-fitting load uniformly to the cover 30 during press-fitting.

[0050] In the second embodiment, the outward surface 30A of the lid 30 is formed with the heat dissipation surface 37, and the pressing surface is formed flush with the heat dissipation surface 37. With this configuration, when the pressing surface of the processed portion 36 and the heat dissipation surface 37 are shared, a wide area of ​​the heat dissipation surface 37 can be ensured, enabling heat dissipation over a wide area. Furthermore, when the pressing surface of the processed portion 36 and the heat dissipation surface 37 are shared, a wide area of ​​the pressing surface can be ensured, making it easier to apply a press-fit load uniformly to the lid 30.

[0051] Fig. 5 is a schematic diagram showing a first modified example of the lid 30 of the second embodiment. The lid 30 shown in Fig. 5 includes a processed portion 36 formed symmetrically with respect to a reference line (not shown) that bisects the through hole 31 in a plan view. The processed portion 36 is formed in an annular shape in a plan view, and a portion corresponding to the screw hole 35 shown in Fig. 3 is constricted into a semicircular shape.

[0052] 6 is a schematic diagram showing a second modification of the lid 30 of the embodiment 2. The lid 30 shown in FIG. 6 includes a processed portion 36 formed point-symmetrically with respect to the center of the through-hole 31.

[0053] 5 and 6, when the processed portion 36 is provided, the lid 30 can be assembled with high precision to the housing 20 because the processed portion 36 is disposed symmetrically with respect to the rotation axis 2. Note that the processed portion 36 does not have to be disposed completely symmetrically as long as it has a shape that allows the press-fit load to be uniform.

[0054] Embodiment 3. Figure 7 is a schematic diagram showing a vehicle in embodiment 3. In the following description, the same components as those in the above-described embodiments will be denoted by the same reference numerals as appropriate, and the description thereof may be omitted.

[0055] The above-described rotating electric machine 1 can be used in an electric power steering device 200 mounted on a vehicle 300 shown in Fig. 7. The vehicle 300 has a pair of wheels 301. The vehicle 300 is mounted with the electric power steering device 200. The electric power steering device 200 includes the above-described rotating electric machine 1, a steering wheel 201, a steering shaft 202, a rack and pinion gear 203, a tie rod 204, and a torque detector 205.

[0056] A steering torque is applied to the steering wheel 201 by a driver (not shown) operating the steering wheel, etc. The steering shaft 202 has an input shaft 202a connected to the steering wheel 201 and an output shaft 202b connected to a rack and pinion gear 203. The input shaft 202a and the output shaft 202b are connected to each other by a torsion bar (not shown). The torsion bar is disposed inside the torque detector 205 and passes through the torque detector 205 in the axial direction.

[0057] Steering torque applied to steering wheel 201 is transmitted to a rack (not shown) in rack-pinion gear 203 via a torsion bar in torque detector 205, steering shaft 202, and a pinion (not shown) in rack-pinion gear 203. The rack and wheels 301 are connected via tie rod 204 and knuckle arm 206. Therefore, when steering torque caused by steering wheel operation is transmitted to the rack, tie rod 204 pushes knuckle arm 206 at one wheel 301, and tie rod 204 pulls knuckle arm 206 at the other wheel 301. This imparts a steering angle to wheels 301, causing them to turn.

[0058] The motor main body 10 of the rotating electric machine 1 generates torque according to the voltage. The torque (output torque) generated by the rotating electric machine 1 is transmitted to a rack (or a tie rod 204) in a rack-and-pinion gear 203. This electric power steering device 200 is a so-called rack-assist type electric power steering device. For example, one end (output end) of the rotating shaft 2 may be engaged with the rack via a boss or the like. The output torque of the rotating electric machine 1 functions as a steering assist force, reducing the steering torque that the driver must apply when steering.

[0059] The torque detector 205 detects the steering torque applied to the steering wheel 201 by the driver. More specifically, when a steering torque is applied, a twist occurs in the torsion bar that is approximately proportional to the steering torque. The torque detector 205 detects the direction and angle of twist of the torsion bar. The torque detector 205 outputs the detected steering torque to the control board 40. The rotation sensor 42 detects the rotation speed of a rotating shaft (e.g., rotating shaft 2). The rotation sensor 42 outputs the detected rotation speed to the control board 40. The control board 40 calculates a voltage to be applied to the motor main body 10 based on the steering torque output from the torque detector 205, the rotation speed output from the rotation sensor 42, and other information. The control board 40 applies a voltage to the motor main body 10 based on the calculation result. In other words, the control board 40 performs feedback control based on the information detected by the torque detector 205 and the rotation sensor 42.

[0060] As described above, the vehicle 300 according to this embodiment includes the wheels 301 and the electric power steering device 200 having the above-described rotating electric machine 1. This configuration can prevent the electric power steering device from failing due to the intrusion of foreign matter.

[0061] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be adopted.

[0062] The rotating electric machine 1 may be used in a so-called column-assist electric power steering device in which output torque is transmitted to a steering shaft 202. Alternatively, the rotating electric machine 1 may be used in a so-called pinion-assist electric power steering device in which output torque is transmitted to a pinion in a rack and pinion gear 203. Alternatively, the rotating electric machine 1 does not have to be a motor used in an electric power steering device.

[0063] The configurations and methods described in this specification can be combined as appropriate within the scope of not contradicting each other.

[0064] 1...rotating electric machine, 2...rotating shaft, 10...motor body, 11...rotor, 12...stator, 20...casing, 21...accommodating section, 22...opening, 23...step portion, 30...lid body, 30A...outward surface, 30B...inward surface, 31...through hole, 33...press-fit portion, 33a...inclined portion, 33b...groove portion, 36...processed portion, 37...heat dissipation surface, 38...projection portion, 40...control board, 60A...closed space, 60B...gap, 70...abutment portion, 71...press-contact portion, 72...gap, 81...rotation restricting portion, 90A...press-fit portion inner region, 90B...press-fit portion outer region, 200...electric power steering device, 300...vehicle, 301...wheel

Claims

1. A rotating electric machine comprising: a motor body having a rotor and a stator; a housing having a storage section that stores the motor body; a lid fixed to the housing and closing an opening of the storage section; and a control board provided on the outward surface of the lid facing away from the storage section and electrically connected to the motor body, wherein the housing has a step protruding inward from the inner wall surface of the opening, the lid protruding on its inward surface facing the storage section and having a press-fit portion that is press-fit into the opening, the outer wall surface of the press-fit portion presses against the inner wall surface of the opening to form a press-fit portion, and the tip surface of the press-fit portion abuts against the step portion to form an abutment portion, and a closed space surrounded by the housing and the lid is formed between the press-fit portion and the abutment portion.

2. A rotating electric machine as described in claim 1, wherein at least one of the outer wall surface of the press-fit portion and the inner wall surface of the opening is formed with a groove portion that forms a gap adjacent to the side opposite the closed space side of the press-fit portion, and a protrusion that narrows the width of the opening of the groove facing the side opposite the press-fit portion.

3. A rotating electric machine according to claim 1 or 2, wherein the press-fit portion has an inclined portion whose outer shape becomes smaller toward the tip end surface.

4. A rotating electric machine according to any one of claims 1 to 3, wherein the cover has a press-fit portion inner region located inside the press-fit portion and a press-fit portion outer region located outside the press-fit portion when viewed from the press-fitting direction.

5. A rotating electric machine according to claim 4, further comprising a rotation restricting portion that restricts rotation of the housing and the cover body along the circumferential direction of the opening, the rotation restricting portion being provided in an outer region of the press-fit portion.

6. A rotating electric machine according to claim 4 or 5, wherein the outward surface of the lid body is formed with a processed portion that is a pressing surface for applying force when the press-fit portion is pressed into the opening, and the processed portion is provided in the press-fit portion inner region or straddling the boundary line between the press-fit portion inner region and the press-fit portion outer region.

7. A rotating electric machine according to claim 6, wherein the cover has a through hole through which a rotating shaft fixed to the rotor passes, and the processed portions are provided at equal intervals around the periphery of the through hole.

8. A rotating electric machine according to claim 6 or 7, wherein a heat dissipation surface is formed on the outward surface of the lid, and the pressing surface is formed in the same plane as the heat dissipation surface.

9. A vehicle comprising: a wheel; and an electric power steering device having a rotating electric machine according to any one of claims 1 to 8.

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