JP7102661B2 - motor - Google Patents

Description

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 mold motor described in Patent Document 1, the rotor is arranged on the inner diameter side of the stator formed by molding with a molding 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 bearings and rotates. Then, the bearing is housed in a bearing house formed in brackets arranged on both the output side and the non-output side of the outer shell of the stator.

In this inner rotor type molded motor, when a potential difference occurs between the bracket on the output side and the bracket on the non-output side, a current flows through the bearing. When an electric current flows through the bearing, electrolytic corrosion occurs, and the electrolytic corrosion causes vibration and noise of the motor. Therefore, in the inner rotor type mold motor disclosed in Patent Document 1, the bracket on the output side and the bracket on the non-output side are electrically connected via the conduction plate.

Further, 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 that is wound around the stator core. Then, the stator is molded integrally with the 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 housing made of resin, and further covers the outer surface of the housing with a protective cover made of metal, so that the housing is affected by an external impact. Prevents damage to the housing.

Japanese Unexamined Patent Publication No. 2012-20064 Japanese Unexamined Patent Publication No. 9-261935

In the inner rotor type mold motor described in Patent Document 1, since the outer shell molded by the molding resin is exposed to the outside, the conductive plate may be damaged by an impact from the outside and the conductive plate may fall off. Therefore, by attaching the protective cover having the configuration of Patent Document 2, it is possible to protect the outer shell. At this time, the protective cover and the bracket on the output side and / or the non-output side, or the protective cover and the conductive plate may come into contact with each other, and the protective cover and the bearing may be in a conductive state.

The potential of the protective cover of the molded motor may vary depending on the equipment to be installed. In this case, depending on the potential of the protective cover, there is a possibility that electrolytic corrosion is likely to occur due to the continuity between the protective cover and the bearing.

Therefore, an object of the present invention is to provide a motor capable of protecting from an external impact and taking measures against electrolytic corrosion of bearings regardless of the equipment to be attached.

An exemplary motor of the present invention has a rotor having a rotating shaft extending along a central axis and a plurality of windings wound around a stator core radially facing the outer peripheral surface of the rotor via an insulator. It covers the 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 separated from each other in the central axis direction, and the resin casing. The stator includes a cover and a plurality of bearing storage members in which the plurality of bearings are housed, the bearing storage member has conductivity, and each of the bearing storage members is made of a conductive member. It is electrically conducted, and each of the plurality of bearing accommodating members is electrically insulated from the cover, and the cover is electrically insulated from the conductive member.

According to the exemplary motor of the present invention, it is possible to protect the bearing from external impact and take measures against electrolytic corrosion of the bearing regardless of the attached device.

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 the 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 present embodiment. 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. FIG. 8 is an exploded perspective view of another example of the motor according to the present invention. FIG. 9 is a cross-sectional view of the motor shown in FIG. FIG. 10 is a cross-sectional view of a modified example of the motor according to the second embodiment. FIG. 11 is a cross-sectional view of still another example of the motor according to the present invention. FIG. 12 is a cross-sectional view of still another example of the motor according to the present invention. FIG. 13 is a cross-sectional view of still another example of the motor according to the present invention.

An exemplary embodiment of the present invention will be described below 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. 2 is defined as the axial direction. Further, the direction orthogonal to the axial direction is the radial direction, and the tangential direction of the circle centered on the axis is the circumferential direction.

Further, in this document, the axial direction is set as follows with reference to FIG. That is, in FIG. 2, the direction toward the right side in the axial direction is referred to as the first direction Op, and the direction toward the left side is referred to as the second direction Or. In addition, "left direction" and "right direction" in this document are set for the purpose of explanation. Therefore, these directions do not limit the directions when the motor A is actually used.

<1.1 Motor configuration>
As shown in FIG. 1, the motor A according to the present 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 mold motor in which the stator 1 is sealed with the resin casing 2. The rotor 4 is arranged inside the stator 1. The rotor 4 includes a rotating shaft 40 extending along the central axis Ax. The rotating shaft 40 is supported by the first bearing 51 and the second bearing 52, and is rotatable 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. The plurality of bearings (51, 52) rotatably support the rotating shaft 40 at positions separated from each other in the axial direction.

<1.2 Stator configuration>
The stator 1 will be described with reference to the new drawings. FIG. 3 is a perspective view of the stator core. FIG. 4 is a perspective view of the 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 faces the outer peripheral surface of the rotor 4 in the radial direction via an insulator 12. Further, as shown in FIG. 2, the stator 1 includes a first bearing storage member 61 in which the first bearing 51 is housed, and a second bearing storage member 62 in which the second bearing 52 is housed. That is, the stator 1 includes a plurality of bearing storage members (61, 62) in which a plurality of bearings (51, 52) are 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 is an annular shape extending in the axial direction. The tooth portion 112 protrudes inward in the radial direction from the inner peripheral surface of the core back portion 111. That is, the stator core 11 has an annular core back portion 111 and a teeth portion 112 extending radially inward from the core back portion 111. As shown in FIG. 4, the stator core 11 includes 12 tooth portions 112. The teeth portions 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 entire teeth portion 112 and both end faces in the axial direction of the core back portion 111. A winding 13 is formed by winding a conducting wire around a tooth portion 112 covered with an insulator 12. That is, the insulator 12 has an insulator teeth portion 121 that covers the teeth portion 112, and an insulator core back portion 122 that covers at least the axial end portion of the core back portion 111. The insulator 12 insulates the stator core 11 and the winding 13. In the present embodiment, the insulator 12 is a molded resin body, but the insulator 12 is not limited to this. A configuration capable of insulating the stator core 11 and the winding 13 can be widely adopted.

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

The windings 13 are arranged in each of the teeth portions 112 of the stator core 11. That is, in the motor A, 12 windings 13 are arranged. The 12 windings 13 provided in the stator 1 are divided into three systems (hereinafter referred to as three phases) according to the timing at which the current is supplied. These three phases are referred to as U phase, V phase, and 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 each phase will be collectively referred to as windings 13.

Further, the stator 1 has a crossover portion that connects a plurality of windings 13 to each other or is electrically connected to a control circuit (not shown) mounted on the winding 13 and the substrate Bd provided on the motor A. 131 is provided. The plurality of windings 13 are electrically connected via the crossover section 131. Then, the crossover portion 131 is arranged in the wiring portion 120 provided in the insulator core back portion 122 that covers the axial end surface of the core back portion 111 of the insulator 12. That is, the insulator 12 is provided with a wiring portion 120 to which the crossover portion 131 is wired. As shown in FIG. 2, the stator 1 includes a wiring portion 120 in which the crossover 131 is arranged on the radial outer surface of the insulator 12 that covers the end surface of the core back portion 111 on the Op side in the first direction. That is, the wiring portion 120 extends from the axial end portion of the insulator core back portion 122 toward the axial direction (Op side in the first direction), and the crossover 131 is wired on the radial outer surface of the wiring portion 120. .. Then, the recess 23 is located on the outer peripheral surface of the resin casing 2.

<1.3 Configuration of resin casing and cover>
As shown in FIGS. 1, 2, and the like, 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 inside. 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 of the stator core 11 in the radial direction. The resin casing 2 has a bottomed cylindrical shape in which at least a part of the end portion on the Op side in the first direction is closed. Then, a resin casing hole 20 extending in the axial direction is provided at the central portion in the radial direction of the bottom portion.

A concave hole 21 recessed in the axial direction is provided on the outer side in the radial direction of the resin casing hole 20 on the surface of the bottom portion on the Op side in the first direction. That is, the output shaft side end surface of the resin casing 2 is provided with a concave hole 20 recessed in the axial direction. The rotating shaft 40 attached to the rotor 4 penetrates the resin casing hole 20 in the axial direction. Further, the flange portion 611 of the first bearing accommodating member 61, which will be described later, is fixed to the resin casing hole 20 by insert molding. The details of the first bearing accommodating portion 61 will be described later.

As shown in FIGS. 1, 2 and the like, 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 Op side in the first direction 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. That is, the cover 3 covers at least one resin casing 2 on the radial outer side of the insulator 12 and on one axial side (Op side in the first direction) of the insulator 12. The cover 3 is provided with a casing contact portion 31 in contact with the concave hole 21 of the resin casing 2 at the radial center portion of the bottom portion. That is, the casing contact portion 31 contacts along the concave hole 21. The casing contact portion 31 is recessed from the first direction Op side to the second direction Or side of the cover 3. The center of the casing contact portion 31 is provided with a cover hole 30 penetrating in the axial direction.

Further, the casing contact portion 31 includes a penetration portion 310 that penetrates in the axial direction. The penetrating portion 310 may be a hole having a shape closed in the circumferential direction, or may be a so-called notch in which a part in the circumferential direction is open. A conductive connecting portion 81, which will be described later, of the conductive member 8 is attached at a position where it overlaps the penetrating portion 310 in the axial direction.

When the resin casing 2 is press-fitted into the cover 3, the casing contact portion 31 comes into contact with the concave hole 21. When the cover 3 covers the resin casing 2, the casing contact portion 31 overlaps with the flange portion 611 when viewed in the axial direction. That is, the cover 3 includes a casing contact portion 31 that comes into contact with the resin casing 2 and overlaps with the flange portion at a position viewed from the axial direction. The casing contact portion 31 presses the concave hole 21 and the axial direction. As a result, the concave hole 21 and the casing contact portion 31 are brought into close contact with each other, and the ingress of gas, water, dust, dust, etc. is suppressed.

Next, attachment of the resin casing 2 to the cover 3 will be described. The resin casing 2 is provided with a press-fitting portion 22 and a recess 23 on the outer peripheral surface in the radial direction. That is, the resin casing 2 includes a press-fitting portion 22 that is press-fitted into the cover 3. As shown in FIG. 2, the press-fitting portion 22 is provided in a portion that overlaps the stator core 11 on the outer peripheral surface of the resin casing 2 in the radial direction. That is, the press-fitting portion 22 overlaps with 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. After that, 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-fitting portion 22 is provided at a position where it overlaps with the stator core 11 in the radial direction. At the time of press fitting, a force acts from the cover 3 to the resin casing 2 in the radial direction and the axial direction. Since the press-fitting portion 22 is provided at a position where it overlaps the stator core 11 having higher strength than the resin of the resin casing 2 in the radial direction, deformation of the resin casing 2 is unlikely to occur even if a force is applied from the cover 3 during press-fitting. ..

The recess 23 radially 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. That is, the gap Gp is located outward in the radial direction of the wiring portion 120. (Claim 3) Further, the outer peripheral surface of the resin casing 2 is provided with a recess 23 at a portion in contact with the gap Gp. The recess 23 is provided at the end of the resin casing 2 on the Op side in the first direction, and is formed continuously in the circumferential direction. In the present embodiment, the resin casing 2 is formed at the radial end portion, but the present embodiment is not limited to this.

Further, depending on the conditions of the mounting location of the motor A, water contained in the air inside the motor A may condense and dew condensation 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 Or side in the second direction.

As a result, the dew condensation water accumulated in the recess 23 passes through the recess 200 and is discharged to the outside from between the cover 3 and the second bearing accommodating member 62. In addition, for example, in the case of a structure in which the electric circuit is insulated and the structure is not affected or is not easily affected by the generation of dew condensation water, the concave groove 200 may be omitted. Even if the groove 200 is omitted, the dew condensation water evaporates into the air of the recess 23 due to the heat generated when the motor A is driven. Further, when the resin casing 2 is completely covered by the cover 3, the cover 3 or the second bearing accommodating member 62 may be provided with a hole for draining the dew condensation water.

The resin casing 2 is inserted into the cover 3 from the side where the recess 23 is provided in the axial direction, and is 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. The details of the gap Gp between the resin casing 2 and the cover 3 will be described later.

Further, as shown in FIG. 2, the radial thickness of the portion of the resin casing 2 provided with the recess 23 is thinner than the thickness of the other portion of the resin casing 2. That is, the portion where the recess 23 is provided is a thin portion 24 which is thinner than the other portions. A current may flow through the crossover section 131 to heat the crossover section 131. At this time, since the thin-walled portion 24 is formed, the heat of the crossover portion 131 is likely to be 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 portion 43. The rotor core 41 includes a tubular member 411 extending in the axial direction and a shaft support member 412 arranged radially inside the tubular member. The tubular member 411 and the shaft support member 412 are mutually fixed by a mold portion 43 which is a resin molded body. The rotor core 41 is a magnetic material. The rotor core 41 may be a laminated body in which magnetic plates are laminated in the radial direction, or may be, for example, a molded body formed by sintering powders to form the same member.

The rotating shaft 40 has a cylindrical shape. The rotating shaft 40 penetrates the radial center of the shaft support member 412 of the rotor core 41. The rotating shaft 40 and the shaft support member 412 are relatively fixed. The fixing method includes, but is not limited to, press fitting, welding, and the like. A method capable of fixing the rotating shaft 40 and the shaft support member 412 can be widely adopted. That is, the rotating shaft 40 is fixed to the rotor 4, and when the rotor 4 rotates, the rotating shaft 40 rotates about the central axis Ax.

The plurality of magnets 42 are arranged on the outer side in the radial direction 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 this embodiment, a 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 with respect to a cylindrical magnetic material.

That is, in the rotor core 41, the north pole and the south pole are paired magnetic poles, and a plurality of paired magnetic poles are provided. The magnet 42 is fixed to the rotor core 41 by, for example, a resin mold or the like. The method of fixing the magnet 42 is not limited to the resin mold, and a method such as adhesion, welding, or mechanical fixing that does not adversely affect the rotation of the rotor 4 or is difficult to apply is adopted.

<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 locations different in the axial direction. The end of the rotating shaft 40 on the Or side in the second direction is press-fitted into the inner ring of the second bearing 52. A portion on the Op side in the first direction 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 rotating shaft 40.

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

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

The shaft retaining ring 402 comes into contact with the Op side of the inner ring of the second bearing 52 in the first direction. The shaft retaining ring 402 restricts the movement of the rotating shaft 40 with respect to the second bearing 52 in the second direction Or. 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-rings and E-rings, but are not limited thereto. A configuration in which the inner rings of the pair of bearings 51 and 52 are in contact with each other and the movement of the rotating shaft 40 can be restricted can be widely adopted. In each embodiment of this document, the rotary shaft 40 is rotatably supported by two bearings (first bearing 51 and second bearing 52), but the present invention is not limited to this. It may be supported by three or more bearings.

<1.6 Bearing storage member configuration>
The first bearing accommodating member 61 and the second bearing accommodating member 62 are made of metal such as iron and brass here. That is, the bearing accommodating members (61, 62) have conductivity.

<1.6.1 First bearing storage member>
The first bearing accommodating member 61 has a tubular shape in which the first bearing 51 can be accommodated. The end portion on one side in the axial direction of the first bearing accommodating member 61 includes an end face portion 610 penetrating in the axial direction at the center portion in the radial direction. Further, the end portion of the first bearing accommodating member 61 on the other side in the axial direction includes a flange portion 611 extending outward in the radial direction. At least a part of the flange portion 611 is insert-molded into the resin casing 2. The flange portion 611 may be provided with a penetrating portion that penetrates in the axial direction. By filling the penetrating portion with resin during insert molding, the movement of the first bearing accommodating member 61 in the circumferential direction is restricted, and the rotation is prevented.

The penetrating portion is not limited to the hole as long as the detent is surely performed by the resin, and may be, for example, a concave portion recessed inward in the radial direction or a convex portion protruding outward in the radial direction. Further, the flange portion 611 itself may be formed into a polygonal shape (for example, a triangle or a quadrangle) or an elliptical shape to prevent rotation. The first bearing accommodating member 61 is fixed to the resin casing 2 so that the central axis coincides with the central 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 inside of the first bearing accommodating member 61.

In the motor A, the first bearing accommodating member 61 is a resin-sealed bearing accommodating member in which a part of the flange portion 611 is sealed by the resin casing 2. That is, at least one of the plurality of bearing accommodating members (first bearing accommodating member 61 and second bearing accommodating member 62) (first bearing accommodating member 61) is a resin-sealed bearing accommodating sealed by the resin casing 2. It is a member. The resin-sealed bearing accommodating member (first bearing accommodating member 61) includes a flange portion 611 extending in the radial direction. A part of the flange portion 611 is sealed in the resin casing.

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

The outer cylinder portion 620 has a larger diameter than the storage portion 621, and the end portion of the resin casing 2 on the second direction Or side is press-fitted into the outer cylinder portion 620. That is, after the second bearing 52 is press-fitted into the accommodating portion 621, the end portion of the resin casing 2 on the Or side in the second direction is press-fitted into the outer cylinder portion 620 of the second bearing accommodating member 62. Then, the resin casing 2 is press-fitted into the second bearing accommodating member 62, so that 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 central axis of the second bearing 52 coincides with the central axis Ax of the stator 1.

As shown in FIG. 2, the storage portion 621 and the outer cylinder portion 620 are formed of the same member. Here, the second bearing accommodating member 62 is manufactured by drawing a metal plate. However, it is not limited to this. Further, as shown in FIG. 2, the second bearing accommodating member 62 and the cover 3 are separated from each other. That is, the second bearing accommodating member 62 is electrically insulated from the cover 3.

<1.7 Conductive member>

In the motor A, the conductive member 8 has conductivity. As shown in FIG. 2, the conductive member 8 includes a lead wire portion 80 and a conductive connecting portion 81. The lead wire portion 80 includes a lead wire. The lead wire portion 80 is arranged inside the groove 201 formed on the outer peripheral surface of the resin casing 2. The outer circumference of the lead wire portion 80 is covered with an insulating coating. As a result, the lead wire portion 80 is electrically insulated from the cover 3. In the present embodiment, the lead wire portion 80 is arranged in the groove 201 formed on the outer peripheral surface of the resin casing 2, but the present invention is not limited to this. When the stator 1 and the first bearing accommodating member 61 are resin-molded to form the resin casing 2, the portion of the lead wire portion 80 arranged in the groove 201 may be inserted and molded together.

A first terminal 801 and a second terminal 802 are attached to both ends of the lead wire portion 80. The first terminal 801 and the second terminal 802 are conductive terminals attached to the ends of the lead wires, and examples thereof include flat terminals. The first terminal 801 is electrically conductive with the flange portion 611 of the first bearing accommodating member 61. Further, the second terminal 802 is electrically conductive with the outer cylinder portion 620 of the second bearing accommodating member 62. That is, each of the bearing accommodating members (first bearing accommodating member 61 and second bearing accommodating member 62) is electrically conducted by the conductive member 8.

The first terminal 801 is arranged at a position where it overlaps with the penetrating portion 310 of the casing contact portion 31 when viewed from the axial direction. Then, the first terminal 801 is electrically conductive with the flange portion 611 of the first bearing accommodating member 61. The conductive connection portion 81 includes bolts and nuts. The conductive connection portion 81 penetrates and fixes the first terminal 801 and the flange portion 611. As a result, the first terminal 801 is fixed to the flange portion 611. The conductive connecting portion 81 overlaps with the penetrating portion 310 of the casing contact portion 31 of the cover 3 when viewed from the axial direction. That is, the conductive connecting portion 81 is located at the penetrating portion 310 (claim 7). As a result, the conductive connection portion 81 is electrically insulated from the casing contact portion 31. That is, the cover 3 is electrically insulated from the conductive member 8.

The conductive connection portion 81 is not limited to a structure using screws. For example, the first terminal 801 and the flange portion 611 may be soldered and fixed by adhesion using a conductive adhesive or the like. Further, the first terminal 801 and the flange portion 611 do not have to be fixed as long as they are electrically conductive, that is, they are in contact with each other. As the conductive connection portion 81, a configuration in which the flange portion 611 and the first terminal 801 are electrically conductive and insulated from the cover 3 can be widely adopted. Further, the first terminal 801 may be electrically conductive with the flange portion 611. Therefore, the first terminal 801 is not limited to a configuration in which a terminal for connection (for example, a flat terminal or the like) is attached, and may be a configuration in which the ends of the lead wire portions 80 are put together.

The second terminal 802 is sandwiched between the second bearing accommodating member 62 and the resin casing 2. As a result, the second terminal 802 is electrically conductive with the second bearing accommodating member 62. When the end portion of the resin casing 2 on the second direction Or side is press-fitted into the outer cylinder portion 620 of the second bearing accommodating member 62, the second terminal 802 is the end portion of the resin casing 2 on the second direction Or side and the second terminal 802. It is sandwiched between the outer cylinder portion 620 of the bearing accommodating member 62. That is, the second terminal 802 is sandwiched between the resin casing 2 and the outer cylinder portion 620 by the force at the time of press fitting. Therefore, the second terminal 802 is electrically conductive with the second bearing accommodating member 62.

As shown in FIG. 2, the first bearing accommodating member 61 and the cover 3 are electrically insulated from each other. Further, the second bearing accommodating member 62 and the cover 3 are electrically insulated from each other. That is, the cover 3 and the bearing accommodating members (61, 62) are electrically insulated. For this reason, the first bearing accommodating member 61, the second bearing accommodating member 62, and the conductive member 8 are electrically insulated from each other. That is, the bearings (51, 52) and the conductive member 8 are electrically insulated.

In a conventional motor as in the cited document, when a potential difference is generated between the outer ring and the inner ring of the first bearing 51 or 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 and the outer ring A discharge (spark) may occur between the ball, the inner ring and the ball. The generation of electric discharge damages the surfaces of the outer ring, ball, and inner ring of the bearing, so-called electrolytic corrosion of the bearing. Electrolytic corrosion of the first bearing 51 and the second bearing 52 causes vibration and noise of the motor A. The cause of electrolytic corrosion is that the switching element included in the inverter circuit that drives the motor A is driven by a high frequency and a high voltage. Further, as a factor other than this, the potential state of the stator core and the rotor core can be mentioned.

Therefore, in the motor A according to the present embodiment, in order to suppress the electrolytic corrosion of the bearing, the conductive member 8 electrically conducts the first bearing accommodating member 61 and the second bearing accommodating member 62. As a result, the outer ring of the first bearing 51 and the outer ring of the second bearing 52 are electrically conducted, so that the potential difference between the inner ring and the outer ring of the first bearing and the second bearing is reduced, and the motor A It is possible to suppress the occurrence of electrolytic corrosion of the bearings (51, 52).

When the motor A is attached to the device to be attached, the cover 3 of the motor A comes into contact with the frame of the device. The frame of a general device is adjusted to a reference voltage predetermined in the device, and the cover 3 is also adjusted to the reference voltage. However, the reference voltage may fluctuate due to the motor A provided in the device or the drive of a device different from the motor A. That is, the cover 3 is electrically insulated from the conductive member 8. Further, each of the bearing accommodating members (first bearing accommodating member 61 and second bearing accommodating member 62) is electrically conducted by the conductive member 8. Then, when at least one of the first bearing accommodating member 61 and the second bearing accommodating member 62 is electrically conducted with the frame, the outer ring of the first bearing 51 and the outer ring of the second bearing 52 also fluctuate, in other words. , The potential becomes the same as the unstable reference voltage, and depending on the conditions, bearing electrolytic corrosion may occur.

In the motor A, the cover 3 is insulated from the first bearing accommodating member 61 which is electrically conductive with the outer ring of the first bearing 51 and the second bearing accommodating member 62 which is electrically conductive with the outer ring of the second bearing 52. As a result, the first bearing 51 and the second bearing 52 are suppressed from being adjusted to the reference voltage of the device, and the occurrence of electrolytic corrosion due to the variation in the reference voltage is suppressed.

In the motor A, by suppressing the occurrence of bearing electrolytic corrosion, the first bearing 51 and the second bearing 52 can rotate with high accuracy for a long period of time. This enables stable operation of the mold motor A for a long period of time. That is, the life of the mold motor A can be extended.

<1.8 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 accommodating member 62. Therefore, foreign matter such as water, dust, and dust is suppressed from entering through the gap between the outer cylinder portion 620 and the cover press-fitting portion 300. On the other hand, on the Op side of the motor A in the first direction, the rotating shaft 40 is provided with a bearing accommodating portion hole in the end face portion 610 of the first bearing accommodating portion 61. The bearing accommodating hole has a size such that a gap is formed between the bearing accommodating portion and the rotating shaft 40 so as not to interfere with the rotation of the rotating shaft 40. Foreign matter such as water, dust, and dust easily enters the inside of the motor A from this gap. Therefore, the motor A includes a bearing-side intrusion prevention member 71 and a shaft-side intrusion prevention member 72 for suppressing the intrusion of foreign matter from the first bearing storage member 61.

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

Further, the shaft-side intrusion prevention member 72 is arranged in the groove 400 provided in the rotating shaft 40. That is, a bearing cover 72 that covers the bearing accommodating portion 61 is attached to the output shaft 40. As a result, the axial movement of the shaft-side intrusion prevention member 72 is restricted. The shaft-side intrusion prevention member 72 has a cylindrical shape extending along the axial direction. It is arranged so as to surround the radial outside of the bearing-side intrusion prevention member 71. By reducing the space between the bearing-side intrusion prevention member 71 and the shaft-side intrusion prevention member 72, the entry of foreign matter into the motor A is suppressed. That is, by attaching the bearing-side intrusion prevention member 71 and the shaft-side intrusion prevention member 72 to the motor A at the same time, it plays a role of suppressing the invasion of foreign matter into the motor A.

A part of the tip of the shaft-side intrusion prevention member 72 on the second direction Or side overlaps with the concave hole 21. Further, the casing contact portion 31 of the cover 3 is also provided in the concave 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 prevention member 72 is arranged in the concave hole 21. Since the casing contact portion 31 and the shaft side intrusion prevention member 72 are not in contact with each other, the rotating shaft 40 does not limit the rotation.

Further, a substrate Bd and a protective sheet Is are provided on the Or side of the resin casing 2 in the second direction with respect to the stator 1. 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 on the substrate Bd. The control circuit may be provided outside the motor A, in which case the substrate Bd may be omitted. The protective sheet Is is an insulating member arranged between the substrate Bd and the second bearing accommodating member 62. It is provided to prevent a short circuit between the second bearing accommodating member 62 and the substrate Bd. In the case of a motor not provided with the substrate Bd, the protective sheet Is may be omitted.

<1.9 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 electric current. At this time, the stator core 11 is heated together with the winding 13. The stator core 11 and the winding 13 are covered with the resin casing 2. The heat of the stator core 11 and the winding is transferred to the resin casing 2.

The heat of the resin casing 2 is transferred to the cover 3. A metal material is mainly used for the cover 3, and the coefficient of linear expansion is smaller than that of the resin casing 2. As a result, a difference in the amount of deformation due to thermal expansion between the resin casing 2 and the cover 3 occurs. However, the resin casing 2 and the cover 3 are press-fitted in the press-fitting portion 22 of the resin casing 2. Therefore, the heat of the resin casing 2 is transferred to the cover 3 and radiated, so that the thermal expansion of the resin casing 2 is suppressed in the press-fitting portion 22.

In the resin casing 2, the insulator 12 is sealed with the resin casing 2 at a portion displaced in the axial direction from the press-fitting portion 22. The insulator 12 is a resin, and the coefficient of linear expansion 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 with the stator core 11 in the radial direction is more deformed to the outside in the radial direction due to thermal expansion than the press-fitting portion 22 that overlaps with the stator core 11 in the radial direction. Further, since the cover 3 is farther from the stator core 11, the heat dissipation is inferior to that of the press-fitting portion 22. Therefore, problems such as distortion and displacement of the resin casing 2 occur due to the difference in the amount of deformation due to thermal expansion between the insulator 12 and the cover 3.

On the opening side of the cover 3 of the resin casing 2 (Or side in the second direction in FIG. 2), the deformation of the resin casing 2 due to thermal expansion escapes to the opening side. On the other hand, there is no place on the back side of the cover 3 (Op side in the first direction in FIG. 2) to allow the deformation due to thermal expansion to escape. Therefore, in the motor A, a gap Gp is provided between the cover 3 and the resin casing 2 on the outer side in the radial direction of the insulator 12.

As a result, the difference in the amount of deformation between the resin casing 2 and the cover 3 at a position (particularly, the inner side in the press-fitting direction) deviated from the stator core 11 of the resin casing 2 in the axial direction is absorbed by the gap Gp. As a result, problems such as distortion and displacement of the resin casing 2 due to the difference in the amount of deformation due to thermal expansion between the resin casing 2 and the cover 3 can be suppressed.

According to the motor A of the present embodiment, by covering the resin casing 2 with the cover 3, the stator 1, the rotor 4, the first bearing 51, the second bearing 52, etc. arranged inside are subjected to an impact acting from the outside. Protected from vibration. Further, the first bearing accommodating member 61 and the second bearing accommodating member 62 are electrically conductive. Then, by electrically insulating the first bearing accommodating member 61 and the second bearing accommodating member 62 and the cover 3 which may come into electrical contact with the external device, the first bearing 51 and the second bearing 52 are electrically insulated. The influence of fluctuations in the voltage of the external device (for example, the reference voltage at the grounding point) is less likely to affect. As a result, bearing electrolytic corrosion of the first bearing 51 and the second bearing 52 due to voltage fluctuation can be suppressed. That is, the motor A can suppress electrolytic corrosion of the first bearing 51 and the second bearing 52 regardless of the attached device.

<1.10 variant>
<1.10.1 Modification 1>
A modified example 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 designated by the same reference numerals, and detailed description of the same parts will be omitted.

In the motor A1 shown in FIG. 6, the outer peripheral surface of the resin casing 2a1 gradually becomes smaller in diameter toward the inner side in the press-fitting direction, that is, toward the Op side in the first direction 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 tubular shape, and has a gradually smaller diameter toward at least the inner peripheral surface in the press-fitting direction, that is, toward the Op side in the first direction 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, insertion becomes easy. Further, since the press-fitting portion 221 is an inclined surface, the amount of deformation of the resin casing 2a1 at the time of press-fitting can be reduced. As a result, it is easy to suppress the occurrence of strain or the like of the stator 1.

Then, on the outer peripheral surface of the resin casing 2a1, a groove 2011 extending in the axial direction along the inclined surface is formed. The lead wire portion 80 of the conductive member 8 is arranged in the groove 2011.

<1.10.2 Modification 2>
A modified example 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 designated by the same reference numerals, and detailed description of the same parts will be omitted.

In the motor A2 shown in FIG. 7, the outer peripheral surface of the resin casing 2a2 gradually becomes smaller in diameter toward the inner side in the press-fitting direction, that is, toward the Op side in the first direction in FIG. That is, the outer peripheral surface of the resin casing 2a2 has a plurality of different outer shapes. The outer peripheral surface of the resin casing 2a2 has a small diameter on the inner side in the press-fitting direction, and a step is formed at a portion where the outer shape changes. The cover 3a2 has a shape into which the resin casing 2a2 can be inserted. The cover 3a2 has a tubular shape, and at least the inner peripheral surface on the inner side in the press-fitting direction, that is, on the Op side in the first direction in FIG. 7 is gradually reduced in diameter. That is, the inner diameter of the cover 3a2 gradually decreases toward the press-fitting direction of the resin casing 2a2.

By providing the shapes of the resin casing 2a2 and the cover 3a2, insertion becomes easy. Further, the step of the resin casing 2a2 and the step of the cover 3a2 can be brought into contact with each other for positioning 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 press-fitting portion of the cover 3a2, and press-fitting is started. As a result, the force acting by press fitting can be reduced. The amount of deformation of the resin casing 2a2 at the time of press fitting can be reduced. As a result, it is easy to suppress the occurrence of strain or the like of the stator 1.

Then, on the outer peripheral surface of the resin casing 2a2, a groove 2012 extending in the axial direction is formed in each step. The groove 2012 of each stage is a continuous groove. Then, the lead wire portion 80 of the conductive member 8 is arranged in the groove 2012.

<Second Embodiment>
Other examples of the motor according to the present invention will be described with reference to the drawings. FIG. 8 is an exploded perspective view of another example of the motor according to the present invention. FIG. 9 is a cross-sectional view of the motor shown in FIG. As shown in FIGS. 8 and 9, the motor B has the same configuration as the motor A of the first embodiment except that the resin casing 2b and the cover 3b are different. Therefore, regarding the configuration of the motor B, substantially the same parts as those of the motor A are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 8 and 9, the resin casing 2b includes a protrusion 231 projecting radially outward from the recess 23, and a step portion 25 extending radially outward from the outer peripheral surface. As shown in FIG. 8, the outer peripheral surface of the resin casing 2b is provided with a concave portion 23 that is concave in the radial direction and continuous in the circumferential direction at the end portion on the Op side in the first direction. A protrusion 231 projecting outward in the radial direction is provided at one position in the circumferential direction of the recess 23. The protruding portion 231 protrudes from the recess 23, and the curved surface on the outer side in the radial direction coincides with the outer peripheral surface of the resin casing 2b. Then, a part of the groove 201 in which the lead wire portion 80 of the conductive member 8 is arranged is formed in the protruding portion 231. By providing the protruding portion 231 and forming a part of the groove 201 in this way, the depth of the groove 201 from the outer peripheral surface can be made constant in the axial direction. As a result, the lead wire portion 80 is less likely to be displaced from the groove 201. That is, a portion of the recess 23 has a protruding portion 231 protruding in the radial direction, and the conductive member 8 is arranged in the protruding portion 231.

Further, in the recess 23, the lead wire portion 80 tends to sag. When the lead wire portion 80 is slack, when the resin casing 2b is press-fitted into the cover 3b, the lead wire portion 80 is sandwiched between the press-fitting portion 22 and the cover 3b. As a result, the lead wire portion 80 may be disconnected. That is, there is a possibility that the first bearing accommodating member 61 and the second bearing accommodating member 62 are not electrically conductive. Further, the cut end of the lead wire portion 80 may be short-circuited with the cover 3b, and the first bearing accommodating member 61 and the second bearing accommodating member 62 may be electrically conductive with the cover 3b. By providing the projecting portion 231, the deviation of the lead wire portion 80 from the groove 201 can be suppressed, and the cutting of the lead wire portion 80 and the short circuit with the cover 3b can be suppressed.

A plurality of step portions 25 (here, four) are provided in the resin casing 2b. In the step portions 25, the resin casings 2b are arranged at the same positions in the axial direction and at equal intervals in the circumferential direction. The cover 3b includes a contact portion 311 protruding outward from the outer peripheral surface. When the resin casing 2b is press-fitted into the cover 3b, the contact portion 311 comes into contact with the step portion 25. The contact portion 311 comes into contact with the surface of the step portion 25 in the press-fitting direction (Op side in the first direction in FIG. 9).

Further, in the motor B of the present embodiment, the resin casing 2b is directly press-fitted into the outer cylinder portion 620 of the second bearing accommodating member 62. Then, the lead wire portion 80 is arranged in the groove 201 formed between the step portions 25 adjacent to each other in the circumferential direction. Then, the lead wire portion 80 extends to the end portion of the resin casing 2b on the Or side in the second direction, and is electrically conducted with the outer cylinder portion 620 of the second bearing accommodating member 62 via the second terminal 802. The second terminal 802 is electrically connected to the lead wire portion 80 and is sandwiched between the outer cylinder portion 620 and the resin casing 2b press-fitted into the outer cylinder portion 620.

The 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. Then, the contact portion 311 in contact with the step portion 25 formed of the same member as the resin casing 2b is formed of the same member as the cover 3b having higher strength than 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 less likely to fall off. The number and position of the step portions 25 are not limited to the above, but may be changed depending on the shape and position of the mounting location (not shown) of the device to which the motor B is mounted.

According to the motor B of the present embodiment, by providing the protrusion 231 in the recess 23, the lead wire portion 80 of the conductive member 8 is less likely to shift. As a result, the first bearing accommodating member 61 and the second bearing accommodating member 62 can be electrically conductive. Further, since the cover 3b is electrically insulated from the first bearing accommodating member 61 and the second bearing accommodating member 62, even if the step portion 25 and the contact portion 311 are fixed to the device to be attached, the cover 3b is to be attached. The device and the first bearing accommodating member 61 and the second bearing accommodating member 62 are insulated. As a result, even if the voltage of the device to be mounted (for example, the reference voltage) fluctuates, the fluctuation of the voltage is unlikely to affect the first bearing accommodating member 61 and the second bearing accommodating member 62. As a result, electrolytic corrosion of the first bearing 51 and the second bearing 52 can be suppressed. That is, the motor B can suppress electrolytic corrosion of the first bearing 51 and the second bearing 52 regardless of the attached device.

Other features are the same as in the first embodiment.

<2.1 Deformation example>
A modified example of the motor according to this embodiment will be described with reference to the drawings. FIG. 10 is a cross-sectional view of a modified example of the motor according to the second embodiment. The motor B1 shown in FIG. 10 is provided with a hole 202 formed inside and extending in the axial direction in place of the groove 201 formed on the outer peripheral surface of the resin casing 2b. The other parts have the same configuration as the motor B shown in FIGS. 8 and 9. Therefore, in the configuration of the motor B1, substantially the same parts as the motor B are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 10, the motor B1 includes a hole 202 extending in the axial direction in the resin casing 2b. Then, the conductive member 8 is arranged in the hole 202. Since the conductive member 8 is attached to the hole 202 formed inside the insulating resin casing 2b, the lead wire portion 80 of the conductive member 8 is insulated from the cover 3 even if it is not covered with a coating. That is, the number of components of the conductive member 8 is reduced, or the number of members that can be selected as the conductive member 8 is increased. This makes it possible to keep the cost of the motor B1 low. In the present embodiment, the lead wire portion 80 is arranged in the hole 202 in order to compare with the groove 201, but the present invention is not limited to this. For example, when the stator 1 and the first bearing accommodating member 61 are resin-molded to produce the resin casing 2b, the conductive member 8 may also be inserted and molded together. By doing so, the manufacturing process can also be simplified.

<3. Third Embodiment>
FIG. 11 is a cross-sectional view of still another example of the motor according to the present invention. In the motor C shown in FIG. 11, 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, in the configuration of the motor C, substantially the same parts as the motor A are designated by the same reference numerals, and detailed description of the same parts will be omitted.

As shown in FIG. 11, the stator 1c of the motor C has an insulator core back portion 122 at an end portion of the insulator 12 on the Op side in the first direction. Then, the insulator core back portion 122 is provided with a wiring portion 120c in which the crossover portion 131 is arranged. Then, a recess 23c is formed at a position where the resin casing 2c overlaps with the wiring portion 120c in the axial direction. A gap Gp is provided between the recess 23c and the cover 3c that overlaps in the axial direction. That is, in the motor C, a gap is partially provided between the cover 3c and the resin casing 2c on one side in the axial direction of the insulator 12. The gap Gp is located on one side in the axial direction (Op side in the first direction) of the wiring portion 120c. Further, the portion of the recess 23c is the thin portion 24c.

The press-fitting 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, the force at the time of press-fitting acts on the outer peripheral surface of the resin casing 2c. In the motor C, by providing the recess 23c at the end on the Op side in the first direction in the axial direction, it is difficult for the force at the time of press fitting to concentrate on the recess 23c. As a result, the displacement of the cover 3c with respect to the resin casing 2c is also suppressed. Further, since the recess is provided at the end in the axial direction, the lead wire portion 80 of the conductive member 8 is unlikely to shift in the groove 201 formed on the outer peripheral surface of the resin casing 2c. As a result, the lead wire portion 80 is less likely to be sandwiched between the resin casing 2c and the cover 3c at the time of press fitting, resulting in disconnection or short circuit with the cover 3c. As a result, the effect of suppressing the occurrence of electrolytic corrosion between the first bearing 51 and the second bearing 52 is enhanced. That is, the motor C can suppress electrolytic corrosion of the first bearing 51 and the second bearing 52 regardless of the attached device.

Other features are the same as in the first embodiment.

<4. Fourth Embodiment>
Yet another example of the present invention will be described with reference to the drawings. FIG. 12 is a cross-sectional view of still another example of the motor according to the present invention. The motor D of the present embodiment has the same configuration as the motor A of the first embodiment except that the cover is different. Therefore, in the configuration of the motor D, substantially the same parts as the configuration of the motor A are designated by the same reference numerals, and detailed description of the same parts will be omitted.

<4.1 Cover>
As shown in FIG. 12, the cover of the motor D includes a first cover member 3da and a second cover member 3db. That is, the cover has a first cover member 3da that covers the resin casing 2 from one side in the axial direction (Op side in the first direction) and a second cover member 3da that covers the resin casing 2 from the other side (Or side in the second direction) in the axial direction. A cover member 3db is provided. The Op side of the resin casing 2 in the first direction 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 Op side in the first direction, but the present invention is not limited to this. For example, the Or side of the resin casing 2 in the second direction may be press-fitted into the second cover member 3db. Moreover, both may be press-fitted. Whether the resin casing 2 is press-fitted into the cover member of the first cover member 3da or the second cover member 3db is determined by the position of the press-fitting portion 22 of the resin casing 2.

<4.2 First cover member>
As shown in FIG. 12, the first cover member 3da has a bottomed cylindrical shape in which at least a part of the end portion on the Op side in the first direction is closed. The first cover member 3da includes a first flange 32 extending radially outward at the end on the Or side in the second direction. That is, the first cover member 3da has a first flange 32 extending radially outward from the outer peripheral surface. The first flange 32 is a quadrangle (for example, a square) when viewed in the axial direction. The first flange 32 adopts a shape that can be attached to a mounting location of a device (not shown) to which the motor D is mounted.

<4.3 Second cover member>
As shown in FIG. 12, the second cover member 3db is a cylindrical member extending in the axial direction. The second cover member 3db includes a second flange 33 extending radially outward at the end on the Op side in the first direction. That is, the second cover member 3db has a second flange 33 extending radially outward from the outer peripheral surface. The second flange 33 is a quadrangle (for example, a square) when viewed in the axial direction. The second flange 33 has a shape that overlaps with the first flange 32 in the axial direction.

The resin casing 2 penetrates the second cover member 3db from the Op side in the first direction to the Or side in the second direction. Then, the portion of the second cover member 3db of the resin casing 2 protruding in the axial direction from the end on the Or side in the second direction is press-fitted into the outer cylinder portion 620 of the second bearing accommodating member 62.

<4.4 Motor assembly>
After arranging the conductive member 8 in the groove 201, the resin casing 2 is inserted into the first cover member 3da from the Op side in the first direction, and the press-fitting portion 22 is press-fitted into the first cover member 3da. The first bearing accommodating member 61 penetrates the cover hole 30 of the first cover member 3da. At this time, the first bearing accommodating member 61 and the edge portion of the cover hole 30 are not in contact with each other, that is, the first bearing accommodating member 61 and the first cover member 3da are electrically insulated.

On the other hand, the second cover member 3db covers the outer peripheral surface of the resin casing 2. Then, by moving the second cover member 3db in the axial direction, the second flange 33 comes into contact with the first flange 32 of the first cover member 3da.

The first flange 32 and the second flange 33 mutually fix the first cover member 3da and the second cover member 3db. Therefore, the first flange 32 and the second flange 33 are provided with screw fixing holes through which the fixture (here, the screw) penetrates. Then, by fixing the first flange 32 and the second flange 33 to each other, the first cover member 3da and the second cover member 3db are fixed 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 directly or indirectly connected to each other.

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. At this time, the end portion of the resin casing 2 on the Or side in the second direction protrudes from the second cover member 3db on the Or side in the second direction. The end of the resin casing 2 on the Or side in the second direction is press-fitted into the outer cylinder portion 620 of the second bearing accommodating member 62. At this time, the second terminal 802 is sandwiched between the outer cylinder portion 620 and the resin casing 2. Further, the outer cylinder portion 620 and the second cover member 3db are separated from each other, that is, electrically insulated.

By covering the resin casing 2 with the first cover member 3da and the second cover member 3db in this way, it is possible to shorten the length at which the press-fitting portion 22 is press-fitted. As a result, the force acting on the resin casing 2 and the cover can be reduced, and deformation such as distortion and displacement of the resin casing 2 and the cover can be suppressed. Further, from this, the stator 1 and the rotor 4 can be accurately aligned with each other, and the decrease in the capacity of the motor D can be suppressed. Further, by shortening the press-fitting length of the press-fitting portion 22, the lead wire portion 80 of the conductive member 8 is less likely to be sandwiched between the first cover member 3da and the resin casing 2. As a result, it is possible to prevent the conductive member 8 from being disconnected or short-circuited with at least one of the first cover member 3da and the second cover member 3db. Therefore, in a state where the first bearing 51 and the second bearing 52 are insulated from the voltage of the external device (for example, the reference voltage), the first bearing 51 and the second bearing 52 are electrically conducted with each other to conduct the bearing. Electrolytic corrosion can be suppressed. That is, the motor D can suppress electrolytic corrosion of the first bearing 51 and the second bearing 52 regardless of the attached device.

In the motor D, the first cover member 3da and the second cover member 3db are in direct contact with each other. Then, the first cover member 3da and the energizing member 8 are electrically insulated. As a result, the second cover member 3db and the energizing member 8 are electrically insulated. As a result, the cover (first cover member 3da and second cover member 3db) and the energizing member 8 are electrically insulated.

<5. Fifth Embodiment>
Yet another example of the present invention will be described with reference to the drawings. FIG. 13 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 the configuration of the motor D are designated by the same reference numerals, and detailed description of the same parts will be omitted. Further, in the motor E, the first bearing 51 is housed in the first bearing storage member 61 having the same configuration as the motor A.

As shown in FIG. 13, the resin casing 2e of the motor E includes a stepped portion 25e protruding outward in the radial direction 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 included in the motor B shown in FIGS. 8 and 9. That is, four step portions 25e are provided in the resin casing 2e and are arranged at equal intervals in the circumferential direction. Further, the first bearing accommodating member 61 is fixed to the end of the resin casing 2e on the Op side in the first direction. The method of fixing the first bearing accommodating member 61 is the same as that of the resin casing 2 of the motor A, and the details will be omitted.

The first cover member 3ea has a bottomed cylindrical shape in which the end on the Op side in the first direction is closed. The bottom portion is provided with a casing contact portion 31 and a conductive portion 312, similarly to the cover 3. Further, 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 accommodating member 62d are formed of the same member. The second bearing accommodating member 62d is continuously formed at the end of the second cover member 3eb on the Or side in the second direction. Further, the second cover member 3eb includes a second flange 33e extending radially outward and a contact portion 35e at an end portion on the Op side in the first direction. The second flange 33e is provided at a position where the second cover member 3eb comes into 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 the second cover member 3eb comes into contact with the surface of the step portion 25e on the second direction Or side when the resin casing 2e is covered from the second direction Or side.

As shown in FIG. 15, in the second cover member 3eb, the second flange 33e is provided on the Op side in the first direction with respect to the contact portion 35e. The second flange 33e and the contact portion 35e are alternately arranged 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 Op side in the first direction. 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 comes into contact with the end surface of the step portion 25e of the resin casing 2e on the second direction Or side, and the second flange 33e comes into contact with the first flange 32.

As described above, when the resin casing 2e is provided with the step portion 25e, positioning in the axial direction at the time of press fitting into the first cover member 3ea becomes easy. Similarly, the axial positioning of the second cover member 3eb with respect to the resin casing 2e becomes easy. For example, when the period of use of the motor E is extended, the outer diameter of the press-fitting portion 22 may become smaller due to aging 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 becomes weak. 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, even if the fixing by press fitting is weakened, the movement of the resin casing 2e is restricted. As a result, it is possible to suppress a decrease in the capacity of the motor E even after long-term use.

In the motor E, the first flange 32 and the second flange 33e come into direct contact with each other. Then, the first cover member 3ea is electrically insulated from the first bearing accommodating member 61. Further, the second cover member 3eb is electrically insulated from the second bearing accommodating member 62. Then, the first bearing accommodating member 61 and the second bearing accommodating member 62 are electrically conductive by the conductive member 8 which is electrically insulated from the first cover member 3ea and the second cover member 3eb. As a result, the first bearing accommodating member 61 and the second bearing accommodating member 62 are electrically conductive and are electrically insulated from the first cover member 3ea and the second cover member 3eb. As a result, even if the reference voltage (frame ground voltage) of the attached device of the motor E fluctuates, the electrolytic corrosion of the first bearing 51 and the second bearing 52 due to the fluctuation of the voltage can be suppressed. That is, the motor E can suppress electrolytic corrosion of the first bearing 51 and the second bearing 52 regardless of the attached device.

Other features are the same as in the fourth embodiment.

Although the embodiments of the present invention have been described above, the embodiments can be modified in various ways within the scope of the gist of the present invention.

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

A ... motor, A1 ... motor, A2 ... motor, B ... motor, B1 ... motor, C ... motor, D ... motor, E ... motor, 1, ...・ ・ Stator, 11 ・ ・ ・ Stator core, 111 ・ ・ ・ Core back part, 112 ・ ・ ・ Teeth part, 12 ・ ・ ・ Insulator, 120 ・ ・ ・ Wiring part, 121 ・ ・ ・ Insulation material part, 122 ・... Insulator core back part, 13 ... winding, 130 ... crossing wire part, 2 ... resin casing, 20 ... resin casing hole, 200 ... concave groove, 201 ... groove , 2011 ... groove, 2012 ... groove, 0202 ... hole, 21 ... concave hole, 22 ... press-fitting part, 23 ... concave part, 231 ... protruding part, 24 ... Thin-walled part, 25 ... step part, 25e ... step part, 3 ... cover, 3b ... cover, 3c ... cover, 3da ... first cover member, 3db ... second Cover member, 3ea ... 1st cover member, 3eb ... 2nd cover member, 30 ... Cover hole, 31 ... Casing contact part, 310 ... Penetration part, 311 ... Contact part , 32 ... 1st flange, 33 ... 2nd flange, 33e ... 2nd flange, 4 ... Rotor, 40 ... Rotating shaft, 411 ... Cylindrical member, 412 ... Shaft support member, 400 ... groove, 401 ... shaft stop ring, 402 ... shaft stop ring, 42 ... magnet, 43 ... mold part, 51 ... first bearing, 52 ... 2nd bearing, 61 ... 1st bearing storage member, 610 ... end face, 611 ... flange part, 62 ... 2nd bearing storage member, 620 ... outer cylinder part, 621 ... Storage part, 71 ... Bearing side intrusion prevention member, 72 ... Shaft side intrusion prevention member, 8 ... Conductive member, 80 ... Lead wire part, 801 ... First terminal, 802 ... 2nd terminal, 81 ... conductive connection, Bd ... substrate, Is ... protective sheet

Claims (13)

A rotor with a rotation axis that extends along the central axis,
A stator having a plurality of windings wound around an stator core that is radially opposed to the outer peripheral surface of the rotor via an insulator, and 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 separated from each other in the central axis direction,
A cover that covers the resin casing is provided.
The stator includes a plurality of bearing accommodating members in which the plurality of bearings are accommodating.
The bearing accommodating member has conductivity and
Each of the bearing accommodating members is electrically conducted by the conductive member, and is electrically conducted.
Each of the plurality of bearing accommodating members is electrically insulated from the cover.
The cover is a motor that is electrically insulated from the conductive member. The cover covers the resin casing at least on one side of the insulator radially outward or on one side in the axial direction.
The motor according to claim 1, wherein at least a part of the insulator is provided with a gap between the cover and the resin casing at least on one side in the radial direction or one side in the axial direction. The plurality of windings are electrically connected via a crossover portion, and the plurality of windings are electrically connected.
The insulator is provided with a wiring portion to which the crossover portion is wired.
The motor according to claim 2, wherein the gap is located at least one of the wiring portions on the outer side in the radial direction or on one side in the axial direction. The motor according to claim 1 or 2 , wherein the gap is a recess recessed in the radial direction from the outer surface of the resin casing . The stator core
With an annular core back
It has a teeth portion extending radially inward from the core back portion.
The insulator is
An insulator tooth portion that covers the tooth portion and
It has an insulator core back portion that covers at least an axial end portion of the core back portion.
The wiring portion extends axially from the axial end portion of the insulator core back portion.
The crossover is wired on the radial outer surface of the wiring portion.
The motor according to claim 4, wherein the recess is located on the outer peripheral surface of the resin casing. It has a protruding portion that protrudes in the radial direction in a part of the recess.
The motor according to claim 4 or 5, wherein the conductive member is arranged on the protruding portion. At least one of the plurality of bearing accommodating members is a resin-sealed bearing accommodating member sealed by the resin casing.
The resin-sealed bearing storage member includes a flange portion extending in the radial direction.
A part of the flange portion is sealed in the resin casing.
The cover includes a casing contact portion that is in contact with the resin casing and whose axial position overlaps with the flange portion.
The conductive member has a conductive connection portion that is electrically conductive with respect to the flange portion.
The casing contact portion includes a penetration portion that penetrates in the axial direction.
The motor according to any one of claims 1 to 6, wherein the conductive connecting portion is located in the penetrating portion. The output shaft side end surface of the resin casing portion is provided with a concave hole recessed in the axial direction.
The casing contact portion contacts along the concave hole and
The motor according to claim 7, wherein a bearing cover that covers the bearing housing portion is attached to the output shaft. The cover has a cylindrical shape extending in the axial direction.
The motor according to any one of claims 1 to 8, wherein the resin casing is provided with a press-fitting portion to be press-fitted inside the cover. The motor according to claim 9, wherein the press-fitting portion overlaps the stator core when the resin casing is viewed in the radial direction. The motor according to claim 9 or 10, wherein the inner diameter of the cover gradually decreases in the press-fitting direction of the resin casing. The motor according to claim 9 or 10, wherein the inner diameter of the cover gradually decreases in the press-fitting direction of the resin casing. The cover is
A first cover member that covers 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 is provided.
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.
Any one of claims 1 to 12, wherein the first cover member and the second cover member are directly or indirectly connected to the first flange and the second flange when the resin casing is covered. The motor described in.

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