WO2019189301A1

WO2019189301A1 - Motor

Info

Publication number: WO2019189301A1
Application number: PCT/JP2019/013083
Authority: WO
Inventors: 浩司三分一; 貴之右田; 真郷青野
Original assignee: 日本電産株式会社
Priority date: 2018-03-29
Filing date: 2019-03-27
Publication date: 2019-10-03
Also published as: JP7275437B2; CN111937277A; JPWO2019189301A1

Abstract

This motor according to an example of the present invention has: a cylindrical housing which has an opening at one end section in the axial direction and a female thread section on an inner circumferential surface of the opening; a stator provided on the radial inside of the housing; a rotor which is provided on the radial inside of the stator and to which a member to be driven is connected; a bearing which is supported by the housing and rotatably supports the rotor around the center axis of the rotor; a bearing retaining section extending to the radial inside from the housing and abutting to the bearing from the other side in the axial direction; a pressing member which is provided in the opening of housing, has a male thread section provided on the outer circumferential surface thereof and fastened to the female thread section, and presses the bearing toward the other side in the axial direction; and a rotation restraining section which restrains the rotation of the pressing member inside the opening.

Description

motor

The present invention relates to a motor.

Conventionally, some motors hold a bearing using a fixing member such as a housing and a ring. For example, Patent Documents 1 and 2 disclose a configuration in which a bearing (bearing) that rotatably supports a rotor of a motor is sandwiched between a housing and a ring member on both sides in the axial direction. In this configuration, the ring member is fixed to the housing by a bolt and holds the bearing.

Japanese Unexamined Patent Publication No. Hei 4-97057 Japanese Patent Laid-Open No. 9-331646

When driving a ball screw or the like in the motor as described above, when the rotor is rotated, the ball screw operates along the axial direction of the rotor and the ball screw. When the ball screw operates in the axial direction, an axial reaction force acts on the rotor via the ball screw from an object driven by the ball screw. When the ring member is pushed in the axial direction via the rotor due to the reaction force or external force applied from the outside, the bolt for fixing the ring member to the housing may be loosened. Then, an axial gap is generated between the bearing, the housing, and the ring member, and the bearing and the rotor move in the axial direction when the motor is operated. In order to firmly fix the ring member, it is only necessary to increase the axial force of the bolt. For this purpose, it is necessary to increase the strength of the housing by increasing the thickness of the housing to which the bolt is fastened. Then, there is a problem that the size of the housing is increased and the cost is increased. *

In view of the above circumstances, the present invention provides a motor capable of suppressing loosening of a member that presses a bearing while suppressing increase in size and cost of the housing, and suppressing rattling of the bearing. One of the purposes.

An exemplary motor of the present invention is cylindrical and has an opening at one end in the axial direction and a female screw portion on the inner peripheral surface of the opening, and is provided inside the housing in the radial direction. A stator provided on the radially inner side of the stator, to which a member to be driven is coupled, a bearing supported by the housing and rotatably supporting the rotor around a central axis of the rotor, and the housing A bearing holding portion that extends radially inward from the other side in the axial direction with respect to the bearing, and a male screw portion that is provided in the opening of the housing and fastened to the female screw portion on an outer peripheral surface A pressing member that presses the bearing toward the other side in the axial direction, and a rotation restraining portion that restrains the pressing member from rotating inside the opening; Having.

According to the exemplary motor of the present invention, it is possible to suppress loosening of a member that presses the bearing while suppressing increase in size and cost of the housing, and it is possible to suppress the backlash of the bearing.

FIG. 1 is a cross-sectional view of an exemplary embodiment motor. FIG. 2 is a perspective view illustrating an appearance of a motor according to an exemplary embodiment. FIG. 3 is a perspective view showing a state in which the holding member of the motor according to an exemplary embodiment is removed from the housing. FIG. 4 is a cross-sectional view illustrating a configuration of a main part of a motor according to an exemplary embodiment. FIG. 5 is a perspective view illustrating an appearance of a motor according to a modification of the exemplary embodiment. FIG. 6 is a cross-sectional view illustrating a configuration of a main part of a motor according to another modification of the exemplary embodiment.

FIG. 1 is a cross-sectional view of a motor according to an embodiment. FIG. 2 is a perspective view showing the external appearance of the motor of this embodiment. FIG. 3 is a perspective view showing a state in which the pressing member of the motor of this embodiment is removed from the housing. FIG. 4 is a cross-sectional view showing the configuration of the main part of the motor of this embodiment.

As shown in FIG. 1, the motor 10 includes a housing 11, a stator 20, a rotor 30, a bearing 35, a flange portion (bearing holding portion) 14, and a pressing member 40.

The housing 11 includes a cylindrical portion 11a having a cylindrical shape, and a radially inner side from the cylindrical portion 11a at one end (right side in FIG. 1) in the axial direction along the central axis J of the cylindrical portion 11a. And an end plate portion 11b extending. The other end portion 11 c in the axial direction of the cylindrical portion 11 a of the housing 11 (left side in FIG. 1) is connected to a device to be driven that is driven by the motor 10. The end portion 11 c of the cylindrical portion 11 a opens toward the device including the drive target member 100. As shown in FIG. 2, a connecting flange portion 13 extending radially outward with respect to the central axis J is provided at the end portion 11c of the cylindrical portion 11a in order to connect the housing 11 to a device to be driven. . *

The flange portion 14 extends radially inward from the inner peripheral surface of the tubular portion 11 a of the housing 11. The flange part 14 is arrange | positioned with respect to the bearing 35 mentioned later on the other side of an axial direction. The flange portion 14 may be continuous in the circumferential direction around the central axis J, or may be provided intermittently in a part of the circumferential direction. *

As shown in FIG. 3, the housing 11 has an opening 12 provided at the center of the end plate portion 11b. A female screw portion 15 is provided on the inner peripheral surface of the opening 12. *

As shown in FIG. 1, the stator 20 is provided inside the cylindrical portion 11 a of the housing 11. The stator 20 is located outside in the radial direction with the central axis J of the rotor 30 as the center. The stator 20 mainly includes a stator core 21, a tooth portion 22, and a coil 23. *

The stator core 21 is provided on the inner peripheral surface of the cylindrical portion 11a. The stator core 21 is formed in a cylindrical shape as a whole by laminating a plurality of annular steel plates in the axial direction. The teeth portion 22 is provided on the inner side in the radial direction of the stator core 21. *

The teeth part 22 has a plurality of teeth 22a provided at equal intervals in the circumferential direction around the central axis J. The coil 23 is wound around the teeth 22a via an insulating member such as resin. *

A bus bar 24 electrically connected to the plurality of coils 23 is provided on the end 11 c side of the cylindrical portion 11 a of the housing 11. The bus bar 24 is provided with a connection terminal 25 extending to the outside of the housing 11. For example, three sets of the bus bar 24 and the connection terminal 25 are provided corresponding to each phase of the stator 20. Each connection terminal 25 is connected to a wiring (not shown) for supplying electric power to the motor 10 from the outside. *

The rotor 30 is provided on the radially inner side of the stator 20. The rotor 30 includes a rotor body 31, a permanent magnet 32, and a rotor cover 33. *

The rotor body 31 includes a cylindrical cylindrical body 31a extending in the axial direction, an end plate 31b extending radially inward from the cylindrical portion 11a, and an end plate 31b at one axial end of the cylindrical body 31a. And a columnar boss portion 31c projecting on one side in the axial direction. The rotor body 31 has a connection recess 31s that opens toward the other side in the axial direction. The driving object member 100 that is rotationally driven by the motor 10 is connected to the connection recess 31s. *

A cylindrical yoke 34 is provided at the other end in the axial direction of the cylindrical body 31a. *

A plurality of permanent magnets 32 are provided at equal intervals in the circumferential direction around the central axis J on the outer peripheral surface of the cylindrical body 31a. The rotor cover 33 has a cylindrical shape and is provided so as to cover the cylindrical body 31a of the rotor body 31 and the plurality of permanent magnets 32 from the radially outer side. The permanent magnet 32 may be annular. When the rotor body 31 is a laminated steel plate, the plurality of permanent magnets 32 may be embedded in the rotor body 31. *

The bearing 35 is provided on the radially outer side of the boss portion 31 c of the rotor body 31. The bearing 35 is a ball bearing, and includes an annular outer ring 35a, an annular inner ring 35b provided on the radially inner side of the outer ring 35a, and a plurality of balls 35c provided between the outer ring 35a and the inner ring 35b. . The inner ring 35 b of the bearing 35 is fitted to the outer peripheral surface of the boss portion 31 c of the rotor 30. The outer ring 35 a of the bearing 35 is fixed to the housing 11 by being sandwiched from both sides in the axial direction by a flange portion 14 and a pressing member 40 described later. Thus, the bearing 35 supports the rotor 30 so as to be rotatable around the central axis J. The bearing 35 is made of, for example, a steel material (iron-based alloy) for bearings. *

As shown in FIGS. 3 and 4, the opening 12 of the housing 11 is provided with a recess 16 that is recessed on the other side in the axial direction. The bearing 35 is accommodated in the recess 16. Accordingly, the flange portion 14 is disposed on the other side in the axial direction with respect to the bearing 35 in the recess 16. The flange portion 14 abuts against the outer ring 35 a of the bearing 35 from the other side in the axial direction. *

The pressing member 40 is provided in the opening 12 of the housing 11. The pressing member 40 has a tool insertion hole 42 for a tool (not shown) for rotating the pressing member 40 around the central axis J at the center. The holding member 40 has a male screw portion 45 fastened to the female screw portion 15 on the outer peripheral surface. As shown in FIG. 4, the pressing member 40 is attached to the opening 12 by fastening the male screw portion 45 to the female screw portion 15 and presses the bearing 35 toward the other side in the axial direction. Thereby, the bearing 35 is clamped from both sides in the axial direction by the pressing member 40 provided on one side in the axial direction and the flange portion 14 provided on the other side in the axial direction.

The outer diameter of the pressing member 40 is larger than the outer diameter of the bearing 35. Further, the inner diameter of the tool insertion hole 42 of the pressing member 40 is smaller than the inner diameter of the outer ring 35 a of the bearing 35. Accordingly, the pressing member 40 abuts against the outer ring 35a of the bearing 35 from one side in the axial direction. Further, the inner diameter of the female screw portion 15 of the opening 12 and the outer diameter of the male screw portion 45 of the holding member 40 are larger than the inner diameter of the flange portion 14. *

The holding member 40 is restricted by the rotation restricting portion 50 </ b> A from rotating inside the opening 12 to loosen the male screw portion 45 from the female screw portion 15. The rotation restricting portion 50 </ b> A includes at least one caulking portion 51. The caulking portion 51 is provided at a boundary portion between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. In the present embodiment, the caulking portions 51 are provided at four locations at equal intervals in the circumferential direction at the boundary between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. Each caulking portion 51 is provided, for example, by hitting a tool such as a punch so as to straddle the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12 with a hammer or a press. *

The caulking portion 51 has a convex portion 51a and a concave portion 51b. The convex portion 51 a is provided on the outer peripheral edge of the pressing member 40. The convex portion 51 a projects in the radial direction toward the other inner peripheral edge of the opening 12. The recess 51 b is provided on the inner peripheral edge of the opening 12. The recess 51 b is recessed toward the outer peripheral edge of the pressing member 40. At least a part of the convex portion 51a is accommodated in the concave portion 51b. As described above, the convex portion 51 a on the pressing member 40 side is accommodated in the concave portion 51 b on the opening 12 side, so that the pressing member 40 is restrained from rotating inside the opening 12. The caulking portion 51 may be provided with a concave portion 51b on the pressing member 40 side and a convex portion 51a on the opening 12 side. *

In the present embodiment, the housing 11 and the pressing member 40 are each made of an aluminum alloy. Thereby, the linear expansion coefficient of the material of the housing 11 becomes close to the linear expansion coefficient of the material of the pressing member 40. For this reason, it is possible to suppress the pressing member 40 from being loosened due to thermal expansion and thermal contraction. *

A coating 61 made of a material harder than the base material (aluminum alloy) constituting the pressing member 40 is provided on the surface of the pressing member 40. The coating 61 may be provided on the pressing member 40 at least in a portion that abuts against the bearing 35 in the axial direction. Further, the coating film 61 may be provided on the entire surface of the pressing member 40 that abuts against the bearing 35 in the axial direction. The coating 61 may cover the entire surface of the pressing member 40. As such a film 61, for example, an aluminum oxide film formed by alumite treatment is suitable. Further, as the coating 61, DLC (diamond-like carbon) may be used. Such a coating 61 preferably has a lower coefficient of friction than the base material (aluminum alloy) constituting the pressing member 40.

Further, a sealing material 70 is provided between the female screw portion 15 of the housing 11 and the male screw portion 45 of the pressing member 40. As the sealing material 70, an anaerobic resin or a sealing agent (adhesive) or the like is suitable. *

Such a motor 10 is supplied with current from an external generator or the like via a connection terminal 25. The supplied current is supplied to the coil 23 via the bus bar 24, and the coil 23 generates a magnetic field (alternating magnetic field). The rotor body 31 of the rotor 30 is rotationally driven around the central axis J by the interaction between the magnetic field generated by the coil 23 and the magnetic field of the permanent magnet 32 of the rotor 30. *

As shown in FIG. 1, the drive target member 100 is connected to the rotor body 31 of the motor 10. In the present embodiment, the end of the ball screw 101 is connected to the rotor body 31 as the drive target member 100. The ball screw 101 is provided with a spiral groove 101a on the outer peripheral surface. A slide member 102 is provided outside the ball screw 101 in the radial direction. The slide member 102 is cylindrical and has a spiral groove 102a on its inner peripheral surface. A plurality of balls 103 are interposed in a spiral space between the groove 101 a of the ball screw 101 and the groove 102 a of the slide member 102. When the ball screw 101 is rotationally driven around the central axis J by the motor 10, the slide member 102 slides along the axial direction. Due to the sliding of the slide member 102, the drive target member 100 exhibits a driving force along the axial direction. *

As described above, when the slide member 102 slides in the axial direction and exerts a driving force along the axial direction, a reaction force from the drive target is input to the slide member 102. The axial reaction force input to the slide member 102 is transmitted to the bearing 35 via the ball 103, the ball screw 101, and the rotor body 31. For example, when the slide member 102 slides from the rotor main body 31 along the central axis J in a direction away from the rotor main body 31, the reaction force F1 presses the bearing 35 toward the pressing member 40. When the slide member 102 slides from the rotor body 31 along the central axis J in a direction approaching the rotor body 31, the reaction force F <b> 2 presses the bearing 35 toward the flange portion 14. *

Even if the pressing member 40 is repeatedly pressed by the bearing 35 by the reaction force F1, the pressing member 40 is prevented from loosening from the opening 12 by the rotation restricting portion 50A including the caulking portion 51. In addition, due to the sealing material 70 provided between the female screw portion 15 of the housing 11 and the male screw portion 45 of the pressing member 40, the pressing member 40 is loosened by repeatedly pressing the bearing 35 with the reaction force F1. Occurrence is suppressed. *

Further, the coating 61 provided on the pressing member 40 suppresses wear of the pressing member 40 due to repeated pressing by the bearing 35 by the reaction force F1. Further, the friction due to the pressing of the bearing 35 is also suppressed by reducing the coefficient of friction between the pressing member 40 and the bearing 35 by the coating 61. *

According to the present embodiment, the motor 10 restrains the pressing member 40 provided with the male screw portion 45 fastened to the female screw portion 15 on the outer peripheral surface, and the pressing member 40 from rotating inside the opening 12. 50A of rotation restraint parts. Thereby, it is possible to prevent the pressing member 40 from loosening in the direction away from the bearing 35 in the axial direction. Therefore, it is possible to prevent the pressing member 40 from loosening without increasing the tightening force (axial force) of the pressing member 40 to prevent the loosening. Thereby, it is possible to suppress the necessity of increasing the strength of the opening 12 (housing 11) provided with the female screw portion 15 to which the male screw portion 45 of the pressing member 40 is fastened, and to suppress the increase in size and cost of the housing 11 and the like. Can do. As a result, it is possible to suppress loosening of the holding member 40 that presses the bearing 35 and to prevent the bearing 35 from rattling, while suppressing an increase in size and cost of the housing 11. *

According to the present embodiment, the pressing member 40 is restrained from rotating inside the opening 12 by the at least one caulking portion 51 provided at the boundary between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. Is done. Thereby, it is possible to prevent the pressing member 40 from loosening in the direction away from the bearing 35 in the axial direction.

According to the present embodiment, the caulking portion 51 is provided on the outer peripheral edge of the pressing member 40, provided on the inner peripheral edge of the opening 12, and the convex portion 51 a that protrudes in the radial direction toward the inner peripheral edge of the opening 12. It has a recess 51b that is recessed toward the outer periphery of the member 40 and that accommodates the protrusion 51a. Accordingly, the caulking portion 51 is provided at the boundary between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12, and it is possible to suppress the pressing member 40 from loosening in the direction away from the bearing 35 in the axial direction. *

According to the present embodiment, the housing 11 and the pressing member 40 are made of an aluminum alloy, and the bearing 35 is made of an iron-based alloy. Thus, when the pressing member 40 is made of a material softer than the bearing 35, the pressing member 40 is likely to be worn. On the other hand, even when the pressing member 40 is made of a material softer than the bearing 35, the rotation restricting portion 50A can prevent the pressing member 40 from loosening from the opening 12. *

According to the present embodiment, the outer ring 35 a of the bearing 35 abuts against the flange portion 14 and the pressing member 40 in the axial direction. According to such a configuration, the bearing 35 is reliably held while suppressing backlash in the axial direction. *

According to the present embodiment, the covering member 61 is provided on the pressing member 40. The coating 61 can suppress wear of the pressing member 40, suppress loosening of the pressing member 40 that presses the bearing 35, and suppress occurrence of rattling in the bearing 35. *

According to the present embodiment, the coating 61 reduces the friction coefficient compared to the base material of the pressing member 40, thereby suppressing wear due to pressing of the bearing 35. Therefore, it is possible to suppress loosening of the pressing member 40 that presses the bearing 35 and to prevent the bearing 35 from being loose. *

According to the present embodiment, the coating 61 covers at least a portion of the pressing member 40 that contacts the bearing 35. Thereby, wear of the pressing member 40 is suppressed by providing the minimum coating 61. *

According to the present embodiment, the sealing material 70 is provided between the female screw portion 15 of the housing 11 and the male screw portion 45 of the pressing member 40, whereby the pressing member 40 is axially moved from the bearing 35. It is possible to suppress loosening in the direction of separation. Therefore, it is possible to prevent the pressing member 40 from loosening without increasing the tightening force (axial force) of the pressing member 40 to prevent the loosening. Thereby, it is possible to suppress the necessity of increasing the strength of the opening 12 (housing 11) provided with the female screw portion 15 to which the male screw portion 45 of the pressing member 40 is fastened, and to suppress the increase in size and cost of the housing 11 and the like. Can do. As a result, it is possible to suppress loosening of the holding member 40 that presses the bearing 35 and to prevent the bearing 35 from rattling, while suppressing an increase in size and cost of the housing 11. *

(Modification)

FIG. 5 is a perspective view showing an appearance of a motor in a modification of the embodiment. The motor of this modification is different from the above-described motor only in the structure of the rotation restricting portion 50B. In addition, about the component of the same aspect as the above-mentioned embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 5, the pressing member 40 is rotated by the rotation restricting portion 50 </ b> B inside the opening 12, and the male screw portion 45 is restricted from loosening from the female screw portion 15. The rotation restricting portion 50B includes at least one welded portion 52. The welded portion 52 is provided at a boundary portion between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. In the present embodiment, the welded portions 52 are provided at four locations at equal intervals in the circumferential direction at the boundary between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. Each welded portion 52 is provided by spot welding so as to straddle the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. Further, the welded portion 52 may be provided continuously in the circumferential direction along a boundary portion between the outer peripheral edge of the pressing member 40 and the inner peripheral edge of the opening 12. Such a welded portion 52 restrains the pressing member 40 from rotating inside the opening 12. *

According to this modification, similarly to the above-described embodiment, the rotation restricting portion 50B that restricts the pressing member 40 from rotating inside the opening 12 is provided. Thereby, it is possible to prevent the pressing member 40 from loosening in the direction away from the bearing 35 in the axial direction. Therefore, it is possible to prevent the pressing member 40 from loosening without increasing the tightening force (axial force) of the pressing member 40 to prevent the loosening. Thereby, it is possible to suppress the necessity of increasing the strength of the opening 12 (housing 11) provided with the female screw portion 15 to which the male screw portion 45 of the pressing member 40 is fastened, and to suppress the increase in size, increase in cost, and the like of the housing 11. it can. As a result, it is possible to suppress loosening of the holding member 40 that presses the bearing 35 and to prevent the bearing 35 from rattling, while suppressing an increase in size and cost of the housing 11. *

Moreover, in the said embodiment, although the film 61 was provided in the pressing member 40, it is not restricted to this.

FIG. 6 is a cross-sectional view showing a configuration of a main part of a motor in another modification of the embodiment.

As shown in FIG. 6, an inclusion 62 made of a material harder than the pressing member 40 is provided between the pressing member 40 and the bearing 35 in the axial direction. The inclusion 62 is annular and has a so-called washer shape. The inclusion 62 has one surface 62 a in contact with the outer ring 35 a of the bearing 35 and the other surface 62 b in contact with the holding member 40. The inclusion 62 has a larger contact area with the pressing member 40 than a contact area with the bearing 35.

According to this modification, the inclusion 62 made of a material harder than the pressing member 40 is provided between the pressing member 40 and the bearing 35. Furthermore, the contact area with the pressing member 40 is larger than the contact area with the bearing 35 of the inclusion 62. Thereby, when repeatedly pressed by the bearing 35 by the reaction force F1, the pressure per unit area input to the pressing member 40 from the outer ring 35a of the bearing 35 via the inclusion 62 is reduced. Therefore, the pressing member 40 is less likely to loosen from the opening 12.

The inclusions 62 can be provided in combination with the coating film 61 of the above embodiment. Further, the inclusion 62 may be a material harder than the pressing member 40, and is, for example, a washer made of a metal material such as a steel material (iron-based alloy).

The inclusions 62 are not limited to an annular shape, and a plurality of inclusions 62 may be provided at intervals in the circumferential direction around the central axis J.

Applications of the motors of the above-described embodiments and modifications thereof are not particularly limited.

Moreover, in the above-mentioned embodiment or its modification, although the ball bearing was illustrated as the bearing 35, it is not restricted to this. For example, a needle roller bearing or the like can be used as the bearing 35. *

Moreover, in the above-mentioned embodiment or its modification, although the film 61, the inclusion 62, and the sealing material 70 were provided, it is good also as a structure which abbreviate | omits these. *

Although one embodiment of the present invention and modifications thereof have been described above, each configuration in the embodiment and modification, combinations thereof, and the like are examples, and addition of configurations within a scope that does not depart from the spirit of the present invention. , Omissions, substitutions and other changes are possible. Further, the present invention is not limited by the embodiment.

DESCRIPTION OF SYMBOLS 10 ... Motor, 11 ... Housing, 12 ... Opening, 14 ... Flange part (bearing holding part), 15 ... Female thread part, 20 ... Stator, 30 ... Rotor, 35 ... Bearing, 35a ... Outer ring, 35b ... Inner ring, 35c ... Ball, 40 ... holding member, 45 ... male screw part, 50A, 50B ... rotation restraint part, 51 ... caulking part, 51a ... convex part, 51b ... concave part, 52 ... welded part, 61 ... coating, 62 ... inclusion, 70 ... Sealing material, 100 ... Drive target member

Claims

A cylindrical housing having an opening at one end in the axial direction and an internal thread portion on the inner peripheral surface of the opening;

A stator provided on the radially inner side of the housing;

A rotor provided on a radially inner side of the stator, to which a member to be driven is coupled;

A bearing supported by the housing and rotatably supporting the rotor around a central axis of the rotor;

A bearing holding portion that extends radially inward from the housing and abuts against the bearing from the other side in the axial direction;

A holding member that is provided in the opening of the housing, has a male screw part fastened to the female screw part on an outer peripheral surface, and presses the bearing toward the other side in the axial direction;

A rotation restraining portion for restraining the pressing member from rotating inside the opening;

Having

motor.
The rotation restraint portion includes at least one caulking portion provided at a boundary portion between an outer peripheral edge of the pressing member and an inner peripheral edge of the opening.

The motor according to claim 1.
The caulking portion is

A convex portion provided on one of the outer peripheral edge of the pressing member and the inner peripheral edge of the opening, and protruding in the radial direction toward the other of the outer peripheral edge of the pressing member and the inner peripheral edge of the opening;

A recess provided in the other of the outer peripheral edge of the pressing member and the inner peripheral edge of the opening, and recessed toward one of the outer peripheral edge of the pressing member and the inner peripheral edge of the opening; ,

Having

The motor according to claim 2.
The rotation restricting portion is composed of at least one welded portion provided at a boundary portion between an outer peripheral edge of the pressing member and an inner peripheral edge of the opening.

The motor according to claim 1 or 2.
The housing and the pressing member are made of an aluminum alloy.

The motor according to any one of claims 1 to 4.
The bearing is a ball bearing comprising an outer ring, an inner ring provided on the radially inner side of the outer ring, and a plurality of balls provided between the outer ring and the inner ring,

The outer ring abuts against the bearing holding portion and the pressing member in the axial direction;

The motor according to any one of claims 1 to 5.
The inner diameter of the female screw portion and the outer diameter of the male screw portion are larger than the inner diameter of the bearing holding portion,

The motor according to any one of claims 1 to 6.
The pressing member is provided with a coating made of a material harder than a material constituting the pressing member on at least a surface that abuts on the bearing in the axial direction.

The motor according to any one of claims 1 to 7.
An inclusion made of a material harder than the pressing member is provided between the pressing member and the bearing in the axial direction,

The inclusion has a larger contact area with the pressing member than a contact area with the bearing,

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