WO2018179831A1

WO2018179831A1 - Motor

Info

Publication number: WO2018179831A1
Application number: PCT/JP2018/003655
Authority: WO
Inventors: 康伸柚木; 将之石川
Original assignee: 日本電産テクノモータ株式会社
Priority date: 2017-03-31
Filing date: 2018-02-02
Publication date: 2018-10-04
Also published as: CN110495078A; KR20190111111A; JPWO2018179831A1

Abstract

This motor is provided with: a rotor; a stator; a resin casing that seals at least an insulator and a winding of the stator; a plurality of bearings that rotatably support a rotating shaft at positions separated from each other in the axial direction; and a cover that covers the resin casing. The stator is provided with a plurality of bearing housing members in which the plurality of bearings are housed. The bearing housing members and the cover are conductive members. The cover is directly or indirectly electrically conductive with each of the plurality of bearing housing members.

Description

motor

The present invention relates to a motor.

Conventional motors are disclosed in Patent Document 1, Patent Document 2, and the like. In the inner rotor type molded motor described in Patent Document 1, the rotor is disposed on the inner diameter side of the stator that is molded with a mold resin to form an outer shell, and the output side and the non-output side of the output rotation shaft of the rotor are arranged. It is supported by a bearing and rotates. And a bearing is stored in the bearing house formed in the bracket arrange | positioned at the output side of a shell of a stator, and the both sides of a counter-output side.

In this inner rotor type molded motor, if a potential difference occurs between the output side bracket and the non-output side bracket, a current flows through the bearing. When current flows through the bearing, electrolytic corrosion occurs, and motor corrosion and noise occur due to electrolytic corrosion. Therefore, in the inner rotor type molded motor disclosed in Patent Document 1, the output-side bracket and the counter-output-side bracket are electrically connected via a conductive plate.

Moreover, the brushless DC motor described in Patent Document 2 includes a rotor and a stator. The stator includes an annular stator core that forms a rotating magnetic field with the rotor, and a stator coil wound around the stator core. The stator is molded integrally with a housing made of resin, and the outer surface of the housing is covered with a protective cover made of metal.

This brushless DC motor dissipates heat generated by the stator coil to the outside through a resin housing, and further covers the outer surface of the housing with a protective cover made of metal, so that the housing can be protected by an external impact. To prevent damage.

JP 2012-210064 A JP-A-9-261935

In the inner rotor type mold motor described in Patent Document 1, since the outer shell molded with the mold resin is exposed to the outside, the outer shell may be damaged by an external impact. Moreover, it becomes possible to protect an outline by attaching the protective cover of the structure of patent document 2, However, the man-hour for attaching each component is required, and an assembly operation becomes complicated and it raises cost. Connected.

Therefore, an object of the present invention is to provide a motor with reduced assembly man-hours, and to protect against external impacts and take measures against electric corrosion of bearings.

An exemplary motor of the present invention includes a rotor having a rotating shaft extending along a central axis, and a plurality of windings wound around a stator core that is radially opposed to the outer peripheral surface of the rotor via an insulator. A stator, a resin casing that seals at least the insulator and the winding of the stator, a plurality of bearings that rotatably support the rotating shaft at positions spaced apart from each other in the axial direction, and a cover that covers the resin casing The stator includes a plurality of bearing housing members in which the plurality of bearings are respectively housed, the bearing housing member and the cover are conductive members, and the cover is the plurality of bearings. It is electrically connected to each of the storage members directly or indirectly.

According to the exemplary motor of the present invention, it is possible to protect against external impacts and to prevent electric corrosion of the bearing while suppressing assembly man-hours.

FIG. 1 is an exploded perspective view of an example of a motor according to the present invention. FIG. 2 is a cross-sectional view of the motor shown in FIG. FIG. 3 is a perspective view of the stator core. FIG. 4 is a perspective view of a stator core provided in the stator. FIG. 5 is a perspective view of the rotor. FIG. 6 is a partial cross-sectional view showing a resin casing and a cover of a modified example of the motor according to the first embodiment. FIG. 7 is a partial cross-sectional view showing a resin casing and cover of another modification of the motor according to the first embodiment. FIG. 8 is a partial cross-sectional view showing a first bearing housing member and its surroundings of another modified example of the motor according to the first embodiment. FIG. 9 is a partial cross-sectional view showing a first bearing housing member and its surroundings of another modified example of the motor according to the first embodiment. FIG. 10 is an exploded perspective view of another example of the motor according to the present invention. 11 is a cross-sectional view of the motor shown in FIG. FIG. 12 is a cross-sectional view of still another example of the motor according to the present invention. FIG. 13 is an exploded perspective view of still another example of the motor according to the present invention. 14 is a cross-sectional view of the motor shown in FIG. FIG. 15 is a cross-sectional view of still another example of the motor according to the present invention. FIG. 16 is a cross-sectional view of still another example of the motor according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
FIG. 1 is an exploded perspective view of an example of a motor according to the present invention. FIG. 2 is a cross-sectional view of the motor shown in FIG. In the following description, the direction in which the central axis Ax extends, that is, the left-right direction in FIG. A direction perpendicular to the axial direction is a radial direction, and a tangential direction of a circle centering on the axis is a circumferential direction.

In this document, the axial direction is set as follows with reference to FIG. That is, in FIG. 2, a direction toward the right side in the axial direction is defined as a first direction Op, and a direction toward the left side is defined as a second direction Or. The “left direction” and “right direction” in this document are set for explanation. Therefore, these directions do not limit the direction when the motor A is actually used.

<1.1 Motor configuration>
As shown in FIG. 1, the motor A according to this embodiment includes a stator 1, a resin casing 2, a cover 3, a rotor 4, a first bearing 51, and a second bearing 52. The resin casing 2 covers the outer peripheral surface of the stator 1. That is, the motor A is a so-called molded motor in which the stator 1 is sealed with the resin casing 2. The rotor 4 is disposed inside the stator 1. The rotor 4 includes a rotating shaft 40 that extends along the central axis Ax. The rotating shaft 40 is supported by the first bearing 51 and the second bearing 52 and can rotate with respect to the stator 1. That is, the motor A according to the present embodiment is an inner rotor type DC brushless motor in which the rotor 4 rotates inside the stator 1. And a some bearing (51, 52) supports the rotating shaft 40 rotatably in the position mutually spaced apart to the axial direction.

<1.2 Stator configuration>
The stator 1 will be described with reference to a new drawing. FIG. 3 is a perspective view of the stator core. FIG. 4 is a perspective view of a stator core provided in the stator. As shown in FIGS. 3 and 4, the stator 1 includes a stator core 11, an insulator 12, and a winding 13. The stator 1 has a plurality of windings 13 wound around a stator core 11 that is radially opposed to the outer peripheral surface of the rotor 4 via an insulator 12. As shown in FIG. 2, the stator 1 includes a first bearing housing member 61 in which the first bearing 51 is housed, and a second bearing housing member 62 in which the second bearing 52 is housed. That is, the stator 1 includes a plurality of bearing housing members (61, 62) in which a plurality of bearings (51, 52) are respectively housed.

The stator core 11 has conductivity. As shown in FIG. 4, the stator core 11 includes an annular core back portion 111 and a teeth portion 112. The core back portion 111 has an annular shape that extends in the axial direction. The teeth portion 112 protrudes radially inward from the inner peripheral surface of the core back portion 111. As shown in FIG. 4, the stator core 11 includes twelve teeth portions 112. The teeth parts 112 are arranged at equal intervals in the circumferential direction. That is, in the motor A of the present embodiment, the stator 1 has 12 slots.

The insulator 12 covers the stator 11. The insulator 12 is a resin molded body. The insulator 12 covers the whole tooth portion 112 and covers both end surfaces of the core back portion 111 in the axial direction. The insulator 12 includes an insulator tooth portion 121 that covers the tooth portion 112 and an insulator core back portion 122 that covers at least the axial end of the core back portion 111. A winding wire 13 is formed by winding a conductive wire around the tooth portion 112 (insulator tooth portion 122) covered with the insulator 12. The insulator 12 insulates the stator core 11 and the winding 13 from each other. In the present embodiment, the insulator 12 is a resin molded body, but is not limited thereto. The structure which can insulate the stator core 11 and the coil | winding 13 is employable widely.

As described above, the insulator 12 insulates the stator core 11 and the winding 13. Therefore, in the stator core 11, the radially outer peripheral surface of the core back portion 111 may be exposed without being covered with the insulator 12. The stator core 11 may have a structure in which electromagnetic steel plates are laminated, or may be a single member such as powder firing or casting. Further, the stator core 11 may be configured to be divided into divided cores including one tooth portion 112, or may be formed by winding a belt-shaped member. A rotor 4 is disposed in the center of the stator 1 in the radial direction so as to penetrate in the axial direction.

The windings 13 are disposed on each of the tooth portions 112 of the stator core 11. That is, in the motor A, twelve windings 13 are arranged. The twelve windings 13 provided in the stator 1 are divided into three systems (hereinafter referred to as three phases) according to the timing at which current is supplied. These three phases are referred to as a U phase, a V phase, and a W phase, respectively. That is, the stator 1 includes four U-phase windings, four V-phase windings, and four W-phase windings. In the following description, the windings of the respective phases are collectively described as the windings 13.

In addition, the stator 1 is connected to a plurality of windings 13 or connected to a control circuit (not shown) connected to the windings 13 and a substrate Bd provided in the motor A. 131. And the crossover part 131 is arrange | positioned at the wiring part 120 with which the insulator core back part 122 which covers the axial end surface of the core back part 111 of the insulator 12 was equipped. As shown in FIG. 2, the stator 1 includes a wiring portion 120 in which a crossover wire 131 is disposed on a radially outer surface of the insulator 12 that covers an end surface of the core back portion 111 on the first direction Op side.

<1.3 Structure of resin casing and cover>
As shown in FIGS. 1 and 2, the resin casing 2 has a cylindrical shape. The resin casing 2 is a resin molded body in which the stator core 11 is sealed. That is, the resin casing 2 seals at least the insulator 13 and the winding 12 of the stator 1. As shown in FIG. 2, the motor A also covers the outer surface in the radial direction of the stator core 11. The resin casing 2 has a bottomed cylindrical shape in which at least a part of the end portion on the first direction Op side is closed. And the resin casing hole 20 extended in an axial direction is provided in the radial direction center part of a bottom part.

A concave hole 21 that is recessed in the axial direction is provided on the outer side in the radial direction of the resin casing hole 20 on the surface on the first direction Op side of the bottom. A rotating shaft 40 attached to the rotor 4 passes through the resin casing hole 20 in the axial direction. The first bearing housing member 61 is fixed to the resin casing hole 20 by insert molding. The details of the first bearing storage 61 will be described later.

As shown in FIGS. 1 and 2, the cover 3 covers the resin casing 2. The cover 3 has a bottomed cylindrical shape in which at least a part of the end portion on the first direction Op side is closed. That is, the cover 3 has a cylindrical shape extending in the axial direction. The cover 3 is formed, for example, by extruding a metal plate. And the cover hole 30 penetrated to an axial direction is provided in the radial direction center part of the bottom part of the cover 3. FIG. A casing contact portion 31 that protrudes inward in the axial direction (in the second direction Or side in FIG. 2) is provided outside the cover hole 30 in the radial direction. That is, the cover 3 includes a casing contact portion 31 that protrudes inwardly into the radial center of the bottom portion, and includes a cover hole 30 in the center of the casing contact portion 31.

The resin casing 2 is inserted into the cover 3 on the first direction Op side in FIG. Then, a press-fit portion 22 described later is press-fitted into the cover 3. When the resin casing 2 is press-fitted into the cover 3, the casing contact portion 31 overlaps the recessed hole 21 in the axial direction. Furthermore, the resin casing hole 20 and the cover hole 30 also overlap in the axial direction. The rotation shaft 40 passes through the resin casing hole 20 and the cover hole 30.

In addition, when the resin casing 2 is press-fitted into the cover 3, the casing contact portion 31 comes into contact with the recessed hole 21. The casing contact portion 31 contacts the recessed hole 21 in the axial direction. A conductive portion 312 extending in the axial direction (here, the outside, that is, the first direction Op side) is formed as an integral member at the radially inner end of the casing contact portion 31. And as for the electroconductive part 312, the outer peripheral surface of the 1st bearing storage member 61 is press-fit inside. In other words, the first bearing housing member 61 is directly electrically connected to the cover 3 by being press-fitted into the conductive portion 312. (Claim 1) In addition, a conductive portion 312 for electrically connecting the bearing housing member 61 and the cover 3 is provided. Further, the radially inner side of the conductive portion 312 is the cover hole 30, and entry of gas, water, dust, dust, and the like from the contact portion portion between the cover hole 30 and the first bearing housing member 61 is suppressed.

Next, attachment of the resin casing 2 to the cover 3 will be described. The resin casing 2 includes a press-fit portion 22 and a concave portion 23 on a radially outer peripheral surface. That is, the resin casing 2 includes a press-fit portion 22 that is press-fit into the cover 3. As shown in FIG. 2, the press-fit portion 22 is provided in a portion overlapping the stator core 11 on the outer peripheral surface of the resin casing 2 in the radial direction. That is, the press-fit portion 22 overlaps the stator core 22 when the resin casing 2 is viewed in the radial direction. The resin casing 2 is inserted into the opening of the cover 3 from the end on the side where the recess 23 is formed. Thereafter, the resin casing 2 is fixed to the cover 3 by press fitting.

That is, the resin casing 2 is press-fitted into the inner peripheral surface of the cover 3 at the press-fitting portion 22. The press-fit portion 22 is provided at a position overlapping the stator core 11 in the radial direction. At the time of press fitting, force acts on the resin casing 2 from the cover 3 in the radial direction and the axial direction. Since the press-fit portion 22 is provided at a position that overlaps the stator core 11 having a higher strength than the resin of the resin casing 2 in the radial direction, even if a force is applied from the cover 3 during press-fit, the deformation of the resin casing 2 is unlikely to occur. .

The concave portion 23 overlaps with the wiring portion 120 in which the crossover portion 131 of the insulator 12 on the outer peripheral surface of the resin casing 2 is arranged in the radial direction. The recessed part 23 is provided in the edge part by the side of the 1st direction Op of the resin casing 2, and is formed continuously in the circumferential direction. In this embodiment, although formed in the radial direction edge part of the resin casing 2, it is not limited to this.

Also, depending on the conditions of the installation location of the motor A, water contained in the air inside the motor A may condense and the condensed water may accumulate. Air is also accumulated in the recess 23, and moisture contained in the accumulated air may condense. Therefore, the outer peripheral surface of the resin casing 2 is provided with a concave groove 200 extending from the concave portion 23 toward the second direction Or side. And the drain hole 301 which connects the exterior of the cover 3 and the ditch | groove 200 in the position which continues with the ditch | groove 200 of the cover 3 is provided.

Thus, the condensed water accumulated in the recess 23 passes through the groove 200 and is discharged to the outside through the drain hole 301. Note that, for example, in the case of a structure that is not affected or hardly affected even when condensed water is generated due to insulation of an electric circuit, the recessed groove 200 and the drain hole 301 may be omitted. Even if the recessed groove 200 and the drain hole 301 are omitted, the condensed water evaporates into the air in the recessed portion 23 by the heat when the motor A is driven.

The resin casing 2 is inserted into the cover 3 from the side where the recess 23 is provided in the axial direction, and fixed by press-fitting. When the resin casing 2 is press-fitted into the cover 3, a gap Gp is formed in the radial direction between the portion where the recess 23 is formed and the inner surface of the cover 3.

Further, as shown in FIG. 2, the radial thickness of the portion of the resin casing 2 where the recess 23 is provided is thinner than the thickness of the other portion of the resin casing 2. That is, the portion where the concave portion 23 is provided is a thin portion 24 having a smaller thickness than other portions. In some cases, a current flows through the crossover part 131 and the crossover part 131 is heated. At this time, by forming the thin portion 24, the heat of the connecting wire portion 131 is easily released to the outside of the resin casing 2.

<1.4 Rotor configuration>
FIG. 5 is a perspective view of the rotor. As shown in FIG. 5, the rotor 4 includes a rotor core 41, a plurality of magnets 42, and a mold part 43. The rotor core 41 includes a tubular member 411 extending in the axial direction and a shaft support member 412 disposed on the radially inner side of the tubular member. The cylindrical member 411 and the shaft support member 412 are fixed to each other by a mold part 43 which is a resin molded product. The rotor core 41 is a magnetic body. The rotor core 41 may be a laminated body in which magnetic plates are laminated in the radial direction, or may be a molded body formed by sintering a powder as the same member, for example.

The rotary shaft 40 has a cylindrical shape. The rotary shaft 40 passes through the central portion in the radial direction of the shaft support member 412 of the rotor core 41. The rotating shaft 40 and the shaft support member 412 are relatively fixed. Examples of the fixing method include press-fitting and welding, but are not limited thereto. A method that can fix the rotating shaft 40 and the shaft support member 412 can be widely employed. That is, the rotating shaft 40 is fixed to the rotor 4, and the rotating shaft 40 rotates about the central axis Ax when the rotor 4 rotates.

The plurality of magnets 42 are arranged on the radially outer side of the rotor core 41. In the rotor 4 of the present embodiment, a plurality of magnets 42 are arranged side by side in the circumferential direction. For example, the rotor core 41 includes eight magnets 42. In the present embodiment, the plurality of magnets 42 are arranged, but the present invention is not limited to this. For example, a magnet in which N poles and S poles are alternately magnetized in the circumferential direction may be used for a cylindrical magnetic body.

That is, in the rotor core 41, the N pole and the S pole are used as a pair of magnetic poles, and a plurality of pairs of magnetic poles are provided. The magnet 42 is fixed to the rotor core 41 by, for example, a resin mold. The method of fixing the magnet 42 is not limited to resin molding, and a method that does not adversely affect the rotation of the rotor 4 such as adhesion, welding, or a mechanical fixing method is employed.

<1.5 Bearing configuration>
The rotating shaft 40 is press-fitted into the first bearing 51 and the second bearing 52 at two locations separated in the axial direction. That is, the rotating shaft 40 is rotatably supported by the first bearing 51 and the second bearing 52 at two different locations in the axial direction. The end of the rotary shaft 40 on the second direction Or side is press-fitted into the inner ring of the second bearing 52. A portion on the first direction Op side is press-fitted into the inner ring of the first bearing 51 with respect to a portion press-fitted into the second bearing 52 of the rotary shaft 40.

The first bearing 51 is housed in the first bearing housing member 61. The second bearing 52 is housed in the second bearing housing member 62. Although the details will be described later, the first bearing housing member 61 and the second bearing housing member 62 are fixed to the resin casing 2 directly or indirectly. Accordingly, the rotating shaft 40 is rotatably supported by the resin casing 2 (the stator 1 covered with the resin casing 2) by the pair of

bearings

51 and 52.

A shaft retaining ring 401 is attached to the rotating shaft 40 on the first direction Op side, and a shaft retaining ring 402 is attached to an end portion on the second direction Or side. The shaft retaining ring 401 is in contact with the first bearing 51. The shaft retaining ring 402 is in contact with the second bearing 52. Note that the shaft retaining ring 401 and the shaft retaining ring 402 are fixed by being fitted into a groove provided on the outer peripheral surface of the rotating shaft 40. The shaft retaining ring 401 is in contact with the inner ring of the first bearing 51 in the second direction Or side. The shaft retaining ring 401 limits the movement of the rotary shaft 40 in the first direction Op relative to the first bearing 51.

The shaft retaining ring 402 is in contact with the first direction Op side of the inner ring of the second bearing 52. The shaft retaining ring 402 restricts the movement of the rotating shaft 40 toward the second direction Or with respect to the second bearing 52. The axial movement of the first bearing 51 and the second bearing 52 with respect to the stator 1 is relatively restricted, and the axial movement of the rotating shaft 40 with respect to the stator 1 is restricted. The shaft retaining rings 401 and 402 employ, for example, shaft retaining rings generally called C-ring and E-ring, but are not limited thereto. A configuration that can contact the inner rings of the pair of

bearings

51 and 52 and limit the movement of the rotating shaft 40 can be widely employed. In addition, in each embodiment in this document, although the rotating shaft 40 is rotatably supported by two bearings (the 1st bearing 51 and the 2nd bearing 52), it is not limited to this. It may be supported by three or more bearings.

<1.6 Configuration of bearing housing member>
Here, the first bearing housing member 61 and the second bearing housing member 62 are made of metal such as iron or brass. That is, the bearing housing members (61, 62) and the cover 3 have conductivity.

<1.6.1 First Bearing Housing Member>
The first bearing housing member 61 has a cylindrical shape in which the first bearing 51 can be housed. The end portion on the one axial side of the first bearing housing member 61 is provided with an end surface portion 610 penetrating in the axial direction at the central portion in the radial direction. Further, the end portion on the other axial side of the first bearing housing member 61 includes a flange portion 611 extending outward in the radial direction. At least a part of the flange portion 611 is insert-molded in the resin casing 2. The first bearing housing 61 is fixed to the resin casing 2 by insert molding. The flange portion 611 may be provided with a through portion in the axial direction. By filling the penetration part with resin at the time of insert molding, the movement of the first bearing housing member 61 in the circumferential direction is restricted, that is, the rotation is prevented.

Note that the through portion is not limited to the hole as long as the rotation can be reliably prevented by the resin, and may be, for example, a concave portion recessed radially inward or a convex portion protruding radially outward. Further, the flange portion 611 itself may be formed in a polygonal shape (for example, a triangle or a quadrangle) or an elliptical shape to prevent rotation. The first bearing housing member 61 is fixed to the resin casing 2 such that the center axis thereof coincides with the center axis Ax of the stator 1 covered with the resin casing 2. The outer ring of the first bearing 51 is press-fitted into the first bearing housing member 61.

<1.6.2 Second bearing housing member>
As shown in FIG. 2, the second bearing housing member 62 holds the second bearing 52. The second bearing housing member 62 includes a housing portion 621 and an outer cylinder portion 620. The storage portion 621 has a cylindrical shape and stores the second bearing 52 therein. The outer ring of the second bearing 52 is press-fitted into the storage portion 621.

The outer cylinder part 620 has a larger diameter than the storage part 621, and the end part of the cover 3 in the second direction Or side is press-fitted inside the outer cylinder part 620. A portion of the cover 3 that is press-fitted into the outer tube portion 620 at the end portion on the second direction Or side is the cover press-fit portion 300. That is, the cover 3 is directly electrically connected to each of the plurality of bearing housing members (61, 62).

That is, after the second bearing 52 is press-fitted into the storage part 621, the cover press-fitting part 300 of the cover 3 is press-fitted into the outer cylinder part 620 of the second bearing storage member 62. Then, when the resin casing 2 is press-fitted into the second bearing housing member 62, the second bearing 62 is fixed to the stator 1 covered with the resin casing 2. The outer ring of the second bearing 52 is fixed to the stator 1, and the center axis of the second bearing 52 coincides with the center axis Ax of the stator 1.

As shown in FIG. 2, the storage part 621 and the outer cylinder part 620 are formed of the same member. Here, the second bearing housing member 62 is manufactured by drawing a metal plate. However, it is not limited to this.

In the conductive portion between the cover 3 and the bearing housing member (first bearing housing member 61), the outer peripheral surface of the bearing housing member (first bearing housing member 61) is press-fitted into the other (the conductive portion 312 of the cover 3). A cylindrical press-fit portion 612 is provided. Further, in the conductive portion between the cover 3 and the bearing housing member (second bearing housing member 62), the outer peripheral surface of the cover 3 is press-fitted into the other (the outer cylinder portion 620 of the second bearing housing member 62). Part (cover press-fitting part 300).

<1.7 Other components>
As shown in FIG. 2, in the motor A, the second direction Or side of the cover 3 is press-fitted into the outer cylinder portion 620 of the second bearing housing member 62. Therefore, entry of foreign matters such as water, dust, and dust from the gap between the outer cylinder portion 620 and the cover press-fit portion 300 is suppressed. On the other hand, the first direction Op side of the motor A includes a bearing housing portion hole in the end surface portion 610 of the first bearing housing portion 61 through which the rotating shaft 40 passes. The bearing housing portion hole has such a size that a gap is formed between the bearing housing hole and the rotating shaft 40 so as not to disturb the rotation of the rotating shaft 40. From this clearance, foreign matters such as water, dust, and dust are likely to enter the motor A. Therefore, the motor A includes a bearing-side intrusion preventing member 71 and a shaft-side intrusion preventing member 72 for suppressing entry of foreign matter from the first bearing housing member 61.

As shown in FIG. 2, the bearing-side intrusion preventing member 71 covers the outer surface of the first bearing housing member 61. And it surrounds the outer side of the rotating shaft 40, and is extended to radial direction. The bearing-side intrusion preventing member 71 is made of, for example, a material such as rubber, and is in close contact with the first bearing housing member 61. Further, the bearing-side intrusion preventing member 71 is attached with a gap between the bearing 40 and the rotating shaft 40, that is, while maintaining non-contact.

Further, the shaft side intrusion preventing member 72 is disposed so as to surround the radially outer side of the bearing side intrusion preventing member 71. The shaft side intrusion preventing member 72 is disposed in the groove 400 provided in the rotating shaft 40. Thereby, the movement of the shaft side intrusion preventing member 72 in the axial direction is limited. By reducing the space between the bearing side intrusion prevention member 71 and the shaft side intrusion prevention member 72, entry of foreign matter into the motor A is suppressed. That is, the bearing-side intrusion preventing member 71 and the shaft-side intrusion preventing member 72 are attached to the motor A at the same time, thereby suppressing the entry of foreign matter into the motor A.

A part of the tip of the shaft side intrusion preventing member 72 on the second direction Or side overlaps the concave hole 21. The casing contact portion 31 of the cover 3 is also provided in the recessed hole 21, but the shaft side intrusion prevention member 72 is fixed to the rotating shaft 40 in a non-contact state with the casing contact portion 31. That is, a part of the opening of the shaft side intrusion preventing member 72 is disposed in the recessed hole 21. And since the casing contact part 31 and the shaft side penetration | invasion prevention member 72 are non-contact, the rotating shaft 40 does not restrict | limit rotation.

Further, a substrate Bd and a protective sheet Is are provided on the resin casing 2 on the second direction Or side of the stator 1. On the substrate Bd, a control circuit (not shown) for controlling the timing of the current supplied to the plurality of windings 13, the magnitude of the current, and the like is mounted. Note that the control circuit may be provided outside the motor A, and in that case, the substrate Bd may be omitted. The protective sheet Is is an insulating member disposed between the substrate Bd and the second bearing housing member 62. In the case of a motor that does not include the substrate Bd, the protective sheet Is may be omitted.

<1.8 Motor operation>
The operation of the motor A shown above will be described. When the motor A is driven, a current is supplied to the winding 13. At this time, the winding 13 generates heat due to the current. At this time, the stator core 11 is also heated by the heat of the winding 13. Stator core 11 and winding 13 are covered with resin casing 2. The heat of the stator core 11 and the winding 13 is transmitted to the resin casing 2.

Resin casing 2 heat is transferred to the cover 3. The cover 3 is mainly made of a metal material and has a smaller linear expansion coefficient than the resin casing 2. Thereby, the difference of the deformation | transformation amount by the thermal expansion of the resin casing 2 and the cover 3 generate | occur | produces. However, the resin casing 2 and the cover 3 are press-fitted in the press-fit portion 22 of the resin casing 2. Therefore, since the heat of the resin casing 2 is transmitted to the cover 3 and radiated, the thermal expansion of the resin casing 2 is suppressed in the press-fit portion 22.

In the resin casing 2, the insulator 12 is sealed with the resin casing 2 at a portion shifted in the axial direction from the press-fit portion 22. The insulator 12 is resin, and the linear expansion coefficient of the insulator 12 is larger than that of the stator core 11. Therefore, the portion of the resin casing 2 that does not overlap the stator core 11 in the radial direction is more deformed outwardly in the radial direction due to thermal expansion than the press-fit portion 22 that overlaps the stator core 11 in the radial direction. In addition, since the distance from the stator core 11 to the cover 3 is further away, the heat dissipation is inferior to the press-fit portion 22. Therefore, problems such as distortion and displacement of the resin casing 2 due to a difference in deformation amount due to thermal expansion between the insulator 12 and the cover 3 occur.

In addition, on the opening side of the cover 3 of the resin casing 2 (in the second direction Or side in FIG. 2), deformation due to thermal expansion of the resin casing 2 escapes to the opening side. On the other hand, the back side of the cover 3 (the first direction Op side in FIG. 2) does not have a place to escape deformation due to thermal expansion. Therefore, in the motor A, a gap Gp is provided between the cover 3 and the resin casing 2 outside the insulator 12 in the radial direction.

Thereby, a difference in deformation amount between the resin casing 2 and the cover 3 at a position shifted in the axial direction from the stator core 11 of the resin casing 2 (in particular, the back side in the press-fitting direction) is absorbed by the gap Gp. Thereby, malfunctions, such as a distortion | strain and shift | offset | difference of the resin casing 2 by the difference of the deformation amount by the thermal expansion of the resin casing 2 and the cover 3, can be suppressed.

According to the motor A of the present embodiment, a gap is provided in a portion where a difference in deformation amount due to heat between the resin casing 2 and the cover 3 becomes large. By absorbing the difference in deformation amount due to heat between the resin casing 2 and the cover 3 with the gap Gp, distortion, deviation, and the like due to the difference in thermal deformation amount can be suppressed. Moreover, the clearance gap between the resin casing 2 and the cover 3 can be easily formed by forming the recessed part 23 in the resin casing 2. FIG. Further, a portion of the resin casing 2 provided with the recess 23, that is, a portion overlapping the recess 23 in the radial direction in FIG. 2 is a thin-walled portion 24 thinner than the other portions of the resin casing 2. As described above, by providing the thin portion 24, it is easy to discharge heat generated when a current flows through the crossover portion 131 to the outside of the resin casing 2.

<About the electric corrosion of the 1.8.1 bearing>
In the conventional motor such as the cited document, when a potential difference is generated between the outer ring and the inner ring of the first bearing 51 or between the outer ring and the inner ring of the second bearing 52, the outer ring of the first bearing 51 and the second bearing 52 A discharge (spark) may occur between the ball, the inner ring and the ball. Due to the occurrence of electric discharge, the surface of the outer ring, ball and inner ring of the bearing is damaged, so-called electrolytic corrosion of the bearing occurs. The electric corrosion of the first bearing 51 and the second bearing 52 causes vibration and noise of the motor A. As a cause of electrolytic corrosion, driving of a switching element included in an inverter circuit for driving the motor A with high frequency and high voltage can be mentioned. Other factors include the potential state of the stator core and the rotor core 41, and the like.

Therefore, in the motor A according to the present embodiment, electrolytic corrosion of the bearing is suppressed by the following method. The outer ring of the first bearing 51 is housed in a first bearing housing member 61 having conductivity. The outer ring of the second bearing 52 is housed in a second bearing housing member 62 having conductivity. The cover 3 is directly connected to each of the first bearing housing member 61 and the second bearing housing member 62. As a result, the outer ring of the first bearing 51 and the outer ring of the second bearing 52 are electrically connected, so that the potential difference between the outer ring and the inner ring of the first bearing 51 and between the outer ring and the inner ring of the second bearing 52 is increased. It becomes small and generation | occurrence | production of the electric corrosion of the bearing (51, 52) of the motor A can be suppressed.

In the motor A, the first bearing 51 and the second bearing 52 can be rotated with high accuracy over a long period of time by suppressing the occurrence of electrolytic corrosion of the bearing. Thereby, the stable operation | movement of the mold motor A over a long period of time is attained. That is, the life of the molded motor A can be extended. Further, the cover 3 electrically connects the outer ring of the first bearing 51 and the outer ring of the second bearing 52, and a member (for example, a conductive tape or the like) for conducting is unnecessary. The cover 3 is an exterior body that protects the motor A from impact and vibration. The first bearing housing member 61 is press-fitted into the conductive portion 312 of the cover 3. Further, the second bearing housing member 62 is press-fitted into the outer cylinder portion 620 at the end portion on the second direction Or side of the cover 3. As described above, the first bearing housing member 61 and the second bearing housing member 62 are fixed to the cover 3 by press fitting. Thereby, the 1st bearing storage member 61 and the 2nd bearing storage member 62, and the cover 3 cannot become a non-contact state, and can suppress generation | occurrence | production of electrolytic corrosion stably.

<1.9 Modification>
<1.9.1 Modification 1>
A modification of the motor shown in this embodiment will be described with reference to the drawings. FIG. 6 is a partial cross-sectional view showing a resin casing and a cover of a modified example of the motor according to the present embodiment. The motor A1 shown in FIG. 6 has the same configuration as the motor A shown in FIG. 2 except that the resin casing 2a1 and the cover 3a1 are different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

In the motor A1 shown in FIG. 6, the outer peripheral surface of the resin casing 2a1 gradually decreases in diameter toward the back side in the press-fitting direction, that is, toward the first direction Op side in FIG. That is, the outer peripheral surface of the resin casing 2a1 is an inclined surface (tapered surface) having a small diameter on the back side in the press-fitting direction. The cover 3a1 has a shape into which the resin casing 2a1 can be inserted. The cover 3a1 has a cylindrical shape and gradually becomes smaller in diameter toward at least the back side of the inner peripheral surface in the press-fitting direction, that is, the first direction Op side in FIG. That is, the inner diameter of the cover 3a1 gradually decreases toward the press-fitting direction of the resin casing 2a1. By changing the shapes of the resin casing 2a1 and the cover 3a1, the insertion becomes easy. Moreover, since the press-fitting portion 221 is an inclined surface, the deformation amount of the resin casing 2a1 during press-fitting can be reduced. Thereby, generation | occurrence | production of distortion etc. of the stator 1 is easy to be suppressed.

<1.9.2 Modification 2>
A modification of the motor shown in this embodiment will be described with reference to the drawings. FIG. 7 is a partial cross-sectional view showing a resin casing and a cover of another modified example of the motor according to the present embodiment. The motor A2 shown in FIG. 7 has the same configuration as the motor A shown in FIG. 2 except that the resin casing 2a2 and the cover 3a2 are different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

In the motor A2 shown in FIG. 7, the outer peripheral surface of the resin casing 2a2 gradually decreases in diameter toward the inner side in the press-fitting direction, that is, toward the first direction Op in FIG. That is, the outer peripheral surface of the resin casing 2a2 has a plurality of different outer shapes. And as for the outer peripheral surface of the resin casing 2a2, the back | inner side of a press injection direction is a small diameter, and a level | step difference is formed in the part from which an external shape changes. The cover 3a2 has a shape into which the resin casing 2a2 can be inserted. The cover 3a2 has a cylindrical shape, and at least the back side in the press-fitting direction of the inner peripheral surface, that is, the first direction Op side in FIG. That is, the inner diameter of the cover 3a2 decreases stepwise toward the press-fitting direction of the resin casing 2a2.

Insertion becomes easy by providing the shape of the resin casing 2a2 and the cover 3a2. Further, the step of the resin casing 2a2 and the step of the cover 3a2 can be brought into contact with each other so as to be positioned when the resin casing 2a2 is inserted into the cover 3a2. Further, the press-fitting portion 222 of the resin casing 2a2 comes into contact with the portion into which the cover 3a2 is press-fitted and press-fitting is started. Thereby, the force which acts by press fit can be reduced. The amount of deformation of the resin casing 2a2 during press fitting can be reduced. Thereby, generation | occurrence | production of distortion etc. of the stator 1 is easy to be suppressed.

<1.9.3 Modification 3>
A modification of the motor shown in this embodiment will be described with reference to the drawings. FIG. 8 is a partial cross-sectional view showing a first bearing housing member and its surroundings of another modified example of the motor according to the present embodiment. The motor A3 shown in FIG. 8 has the same configuration as the motor A shown in FIG. 2 except that the resin casing 2a3 and the cover 3a3 are different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

As shown in FIG. 8, the resin casing 2 a 3 is provided with a notch 210 in the recessed hole 21. The notch 210 is provided at the edge of the resin casing hole 20 and extends in the axial direction. Further, the casing contact portion 31 of the cover 3a3 includes a conductive portion 313. The conductive portion 313 extends radially inward from the casing contact portion 31. In addition, the conductive portion 313 is partially bent and shifted to the second direction Or side. The conductive portion 313 overlaps the notch 210 provided in the resin casing 2a3 in the axial direction.

The conductive portion 313 and the flange portion 611 of the first bearing housing member 61 overlap in the axial direction inside the notch 210. Then, the conductive portion 313 and the flange portion 611 are fixed with the screw Bt. Thereby, the conductive part 313 and the flange part 611 are electrically connected. That is, the cover 3a3 and the first bearing housing member 61 are electrically connected. Thereby, the cover 3a3 electrically connects the first bearing housing member 61 and the second bearing housing member 62. And in motor A3, the outer ring | wheel of the 1st bearing 51 and the outer ring | wheel of the 2nd bearing 52 become the same electric potential, and the electric corrosion of each bearing is suppressed.

In addition, in motor A3 of this modification, although the electrically-conductive member 313 and the flange part 611 were fixed using the screw Bt, it is not limited to this. For example, a fixing tool such as a rivet may be used. Furthermore, welding, adhesion using a conductive adhesive, or the like may be used. Furthermore, the conductive portion 313 may be configured to be elastically deformable, and may be pressed (contacted) against the flange portion 611 by the elastic force of the conductive portion 313. Moreover, these are examples of a method of fixing the conductive portion 313 and the flange portion 611, and are not limited thereto. A method of electrically connecting the conductive portion 313 and the flange portion 611 can be widely employed.

<1.9.4 Modification 4>
A modification of the motor shown in this embodiment will be described with reference to the drawings. FIG. 9 is a partial cross-sectional view showing a first bearing housing member and its surroundings of another modified example of the motor according to the present embodiment. The motor A4 shown in FIG. 9 has the same configuration as the motor A shown in FIG. 2 except that the cover 3a4 is different. Therefore, substantially the same parts are denoted by the same reference numerals, and detailed description of the same parts is omitted.

As shown in FIG. 9, the cover 3 a 4 includes a plurality of conductive portions 314 on the radially inner side of the casing contact portion 31. Here, four conductive portions 314 are provided. The conductive portion 314 extends radially inward, and the tip is bent in the axial direction (here, the first direction Op side). The conductive portion 314 has a bent tip that contacts the outer peripheral surface of the first bearing housing member 61. The bent end of the conductive portion 314 is inclined inward in the radial direction, and pushes the outer peripheral surface of the first bearing housing member 61 inward. Thereby, the tip of the conductive portion 314 is electrically connected to the first bearing housing member 61. Note that the conductive portion 314 can be configured not to easily deform. In this case, the first bearing housing member 61 is press-fitted into the conductive portion 314.

As shown in the motor A4, the cover 3a4 electrically connects the first bearing housing member 61 and the second bearing housing member 62. And in motor A4, the outer ring | wheel of the 1st bearing 51 and the outer ring | wheel of the 2nd bearing 52 become the same electric potential, and the electric corrosion of each bearing is suppressed.

Second Embodiment
Another example of the motor according to the present invention will be described with reference to the drawings. FIG. 10 is an exploded perspective view of another example of the motor according to the present invention. 11 is a cross-sectional view of the motor shown in FIG. As shown in FIGS. 10 and 11, the resin casing 2b of the motor B is provided with a step portion 25 extending radially outward on the second direction Or side. A plurality (four in this case) of stepped portions 25 are provided in the resin casing 2b. As for the step part 25, the resin casing 2b is located in the same position in the axial direction, and is located in the circumferential direction at equal intervals. And the cover 3b is provided with the contact part 311 which protruded outside from the outer peripheral surface. The contact portion 311 comes into contact with the step portion 25 when the resin casing 2b is press-fitted into the cover 3b. The contact portion 311 contacts the surface of the step portion 25 in the press-fitting direction (the first direction Op side in FIG. 11).

Further, the portion between the contact portions 311 adjacent to each other in the circumferential direction of the cover 3b extends from the contact portion 311 to the opening side (the second direction Or side in FIG. 11) along the axial direction. Further, in the motor B of the present embodiment, the resin casing 2 b is directly press-fitted into the outer cylinder portion 620 of the second bearing housing member 62.

This step portion 25 is a mounting convex portion for mounting the motor B to the device. Therefore, a fixing tool such as a screw penetrates the step portion 25. And the contact part 311 which contacts the step part 25 formed with the same member as the resin casing 2b is formed with the same member as the cover 3b whose strength is higher than that of the resin casing 2b. Thereby, the motor B can be firmly fixed. Further, even if vibration, impact, or the like acts, the motor B is difficult to drop off. Note that the number and position of the stepped portions 25 are not limited to those described above, and are changed depending on the shape and position of an attachment location (not shown) of the device to which the motor B is attached.

In the resin casing 2b, the step portion 25 is a convex portion arranged in the circumferential direction. The space between the step portions 25 arranged in the circumferential direction is a curved surface continuous in the axial direction (that is, a curved surface obtained by cutting off a part of the circumferential shape of the columnar shape). A portion between the contact portions 311 adjacent to each other in the circumferential direction of the cover 3b includes an extending portion 3111 extending toward the second axial direction Or side. An end of the extending portion 3111 on the second direction Or side is a cover press-fitting portion 300 and is press-fitted into the second bearing housing member 62.

The cover 3 b is electrically connected to the first bearing housing member 61 and the second bearing housing member 62. That is, the outer ring of the first bearing 51 and the outer ring of the second bearing 52 have the same potential, and the occurrence of electrolytic corrosion of the first bearing 51 and the second bearing 52 is suppressed.

Other features are the same as in the first embodiment.

<3. Third Embodiment>
FIG. 12 is a cross-sectional view of still another example of the motor according to the present invention. In the motor C shown in FIG. 12, the stator 1c and the resin casing 2c are different, but the other parts are the same as those of the motor A of the first embodiment. Therefore, substantially the same parts as those of the motor A having the configuration of the motor C are denoted by the same reference numerals, and detailed description of the same parts is omitted.

As shown in FIG. 12, the stator 1c of the motor C has an insulator core back portion 122 at the end of the insulator 12 on the first direction Op side. And the insulator core back part 122 is provided with the wiring part 120c by which the crossover part 131 is arrange | positioned. And the recessed part 23c is formed in the position which overlaps with the wiring part 120c of the resin casing 2c in an axial direction.

And the part of the recessed part 23c is the thin part 24c. A gap Gp is provided between the recess 23c and the cover 3c overlapping in the axial direction.

The press-fit portion 22 of the resin casing 2c is provided on the outer peripheral surface. Therefore, when the resin casing 2c is press-fitted into the cover 3c, a force during press-fitting acts on the outer peripheral surface of the resin casing 2c. In the motor C, the recess 23c is provided at the end on the first direction Op side in the axial direction, so that the force during press-fitting is less likely to concentrate on the recess 23c. Thereby, the shift | offset | difference with respect to the resin casing 2c of the cover 3c is also suppressed. From this, the resin casing 2c can make the 1st bearing accommodating member 61 and the 2nd bearing accommodating member 62 electrically conduct | electrically_connected.

Other features are the same as in the first embodiment.

<4. Fourth Embodiment>
Still another example of the present invention will be described with reference to the drawings. FIG. 13 is an exploded perspective view of still another example of the motor according to the present invention. 14 is a cross-sectional view of the motor shown in FIG. The motor D of the present embodiment has the same configuration as the motor A of the first embodiment, except for the cover, the first bearing housing member 61d, the second bearing housing member 62d, and the bearing side intrusion prevention member 71d. Therefore, in the configuration of the motor D, parts that are substantially the same as the configuration of the motor A are denoted by the same reference numerals, and detailed description of the same parts is omitted.

<4.1 Cover>
As shown in FIGS. 13 and 14, the cover of the motor D includes a first cover member 3da and a second cover member 3db. That is, the cover covers the resin casing 2 from one side in the axial direction (first direction Op side) and the second cover covers the resin casing 2 from the other side in the axial direction (second direction Or side). Cover member 3db. The first direction Op of the resin casing 2 is press-fitted into the first cover member 3da. Further, the second direction Or side of the resin casing 2 is inserted into the second cover member 3db. In the motor D of the present embodiment, the resin casing 2 is press-fitted into the first cover member 3da on the first direction Op side, but is not limited thereto. For example, the second direction Or side of the resin casing 2 may be press-fitted into the second cover member 3db. Moreover, both may be press-fitted. Which of the first cover member 3da and the second cover member 3db is to be press-fitted with the resin casing 2 is determined by the position of the press-fitting portion 22 of the resin casing 2.

<4.2 First cover member>
As shown in FIGS. 13 and 14, the first cover member 3da has a bottomed cylindrical shape with the end on the first direction Op side closed. The first cover member 3da includes a first flange 32 that extends outward in the radial direction at an end portion on the second direction Or side. That is, the first cover member 3da has a first flange 32 that extends radially outward from the outer peripheral surface. As shown in FIG. 11, the first flange 32 is a quadrangle (for example, a square) when viewed in the axial direction. In addition, the shape which can be attached to the attachment location of the apparatus (not shown) to which the motor D is attached is employ | adopted for the 1st flange 32. FIG.

Also, the radial center of the bottom portion of the first cover member 3da and the first bearing housing member 61d are formed of the same member. That is, the cover (first cover member 3da) holds at least one of the plurality of bearings (bearing 51). The first bearing housing member 61d and the bearing side intrusion preventing member 71d are formed of the same member. That is, the first cover member 3da, the first bearing housing member 61d, and the bearing side intrusion preventing member 71d are formed of the same member. That is, the first bearing housing member 61d protrudes from the bottom of the first cover member 3da toward the first direction Op. 71 d of bearing side penetration | invasion prevention members protrude from the radial direction center part to the 1st direction Op side. And the bearing side penetration | invasion prevention member 71d protrudes from the radial direction center part of the end surface part 610d of the 1st bearing storage member 61d at the 1st direction Op side to the 1st direction Op side. The bearing-side intrusion preventing member 71d is formed of the same member as the first bearing housing member 61d, that is, a metal.

The first bearing housing member 61d is formed of the same member as the first cover member 3da, but plays the same role as the first bearing housing member 61 of the motor A in that the first bearing 51 is housed therein. . The bearing-side intrusion preventing member 71d is also made of a different material, but the use of the shaft-side intrusion preventing member 72 in combination with the shaft-side intrusion preventing member 72 prevents the entry of foreign matter such as water, dust, dust, etc. It plays the same role as the member 71.

<4.3 Second cover member>
As shown in FIGS. 13 and 14, the second cover member 3db is a cylindrical member extending in the axial direction. The second cover member 3db and the second bearing housing member 62d are formed of the same member. The second bearing housing member 62d is continuously formed at the end of the second cover member 3db on the second direction Or side. The second cover member 3db includes a second flange 33 that extends radially outward at an end on the first direction Op side. That is, the second cover member 3db has a second flange 33 that extends radially outward from the outer peripheral surface. As shown in FIG. 11, the second flange 33 is a quadrangle (for example, a square) when viewed in the axial direction. The second flange 33 has a shape overlapping the first flange 32 in the axial direction.

The second bearing housing member 62d includes a second bearing housing member 62 used in the motor A, except that a portion corresponding to the outer cylindrical portion 620 of the second bearing housing member 62 of the motor A is continuous with the same member as the second cover member 3db. Have the same configuration. That is, the second bearing housing member 62 d includes a housing portion 621 d that houses the second bearing 52. The cover (second cover member 3db) holds at least one of the plurality of bearings (bearing 52).

<4.4 Motor assembly>
The resin casing 2 is inserted into the first cover member 3da from the first direction Op side, and the press-fit portion 22 is press-fitted into the first cover member 3da. On the other hand, the second cover member 3db only covers the resin casing 2 and is not press-fitted. Therefore, the second cover member 3db into which the portion of the resin casing 2 on the second direction Or side is inserted may be able to rotate around the central axis Ax. Therefore, a protrusion 330 that protrudes toward the first direction Op is provided on the surface of the second flange 33 on the first direction Op side. The protrusion 330 is inserted into a positioning hole 320 provided in the first flange 32. Thereby, the position of the circumferential direction of the 1st flange 32 and the 2nd flange 33, ie, the 1st cover member 3da, and the 2nd cover member 3db is adjusted.

The first flange 32 and the second flange 33 fix the first cover member 3da and the second cover member 3db to each other. Therefore, the first flange 32 and the second flange 33 are provided with screw fixing holes through which a fixing tool (here, a screw) passes. Then, the first cover member 3da and the second cover member 3db are fixed to each other by fixing the first flange 32 and the second flange 33 to each other. That is, when the first cover member 3da and the second cover member 3db cover the resin casing 2, the first flange 32 and the second flange 33 are connected directly or indirectly.

The resin casing 2 is press-fitted into the first cover member 3da, and the second cover member 3db is fixed to the first flange 32 of the first cover member 3da via the second flange 33. Therefore, the relative positions of the stator 1 covered with the resin casing 2 and the first bearing 51 and the second bearing 52 are determined. The rotating shaft 40 is rotatably supported by the first bearing 51 and the second bearing 52.

That is, in the motor D, the rotary shaft 40 is supported by the first bearing member 3da into which the resin casing 2 is press-fitted and the first bearing 51 and the second bearing 52 attached to the covering second cover member 3db. As a result, the rotor 4 is supported in a rotatable manner in the stator 1 while having a constant interval in the radial direction.

Thus, by covering the resin casing 2 with the first cover member 3da and the second cover member 3db, it is possible to shorten the length of the press-fitted portion 22 to be press-fitted. Thereby, the force which acts on the resin casing 2 and a cover can be reduced, and deformation | transformation of distortion, a shift | offset | difference, etc. of the resin casing 2 or a cover can be suppressed. Furthermore, from this, the stator 1 and the rotor 4 can be accurately aligned, and the capability reduction of the motor D can be suppressed.

Further, the first bearing housing member 61d is formed of the same member as the conductive first cover member 3da, and the second bearing storage member 62d is formed of the same member as the conductive second cover member 3db. Yes. The first cover member 3da and the second cover member 3db are in contact with each other. Thereby, the first bearing housing member 61d and the second bearing housing member 62d are in an electrically conductive state. Further, it can be said that the first cover member 3da is a part of the first bearing housing member 61d, and the second cover member 3db is a part of the second bearing housing member 62d. In the motor D, the first cover member 3da and the second cover member 3db are in direct contact. That is, in the motor D, the cover is directly connected to each of the first bearing housing member 61d and the second bearing housing member 62d.

<5. Fifth Embodiment>
Still another example of the present invention will be described with reference to the drawings. FIG. 15 is a cross-sectional view of still another example of the motor according to the present invention. The motor E of the present embodiment has the same configuration as the motor D of the fourth embodiment, except that the resin casing 2e, the first cover member 3ea, and the second cover member 3eb are different. Therefore, in the configuration of the motor E, substantially the same parts as those of the motor D are denoted by the same reference numerals, and detailed description of the same parts is omitted. In the motor E, the first bearing 51 is housed in the first bearing housing member 61 having the same configuration as the motor A.

As shown in FIG. 15, the resin casing 2e of the motor E includes a step portion 25e that protrudes radially outward from a portion closer to the second direction Or than the press-fitting portion 22 on the outer peripheral surface. The step portion 25e has a similar shape and is provided for the same purpose, although the position in the axial direction is different from that of the step portion 25 provided in the motor B shown in FIGS. That is, four step portions 25e are provided in the resin casing 2e, and are arranged at equal intervals in the circumferential direction. The first bearing housing member 61 is fixed to the end of the resin casing 2e on the first direction Op side. The first bearing housing member 61 is fixed in the same manner as the resin casing 2 of the motor A, and details thereof are omitted.

The first cover member 3ea has a bottomed cylindrical shape with the end on the first direction Op side closed. And the bottom part is provided with the casing contact part 31 and the electroconductive part 312 similarly to the cover 3. As shown in FIG. The first cover member 3ea includes a first flange 32 having the same configuration as the first cover member 3da.

The second cover member 3eb is a cylindrical member extending in the axial direction. The second cover member 3eb and the second bearing housing member 62d are formed of the same member. The second bearing housing member 62d is formed continuously at the end of the second cover member 3eb on the second direction Or side. In addition, the second cover member 3eb includes a second flange 33e extending outward in the radial direction and an abutting portion 35e at the end on the first direction Op side. The second flange 33e is provided at a position in contact with the first flange 32 of the first cover member 3ea when the second cover member 3eb is covered from the second direction Or side of the resin casing 2e. Further, the contact portion 35e is provided at a position where it comes into contact with the surface of the step portion 25e on the second direction Or side when the second cover member 3eb is covered from the second direction Or side of the resin casing 2e.

As shown in FIG. 15, in the second cover member 3eb, the second flange 33e is provided closer to the first direction Op than the contact portion 35e. And the 2nd flange 33e and the contact part 35e are alternately arrange | positioned in the circumferential direction.

When the resin casing 2 is press-fitted into the first cover member 3da, the first flange 32 comes into contact with the surface of the step portion 25e on the first direction Op side. Then, the second cover member 3eb covers the second direction Or side of the resin casing 2e. At this time, the contact portion 35e of the second cover member 3eb is in contact with the end surface on the second direction Or side of the step portion 25e of the resin casing 2e, and the second flange 33e is in contact with the first flange 32.

Thus, since the resin casing 2e includes the step portion 25e, the positioning in the axial direction during press-fitting into the first cover member 3da is facilitated. Similarly, the axial positioning of the second cover member 3eb with respect to the resin casing 2e is facilitated. For example, when the usage period of the motor E is extended, the outer diameter of the press-fit portion 22 may be reduced due to secular change of the resin constituting the resin casing 2e. At this time, the fixing of the resin casing 2e to the first cover member 2da by press fitting is weakened. In the case of the motor E, the step portion 25e is fixed together with the first flange 32 and the contact portion 35e at the mounting position. Therefore, the movement of the resin casing 2e is restricted even if the fixation by press-fitting becomes weak. Thereby, even if it is long-term use, the capability fall of the motor E can be suppressed.

In the motor E, the first flange 32 and the second flange 33e are in direct contact. Thereby, the 1st cover member 3ea electrically connected with the 1st bearing storage member 61 and the 2nd cover member 3eb formed with the same member as the 2nd bearing storage member 62d directly contact. Thereby, the 1st bearing storage member 61 and the 2nd bearing storage member 62 will be in a conduction state indirectly.

Other features are the same as in the fourth embodiment.

<6. Sixth Embodiment>
Still another example of the present invention will be described with reference to the drawings. FIG. 16 is a cross-sectional view of still another example of the motor according to the present invention. The motor F of the present embodiment has the same configuration as the motor A of the first embodiment except that the motor F of the first embodiment is provided. Therefore, in the configuration of the motor F, substantially the same parts as the motor A are denoted by the same reference numerals, and detailed description of the same parts is omitted.

As shown in FIG. 16, in the motor F, the end of the cover 3 on the second direction Or side is separated from the second bearing housing member 62. And the connection part 36 which electrically connects the cover 3 and the 2nd bearing storage member 62 is provided. The connection part 35 has electroconductivity, and is here metal. The connecting portion 36 has a step that fits between the cover 3 and the second bearing housing member 62. By attaching the connecting portion 36, the first bearing housing member 61 and the second bearing housing member 62 are electrically connected via the cover 3 and the connecting portion 36. Thereby, in the motor F, the electrolytic corrosion in the 1st bearing 51 and the 2nd bearing 52 is suppressed. Further, by connecting the cover 3 and the second bearing housing member 62 with the connecting portion 36, the cover 3 and the second bearing housing member 62 can be electrically connected even if the axial length of the cover 3 varies. It is possible to conduct.

Other features are the same as in the fifth embodiment.

In addition, the connection part 36 of this embodiment is made into the annular | circular shape provided with the discontinuous part in a part of circumferential direction. With such a configuration, the discontinuous portion can be opened and attached to the cover 3 and the second bearing housing member 62. The connection portion 36 may be fixed by gripping the cover 3, the second bearing housing member 62, and the resin casing 2 with its own elastic force. Moreover, you may utilize fixing methods, such as screwing, adhesion | attachment, welding, and welding.

Although the embodiment of the present invention has been described above, the embodiment can be variously modified within the scope of the gist of the present invention.

The present invention can be used as a motor for driving an air conditioner, a fan, or the like.

A ... motor, A1 ... motor, A2 ... motor, A3 ... motor, A4 ... motor, B ... motor, C ... motor, D ... motor, E ..Motor, F ... motor, 1 ... stator, 11 ... stator core, 111 ... core back part, 112 ... teeth part, 12 ... insulator, 120 ... wiring part 121 ... Insulator teeth part, 122 ... Insulator core back part, 13 ... Winding, 130 ... Crossover part, 2 ... Resin casing, 20 ... Resin casing hole, 200 ... concave groove, 201 ... groove, 2011 ... groove, 2012 ... groove, 202 ... hole, 21 ... concave hole, 22 ... press-fitting part, 23 ... concave part 231 ... Projection, 24 ... Thin part, 25 ... Step, 25e ... Step, 3, ... Cover, 3b ... cover, 3c ... cover, 3da ... first cover member, 3db ... second cover member, 3ea ... first cover member, 3eb ... second cover member, 30 ... cover hole, 31 ... casing contact part, 310 ... penetration part, 311 ... contact part, 3111 ... extension part, 312 ... conductive part, 313 ... conductive part 314 ... conductive portion, 32 ... first flange, 33 ... second flange, 33e ... second flange, 4 ... rotor, 40 ... rotating shaft, 411 ... cylinder Shape member, 412 ... Shaft support member, 400 ... Groove, 401 ... Shaft retaining ring, 402 ... Shaft retaining ring, 42 ... Magnet, 43 ... Mold part, 51 ... First bearing 52, second bearing 61, first bearing housing member 61d First bearing housing member, 610... End surface portion, 610d... End surface portion, 611... Bearing flange, 612. Second bearing housing member, 620 ... outer cylinder portion, 621 ... housing portion, 71 ... bearing side intrusion preventing member, 71d ... bearing side intrusion preventing member, 72 ... shaft side intrusion preventing member 72, Bd ... substrate, Is ... protective sheet

Claims

A rotor having a rotation axis extending along the central axis;
A stator having a plurality of windings wound around a stator core radially facing the outer peripheral surface of the rotor via an insulator;
A resin casing for sealing at least the insulator and the winding of the stator;
A plurality of bearings rotatably supporting the rotary shaft at positions spaced apart from each other in the axial direction;
A cover that covers the resin casing,
The stator includes a plurality of bearing storage members in which the plurality of bearings are respectively stored.
The bearing housing member and the cover are conductive members,
The cover is a motor that is directly or indirectly electrically connected to each of the plurality of bearing housing members.
The motor according to claim 1, further comprising a conductive portion that electrically connects the bearing housing member and the cover.
3. The motor according to claim 1, wherein one of the cover and the bearing housing member is press-fitted into the other at a conduction portion between the cover and at least one of the bearing housing member.
The motor according to any one of claims 1 to 3, wherein at least one of the cover and the bearing housing portion includes an extending portion that extends in an axial direction and contacts the other.
The motor according to any one of claims 1 to 4, wherein the cover and at least one of the bearing housing portions are formed of the same member.
The cover has a cylindrical shape extending in the axial direction,
The motor according to any one of claims 1 to 5, wherein the resin casing includes a press-fitting portion that is press-fitted inside the cover.
The motor according to claim 6, wherein the press-fitting portion overlaps the stator core when the resin casing is viewed in a radial direction.
The motor according to claim 6 or 7, wherein an inner diameter of the cover gradually decreases in a press-fitting direction of the resin casing.
The motor according to claim 6 or 7, wherein an inner diameter of the cover decreases stepwise in a press-fitting direction of the resin casing.
The cover is
A first cover member covering the resin casing from one side in the axial direction;
A second cover member that covers the resin casing from the other side in the axial direction,
The first cover member has a first flange extending radially outward from the outer peripheral surface,
The second cover member has a second flange extending radially outward from the outer peripheral surface,
The first cover member and the second cover member are connected to the first flange and the second flange directly or indirectly when the resin casing is covered. The motor according to Crab.