JPWO2018179832A1 - motor - Google Patents

Abstract

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 spaced apart from each other in an axial direction, and cover an outer peripheral surface of the resin casing; The stator includes a cover and a conductive member having conductivity, the stator includes a plurality of bearing storage members each storing a plurality of bearings, the conductive member is supported by the cover, and the conductive member is provided on one side. A motor having a contact portion that contacts a stator core and a ground portion grounded on the other side, wherein a bearing and the current-carrying member are electrically insulated.

Description

  The present invention relates to a motor.

  In recent years, motors driven by a PWM (Pulse Width Modulation) method (hereinafter referred to as a PWM method) have been increasing. When the electric motor is driven by the PWM method, the neutral point potential of the winding does not become zero, and a potential difference (hereinafter, referred to as shaft voltage) may occur between the outer ring and the inner ring of the bearing. When the shaft voltage becomes a constant voltage, a current flows inside the bearing, causing electrolytic corrosion inside the bearing. The electrolytic corrosion of the bearing causes vibration and noise. Therefore, an electric motor in which the generation of the shaft voltage is suppressed is disclosed in, for example, Patent Document 1.

  The electric motor described in Patent Literature 1 includes a stator in which a fixing member including a stator core having windings wound thereon is molded with an insulating resin, and a rotor that is arranged to face the stator around a shaft, The bearing includes a bearing that rotatably supports the shaft, a bracket that fixes the bearing, and a drive circuit board on which a drive circuit that drives the winding is mounted. Then, an iron core connection terminal is connected to the stator iron core, and by inserting the iron core connection terminal into the drive circuit board, the stator iron core is electrically connected to a ground which is a zero potential reference on the drive circuit board. ing.

  The stator core is considered to be a voltage source that induces a high-frequency voltage on the bearing inner ring and the bearing outer ring when the switching element that drives the motor is driven.The stator core is connected to ground on the drive circuit board, and the stator core is connected to the stator. The shaft voltage is reduced by setting the potential of the iron core to zero potential.

International Publication No. WO 2010/067614

  The motor described in Patent Document 1 has a configuration in which the conductive member is brought into contact with the stator core and the conductive member is connected to the drive circuit board. Therefore, the motor that does not require a drive circuit also needs a board. Further, since the conductive member is embedded in the mold resin, it is necessary to mold the conductive member so as not to be displaced or deformed at the time of molding the mold resin, which takes time and effort.

  Further, the molding resin holds the conducting member, and when an external force acts on the conducting member, the molding resin is cracked or a gap is opened between the conducting member and the molding resin. As a result, external moisture easily penetrates into the mold resin, and the conductive member does not come into contact with the stator core, so that the effect of preventing electrolytic corrosion cannot be obtained.

  Therefore, an object of the present invention is to provide a motor capable of protecting against external impact and taking measures against electrolytic corrosion of a bearing while suppressing an increase in the number of parts.

  An exemplary motor according to the present invention includes a rotor having a rotation axis extending along a central axis, and a plurality of windings wound around a stator core radially opposed to an outer peripheral surface of the rotor via an insulator. A stator, a resin casing that seals at least the insulator and the windings of the stator, a plurality of bearings that rotatably support the rotating shaft at positions axially separated from each other, and an outer peripheral surface of the resin casing And a conductive member having conductivity.The stator includes a plurality of bearing storage members in which the plurality of bearings are stored, and the conductive member is supported by the cover, and the The member has a contact portion that contacts the stator core on one side, and a grounding portion that is grounded on the other side, wherein the bearing and the current-carrying member are electrically insulated. That.

  According to the exemplary motor of the present invention, it is possible to provide a motor capable of taking measures against electrolytic corrosion of a bearing while suppressing an increase in the number of parts.

FIG. 1 is an exploded perspective view of an example of a motor according to the present invention. FIG. 2 is a 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 illustrating 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 illustrating a resin casing and a cover of another modified example of the motor according to the first embodiment. FIG. 8 is an exploded perspective view of another example of the motor according to the present invention. FIG. 9 is a sectional view of the motor shown in FIG. FIG. 10 is a sectional view of still another example of the motor according to the present invention. FIG. 11 is an exploded perspective view of still another example of the motor according to the present invention. FIG. 12 is a sectional view of the motor shown in FIG. FIG. 13 is a sectional view of a modified example of the motor according to the fourth embodiment. FIG. 14 is a 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 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 defined as a radial direction, and a tangential direction of a circle around the axis is defined as a circumferential direction.

  In this document, the axial direction is set as follows with reference to FIG. That is, in FIG. 2, the direction toward the right in the axial direction is defined as a first direction Op, and the direction toward the left is defined as a second direction Or. Note that “left direction” and “right direction” in this document are set for 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, a second bearing 52, an energizing member 8, Having. 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 arranged inside the stator 1. The rotor 4 has 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 rotary shaft 40 at positions separated from each other in the axial direction.

<1.2 Configuration of Stator>
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, which is radially opposed to the outer peripheral surface of the rotor 4, via an insulator 12. Further, 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 housed, respectively.

  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 extending 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 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 covers both end surfaces of the core back portion 111 in the axial direction. The insulator 12 has an insulator teeth portion 121 covering the teeth portion 112 and an insulator core back portion 122 covering at least an axial end of the core back portion 111. A winding is formed by winding a conductive wire around the teeth 112 (insulator teeth 121) covered with the insulator 12. The stator 12 and the winding 13 are insulated by the insulator 12. In the present embodiment, the insulator 12 is a molded body of a resin, but is not limited to this. A configuration that can insulate 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 radially outer peripheral surface of the core back portion 111 may be exposed without being covered with the insulator 12. In addition, 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 a powder. Further, the stator core 11 may have a configuration that can be divided into divided cores each including one tooth portion 112, or may have a configuration formed by winding a belt-shaped member.

  The windings 13 are arranged on each of the teeth 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, 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 each phase will be collectively described simply as the winding 13.

  Further, the stator 1 has a plurality of windings 13 connected to each other, or a crossover portion electrically connected to a control circuit (not shown) mounted on the board Bd provided on the motor A and the windings 13. 131 is provided. The crossover portion 131 is disposed on the wiring portion 120 provided on the insulator core back portion 122 that covers the axial end surface of the core back portion 111 of the insulator 12. As shown in FIG. 2, the stator 1 includes a wiring portion 120 on which a crossover 131 is arranged 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 Configuration 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, in the motor A, the outer surface of the stator core 11 in the radial direction is also covered. The resin casing 2 has a bottomed cylindrical shape in which at least a part of the end on the first direction Op side is closed. A resin casing hole 20 extending in the axial direction is provided at a radially central portion of the bottom.

  A concave hole 21 that is concave in the axial direction is provided radially outside the resin casing hole 20 on the bottom end surface on the first direction Op side. The 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 housing 61 will be described later.

  As shown in FIGS. 1 and 2, the cover 3 covers the outer peripheral surface of the resin casing 2. The cover 3 has a bottomed cylindrical shape in which at least a part of the end 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 by, for example, extruding a metal plate. A cover hole 30 penetrating in the axial direction is provided at the radial center of the bottom of the cover 3. A casing contact portion 31 that protrudes inward in the axial direction (the second direction Or side in FIG. 2) is provided radially outside the cover hole 30. That is, the cover 3 includes the casing contact portion 31 protruding inward at the radial center of the bottom portion, and the cover hole 30 at the center of the casing contact portion 31.

  The resin casing 2 has 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 pressed into the cover 3, the casing contact portion 31 overlaps the concave hole 21 in the axial direction. Further, the resin casing hole 20 and the cover hole 30 also overlap in the axial direction. The rotating shaft 40 passes through the resin casing hole 20 and the cover hole 30.

  When the resin casing 2 is pressed into the cover 3, the casing contact portion 31 comes into contact with the concave hole 21. The casing contact portion 31 presses the concave hole 21 so that the resin casing 2 and the cover 3 are in close contact with each other. This suppresses entry of gas, water, dust, dust, and the like from the boundary between the resin casing hole 20 and the cover hole 30 from the boundary between the resin casing 2 and the cover 3.

  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 the press-fit portion 22 that is press-fitted inside the cover 3. As shown in FIG. 2, the press-fit portion 22 is provided at a portion radially overlapping the stator core 11 on the outer peripheral surface of the resin casing 2. 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-fit portion 22. The press-fit portion 22 is provided at a position radially overlapping the stator core 11. At the time of press fitting, a 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 radially overlapping with the stator core 11 having higher strength than the resin of the resin casing 2, even if a force acts from the cover 3 at the time of press-fitting, the resin casing 2 is hardly deformed. .

  The concave portion 23 radially overlaps the wiring portion 120 on the outer peripheral surface of the resin casing 2 where the crossover portion 131 of the insulator 12 is arranged. The concave portion 23 is provided at an end of the resin casing 2 on the first direction Op side, and is formed continuously in the circumferential direction. In the present embodiment, the resin casing 2 is formed at the radial end, but is not limited to this.

  Further, depending on the condition of the place where the motor A is mounted, water contained in the air inside the motor A may be dewed and condensed water may be accumulated. Air is also accumulated in the concave portion 23, and moisture contained in the accumulated air may condense. Therefore, a groove 200 extending from the recess 23 toward the second direction Or is provided on the outer peripheral surface of the resin casing 2.

  As a result, the dew water accumulated in the concave portion 23 passes through the concave groove 200 and is discharged outside from between the second bearing housing member 62 and the cover 3. In addition, for example, in the case of a structure that is not affected or hardly affected by the generation of dew water due to insulation of an electric circuit or the like, the concave groove 200 may be omitted. Even if the concave groove 200 is omitted, the dew condensation water evaporates into the air in the concave portion 23 by the heat generated when the motor A is driven. In the case where dew water cannot be drained to the outside of the resin casing due to the shape of the cover or the like, a drainage hole penetrating to the outside may be formed in the cover or the bearing housing member, and drainage may be performed using the drainage hole. .

  The resin casing 2 is inserted into the cover 3 from the side where the concave portion 23 is provided in the axial direction, and is fixed by press-fitting. When the resin casing 2 is pressed into the inside of the cover 3, a gap Gp is formed in the radial direction between the portion where the concave portion 23 is formed and the inner surface of the cover 3. The gap Gp between the resin casing 2 and the cover 3 will be described later in detail.

  As shown in FIG. 2, the radial thickness of a portion of the resin casing 2 where the recess 23 is provided is smaller than the thickness of other portions of the resin casing 2. That is, the portion where the concave portion 23 is provided is the thin portion 24 which is thinner than other portions. There is a case where a current flows through the crossover portion 131 and the crossover portion 131 is heated. At this time, since the thin portion 24 is formed, the heat of the crossover 131 is easily released to the outside of the resin casing 2.

<1.4 Configuration of rotor>
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 cylindrical member 411 extending in the axial direction, and a shaft support member 412 disposed radially inside the cylindrical member. The cylindrical member 411 and the shaft support member 412 are fixed to each other by a mold portion 43 which is a molded resin 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 a powder to form the same member.

  The rotation shaft 40 has a cylindrical shape. The rotating shaft 40 penetrates a radial center of the shaft supporting member 412 of the rotor core 41. The rotation shaft 40 and the shaft support member 412 are relatively fixed. In addition, as a fixing method, press-fitting, welding, and the like can be given, but are not limited thereto. A method that can fix the rotating shaft 40 and the shaft support member 412 can be widely adopted. That is, the rotation shaft 40 is fixed to the rotor 4, and the rotation of the rotor 4 causes the rotation shaft 40 to rotate about the central axis Ax.

  The plurality of magnets 42 are arranged radially outside 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, a plurality of magnets 42 are arranged, but the invention is not limited to this. For example, a magnet in which N poles and S poles are alternately magnetized in the circumferential direction on a cylindrical magnetic body may be used.

  That is, the rotor core 41 has an N pole and an S pole as a pair of magnetic poles, and includes a plurality of pairs of magnetic poles. 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 resin molding, and a method that does not adversely affect the rotation of the rotor 4 or that does not easily affect the rotation of the rotor 4, such as adhesion, welding, and mechanical fixing.

<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 positions in the axial direction. The end of the rotation shaft 40 on the second direction Or side is press-fitted into the inner ring of the second bearing 52. A portion of the rotating shaft 40 closer to the first direction Op than a portion pressed into the second bearing 52 of the rotary shaft 40 is press-fitted into the inner ring of the first bearing 51.

  The first bearing 51 is housed in the first bearing housing member 61. The second bearing 52 is housed in a second bearing housing member 62. Although details will be described later, the first bearing housing member 61 and the second bearing housing 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 by) 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 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 fitted and fixed in grooves 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. The movement of the rotating shaft 40 in the first direction Op with respect to the first bearing 51 is restricted by the shaft retaining ring 401.

  The shaft retaining ring 402 contacts the inner ring of the second bearing 52 in the first direction Op. The movement of the rotating shaft 40 in the second direction Or with respect to the second bearing 52 is restricted by the shaft retaining ring 402. The axial movement of the first bearing 51 and the second bearing 52 with respect to the stator 1 is relatively limited, and the axial movement of the rotating shaft 40 with respect to the stator 1 is limited. 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 capable of restricting the movement of the rotating shaft 40 by contacting the respective inner rings of the pair of bearings 51 and 52 can be widely adopted. In addition, in each embodiment in this document, the rotating shaft 40 is rotatably supported by two bearings (the first bearing 51 and the second bearing 52), but is not limited thereto. It may be supported by three or more bearings.

<1.6 Configuration of bearing storage member>
Here, the first bearing housing member 61 and the second bearing housing member 62 are made of metal such as iron and brass.

<1.6.1 First bearing storage member>
The first bearing housing member 61 has a cylindrical shape in which the first bearing 51 can be housed. One end of the first bearing housing member 61 on the one side in the axial direction is provided with an end face portion 610 through which the rotary shaft 40 penetrates a radial center portion in the axial direction. Further, the other end in the axial direction of the first bearing housing member 61 includes a flange portion 611 extending radially outward. At least a part of the flange portion 611 is insert-molded in the resin casing 2. The first bearing housing portion 61 is fixed to the resin casing 2 by insert molding. The flange portion 611 may be provided with a penetrating portion penetrating in the axial direction. By filling the penetrating portion with resin at the time of insert molding, the movement of the first bearing housing member 61 in the circumferential direction is limited, that is, the rotation is prevented.

  The penetrating portion is not limited to a hole as long as the rotation is reliably prevented by the resin, and may be, for example, a concave portion recessed inward in the radial direction or a convex portion projecting outward in the radial direction. Alternatively, 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 housing member 61 is fixed to the resin casing 2 with its central axis aligned with the central axis Ax of the stator 1 covered by the resin casing 2. The outer race of the first bearing 51 is press-fitted into the first bearing housing member 61.

  When the resin casing 2 is press-fitted into the cover 3, the first bearing housing member 61 insert-molded in the resin casing 2 passes through the cover hole 30 of the cover 3 in the axial direction. At this time, the cover 3 and the bearing housing member 61 are not in contact with each other. That is, the cover 3 and the first bearing housing member 61 are electrically insulated.

<1.6.2 Second bearing storage member>
As shown in FIG. 2, the second bearing storage member 62 holds the second bearing 52. The second bearing storage member 62 has a storage part 621 and an outer cylindrical part 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 cylindrical portion 620 has a larger diameter than the storage portion 621, and an end of the resin casing 2 on the second direction Or side is press-fitted into the outer cylindrical portion 620. Then, the second bearing 62 is fixed to the stator 1 covered with the resin casing 2 by press-fitting the resin casing 2 into the second bearing housing member 62. The outer ring of the second bearing 52 is fixed to the stator 1, and the center axis of the second bearing 52 matches the center axis Ax of the stator 1. The end of the cover 3 on the second direction Or side is separated from the outer cylindrical portion 620 of the second bearing housing member 62 in the axial direction. That is, the cover 3 and the bearing housing member are electrically insulated.

  As shown in FIG. 2, the storage section 621 and the outer cylinder section 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.

<1.7 Current-carrying member>
Motor A is a brushless DC motor. Therefore, the motor A includes an inverter circuit (not shown) in the drive circuit. When the motor A is driven, a high-frequency high voltage may be induced in the stator core 11. A voltage difference is generated between the inner ring and the outer ring of each of the first bearing 51 and the second bearing 52 by the voltage induced in the stator core 11. If the potential difference between the inner ring and the outer ring exceeds a certain value, discharge (spark) may occur between the outer ring and the ball of the first bearing 51 and the second bearing 52 and between the inner ring and the ball. The occurrence of discharge causes damage to the surfaces of the outer ring, the ball, and the inner ring of the bearing, that is, so-called electrolytic corrosion of the bearing. The electrolytic corrosion of the first bearing 51 and the second bearing 52 causes vibration and noise of the motor A. A cause of the electrolytic corrosion is that a switching element included in an inverter circuit for driving the motor A is driven at a high frequency and a high voltage. Other factors include the potential state of the stator core and the rotor core.

  Therefore, in the motor A according to the present embodiment, the stator core 11 is electrically connected to the ground point (reference voltage) of the device in which the motor A is installed by using the current-carrying member 8. Thereby, the voltage of the stator core 11 is reduced, and the occurrence of electrolytic corrosion due to the voltage induced in the stator core 11 is suppressed.

  In the motor A, the current-carrying member 8 has conductivity. As shown in FIG. 2, the conducting member 8 includes a contact portion 81 and a ground portion 82. As shown in FIG. 2, the grounding section 82 includes a lead wire and the like, and is electrically connected to a grounding point (frame ground) of the device to which the motor A is attached. Further, in the conducting member 8, the contact portion 81 is electrically connected to the ground portion 82. The contact portion 81 is in contact with the stator core 11. That is, the current-carrying member 8 has a contact portion 81 that contacts the stator core 11 on one side, and a ground portion 82 that is grounded on the other side. In this manner, the contact portion 81 contacts the stator core 11 and the ground portion 82 that is electrically connected to the contact portion 81 is electrically connected to the ground point (frame ground), so that the potential of the stator core 11 can be reduced. .

  As shown in FIG. 2, in the motor A, the contact portion 81 is a screw, and includes a connection portion 811, a top portion 812, and a flat portion 813. That is, the connection part 811 is a male screw part, and the crown 812 is a screw head. The connection part 811 is a columnar shape provided with a male screw. A crown 812 is formed of the same member at one end (radially outward in FIG. 2) of the connection portion 811. The surface portion 813 is a surface on the connection portion 811 side of the crown portion 812 and is a flat surface. That is, the current-carrying member 8 is provided with a connection portion 811 and a top portion 812 at one end of the connection portion 811. The connecting portion 811 and the crown 812 are formed of the same member. The flat portion 812 is a surface of the top portion 812 on the connection portion 811 side, and is a flat surface.

  The other end of the contact portion 81 on the opposite side (the other side) to the top portion 812 of the connecting portion 811 is connected to the contact portion 81 of the energizing member 8 with the resin casing 2 and the cover 3 covering the outer peripheral surface of the resin casing 2 radially outward. Penetrates inward from Then, the male screw at the tip of the contact portion 81 is attached by meshing with the female screw of the screw hole 110 provided in the stator core 11. Thereby, the connecting portion 811 and the stator core 11 come into contact with each other. That is, the other end of the connection portion 811 contacts the stator core 11. The male screw of the connecting portion 811 is attached by being engaged with the female screw of the screw hole 302 of the cover 3. The conducting member 8 is supported by the cover 3. In addition, the flat portion 813 contacts the outer peripheral surface of the cover 3. That is, the outer surface of the cover 3 and the flat portion 813 of the crown 812 come into contact with each other. Since the current-carrying member 8 is supported by the cover 3 having a higher strength than the resin casing 2, even when an external force acts on the current-carrying member 8, the cover 3 opposes the external force. Therefore, an excessive force is hardly applied to the resin casing 2 and a trouble is hardly generated.

  The end of the lead wire serving as the ground portion 82 is sandwiched between the flat portion 813 and the outer peripheral surface of the cover 3. Then, the end of the ground portion 82 opposite to the flat portion 813 is connected to the ground point (frame ground) of the device to which the motor A is attached. Thereby, the potential of the stator core 11 can be reduced. The ground portion 82 may be connected to a ground provided separately from the frame ground.

  As shown in FIG. 2, the first bearing housing member 61 and the cover 3 are electrically insulated. Further, the second bearing housing member 62 and the cover 3 are electrically insulated. That is, the cover 3 and the bearing housing members (61, 62) are electrically insulated. For this reason, the first bearing housing member 61 and the second bearing housing member and the conducting member 8 are electrically insulated. That is, the bearings (51, 52) and the conducting member 8 are electrically insulated. In the present embodiment, the bearing and the current-carrying member are insulated from each other by insulating the cover 3 and the bearing housing members (61, 62). However, the present invention is not limited to this. For example, the bearing and the bearing housing member may be insulated. In addition to these, a method of electrically insulating the bearing and the current-carrying member can be widely adopted.

  In the present embodiment, the distal end of the connection portion 811 is screwed into the screw hole 110 of the stator core 11, but the connection portion 811 and the stator core 11 need not be screwed as long as they are electrically connected. Further, as the contact portion 81 of the current-carrying member 8, a screw having a male screw in the connecting portion 811 and a crown 812 which is a screw head formed of the same member as the male screw is described as an example. Not limited. As the contact portion, for example, a configuration such as a rivet or a cotter pin, which can be in contact with the stator core 11 and whose top portion can be in contact with the outer peripheral surface of the cover 3, can be widely used. Further, the tip of the lead wire included in the grounding portion 82 may be inserted into a hole provided in the resin casing 2 and the cover 3 and adhered to the stator core 11 with a conductive adhesive to form the contact portion 81. As the contact portion 81, a configuration that can electrically conduct the ground portion 82 and the stator core 11 can be widely adopted.

<1.8 Other components>
As shown in FIG. 2, in the motor A, the second direction Or side of the resin casing 2 is press-fitted into the outer cylindrical portion 620 of the second bearing housing member 62. For this reason, entry of foreign matters such as water, dust, and dust from the gap between the outer cylindrical portion 620 and the resin casing 2 is suppressed. On the other hand, on the Op side in the first direction of the motor A, the portion of the end face portion 610 through which the rotating shaft 40 penetrates does not hinder the rotation of the rotating shaft 40, so that a gap is formed between the motor A and the rotating shaft 40. That's it. Foreign substances such as water, dust, and dust easily enter the inside of the motor A from the gap. Therefore, the motor A is provided with a bearing-side intrusion prevention member 71 and a shaft-side intrusion prevention member 72 for suppressing entry of foreign matter from the first bearing housing member 61.

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

  The shaft-side intrusion prevention member 72 is disposed so as to surround the bearing-side intrusion prevention member 71 in the radial direction. The shaft-side intrusion prevention member 72 is disposed in a groove 400 provided on the rotating shaft 40. Thereby, the axial movement of the shaft-side intrusion prevention member 72 is restricted. 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 prevention member 71 and the shaft-side intrusion prevention member 72 are attached to the motor A at the same time, thereby playing a role of suppressing the entry of foreign matter into the motor A.

  A part of the tip on the second direction Or side of the shaft-side intrusion prevention member 72 overlaps 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 disposed in the concave hole 21. Since the casing contact portion 31 is not in contact with the shaft-side intrusion prevention member 72, the rotation of the rotating shaft 40 is not limited.

  Further, a substrate Bd and a protection sheet Is are provided on the resin casing 2 on the second direction Or side 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. Note that the control circuit may be provided outside the motor A, and in that case, the board Bd may be omitted. The protection sheet Is is an insulating member disposed between the substrate Bd and the second bearing housing member 62. It is provided to prevent a short circuit between the second bearing housing member 62 and the board Bd. In the case of a motor without the substrate Bd, the protection sheet Is may be omitted.

<1.9 Motor operation>
The operation of the motor A described 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 by 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. Heat of stator core 11 and windings 13 is transmitted to resin casing 2.

  The heat of the resin casing 2 is transmitted 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. As a result, a difference occurs in the amount of deformation between the resin casing 2 and the cover 3 due to thermal expansion. However, the resin casing 2 and the cover 3 are press-fitted in the press-fitting 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 in the press-fit portion 22 is suppressed.

  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 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 greatly deformed radially outward due to thermal expansion than the press-fit portion 22 that overlaps with the stator core 11 in the radial direction. Further, since the cover 3 is farther away from the stator core 11, heat radiation is inferior to that of the press-fit portion 22. Therefore, problems such as distortion and displacement of the resin casing 2 occur due to a 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 (the second direction Or side in FIG. 2), the deformation due to the 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) has no place to escape the 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.

  As a result, the difference in the amount of deformation between the resin casing 2 and the cover 3 at a position axially displaced from the stator core 11 of the resin casing 2 (particularly on the inner side in the press-fitting direction) is absorbed by the gap Gp. Thereby, it is possible to suppress problems such as distortion and displacement of the resin casing 2 due to a difference in the amount of deformation due to thermal expansion between the resin casing 2 and the cover 3.

  According to the motor A of the present embodiment, the gap is provided in a portion where the difference in the amount of deformation of the resin casing 2 and the cover 3 due to heat becomes large. By absorbing the difference in the amount of deformation due to heat between the resin casing 2 and the cover 3 in the gap Gp, it is possible to suppress distortion, displacement, and the like due to the difference in the amount of heat deformation. Further, by forming the concave portion 23 in the resin casing 2, a gap between the resin casing 2 and the cover 3 can be easily formed. Further, a portion of the resin casing 2 provided with the concave portion 23, that is, a portion radially overlapping the concave portion 23 in FIG. 2 is a thin portion 24 thinner than other portions of the resin casing 2. By providing the thin portion 24 in this manner, heat generated when a current flows through the crossover 131 can be easily discharged to the outside of the resin casing 2.

  In the present embodiment, the current-carrying member 8 in contact with the cover 3 is grounded to a ground point (frame ground). The ground point (frame ground) is a reference voltage of the apparatus, and may vary under the influence of driving of the motor A and a power supply circuit (not shown), for example. If the outer rings of the first bearing 51 and the second bearing 52 are connected to the ground point at which the reference voltage varies, there is a possibility that electrolytic corrosion may occur depending on conditions. Therefore, in the motor A, the cover 3 is insulated from the first bearing housing member 61 and the second bearing housing member 62 electrically connected to the outer ring of the second bearing 52 and the outer ring of the first bearing 51. I do. Thereby, the first bearing 51 and the second bearing 52 are prevented from being connected to the ground point (frame ground), and the electrolytic corrosion caused by the variation in the reference voltage is suppressed. Further, as described above, the voltage of the stator core 11 is reduced to the reference voltage by being connected to the ground point (frame ground). Thereby, electrolytic corrosion generated based on the induced voltage generated in stator core 11 is also suppressed.

  In the motor A, by suppressing the occurrence of electrolytic corrosion of the bearing, the first bearing 51 and the second bearing 52 can rotate with high accuracy over a long period of time. Thereby, stable operation of the molded motor A over a long period of time becomes possible. That is, the life of the molded motor A can be extended.

<1.10 Modification>
<1.10.1 Modification 1>
A modified example of the motor shown in the present embodiment will be described with reference to the drawings. FIG. 6 is a partial 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 portions are denoted by the same reference numerals, and detailed description of the same portions 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 in the press-fitting direction, that is, toward the first direction Op in FIG. That is, the outer peripheral surface of the resin casing 2a1 is an inclined surface (taper surface) having a small diameter on the inner 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 has a gradually decreasing diameter at least toward the inner side of the inner peripheral surface in the press-fitting direction, that is, toward the first direction Op in FIG. That is, the inner diameter of the cover 3a1 gradually decreases in 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. In addition, since the press-fitting portion 221 has an inclined surface, the amount of deformation of the resin casing 2a1 during press-fitting can be reduced. Thereby, it is easy to suppress the occurrence of distortion and the like of the stator 1.

<1.10.2 Modification 2>
A modified example of the motor shown in the present embodiment will be described with reference to the drawings. FIG. 7 is a partial cross-sectional view illustrating a resin casing and a cover of another modification 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 portions are denoted by the same reference numerals, and detailed description of the same portions will be 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. The outer peripheral surface of the resin casing 2a2 has a small diameter on the back side in the press-fitting direction, and a step is formed in 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 cylindrical shape, and at least the inner side of the inner peripheral surface in the press-fit direction, that is, the first direction Op in FIG. That is, the inner diameter of the cover 3a2 gradually decreases in 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 to perform positioning when the resin casing 2a2 is inserted into the cover 3a2. Further, the press-fit portion 222 of the resin casing 2a2 comes into contact with the press-fit portion of the cover 3a2, and press-fit starts. As a result, the force acting on the press fit can be reduced. The amount of deformation of the resin casing 2a2 during press fitting can be reduced. Thereby, it is easy to suppress the occurrence of distortion and the like of the stator 1.

<Second embodiment>
Another example 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 sectional view of the motor shown in FIG. As shown in FIGS. 8 and 9, the resin casing 2b of the motor B is provided with a step 25 extending radially outward on the second direction Or side. A plurality of (here, four) step portions 25 are provided in the resin casing 2b. In the step portion 25, the resin casing 2b is arranged at the same position 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 pressed into the cover 3b, the contact portion 311 comes into contact with the step portion 25. The contact portion 311 contacts a surface of the step portion 25 in the press-fitting direction (in FIG. 9, the first direction Op side).

  The step 25 is a mounting projection 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 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. In addition, even if vibrations, shocks, or the like act, the motor B does not easily fall off. The number and position of the steps 25 are not limited to those described above, but may be changed depending on the shape and position of a mounting portion (not shown) of a device to which the motor B is mounted.

  The cover 3b is electrically insulated from the first bearing housing member 61 and the second bearing housing member 62. Then, the stator core 11 is electrically connected to the ground point (frame ground) by the conducting member 8 to lower the potential of the stator core 11. Thereby, the occurrence of electrolytic corrosion due to the induced voltage generated in the stator core 11 is suppressed. The contact part 311 may come into contact with the device to which the motor A is attached. When the portion of the device that comes into contact with the contact portion 311 has the same potential as the ground point (frame ground), the energizing member 8 has the same voltage as the ground point (frame ground) via the cover 3, ie, Connected to ground point. At this time, the grounding portion 82 of the conducting member 8 may be omitted.

  Other features are the same as in the first embodiment.

<3. Third Embodiment>
FIG. 10 is a sectional view of still another example of the motor according to the present invention. In the motor C shown in FIG. 10, the stator 1c and the resin casing 2c are different, but the other parts are the same as the motor A of the first embodiment. Therefore, substantially the same parts as those of the motor A in 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. 10, the stator 1c of the motor C has an insulator core back portion 122 at an end of the insulator 12 on the first direction Op side. The insulating core back portion 122 includes a wiring portion 120c on which the crossover portion 131 is arranged. Then, a concave portion 23c is formed at a position axially overlapping the wiring portion 120c of the resin casing 2c.

  The recess 23c is a thin portion 24c. A gap Gp is provided between the recess 23c and the cover 3c that overlaps 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 at the time of press-fitting acts on the outer peripheral surface of the resin casing 2c. In the motor C, since the concave portion 23c is provided at the end in the first direction Op side in the axial direction, the force at the time of press-fitting is not easily concentrated on the concave portion 23c. Thereby, the displacement of the cover 3c with respect to the resin casing 2c is also suppressed. Accordingly, the resin casing 2c can be in a state where the first bearing housing member 61 and the second bearing housing member 62 are electrically connected.

  Other features are the same as in the first embodiment.

<4. Fourth embodiment>
Still another example according to the present invention will be described with reference to the drawings. FIG. 11 is an exploded perspective view of still another example of the motor according to the present invention. FIG. 12 is a 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 that the cover, the first bearing housing member 61d, the second bearing housing member 62d, and the bearing-side intrusion prevention member 71d are different. Therefore, in the configuration of the motor D, substantially the same portions as those of the motor A are denoted by the same reference numerals, and detailed description of the same portions will be omitted.

<4.1 Cover>
As shown in FIGS. 11 and 12, the cover of the motor D includes a first cover member 3da and a second cover member 3db. That is, the cover includes a first cover member 3da that covers the resin casing 2 from one side (the first direction Op side) in the axial direction, and a second cover that covers the resin casing 2 from the other side (the second direction Or side) in the axial direction. And a 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 pressed 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 pressed into the second cover member 3db. Alternatively, both may be press-fitted. Which of the first cover member 3da and the second cover member 3db is press-fitted with the resin casing 2 is determined by the position of the press-fit portion 22 of the resin casing 2.

<4.2 First cover member>
As shown in FIGS. 11 and 12, the first cover member 3da has a bottomed cylindrical shape in which at least a part of the end on the first direction Op side is closed. The first cover member 3da includes a first flange 32 extending radially outward at an end on the second direction Or side. That is, the first cover member 3da has the first flange 32 extending 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. Note that the first flange 32 has a shape that can be attached to an attachment location of a device (not shown) to which the motor D is attached.

  The radial center of the bottom 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) and the bearing housing member (first bearing housing member 61d) are formed of the same member. The first bearing housing member 61d and the bearing-side intrusion prevention 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 prevention 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. Then, the bearing-side intrusion prevention member 71d projects from the radial center portion of the end surface portion 610d on the first direction Op side of the first bearing housing member 61d toward the first direction Op. Note that the bearing-side intrusion prevention member 71d is formed of the same member as the first bearing housing member 61d, that is, 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 inside. . Although the material of the bearing-side intrusion prevention member 71d is also different, the use of the shaft-side intrusion prevention member 72 in combination with the shaft-side intrusion prevention member 72 prevents the entry of foreign substances such as water, dust, and dust. It plays the same role as the member 71.

  An insulating member 303 having an inner diameter larger than the outer shape of the connecting portion 811 of the conducting member 8 penetrates the outer peripheral surface of the first cover member 3da. Then, the connecting portion 811 of the conducting member 8 penetrates the insulating member 303. At this time, the connecting portion 811 and the first cover member 3da are not in contact with each other, that is, are electrically insulated.

<4.3 Second cover member>
As shown in FIGS. 11 and 12, 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. Note that a second bearing housing member 62d is formed continuously at an end of the second cover member 3db on the second direction Or side. That is, the cover (second cover member 3db) and the bearing housing member (second bearing housing member 62d) are formed of the same member. The second cover member 3db includes a second flange 33 extending radially outward at an end on the first direction Op side. That is, the second cover member 3db has the second flange 33 extending radially outward from the outer peripheral surface. As shown in FIG. 11, the second flange 33 has a quadrangular shape (for example, a square shape) when viewed in the axial direction. The second flange 33 has a shape that overlaps the first flange 32 in the axial direction.

  The second bearing housing member 62d is different from the 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 the same member as the second cover member 3db. It has the same configuration. That is, the second bearing storage member 62d includes a storage portion 621d that stores the second bearing 52.

<4.4 Assembling the motor>
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 projection 330 protruding in the first direction Op is provided on an end 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 circumferential positions of the first flange 32 and the second flange 33, that is, the first cover member 3da and the second cover member 3db are 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 fixing tools (here, screws) penetrate. 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.

  The resin casing 2 is pressed 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 rotating shaft 40 is supported by the first bearing 51 and the second bearing 52 attached to the first cover member 3da into which the resin casing 2 is press-fitted and the second cover member 3db to cover. Thus, the rotor 4 is rotatably supported inside the stator 1 with a certain interval in the radial direction.

  As described above, 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-fit portion 22 that is press-fitted. Thereby, 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 positioned, and a decrease in the performance of the motor D can be suppressed.

  Further, the first bearing housing member 61d is formed of the same member as the first cover member 3da having conductivity, and the second bearing housing member 62d is formed of the same member as the second cover member 3db having conductivity. I have. And the 1st cover member 3da and the 2nd cover member 3db are contacting. Thus, the first bearing housing member 61d and the second bearing housing member 62d are in an electrically conductive state. Also, the first cover member 3da can be said to be a part of the first bearing housing member 61d, and the second cover member 3db can be said to be 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.

  In the motor D, the first cover member 3da and the second cover member 3db are in direct contact. Further, the first cover member 3da and the conducting member 8 are electrically insulated. Thereby, the second cover member 3db and the conducting member 8 are electrically insulated. Thus, the covers (the first cover member 3da and the second cover member 3db) and the conducting member 8 are electrically insulated.

  In the present embodiment, the insulating member 303 penetrates the conducting member 8 of the first cover member 3da. However, it is not limited to this. At least the first cover member 3da may be formed of an insulating material such as an insulating ceramic. With such a configuration, the first bearing 51 and the second bearing 52 and the conducting member 8 can be electrically insulated without the insulating member 303. This suppresses the connection between the outer ring of the first bearing 51 and the outer ring of the second bearing 52 to the ground point (frame ground). That is, the cover may have an insulating property.

<4.5 Modification>
A modified example of the motor shown in the present embodiment will be described with reference to the drawings. FIG. 13 is a cross-sectional view of a modified example of the motor according to the present embodiment. The motor D1 shown in FIG. 13 has the same configuration as the motor D shown in FIGS. 11 and 12 except that the first cover member 3da1 and the second cover member 3db1 are different. Therefore, substantially the same portions are denoted by the same reference numerals, and detailed description of the same portions will be omitted.

  In the motor D1 shown in FIG. 13, the resin casing 2 and the first bearing housing member 61 have the same configuration as the motor A of the first embodiment. That is, the first bearing housing member 61 is arranged in the resin casing hole 20 of the resin casing 2, and the flange portion 611 is insert-molded in the resin casing 2. The first cover member 3da1 has a cover hole 30 at an end on the Op side in the first direction, and the casing contact portion 31 presses the concave hole 21 of the resin casing 2. That is, the first cover member 3da1 and the first bearing housing member 61 are formed of different members. Then, the first bearing housing member 61 passes through the cover hole 30. At this time, a gap is formed between the inner peripheral portion of the cover hole 30 and the first bearing housing member 61. Thereby, the first cover member 3da1 and the first bearing 51 are electrically insulated.

  As shown in FIG. 13, in the motor D1, the second cover member 3db1 and the second bearing housing member 62 are separate bodies. That is, the second cover member 3db1 moves the end on the second direction Or side away from the end on the first direction Op side of the outer cylinder 620 of the second bearing housing member 62. Thereby, the second cover member 3db1 and the second bearing housing member 62 are electrically insulated.

  Then, by bringing the first flange 32 of the first cover member 3da1 into contact with the second flange 33 of the second cover member 3db1, the first cover member 3da1 and the second cover member 3db1 are electrically conducted. On the other hand, the first cover member 3da1 supports the conducting member 8. The first cover member 3da1 and the first bearing housing member 61 are insulated, and the second cover member 3db1 and the second bearing housing member 62 are insulated. For this reason, the energizing member 8 is supported by the first cover member 3da1, and the stator core 11 is connected to the ground point (frame ground) via the energizing member 8. At this time, it is possible to prevent the outer ring of the first bearing 51 and the outer ring of the second bearing 52 from having the same potential as the ground point (frame ground). Thereby, the electrolytic corrosion of the first bearing 51 and the second bearing 52 generated by the voltage induced in the stator core 11 is suppressed.

<5. Fifth Embodiment>
Still another example according to the present invention will be described with reference to the drawings. FIG. 14 is a 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 portions as those of the motor D are denoted by the same reference numerals, and detailed description of the same portions will be omitted. In the motor E, the first bearing 51 is housed in a first bearing housing member 61 having the same configuration as the motor A.

  As shown in FIG. 14, the resin casing 2e of the motor E includes a stepped portion 25e which projects radially outward from a portion closer to the second direction Or than the press-fit portion 22 on the outer peripheral surface. The step 25e has a different shape in the axial direction from the step 25 of the motor B shown in FIGS. 8 and 9, but has the same shape and is provided for the same purpose. That is, four step portions 25e are provided in the resin casing 2e, and are arranged at equal intervals in the circumferential direction. Further, a first bearing housing member 61 is fixed to an end of the resin casing 2e on the first direction Op side. Note that the method of fixing the first bearing housing member 61 is the same as that of the resin casing 2 of the motor A, and the details are omitted.

  The first cover member 3ea has a closed-end cylindrical shape with an end on the first direction Op side closed. And, like the cover 3, a cover hole 30 and a casing contact portion 31 are provided at the bottom. Further, the first cover member 3ea includes a first flange 32 having a configuration similar to that of the first cover member 3da. When the resin casing 2e is pressed into the first cover member 3ea, the first bearing housing member 61 penetrates through the cover hole 30. At this time, the first bearing housing member 61 and the first cover member 3ea are non-contact, that is, electrically insulated.

  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 62 are formed of different members. The end of the second cover member 3eb on the second direction Or side and the end of the outer cylinder 620 of the second bearing housing member 62 on the first direction Op side are separated in the axial direction. Thereby, the second cover member 3eb and the second bearing housing member 62 are electrically insulated.

  The second cover member 3eb includes a second flange 33e extending radially outward and an abutting portion 35e at an 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. When the second cover member 3eb is covered from the second direction Or side of the resin casing 2e, the contact portion 35e is provided at a position where it comes into contact with the end surface of the step portion 25e on the second direction Or side.

  As shown in FIG. 14, in the second cover member 3eb, the second flange 33e is provided on the first direction Op side with respect to 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 end 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 contacts the end surface of the step portion 25e of the resin casing 2e on the second direction Or side, and the second flange 33e contacts the first flange 32.

  As described above, since the resin casing 2e includes the step portion 25e, positioning in the axial direction at the time of press-fitting the first cover member 3ea is facilitated. Similarly, the positioning of the second cover member 3eb in the axial direction with respect to the resin casing 2e is facilitated. Further, the first cover member 3ea and the first bearing housing member 61 are electrically insulated. Further, the second cover member 3eb and the second bearing housing member 62 are electrically insulated. Thus, even when the conductive member 8 supported by the first cover member 3ea connects the stator core 11 to a ground point (frame ground), the first bearing housing member 61 and the second bearing housing member 62 are connected to the ground point (frame ground). ) Is not connected. Thereby, the first bearing 51 and the second bearing 52 are prevented from being connected to the ground point (frame ground), and the electrolytic corrosion caused by the variation in the reference voltage is suppressed. Further, as described above, the voltage of the stator core 11 is reduced to the reference voltage by being connected to the ground point (frame ground). Thereby, electrolytic corrosion generated based on the induced voltage generated in stator core 11 is also suppressed.

  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 a blower fan such as an air conditioner and a fan.

A: motor, A1: motor, A2: motor, B: motor, C: motor, D: motor, D1: motor, E: motor, 1. ..Stator, 11: stator core, 110: screw hole, 111: core back portion, 112: teeth portion, 12: insulator, 120: wiring portion, 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, 0202 ... hole, 21 ... concave hole, 211 ... first opening, 212 ... second opening, 22 ... Press-fitting part, 23 ... Concave part, 231 ... Protruding part, 24 ... Thin part, 25 ... Part, 25e step, 3 ... cover, 3b ... cover, 3c ... cover, 3da ... first cover member, 3db ... second cover member, 3ea ... 1 cover member, 3 eb: second cover member, 30: cover hole, 31: casing contact portion, 310: through portion, 311: contact portion, 41: inner cylinder, 32 first flange, 33 second flange, 33e second flange, 4 rotor, 40 rotating shaft, 411 cylindrical member, 412 shaft Support member, 400: groove, 401: shaft retaining ring, 402: shaft retaining ring, 42: magnet, 43: molded part, 51: first bearing, 52 ... 2nd bearing, 61 ... 1st bearing storage member, 610 ... end surface, 611 ... bearing flange, 6 ... Second bearing storage member, 620... Outer cylinder, 621. 81 contact part, 811 connecting part, 812 top part, 813 flat part, 82 ground part, Bd board, Is ... protective sheet

Claims (11)

A rotor having a rotation axis extending along a central axis;
A stator having a plurality of windings wound via an insulator on a stator core radially facing the outer peripheral surface of the rotor,
A resin casing for sealing at least the insulator and the windings of the stator;
A plurality of bearings that rotatably support the rotating shaft at positions spaced apart from each other in the axial direction;
A cover that covers an outer peripheral surface of the resin casing,
A conductive member having conductivity,
The stator includes a plurality of bearing storage members in which the plurality of bearings are stored, respectively.
The energizing member is supported by the cover,
The current-carrying member has a contact portion that contacts the stator core on one side, and a ground portion that is grounded on the other side,
A motor in which the bearing and the current-carrying member are electrically insulated.   The motor according to claim 1, wherein the cover and the bearing housing member are electrically insulated.   The motor according to claim 1, wherein the cover has an insulating property.   4. The motor according to claim 1, wherein the cover and the current-carrying member are electrically insulated. 5.   The motor according to claim 4, wherein the cover and the bearing housing member are formed of the same member. The energizing member,
A connection portion, comprising a crown provided at one end of the connection portion,
The connection portion and the crown portion are formed of the same member,
A surface on the connection portion side of the crown has a flat surface, and
The other end of the connection portion contacts the stator core,
The motor according to claim 1, wherein an outer surface of the cover is in contact with the flat portion of the crown. The cover has a cylindrical shape extending in the axial direction,
The motor according to any one of claims 1 to 6, wherein the resin casing includes a press-fit portion that is press-fitted inside the cover.   The motor according to claim 7, wherein the press-fit portion overlaps the stator core when the resin casing is viewed in a radial direction.   9. The motor according to claim 7, wherein an inner diameter of the cover gradually decreases in a press-fit direction of the resin casing. 10.   9. The motor according to claim 7, wherein an inner diameter of the cover decreases stepwise in a press-fit direction of the resin casing. 10. The cover,
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,
The first cover member has a first flange extending radially outward from an outer peripheral surface,
The second cover member has a second flange extending radially outward from an outer peripheral surface,
The said 1st cover member and the said 2nd cover member, when covering the said resin casing, the said 1st flange and the said 2nd flange are connected directly or indirectly. A motor as described in Crab.

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