JP2020162367A - motor - Google Patents

Abstract

To provide a motor having a structure capable of suppressing an adhesion of a foreign matter to a sensor magnet.SOLUTION: A motor comprises: a rotor 20 that can be rotated around a center axis J; a stator 30 that is positioned at a radial direction outer side of the rotor 20; a housing that houses the rotor 20 inside and holds the stator 30; bearings 51 and 52 that rotatably support the rotor 20; and a bearing holder 240 that is fixed to the housing, and holds the bearings 51 and 52. The rotor 20 includes: a rotor main body 20a having a rotor core 22 and a rotor magnet 23; and a sensor magnet 25. The bearing holder 240 is positioned at one side of an axial direction of the rotor main body 20a. At least a part of the sensor magnet 25 is positioned between the rotor main body 20a and the bearing holder 240 in the axial direction.SELECTED DRAWING: Figure 10

Description

The present invention relates to a motor.

A motor including a sensor magnet in which magnetic flux is detected by a magnetic sensor is known. For example, Patent Document 1 describes a motor including a sensor magnet mounted on a rotating shaft.

Japanese Unexamined Patent Publication No. 2015-91152

In a motor as described above, the sensor magnet is exposed to the outside of the motor case, and the magnetic flux of the sensor magnet is detected by a magnetic sensor provided in the control device. Therefore, there is a problem that foreign matter such as iron scraps easily adheres to the sensor magnet.

In view of the above circumstances, one of the objects of the present invention is to provide a motor having a structure capable of suppressing foreign matter from adhering to the sensor magnet.

One embodiment of the motor of the present invention includes a rotor that can rotate about a central axis, a stator that is located radially outside the rotor, a housing that houses the rotor inside and holds the stator, and the like. A bearing that rotatably supports the rotor and a bearing holder that is fixed to the housing and holds the bearing are provided. The rotor includes a rotor body having a rotor core and a rotor magnet, and a sensor magnet. The bearing holder is located on one side in the axial direction of the rotor body. At least a part of the sensor magnet is located between the rotor body and the bearing holder in the axial direction.

According to one aspect of the present invention, it is possible to prevent foreign matter from adhering to the sensor magnet in the motor.

FIG. 1 is a perspective view showing a motor of the first embodiment. FIG. 2 is a cross-sectional view showing a part of the motor of the first embodiment, and is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a cross-sectional view showing a part of the motor of the first embodiment, and is a partially enlarged view of FIG. FIG. 4 is a perspective sectional view showing a part of the motor of the first embodiment. FIG. 5 is a cross-sectional view showing a part of the motor of the first embodiment, and is a VV cross-sectional view in FIG. FIG. 6 is a perspective view showing a part of the rotor of the first embodiment. FIG. 7 is a perspective view showing a part of the motor of the first embodiment. FIG. 8 is a perspective view showing a part of the motor of the first embodiment. FIG. 9 is a cross-sectional view showing a part of the motor in the first modification of the first embodiment. FIG. 10 is a cross-sectional view showing a part of the motor in the second modification of the first embodiment. FIG. 11 is a cross-sectional view showing a part of the motor of the second embodiment. FIG. 12 is a perspective view showing a part of the rotor of the second embodiment.

The Z-axis direction appropriately shown in each figure is a vertical direction in which the positive side is the upper side and the negative side is the lower side. The central axis J appropriately shown in each figure is a virtual line that is parallel to the Z-axis direction and extends in the vertical direction. In the following description, the axial direction of the central axis J, that is, the direction parallel to the vertical direction is simply referred to as "axial direction", and the radial direction centered on the central axis J is simply referred to as "radial direction". The circumferential direction centered on is simply called the "circumferential direction". In this embodiment, the upper side corresponds to one side in the axial direction. It should be noted that the vertical direction, the upper side, and the lower side are simply names for explaining the relative positional relationship of each part, and the actual arrangement relationship, etc. is an arrangement relationship, etc. other than the arrangement relationship, etc. indicated by these names. You may.

<First Embodiment>
The motor 1 of the present embodiment shown in FIGS. 1 and 2 is mounted on a vehicle. In the present embodiment, the motor 1 is a motor that is arranged inside the power slide door of the vehicle and drives the power slide door of the vehicle. The motor 1 is an inner rotor type motor. As shown in FIGS. 1 to 3, the motor 1 includes a housing 10, a rotor 20, a stator 30, a bearing holder 40, a first bearing 51, a second bearing 52, a support member 60, and a conductive portion. 80 and.

As shown in FIG. 1, the housing 10 has a substantially rectangular parallelepiped shape extending in one direction orthogonal to the axial direction. The X-axis direction appropriately shown in each figure indicates one direction in which the housing 10 extends. The Y-axis direction appropriately shown in each figure indicates a direction orthogonal to both the axial direction and one direction in which the housing 10 extends. In the following description, the direction parallel to the X-axis direction is referred to as "longitudinal direction X", and the direction parallel to the Y-axis direction is referred to as "short direction Y".

As shown in FIG. 2, the housing 10 houses the rotor 20 inside. The housing 10 holds the stator 30, the bearing holder 40, the first bearing 51, the second bearing 52, the support member 60, and the conductive portion 80. In this embodiment, the housing 10 is made of resin. The housing 10 is formed as a single member by insert molding in which resin is poured into a mold into which a stator 30, a support member 60, and a conductive portion 80 are inserted. As a result, the stator 30, the support member 60, and the conductive portion 80 are embedded and held in the housing 10.

As shown in FIG. 1, the housing 10 has a holding portion 11 and a mounting portion 12. The holding portion 11 is a portion that holds each portion of the motor 1. The holding portion 11 has a main body portion 13 and a connector portion 14. In the present embodiment, the main body portion 13 has an annular shape centered on the central axis J. As shown in FIG. 2, the main body portion 13 has a stator holding portion 13a and a bearing holding portion 13b.

The stator holding portion 13a surrounds the central axis J. In the present embodiment, the stator holding portion 13a is an annular shape centered on the central axis J. A part of the stator 30 and the support member 60 is embedded in the stator holding portion 13a. As shown in FIG. 4, the stator holding portion 13a has an opening 13h that opens upward. That is, the housing 10 has an opening 13h. In FIG. 4, the housing 10, the rotor 20, and the bearing holder 40 are not shown.

The stator holding portion 13a has an intervening portion 13f located between the teeth 31b adjacent to each other in the circumferential direction, which will be described later. A plurality of intervening portions 13f are provided along the circumferential direction. The intervening portion 13f includes a portion located between insulators 32 adjacent to each other in the circumferential direction, which will be described later. The lower end of the intervening portion 13f and the upper end of the intervening portion 13f are located between the insulators 32 adjacent to each other in the circumferential direction.

A fixed convex portion 13e and a holding convex portion 13g are provided on the upper surface of the stator holding portion 13a. The fixed convex portion 13e and the holding convex portion 13g project upward from the upper surface of the stator holding portion 13a. The fixed convex portion 13e is columnar. The holding convex portion 13g has an arc shape extending in the circumferential direction. As shown in FIG. 1, a pair of the fixed convex portion 13e and the holding convex portion 13g are provided so as to sandwich the central axis J in the radial direction. The pair of fixed convex portions 13e are provided so as to sandwich the central axis J in the lateral direction Y. The pair of holding convex portions 13g are provided so as to sandwich the central axis J in the longitudinal direction X. The fixed convex portion 13e is located between the pair of holding convex portions 13g in the circumferential direction.

As shown in FIG. 2, the bearing holding portion 13b holds the first bearing 51. The bearing holding portion 13b is located inside the stator holding portion 13a in the radial direction. The bearing holding portion 13b extends radially inward from the lower end of the stator holding portion 13a. The bearing holding portion 13b has a bottom portion 13c and a tubular portion 13d.

The bottom portion 13c extends radially inward from the radial inner edge portion at the lower end of the stator holding portion 13a. In the present embodiment, the bottom portion 13c is an annular shape centered on the central axis J. The lower surface of the bottom portion 13c and the lower surface of the stator holding portion 13a are continuously connected and arranged on the same plane orthogonal to the axial direction. As shown in FIG. 4, the radial outer edge portion of the bottom portion 13c is connected to the lower end portion of the plurality of intervening portions 13f. That is, a part of the bottom portion 13c connected to the stator holding portion 13a is located above the lower end portion of the insulator 32 described later. As a result, at least a part of the bearing holding portion 13b connected to the stator holding portion 13a is located above the lower end portion of the stator 30.

The tubular portion 13d projects upward from the bottom portion 13c. In the present embodiment, the tubular portion 13d has a cylindrical shape that opens upward with the central axis J as the center. The tubular portion 13d is located at a position separated radially outward from the radial inner edge portion of the bottom portion 13c. The first bearing 51 is held inside the tubular portion 13d in the radial direction.

As shown in FIG. 1, the connector portion 14 projects from the main body portion 13 to one side (−X side) of the longitudinal direction X. In the present embodiment, the connector portion 14 has a rectangular parallelepiped shape. As shown in FIG. 2, the support member 60 and the conductive portion 80 are embedded in the connector portion 14.

As shown in FIG. 1, the mounting portion 12 has a substantially rectangular parallelepiped box shape that is long in the longitudinal direction X. The mounting portion 12 opens upward. The mounting portion 12 surrounds the periphery of the holding portion 11. The mounting portion 12 is a portion fixed to the power slide door of the vehicle. The mounting portion 12 is fixed to the power slide door of the vehicle by, for example, a screw. As a result, the motor 1 is mounted inside the power slide door of the vehicle. Note that the housing 10 is not shown in FIGS. 5, 7, and 8.

The rotor 20 can rotate about the central axis J. As shown in FIG. 2, the rotor 20 is housed inside the housing 10. More specifically, the rotor 20 is housed inside the main body 13. The rotor 20 includes a shaft 21, a rotor core 22, a rotor magnet 23, a resin portion 24, a sensor magnet 25, and a rotor cover 26. In the present embodiment, the rotor core 22 and the rotor magnet 23 form a rotor main body 20a. That is, the rotor 20 has a rotor body 20a having a rotor core 22 and a rotor magnet 23.

The shaft 21 extends along the central axis J. In the present embodiment, the shaft 21 is a columnar shape extending in the axial direction about the central axis J. The upper end of the shaft 21 projects upward from the housing 10. The upper end of the shaft 21 is an output unit that outputs the rotation of the motor 1. The upper end of the shaft 21 is connected to the power slide door of the vehicle. The lower end of the shaft 21 is located above the lower surface of the housing 10. The lower end of the shaft 21 is located radially inside the bottom 13c.

The rotor core 22 is a magnetic member made of a magnetic material. The rotor core 22 is housed inside the main body 13. As shown in FIG. 5, in the present embodiment, the rotor core 22 has a regular hexagonal columnar shape centered on the central axis J. The rotor core 22 has a plurality of magnet support surfaces 22c. The magnet support surface 22c is a flat surface orthogonal to the radial direction. The plurality of magnet support surfaces 22c are arranged at equal intervals over one circumference along the circumferential direction. Each of the plurality of magnet support surfaces 22c is a plurality of radial outer surfaces of the rotor core 22 having a regular pentagonal columnar shape. The shape of the rotor core 22 may be a polygonal column other than a regular ten-sided column, or a columnar shape.

The rotor core 22 has a fixing hole portion 22d that penetrates the rotor core 22 in the axial direction. The shape of the fixed hole portion 22d viewed along the axial direction is a circular shape centered on the central axis J. As shown in FIG. 2, the shaft 21 is passed through the fixing hole portion 22d. The shaft 21 is press-fitted into the fixing hole 22d, for example. As a result, in the present embodiment, the rotor core 22 is directly fixed to the outer peripheral surface of the shaft 21. The rotor core 22 may be indirectly fixed to the outer peripheral surface of the shaft 21 via a resin or another member.

As shown in FIG. 6, the rotor core 22 has a plurality of through holes 22e that penetrate the rotor core 22 in the axial direction. The plurality of through holes 22e are located on the radial outer side of the fixing hole portion 22d. The plurality of through holes 22e are arranged at equal intervals along the circumferential direction. For example, five through holes 22e are provided. Although not shown, the rotor core 22 is configured by, for example, a plurality of plate members laminated in the axial direction. The plate member constituting the rotor core 22 is, for example, an electromagnetic steel plate. The rotor core 22 may be a single member.

As shown in FIG. 2, the rotor core 22 has a first core portion 22a and a second core portion 22b. The first core portion 22a is a portion fixed to the outer peripheral surface of the shaft 21. The second core portion 22b is a portion that projects downward from the radial outer end portion of the first core portion 22a. The second core portion 22b is arranged radially outwardly from the shaft 21 and is an annular shape surrounding the shaft 21. The radial outer surface of the first core portion 22a and the radial outer surface of the second core portion 22b form the radial outer surface of the rotor core 22. That is, each of the magnet support surfaces 22c is configured such that the radial outer surface of the first core portion 22a and the radial outer surface of the second core portion 22b are connected in the axial direction. The axial dimension of the second core portion 22b is smaller than the axial dimension of the first core portion 22a. As shown in FIG. 3, the lower end of the second core portion 22b is located radially outside the tubular portion 13d.

As shown in FIGS. 5 and 6, the rotor magnet 23 is a substantially square columnar shape that is flat in the radial direction and extends in the axial direction. As shown in FIG. 5, the plurality of rotor magnets 23 are arranged along the circumferential direction. The rotor magnets 23 adjacent to each other in the circumferential direction are arranged apart from each other in the circumferential direction. In the present embodiment, the plurality of rotor magnets 23 are arranged at equal intervals along the circumferential direction.

As shown in FIG. 3, the rotor magnet 23 is located radially outside the rotor core 22. More specifically, the rotor magnet 23 is located radially outside the second core portion 22b. The rotor magnet 23 is located inside the stator core 31 described later in the radial direction. The rotor magnet 23 is directly or indirectly fixed to the rotor core 22. In the present embodiment, the rotor magnet 23 comes into contact with the radial outer surface of the rotor core 22 and is directly fixed to the rotor core 22.

As shown in FIG. 5, each of the plurality of rotor magnets 23 is supported by each of the plurality of magnet support surfaces 22c from the inside in the radial direction. The radial inner surface of the rotor magnet 23 is a flat surface orthogonal to the radial direction and comes into contact with the magnet support surface 22c. More specifically, as shown in FIG. 3, the radial inner surface of the rotor magnet 23 comes into contact with the lower portion of the magnet support surface 22c.

As shown in FIG. 5, the radial outer surface of the rotor magnet 23 is a curved surface that is convex outward in the radial direction. Of the radial outer surfaces of the rotor magnet 23, the central portion in the circumferential direction comes into contact with the inner peripheral surface of the tubular portion 26b described later of the rotor cover 26. As a result, the rotor magnet 23 is sandwiched in the radial direction in a state of being in contact with the rotor core 22 and the rotor cover 26. The radial outer surface of the rotor magnet 23 is radially inward from the inner peripheral surface of the tubular portion 26b as it is separated from the circumferential central portion to both sides in the circumferential direction.

As shown in FIG. 3, the axial dimension of the rotor magnet 23 in this embodiment is smaller than the axial dimension of the rotor core 22. The axial dimension of the rotor magnet 23 is larger than, for example, the axial dimension of the second core portion 22b. In the present embodiment, the lower end portion of the rotor magnet 23 is located at the same position in the axial direction as the lower end portion of the second core portion 22b. In the present embodiment, the upper end portion of the rotor magnet 23 is located above the lower end portion of the first core portion 22a and the second core portion 22b. The upper end of the rotor magnet 23 is located below the upper end of the first core 22a. In the present embodiment, the rotor magnet 23 is fixed so as to straddle the radial outer surface of the first core portion 22a and the radial outer surface of the second core portion 22b.

The resin portion 24 is a portion made of resin. The resin portion 24 holds the rotor core 22 and the rotor magnet 23 connected to each other. The resin portion 24 is formed as a single member by, for example, insert molding in which resin is poured into a mold into which a rotor core 22 and a rotor magnet 23 are inserted. The resin portion 24 may be molded separately from the rotor core 22 and the rotor magnet 23. As shown in FIG. 6, the resin portion 24 has an annular portion 24a and a plurality of pillar portions 24b.

The annular portion 24a is an annular portion surrounding the central axis J. The annular portion 24a is, for example, an annular shape centered on the central axis J. The annular portion 24a surrounds the shaft 21. As shown in FIG. 3, the annular portion 24a is located above the rotor magnet 23. The lower end of the annular portion 24a contacts the upper end of the rotor magnet 23. As a result, the annular portion 24a supports the rotor magnet 23 from above. The upper end of the annular portion 24a is located above the rotor core 22. The radial outer corner portion 24f at the upper end portion of the annular portion 24a has a round chamfered shape and is rounded.

The radial inner edge at the upper end of the annular portion 24a has a recess 24c recessed downward. As shown in FIG. 6, the recess 24c is an annular shape centered on the central axis J. The recess 24c opens inward in the radial direction. As shown in FIG. 3, the bottom surface of the recess 24c is located at the same position in the axial direction as the upper surface of the rotor core 22. The bottom surface of the recess 24c is the inner side surface of the recess 24c that faces upward. In the present embodiment, the upper surface of the rotor core 22 is the upper surface of the first core portion 22a. The radial inner edge of the bottom surface of the recess 24c is connected to the radial outer edge on the upper surface of the rotor core 22.

As shown in FIG. 6, the plurality of pillar portions 24b extend downward from the annular portion 24a. The plurality of pillar portions 24b are arranged at equal intervals over one circumference along the circumferential direction. The plurality of pillar portions 24b are located between the rotor magnets 23 that are adjacent to each other in the circumferential direction. The pillar portion 24b can prevent the rotor magnet 23 from moving in the circumferential direction with respect to the rotor core 22.

The axial dimension of the pillar portion 24b is, for example, the same as the axial dimension of the rotor magnet 23. The lower end of the pillar portion 24b is arranged at the same position in the axial direction as, for example, the lower end of the second core portion 22b and the lower end of the rotor magnet 23.

As shown in FIG. 5, both side surfaces of the pillar portion 24b in the circumferential direction come into contact with the rotor magnets 23 adjacent to each other in the circumferential direction. The plurality of pillar portions 24b are respectively arranged on the radial outer side of the corner portion of the rotor core 22. The radial inner surface of the column 24b comes into contact with the radial outer surface at the corners of the rotor core 22. As a result, it is possible to prevent the pillar portion 24b from being caught in the circumferential direction with respect to the corner portion of the rotor core 22 and the resin portion 24 from rotating in the circumferential direction with respect to the rotor core 22. The radial outer surface of the pillar portion 24b comes into contact with the inner peripheral surface of the tubular portion 26b described later of the rotor cover 26. The radial outer surface of the pillar portion 24b has a shape along the inner peripheral surface of the tubular portion 26b.

The pillar portion 24b has a pillar portion main body 24d and a pressing portion 24e. The pressing portion 24e projects from the radial outer end portion of the pillar portion main body 24d to both sides in the circumferential direction. The pressing portion 24e comes into contact with the radial outer surfaces of the rotor magnets 23 adjacent to each other on both sides of the pillar portion 24b in the circumferential direction. As a result, the pressing portion 24e supports the rotor magnet 23 from the outside in the radial direction. Therefore, it is possible to prevent the rotor magnet 23 from moving outward in the radial direction with respect to the rotor core 22.

As shown in FIG. 6, in the present embodiment, the sensor magnet 25 is an annular shape surrounding the central axis J. The sensor magnet 25 is, for example, an annular shape centered on the central axis J. The sensor magnet 25 has a plate shape with the plate surface facing the axial direction. The sensor magnet 25 has a plurality of magnetic poles along the circumferential direction. The sensor magnet 25 is directly or indirectly fixed to the rotor core 22. In this embodiment, the sensor magnet 25 is fixed to the upper surface of the rotor core 22. As a result, the sensor magnet 25 comes into contact with the rotor core 22 and is directly fixed to the rotor core 22.

As shown in FIG. 3, the lower surface of the sensor magnet 25 comes into contact with the upper surface of the rotor core 22 straddling the bottom surface of the recess 24c. The upper surface of the sensor magnet 25 is located, for example, at the same position in the axial direction as the upper end of the resin portion 24, that is, the upper end of the annular portion 24a. The upper surface of the sensor magnet 25 is exposed to the outside of the rotor 20.

The radial outer edge portion of the sensor magnet 25 faces the inner side surface of the recess 24c facing the radial inward side via a gap. The sensor magnet 25 may come into contact with the inner surface of the recess 24c facing inward in the radial direction and may be fitted into the inner surface of the recess 24c in the radial direction. The sensor magnet 25 is fixed to the rotor core 22 and the annular portion 24a with, for example, an adhesive or the like.

The sensor magnet 25 is arranged above the rotor magnet 23. In the present embodiment, the radial outer edge portion of the sensor magnet 25 overlaps the radial inner edge portion of the rotor magnet 23 when viewed along the axial direction. That is, in the present embodiment, at least a part of the rotor magnet 23 and the sensor magnet 25 overlap each other when viewed along the axial direction. The rotor magnet 23 and the sensor magnet 25 sandwich the annular portion 24a in the axial direction in a state of being in contact with the annular portion 24a.

In the present embodiment, the sensor magnet 25 overlaps with the second core portion 22b when viewed along the axial direction. The inner diameter of the sensor magnet 25 is substantially the same as the inner diameter of the second core portion 22b. The radial inner edge portion of the sensor magnet 25 is located slightly outside the radial inner edge portion of the second core portion 22b. The magnetic flux M2 of the sensor magnet 25 is detected by the magnetic sensor S1. The magnetic sensor S1 is, for example, a Hall element such as a Hall IC. The rotation of the rotor 20 can be detected by detecting the magnetic flux M2 of the sensor magnet 25 with the magnetic sensor S1. The magnetic sensor S1 may be a magnetoresistive element.

The rotor cover 26 is a non-magnetic member made of a non-magnetic material. As shown in FIG. 3, the rotor cover 26 has a bottom portion 26a and a tubular portion 26b. The bottom portion 26a is located below the rotor core 22 and the rotor magnet 23. More specifically, in the present embodiment, the bottom portion 26a is located below the radial outer edge portion of the second core portion 22b and the rotor magnet 23.

The bottom portion 26a is, for example, an annular shape centered on the central axis J. The bottom portion 26a has a plate shape in which the plate surface faces the axial direction. The upper surface of the bottom 26a comes into contact with the radial outer edge of the lower surface of the rotor core 22 and the lower surface of the rotor magnet 23. As a result, the bottom portion 26a supports the rotor core 22 and the rotor magnet 23 from below. In the present embodiment, the radial outer edge portion on the lower surface of the rotor core 22 is the radial outer edge portion on the lower surface of the second core portion 22b. Although not shown, the upper surface of the bottom portion 26a in the present embodiment comes into contact with the lower surface of the pillar portion 24b. As a result, the bottom portion 26a supports the resin portion 24 from below.

The tubular portion 26b extends upward from the radial outer edge of the bottom portion 26a. As shown in FIG. 5, the tubular portion 26b has, for example, a cylindrical shape centered on the central axis J. The tubular portion 26b opens upward. The tubular portion 26b is located on the outer side in the radial direction of the rotor magnet 23. The tubular portion 26b surrounds the rotor core 22, the rotor magnet 23, and the resin portion 24 from the outside in the radial direction. As shown in FIG. 3, the upper end portion of the tubular portion 26b is a caulked portion 26c bent inward in the radial direction. The caulked portion 26c is bent along the rounded corner portion 24f. The crimped portion 26c comes into contact with the annular portion 24a from above. The caulking portion 26c and the bottom portion 26a sandwich the annular portion 24a and the rotor magnet 23 in the axial direction. As a result, it is possible to prevent the rotor cover 26 from coming off in the axial direction with respect to the rotor core 22. In FIG. 6, the rotor cover 26 is not shown.

In the present embodiment, the rotor 20 is provided with a magnetic material portion made of a magnetic material. In the present embodiment, the magnetic material portion is the rotor core 22. As shown in FIG. 3, at least a part of the rotor core 22 which is a magnetic material portion is located above the rotor magnet 23 and below the sensor magnet 25. In the present embodiment, the upper portion of the first core portion 22a of the rotor core 22 is located above the rotor magnet 23 and below the sensor magnet 25. The upper portion of the first core portion 22a is located radially inside the annular portion 24a.

As shown in FIG. 2, the stator 30 is located radially outside the rotor 20. The stator 30 surrounds the rotor 20. The stator 30 is embedded in the stator holding portion 13a. The stator 30 has a stator core 31, an insulator 32, and a plurality of coils 33.

The stator core 31 is located on the outer side in the radial direction of the rotor magnet 23. The axial dimension of the stator core 31 is smaller than the axial dimension of the rotor magnet 23. The upper end of the stator core 31 is located below the upper end of the rotor magnet 23. The lower end of the stator core 31 is located above the lower end of the rotor magnet 23.

The stator core 31 has a core back 31a and a plurality of teeth 31b. As shown in FIG. 5, the core back 31a is an annular shape surrounding the rotor 20. In the present embodiment, the core back 31a is an annular shape centered on the central axis J. The core back 31a may be a polygonal ring or an elliptical ring.

The plurality of teeth 31b extend radially inward from the core back 31a. The plurality of teeth 31b are arranged at intervals along the circumferential direction. The plurality of teeth 31b are arranged at equal intervals along the circumferential direction. For example, 12 teeth 31b are provided. As shown in FIG. 4, the radial inner end surface of the teeth 31b is exposed to the inner peripheral surface of the stator holding portion 13a. As shown in FIG. 3, the radial inner end surface of the teeth 31b faces the axial portion of the rotor cover 26 located on the radial outer side of the rotor magnet 23 via a gap in the radial direction.

As shown in FIG. 5, in the present embodiment, the stator core 31 is configured by connecting a plurality of stator core pieces 31p in the circumferential direction. Each of the plurality of stator core pieces 31p has one core back piece 31c that forms a part of the core back 31a in the circumferential direction, and one tooth 31b that extends radially inward from the core back piece 31c. Both ends in the circumferential direction of the core back piece 31c are contacted and connected to the peripheral ends of the core back pieces 31c adjacent to each other in the circumferential direction. Although not shown, each stator core piece 31p is configured by, for example, a plurality of plate members laminated in the axial direction. The plate member constituting the stator core piece 31p is, for example, an electromagnetic steel plate.

The stator core piece 31p may be a single member. Further, the stator core 31 may not have a plurality of stator core pieces 31p and may be configured not to be divided in the circumferential direction. In this case, the stator core 31 may be configured by laminating a plurality of plate members in the axial direction, or may be a single member.

The insulator 32 is mounted on the stator core 31. More specifically, the insulator 32 is attached to each of the plurality of teeth 31b. For example, 12 insulators 32 are provided. The insulator 32 is made of resin, for example. As shown in FIG. 3, each of the insulators 32 has an insulator main body portion 32a, a pair of inner side wall portions 32b and 32c, and a pair of outer wall portions 32d and 32e. The insulator main body 32a has a tubular shape through which the teeth 31b are passed.

The pair of inner side wall portions 32b and 32c extend axially from the radially inner end portion of the insulator main body portion 32a. The pair of inner side wall portions 32b and 32c have a plate shape in which the plate surfaces face in the radial direction. The inner side wall portion 32b extends upward from the radially inner end portion of the insulator main body portion 32a. The inner side wall portion 32b is located on the radial outer side of the annular portion 24a. The inner side wall portion 32b is located between the coil end 33a on the upper side of the coil 33 and the annular portion 24a in the radial direction. The inner side wall portion 32c extends downward from the radially inner end portion of the insulator main body portion 32a. The lower end of the inner side wall 32c is located below the upper surface of the bottom 13c. The radial inner surface of the inner side wall portions 32b, 32c is located at the same position in the radial direction as, for example, the radial inner end surface of the teeth 31b. As shown in FIG. 4, the radial inner surfaces of the inner side wall portions 32b and 32c are exposed to, for example, the inner peripheral surface of the stator holding portion 13a.

As shown in FIG. 3, the pair of outer wall portions 32d and 32e extend in the axial direction from the radially outer end portion of the insulator main body portion 32a. The outer side wall portion 32d extends upward from the radial outer end portion of the insulator main body portion 32a. The outer side wall portion 32e extends downward from the radial outer end portion of the insulator main body portion 32a. As shown in FIG. 7, each of the outer wall portions 32d has two through grooves 32f penetrating the outer wall portion 32d in the radial direction. The two through grooves 32f are provided at intervals in the circumferential direction. As shown in FIG. 8, each of the outer wall portions 32e has two through grooves 32g that penetrate the outer wall portion 32e in the radial direction. The two through grooves 32g are provided at intervals in the circumferential direction. In the present embodiment, the outer wall portion 32d and the outer wall portion 32e have the same shape and are arranged symmetrically in the axial direction.

The plurality of coils 33 are mounted on the stator core 31. In the present embodiment, the plurality of coils 33 are attached to each of the plurality of teeth 31b via the insulator 32. For example, 12 coils 33 are provided. As shown in FIG. 3, the coil 33 is mounted on the insulator main body 32a. The coil 33 is configured by winding a lead wire. The plurality of coils 33 are connected by, for example, a delta connection.

The coil 33 has coil ends 33a and 33b protruding in the axial direction from the insulator main body 32a. The coil end 33a is a portion that protrudes upward from the insulator main body 32a. In the present embodiment, the coil end 33a, which is a part of the coil 33, is located above the rotor magnet 23 and below the sensor magnet 25.

The upper end of the coil end 33a is the upper end of the coil 33. Therefore, in the present embodiment, the entire coil 33 is located below the sensor magnet 25. In other words, in the present embodiment, the entire sensor magnet 25 is located above the coil 33. The upper end of the coil end 33a, that is, the upper end of the coil 33, is located below the upper end of the inner side wall 32b and the upper end of the outer wall 32d.

When viewed from the outside in the radial direction, the coil end 33a overlaps the portion of the rotor 20 whose axial position is between the rotor magnet 23 and the sensor magnet 25. In other words, the axial position of the coil end 33a is the same as the axial position between the rotor magnet 23 and the sensor magnet 25. When viewed from the outside in the radial direction, the coil end 33a overlaps the upper portion of the annular portion 24a and the first core portion 22a. As a result, at least a part of the rotor core 22 which is a magnetic body portion in the present embodiment is located inside the coil end 33a which is a part of the coil 33 in the radial direction.

The coil end 33b is a portion that protrudes downward from the insulator main body 32a. The coil end 33b is located below the rotor magnet 23. The coil end 33b overlaps with the first bearing 51 when viewed from the outside in the radial direction. The lower end of the coil end 33b is the lower end of the coil 33.

As shown in FIG. 8, a coil leader wire 33c is drawn out from a part of the coils 33 among the plurality of coils 33. The coil leader wire 33c is the same lead wire as the lead wire constituting the coil 33. Although not shown, the coil leader line 33c is drawn from, for example, each of 6 out of 12 coils 33. Note that FIG. 8 illustrates only one coil leader line 33c, and the other coil leader lines 33c are not shown.

As shown in FIGS. 1 and 2, the bearing holder 40 holds the second bearing 52. In the present embodiment, the bearing holder 40 is a magnetic member made of a magnetic material. The bearing holder 40 is arranged above the housing 10. The bearing holder 40 is fixed to the housing 10. More specifically, the bearing holder 40 is fixed to the upper surface of the main body 13. As shown in FIG. 2, the bearing holder 40 is located above the rotor body 20a. The bearing holder 40 is located above the sensor magnet 25. As a result, at least a part of the sensor magnet 25 in the present embodiment is located between the rotor main body 20a and the bearing holder 40 in the axial direction.

Therefore, at least a part of the sensor magnet 25 is covered from above by the bearing holder 40. As a result, the sensor magnet 25 can be protected by the bearing holder 40, and foreign matter generated outside the motor 1 can be prevented from adhering to the sensor magnet 25. The foreign matter includes, for example, a magnetic material such as iron scrap. Magnetic materials such as iron scraps tend to adhere to the sensor magnet 25 due to magnetic force. Therefore, the effect that the sensor magnet 25 can be protected by the bearing holder 40 is particularly useful when a magnetic material such as iron scrap is likely to be generated outside the motor 1.

Further, for example, when the sensor magnet 25 is arranged on the upper side of the bearing holder 40, the sensor magnet 25 is directly or indirectly fixed to the shaft 21. Therefore, the axial dimension of the shaft 21 tends to be large, and the motor 1 may be large in the axial direction.

On the other hand, when at least a part of the sensor magnet 25 is arranged between the rotor body 20a and the bearing holder 40 in the axial direction as in the present embodiment, the sensor magnet 25 is fixed to the rotor body 20a. it can. Therefore, it is easy to prevent the shaft 21 from increasing in size in the axial direction, and it is possible to prevent the motor 1 from increasing in size in the axial direction.

In the present embodiment, since the sensor magnet 25 is fixed to the rotor core 22, it is not necessary to fix the sensor magnet 25 to a portion of the shaft 21 different from the portion to which the rotor core 22 is fixed. Therefore, the shaft 21 can be shortened in the axial direction, and the motor 1 can be prevented from becoming large in the axial direction.

Further, according to the present embodiment, the bearing holder 40 is a magnetic member made of a magnetic material. Therefore, the magnetic flux M2 of the sensor magnet 25 can be shielded by the bearing holder 40. As a result, it is possible to prevent the magnetic flux M2 of the sensor magnet 25 from leaking to the outside of the motor 1. Therefore, it is possible to prevent foreign matter such as iron scraps generated outside the motor 1 from being attracted to the motor 1 by the magnetic force of the sensor magnet 25.

In this embodiment, at least a part of the sensor magnet 25 is located between the rotor core 22 and the bearing holder 40 in the axial direction. Therefore, the rotor core 22 can be easily used as the yoke of the sensor magnet 25, and the magnetic force of the sensor magnet 25 can be easily increased. Therefore, it is easy to improve the detection accuracy of the magnetic sensor S1. In the present embodiment, the radial outer edge portion of the sensor magnet 25 is located between the rotor magnet 23 and the annular portion 24a and the bearing holder 40 in the axial direction.

In the present embodiment, the bearing holder 40 covers the upper opening 13h provided in the housing 10 from above. Therefore, the bearing holder 40 can prevent foreign matter from entering the inside of the housing 10 through the opening 13h. The bearing holder 40 has a top plate portion 41, a flange portion 42, and a holding portion 43. The top plate portion 41 has a plate shape in which the plate surface faces the axial direction. The top plate portion 41 has an annular shape centered on the central axis J. The top plate portion 41 is located above the rotor core 22 and the sensor magnet 25.

The flange portion 42 extends radially outward from the radial outer edge portion of the top plate portion 41. The flange portion 42 has a plate shape in which the plate surface faces the axial direction. The flange portion 42 is located below the top plate portion 41. As shown in FIG. 1, the flange portion 42 is, for example, an annular shape centered on the central axis J. The flange portion 42 contacts the peripheral edge portion of the opening 13h in the upper surface of the housing 10. The flange portion 42 has an annular flange body portion 42a and a pair of fixing portions 42b protruding radially outward from the flange body portion 42a.

The flange body portion 42a is fitted to the inside of the pair of holding convex portions 13g in the radial direction. The radial outer edge of the flange body 42a comes into contact with the radial inner surface of the pair of holding protrusions 13g. As a result, the bearing holder 40 is positioned radially with respect to the housing 10. The pair of fixing portions 42b are arranged so as to sandwich the central axis J in the radial direction. In the present embodiment, the pair of fixing portions 42b are arranged so as to sandwich the central axis J in the lateral direction Y. The fixed portion 42b has a hole portion 42c through which the fixed convex portion 13e is passed. Although not shown, the portion of the fixed convex portion 13e that protrudes upward from the fixed portion 42b via the hole portion 42c is fixed to the upper surface of the fixed portion 42b by, for example, heat welding. As a result, the bearing holder 40 is fixed to the housing 10.

The holding portion 43 has a tubular shape that projects upward from the radial inner edge portion of the top plate portion 41. In the present embodiment, the holding portion 43 has a cylindrical shape centered on the central axis J. The second bearing 52 is held inside the holding portion 43 in the radial direction. In the present embodiment, the holding portion 43 holds the lower end portion of the second bearing 52.

In the present embodiment, the bearing holder 40 has a holder through hole 41a that penetrates the bearing holder 40 in the axial direction. In the present embodiment, the holder through hole 41a is provided in the top plate portion 41. The holder through hole 41a penetrates the top plate portion 41 in the axial direction. The holder through hole 41a has, for example, an arc shape extending in the circumferential direction. The holder through hole 41a overlaps with a part of the sensor magnet 25 when viewed along the axial direction. Therefore, as shown in FIG. 3, by arranging the magnetic sensor S1 in the holder through hole 41a, the magnetic sensor S1 can be arranged close to the sensor magnet 25 located below the bearing holder 40. As a result, the magnetic flux M2 of the sensor magnet 25 can be detected accurately by the magnetic sensor S1. Therefore, the rotation of the rotor 20 can be detected with high accuracy. Further, as compared with the case where the magnetic sensor S1 is arranged above the bearing holder 40, it is easier to arrange the entire device on which the magnetic sensor S1 is mounted closer to the motor 1 in the axial direction. The device on which the magnetic sensor S1 is mounted is, for example, a control device that controls the motor 1. Therefore, the entire assembly in which the motor 1 and the control device are combined can be easily miniaturized in the axial direction.

As shown in FIG. 1, the holder through hole 41a is provided in a portion of the top plate portion 41 located on the other side (+ X side) of the longitudinal direction X. The holder through hole 41a is provided in a region opposite to a region on the side where the terminal portion 70, which will be described later, is provided, in a region divided in the longitudinal direction X with respect to the central axis J. Therefore, it is possible to prevent the magnetic field generated by the current flowing through the terminal portion 70 from interfering with the magnetic sensor S1 provided in the holder through hole 41a. Therefore, it is possible to suppress a decrease in the detection accuracy of the magnetic sensor S1. In the present embodiment, the bearing holder 40 covers a portion of the sensor magnet 25 other than the portion that overlaps the holder through hole 41a in the axial direction from above.

As shown in FIG. 2, the first bearing 51 and the second bearing 52 rotatably support the rotor 20. The first bearing 51 rotatably supports a portion of the shaft 21 located below the portion to which the rotor core 22 is fixed. The second bearing 52 rotatably supports a portion of the shaft 21 located above the portion to which the rotor core 22 is fixed. In this embodiment, the first bearing 51 and the second bearing 52 are rolling bearings. The first bearing 51 and the second bearing 52 are, for example, ball bearings.

The first bearing 51 is held in the housing 10. More specifically, the first bearing 51 is held by the bearing holding portion 13b. The outer ring of the first bearing 51 is fitted inward in the radial direction of the tubular portion 13d. The outer ring of the first bearing 51 is supported from below by a portion of the bottom portion 13c located radially inside the tubular portion 13d.

At least a part of the first bearing 51 is located inside the stator 30 in the radial direction. Therefore, the motor 1 can be miniaturized in the axial direction as compared with the case where the entire first bearing 51 is arranged axially away from the stator 30. In the present embodiment, the entire first bearing 51 is located inside the stator 30 in the radial direction. Therefore, the motor 1 can be miniaturized in the axial direction. The upper portion of the first bearing 51 is located radially inside the second core portion 22b.

The second bearing 52 is held by the bearing holder 40. The lower end of the outer ring of the second bearing 52 is fitted to the inside of the holding portion 43 in the radial direction. In the present embodiment, the second bearing 52 is located above the stator 30. The second bearing 52 is exposed to the outside of the motor 1.

The support member 60 is a member that supports the conductive portion 80. The support member 60 is made of resin, for example. The support member 60 is located radially outside the stator 30. At least a part of the support member 60 is embedded in the housing 10 on the radial outer side of the stator core 31. In the present embodiment, the support member 60 is entirely embedded in the housing 10. The support member 60 includes a first cylinder portion 61, a second cylinder portion 62, a top wall portion 63, a protruding plate portion 64, and a terminal holding portion 65.

The first tubular portion 61 is located on the outer side in the radial direction of the stator core 31. As shown in FIG. 5, the first cylinder portion 61 surrounds the stator core 31. In the present embodiment, the first tubular portion 61 has a cylindrical shape centered on the central axis J. In the present embodiment, the first tubular portion 61 is fitted to the core back 31a. The inner peripheral surface of the first tubular portion 61 comes into contact with the outer peripheral surface of the core back 31a. As shown in FIG. 2, the upper portion 61a of the first tubular portion 61 is located on the radial outer side of the stator core 31. The lower portion 61b of the first tubular portion 61 is located radially outside the outer wall portion 32e. The lower portion 61b is located radially outside the coil end 33b. The outer diameter and inner diameter of the lower portion 61b are smaller than the outer diameter and inner diameter of the upper portion 61a.

As shown in FIG. 8, the lower portion 61b has a plurality of through holes 61c penetrating the lower portion 61b in the radial direction. The plurality of through holes 61c are arranged at intervals along the circumferential direction. The through hole 61c is arranged at a position where it radially overlaps with the through groove 32g provided in the outer wall portion 32e.

The second tubular portion 62 is located on the radial outer side of the first tubular portion 61. The second tubular portion 62 surrounds the first tubular portion 61. More specifically, the second tubular portion 62 is located radially outside the upper portion 61a of the first tubular portion 61 and surrounds the upper portion 61a. In the present embodiment, the second tubular portion 62 has a cylindrical shape centered on the central axis J.

As shown in FIG. 2, the top wall portion 63 connects the upper end portion of the first cylinder portion 61 and the upper end portion of the second cylinder portion 62. In the present embodiment, the top wall portion 63 is an annular shape centered on the central axis J. The top wall portion 63 has a plate shape in which the plate surface faces the axial direction. The upper surface of the top wall portion 63 is located at substantially the same position in the axial direction as the upper surface of the stator core 31.

The first cylinder portion 61, the second cylinder portion 62, and the top wall portion 63 are embedded in the stator holding portion 13a. The support member 60 is provided with a housing groove 66 that is recessed upward and extends in the circumferential direction by the first cylinder portion 61, the second cylinder portion 62, and the top wall portion 63. As shown in FIG. 8, the accommodating groove 66 has an annular shape centered on the central axis J.

The projecting plate portion 64 projects from the lower end of the second tubular portion 62 to one side (−X side) of the longitudinal direction X. The protruding plate portion 64 has a plate shape in which the plate surface faces the axial direction. The protruding plate portion 64 has a substantially rectangular shape.

As shown in FIG. 7, the terminal holding portion 65 projects upward from the tip end portion of the projecting plate portion 64, that is, one end portion (−X side) of the longitudinal direction X. In this embodiment, a plurality of terminal holding portions 65 are provided. The plurality of terminal holding portions 65 are arranged at intervals along the lateral direction Y. For example, three terminal holding portions 65 are provided. Each of the terminal holding portions 65 has a holding groove 65a. The holding groove 65a opens on one side of the upper side and the longitudinal direction X.

The conductive portion 80 is electrically connected to the coil 33. The conductive portion 80 electrically connects the coil 33 and an external power source (not shown). An external power source (not shown) supplies electric power to the coil 33 via the conductive portion 80. The conductive portion 80 has a plurality of terminal portions 70 and a plurality of coil leader wires 33c. The plurality of terminal portions 70 are portions connected to an external power supply (not shown). Each of the plurality of terminal portions 70 is held by the terminal holding portion 65. For example, three terminal portions 70 are provided. The terminal portion 70 has a base portion 71, a terminal main body portion 72, and a connection portion 73.

The base portion 71 is a portion held by the terminal holding portion 65. The base portion 71 has a plate shape in which the plate surface faces Y in the lateral direction. The base portion 71 is inserted into the holding groove 65a and held by the terminal holding portion 65. The terminal body 72 extends upward from the base 71. The terminal body 72 has a plate shape with the plate surface facing Y in the lateral direction. The terminal body 72 has a rectangular shape. As shown in FIGS. 1 and 2, the upper end portion of the terminal body portion 72 projects upward from the housing 10 and is exposed to the outside of the motor 1. An external power supply (not shown) is electrically connected to the conductive portion 80 via the upper end portion of the terminal body portion 72.

As shown in FIG. 7, the connecting portion 73 is connected to the end portion of the base portion 71 on one side (−X side) of the longitudinal direction X. The connecting portion 73 has a U-shape that opens on one side (−Y side) of the lateral direction Y when viewed along the axial direction. The connection portion 73 sandwiches the coil leader wire 33c inside. The connection portion 73 and the coil leader wire 33c are fixed by, for example, welding. As a result, the terminal portion 70 is electrically connected to the coil leader wire 33c. In the present embodiment, two coil leader wires 33c are connected to the connection portion 73 of each terminal portion 70.

The coil leader wire 33c is a wiring member that connects the terminal portion 70 and the coil 33. As shown in FIG. 8, the coil leader wire 33c is drawn downward from the coil 33, then extends radially outward through the through groove 32g and the through hole 61c, and is accommodated inside the accommodating groove 66. As a result, at least a part of the conductive portion 80 is located between the first cylinder portion 61 and the second cylinder portion 62 in the radial direction. Inside the accommodating groove 66, the coil leader wire 33c extends in the circumferential direction to a portion of the accommodating groove 66 located on one side (−X side) of the longitudinal direction X. The coil leader wire 33c extends from a portion of the accommodating groove 66 located on one side of the longitudinal direction X to one side of the longitudinal direction X along the lower surface of the protruding plate portion 64, and is a connecting portion 73 of the terminal portion 70. Is connected with.

As shown in FIG. 2, a portion of the coil leader wire 33c that passes through the accommodating groove 66 is embedded in the stator holding portion 13a on the radial outer side of the stator core 31. That is, in the present embodiment, the conductive portion 80 has a portion of the coil leader wire 33c that passes through the accommodating groove 66 as a portion embedded in the housing 10 on the radial outer side of the stator core 31. By arranging the conductive portion 80 that electrically connects the coil 33 and the external power source through the radial outside of the stator core 31 in this way, it is possible to prevent the conductive portion 80 from protruding in the axial direction from the stator 30. .. Therefore, the motor 1 can be miniaturized in the axial direction. Such a configuration in which a part of the conductive portion 80 can be arranged radially outside the stator core 31 can be adopted by making the housing 10 made of resin and embedding a part of the conductive portion 80 in the housing 10.

Further, for example, in a configuration in which a stator is inserted into a tubular housing to assemble a motor, it is necessary to provide a gap for insulation between the axial wall portion of the housing and the stator in the axial direction. Therefore, the axial dimension of the housing needs to be larger to some extent than the axial dimension of the stator, and there is a limit to miniaturizing the motor in the axial direction.

On the other hand, if the housing 10 is made of resin as in the present embodiment, the stator 30 can be embedded in the resin housing 10 by insert molding. Therefore, it is not necessary to provide a gap for insulation between the housing 10 and the stator 30. As a result, the axial dimension of the housing 10 holding the stator 30 can be made substantially the same as the axial dimension of the stator 30, and the thickness can be reduced. Therefore, the motor 1 can be miniaturized in the axial direction.

Further, according to the present embodiment, at least a part of the coil leader wire 33c, which is a wiring member connecting the terminal portion 70 and the coil 33, is embedded in the housing 10 on the radial outer side of the stator core 31. In this way, by arranging at least a part of the wiring member whose total length tends to be large in the conductive portion 80 on the radial side of the stator core 31, the conductive portion 80 is more suppressed from protruding in the axial direction than the stator 30. Cheap. As a result, the motor 1 can be miniaturized in the axial direction.

Further, according to the present embodiment, the wiring member connecting the terminal portion 70 and the coil 33 is the coil leader wire 33c drawn from the coil 33. Therefore, the cost of the wiring member can be reduced as compared with the case where the bus bar is provided as the wiring member. Therefore, the manufacturing cost of the motor 1 can be reduced.

Further, according to the present embodiment, a support member 60 for supporting the conductive portion 80 is provided, and the support member 60 is embedded in the housing 10 on the radial outer side of the stator core 31. Therefore, even if the wiring member is the coil leader wire 33c, the coil leader wire 33c can be stably routed outward in the radial direction of the stator core 31 and arranged.

Further, according to the present embodiment, the support member 60 has a first cylinder portion 61 and a second cylinder portion 62, and at least a part of the conductive portion 80 is a first cylinder portion 61 and a second cylinder portion 62. It is located between and in the radial direction. Therefore, the first cylinder portion 61 and the second cylinder portion 62 can prevent the conductive portion 80 from moving in the radial direction on the radial outer side of the stator core 31. As a result, when the resin is poured into the mold to make the housing 10, it is possible to prevent the portion of the conductive portion 80 arranged on the radial outer side of the stator core 31, that is, the coil leader wire 33c from moving in the radial direction. Therefore, it is possible to prevent the coil leader wire 33c from coming into contact with the inner surface of the mold during molding of the housing 10. Therefore, it is possible to prevent the coil leader wire 33c from being exposed on the outer surface of the molded housing 10.

Further, according to the present embodiment, the housing 10 has a stator holding portion 13a in which the stator 30 is embedded, and at least a part of the bearing holding portion 13b connected to the stator holding portion 13a is on the lower side of the stator 30. It is located above the edge. Therefore, even if the axial dimension of the portion of the stator holding portion 13a located below the stator 30 is reduced, the portion of the bearing holding portion 13b that is connected to the stator holding portion 13a, that is, the bottom portion 13c in the axial direction. The dimensions can be increased. As a result, the housing 10 can be miniaturized in the axial direction while ensuring the strength of the bearing holding portion 13b. Therefore, the motor 1 can be easily miniaturized in the axial direction. Further, since at least a part of the bearing holding portion 13b can be arranged inside the stator 30 in the radial direction, a configuration in which at least a part of the first bearing 51 is arranged inside the stator 30 in the radial direction can be adopted. As a result, the motor 1 can be miniaturized in the axial direction.

Further, when the sensor magnet 25 is fixed to the rotor core 22 as in the present embodiment, the distance between the sensor magnet 25 and the coil 33 tends to be relatively small. Therefore, the magnetic field generated by the current flowing through the coil 33 may interfere with the magnetic field of the sensor magnet 25, and the detection accuracy of the magnetic flux M2 of the sensor magnet 25 by the magnetic sensor S1 may decrease. In particular, the magnetic flux M1 generated from the coil end 33a located above the rotor magnet 23 and below the sensor magnet 25 flows to the sensor magnet 25, and the magnetic flux of the sensor magnet 25 by the magnetic sensor S1 flows. It may interfere with the detection of M2.

On the other hand, according to the present embodiment, the rotor core 22 is provided as a magnetic material portion whose at least a part is located above the rotor magnet 23 and below the sensor magnet 25. Therefore, as shown in FIG. 3, the magnetic flux M1 generated from the coil end 33a can be attracted to the portion of the rotor core 22 located above the rotor magnet 23 and below the sensor magnet 25. it can. As a result, the magnetic flux M1 generated from the coil end 33a can be suppressed from flowing to the sensor magnet 25, and the magnetic flux M1 can be prevented from interfering with the magnetic flux M2 of the sensor magnet 25. Therefore, it is possible to suppress a decrease in the detection accuracy of the magnetic sensor S1.

The magnetic flux passing through the inside of the rotor core 22 is mainly the magnetic flux flowing with the stator core 31. Therefore, the magnetic flux M1 flowing from the coil end 33a to the rotor core 22 tends to flow to the stator core 31 along the main flow of the magnetic flux flow inside the rotor core 22. Therefore, the magnetic flux M1 flowing from the coil end 33a to the rotor core 22 is unlikely to interfere with the sensor magnet 25.

Further, according to the present embodiment, at least a part of the rotor core 22 which is a magnetic material portion is located inside the coil end 33a which is a part of the coil 33 in the radial direction. Therefore, the magnetic flux M1 generated from the coil end 33a is easily attracted inward in the radial direction and is easily incident on the rotor core 22. As a result, the magnetic flux M1 generated from the coil end 33a can be further suppressed from flowing to the sensor magnet 25, and the detection accuracy of the magnetic sensor S1 can be further suppressed from being lowered.

Further, according to the present embodiment, the sensor magnet 25 comes into contact with the rotor core 22 which is a magnetic material portion. Therefore, the magnetic flux M1 directed from the coil end 33a toward the sensor magnet 25 can be suitably attracted by the rotor core 22 adjacent to the sensor magnet 25. Therefore, it is possible to further suppress the flow of the magnetic flux M1 to the sensor magnet 25. Further, since the rotor core 22 can be used as the yoke of the sensor magnet 25, the magnetic force of the sensor magnet 25 can be increased. Therefore, the detection accuracy of the magnetic sensor S1 can be improved.

Further, according to the present embodiment, the entire sensor magnet 25 is located above the coil 33. Therefore, it is possible to further suppress the magnetic flux M1 generated from the coil end 33a from flowing to the sensor magnet 25.

Further, according to the present embodiment, the magnetic material portion is the rotor core 22. Therefore, it is not necessary to provide a separate member as the magnetic material portion, and it is possible to suppress an increase in the number of parts of the motor 1. As a result, it is possible to suppress an increase in the manufacturing cost of the motor 1.

[First Modified Example of First Embodiment]
As shown in FIG. 9, in the rotor 120 of the motor 101 of the present modification, the rotor core 122 has a rotor core main body 122f and a protruding portion 122g. The rotor core body 122f has the same shape as the rotor core 22 of the above-described embodiment. The rotor core main body 122f has a first core portion 22a and a second core portion 22b.

The protruding portion 122g projects radially outward from the rotor core main body 122f. In this modification, the protruding portion 122g protrudes radially outward from the upper end portion of the first core portion 22a. The protruding portion 122g is located above the rotor magnet 23 and below the sensor magnet 25. Therefore, as shown by an arrow in FIG. 9, the magnetic flux M1 generated from the coil end 33a is more easily attracted to the rotor core 122 via the protruding portion 122g protruding outward in the radial direction. Therefore, it is possible to further suppress the flow of the magnetic flux M1 generated from the coil end 33a through the sensor magnet 25, and further suppress the decrease in the detection accuracy of the magnetic sensor S1.

In this modification, the radial outer end of the protrusion 122 g is located radially outer of the radial outer edge of the sensor magnet 25. As a result, the rotor core 122, which is a magnetic material portion, has a portion located radially outside the sensor magnet 25. Therefore, the protruding portion 122g, which is a part of the rotor core 122, can be brought closer to the coil end 33a than the sensor magnet 25. As a result, the magnetic flux M1 generated from the coil end 33a can be more easily flowed to the protruding portion 122g, and the flow to the sensor magnet 25 can be further suppressed.

The protruding portion 122g is embedded in the annular portion 24a. The radial outer end of the protruding portion 122g is located radially inward with respect to the outer peripheral surface of the annular portion 24a. The protrusion 122g is located above the rotor magnet 23. The protruding portion 122g is located below the radial outer edge portion of the sensor magnet 25. The radial inner portion of the protruding portion 122 g is located between the rotor magnet 23 and the sensor magnet 25 in the axial direction. That is, at least a part of the rotor core 122, which is a magnetic material portion, is located between the rotor magnet 23 and the sensor magnet 25 in the axial direction. Therefore, a part of the magnetic material portion can be arranged at a position relatively close to the coil end 33a. As a result, the magnetic flux M1 generated from the coil end 33a can be more easily attracted to the magnetic material portion, and the magnetic flux M1 can be further suppressed from flowing to the sensor magnet 25.

The protrusion 122g may be an annular shape surrounding the rotor core main body 122f, or a plurality of protrusions 122g may be provided along the circumferential direction. When a plurality of protrusions 122g are provided along the circumferential direction, the plurality of protrusions 122g are arranged at positions that are radially inside with respect to each of the coil ends 33a of the plurality of coils 33 when viewed along the axial direction. May be done.

[Second variant of the first embodiment]
As shown in FIG. 10, the bearing holder 240 of the motor 201 of this modified example does not have the holder through hole 41a unlike the bearing holder 40 of the above-described embodiment. That is, the holder through hole 41a is not provided in the top plate portion 241 of the bearing holder 240. In this modification, the bearing holder 240 is a non-magnetic member made of a non-magnetic material. The bearing holder 240 covers the upper side of the entire sensor magnet 25. Therefore, the bearing holder 240 can protect the entire upper side of the sensor magnet 25, and it is possible to further suppress foreign matter generated outside the motor 201 from adhering to the sensor magnet 25. The bearing holder 240 covers the entire opening 13h of the housing 10 from above. Therefore, it is possible to further prevent foreign matter from entering the inside of the housing 10.

In this modification, the magnetic sensor S2 that detects the magnetic flux of the sensor magnet 25 is arranged on the upper surface of the bearing holder 240. More specifically, the magnetic sensor S2 is arranged on a portion of the upper surface of the top plate portion 241 that overlaps with the sensor magnet 25 when viewed along the axial direction. In this modification, since the bearing holder 240 is a non-magnetic member, the magnetic flux M2 of the sensor magnet 25 located below the bearing holder 240 axially penetrates the bearing holder 240 and flows to the magnetic sensor S2. As a result, the magnetic sensor S2 can detect the magnetic flux of the sensor magnet 25. The magnetic sensor S2 is the same sensor as the magnetic sensor S1 except for the position where it is arranged.

<Second Embodiment>
As shown in FIG. 11, the rotor 320 of the motor 301 of the present embodiment has a rotor core 322, a rotor magnet 23, a resin portion 324, a magnetic material portion 327, a sensor magnet 325, and a rotor cover 26. .. The rotor core 322 has the same shape as the first core portion 22a of the first embodiment. The axial dimensions of the rotor core 322 are the same as the axial dimensions of the rotor magnet 23. In FIG. 12, the rotor cover 26 is not shown.

As shown in FIG. 12, the resin portion 324 has an annular portion 324a, a plurality of pillar portions 24b, and a plurality of convex portions 324f. The annular portion 324a is an annular shape centered on the central axis J. As shown in FIG. 11, the annular portion 324a is located above the rotor core 322 and the rotor magnet 23. The lower surface of the annular portion 324a is in contact with the upper surface of the rotor core 322 and the upper surface of the rotor magnet 23.

As shown in FIG. 12, the plurality of convex portions 324f project radially inward from the radial inner edge portion of the annular portion 324a. The plurality of convex portions 324f are arranged at equal intervals over one circumference along the circumferential direction. The convex portion 324f has a substantially rectangular shape when viewed along the axial direction. For example, five convex portions 324f are provided.

The resin portion 324 has a groove portion 324c and a plurality of recesses 324g. The groove portion 324c is recessed downward from the upper surface of the annular portion 324a. The groove portion 324c is an annular shape centered on the central axis J. The recess 324g is recessed radially inward from the radial inner surface of the inner surface of the groove 324c. The recess 324g opens upward. The plurality of concave portions 324 g are provided in the convex portions 324 f, respectively.

The magnetic material portion 327 is a magnetic member made of a magnetic material. In the present embodiment, the magnetic material portion 327 is fixed to the rotor core 322 via the resin portion 324. That is, in the present embodiment, the magnetic body portion 327 is a separate member from the rotor core 322. Therefore, at least a part of the magnetic body portion 327 can be easily arranged at an axial position which is above the rotor magnet 23 and below the sensor magnet 325 without changing the shape of the rotor core 322. As a result, the shape of the rotor core 322 can be simplified, and the magnetic body portion 327 can suppress a decrease in the detection accuracy of the magnetic sensor S1.

The magnetic body portion 327 has a main body portion 327a and a plurality of held portions 327b. The main body portion 327a is an annular shape surrounding the central axis J. More specifically, the main body portion 327a is an annular shape centered on the central axis J. The main body 327a has a plate shape in which the plate surface faces the axial direction. The main body portion 327a is arranged inside the groove portion 324c. The main body portion 327a is fitted into the groove portion 324c. As shown in FIG. 11, the lower surface of the main body portion 327a contacts the groove bottom surface of the groove portion 324c. The axial dimension of the main body 327a is smaller than the axial dimension of the groove 324c.

The main body 327a is located above the rotor core 322 and above the rotor magnet 23. More specifically, the radial outer edge of the main body 327a is located above the radial inner edge of the rotor magnet 23. As a result, at least a part of the magnetic body portion 327 and the rotor magnet 23 overlap each other when viewed along the axial direction.

The plurality of held portions 327b project radially inward from the radial inner edge portion of the main body portion 327a. As shown in FIG. 12, the plurality of held portions 327b are arranged at equal intervals over one circumference along the circumferential direction. Each of the plurality of held portions 327b is embedded in each of the plurality of convex portions 324f. As a result, the magnetic material portion 327 is held by the resin portion 324.

The held portion 327b has a substantially rectangular shape when viewed along the axial direction. The held portion 327b has a plate shape in which the plate surface faces the axial direction. The radial inner end face of the held portion 327b is exposed to the radial inner side surface of the convex portion 324f. The held portion 327b has a hole portion 327c that penetrates the held portion 327b in the axial direction. The hole portion 327c is exposed to the upper side of the resin portion 324 via the recessed portion 324g.

The sensor magnet 325 has the same shape as the sensor magnet 25 of the first embodiment. As shown in FIG. 11, the sensor magnet 325 is fitted into the groove portion 324c on the upper side of the magnetic body portion 327. The sensor magnet 325 is fixed to the upper surface of the magnetic body portion 327. The lower surface of the sensor magnet 325 contacts the upper surface of the main body 327a. The inner and outer diameters of the sensor magnet 325 are, for example, the same as the inner and outer diameters of the main body 327a. The radial outer edge portion of the sensor magnet 325 is located, for example, at the same position in the radial direction as the radial outer edge portion of the magnetic body portion 327, that is, the radial outer edge portion of the main body portion 327a. The radial outer edge of the sensor magnet 325 is located above the radial inner edge of the rotor magnet 23.

The holding portion 343 of the bearing holder 340 of the present embodiment has a cylindrical shape centered on the central axis J. The holding portion 343 projects downward from the radial inner edge portion of the top plate portion 41. The holding portion 343 is located inside the annular portion 324a in the radial direction, inside the magnetic material portion 327 in the radial direction, and inside the sensor magnet 325 in the radial direction. In the present embodiment, the holding portion 343 has an outer tubular portion 343a and an inner tubular portion 343b.

The outer tubular portion 343a has a cylindrical shape extending downward from the radial inner edge portion of the top plate portion 41. The radial outer surface of the outer tubular portion 343a is the radial outer surface of the holding portion 343. The inner tubular portion 343b has a cylindrical shape extending upward from the lower end portion of the outer tubular portion 343a on the radial inside of the outer tubular portion 343a. The radial outer surface of the inner tubular portion 343b comes into contact with the radial inner surface of the outer tubular portion 343a. The holding portion 343 holds the second bearing 352 inward in the radial direction. The bearing holder 340 has a support convex portion 344 that projects radially inward from the upper end portion of the inner tubular portion 343b. The support convex portion 344 is an annular shape centered on the central axis J.

Similar to the first embodiment, at least a part of the first bearing 351 is located inside the stator 30 in the radial direction. In the present embodiment, the portion of the first bearing 351 excluding the lower end is located inside the stator 30 in the radial direction. The lower end of the first bearing 351 projects below the stator 30.

In this embodiment, at least a part of the second bearing 352 is located inside the stator 30 in the radial direction. As a result, in the present embodiment, at least a part of the first bearing 351 and at least a part of the second bearing 352 are located inside the stator 30 in the radial direction. Therefore, the motor 301 can be miniaturized in the axial direction. In the present embodiment, the portion of the second bearing 352 excluding the upper end is located inside the stator 30 in the radial direction. The upper end of the second bearing 352 projects upward from the stator 30.

The second bearing 352 is located inside the annular portion 324a in the radial direction. The second bearing 352 is located inside the magnetic body portion 327 and the sensor magnet 325 in the radial direction. That is, the sensor magnet 325 is located inside the second bearing 352 in the radial direction. Therefore, the motor 301 can be miniaturized in the axial direction as compared with the case where the sensor magnet 325 is arranged axially away from the second bearing 352.

The support member 360 of the motor 301 of the present embodiment includes a first support member 360a and a second support member 360b. The first support member 360a is the same as the support member 60 of the first embodiment. The first support member 360a has a first cylinder portion 61, a second cylinder portion 62, and a top wall portion 63. The second support member 360b is connected to the lower side of the first support member 360a. The second support member 360b has a third tubular portion 367 and a bottom wall portion 368.

The third tubular portion 367 has a cylindrical shape centered on the central axis J. The upper end of the third tubular portion 367 is connected to the lower end of the second tubular portion 62. The lower end of the third tubular portion 367 is located at substantially the same position in the axial direction as the lower end of the first tubular portion 61. In the present embodiment, the accommodating groove 366 is composed of a first cylinder portion 61, a second cylinder portion 62, a third cylinder portion 367, and a top wall portion 63.

The bottom wall portion 368 projects radially inward from the lower end of the third tubular portion 367. The bottom wall portion 368 is an annular shape centered on the central axis J. The bottom wall portion 368 has a plate shape in which the plate surface faces the axial direction. The radial inner end of the bottom wall portion 368 faces the outer peripheral surface of the first tubular portion 61 in the radial direction via a gap. The bottom wall portion 368 covers the accommodating groove 366 from below. Therefore, even if the coil leader wire 33c accommodated in the accommodation groove 366 moves downward before the housing 10 is made, the coil leader wire 33c can be hooked on the bottom wall portion 368. As a result, it is possible to prevent the coil leader wire 33c from falling off from the support member 360.

The present invention is not limited to the above-described embodiment, and the following configurations can also be adopted. The material of the magnetic material portion provided on the rotor is not particularly limited as long as it is a magnetic material. The magnetic material portion does not have to be located inside a part of the coil in the radial direction. For example, in the second embodiment described above, the magnetic body portion 327 may be entirely located above the coil end 33a. The magnetic material portion does not have to have a portion located above the rotor magnet and below the sensor magnet.

The arrangement and material of the sensor magnet are not particularly limited as long as at least a part of the sensor magnet is located between the rotor body and the bearing holder in the axial direction. The sensor magnet does not have to come into contact with the magnetic material portion. At least a portion of the sensor magnet may be located radially inside the coil. The portion of the sensor magnet located between the rotor body and the bearing holder in the axial direction does not have to include the portion located between the rotor core and the bearing holder in the axial direction, and the rotor magnet and the bearing holder It is not necessary to include the portion located between the axial directions. The sensor magnet may be fixed directly or indirectly to the shaft. In this case, the sensor magnet is fixed to a portion of the shaft located between the portion where the rotor core is fixed and the portion supported by the second bearing in the axial direction. The shape of the sensor magnet is not particularly limited and does not have to be annular. The sensor magnet may have a disk shape, for example.

The arrangement and type of the first bearing and the second bearing are not particularly limited as long as they rotatably support the rotor. For example, both the first bearing and the second bearing need not be entirely arranged radially inside the stator. The first bearing and the second bearing may be plain bearings. The structure and material of the housing are not particularly limited. Each part of the motor does not have to be embedded in the housing. The housing does not have to be made of resin and may be made of metal.

The shape and configuration of the conductive portion are not particularly limited as long as the coil and the external power source are electrically connected. For example, the conductive portion may have a bus bar as a wiring member. In this case, the bus bar is embedded in the housing on the radial outer side of the stator core. Further, the wiring member may be a lead wire or the like. The conductive portion does not have to have a portion embedded in the housing on the radial outer side of the stator core. The shape and arrangement of the support member is not particularly limited as long as it can support the conductive portion. For example, the support member need not be arranged radially outside the stator core. The support member may not be provided.

The application of the motor of the above-described embodiment is not particularly limited. The motor of the above-described embodiment may be mounted on a vehicle for purposes other than driving a power slide door, or may be mounted on a device other than the vehicle. In addition, each configuration described in this specification can be appropriately combined within a range that does not contradict each other.

1,101,201,301 ... motor, 10 ... housing, 13h ... opening, 20,120,320 ... rotor, 20a ... rotor body, 22,122,322 ... rotor core, 23 ... rotor magnet, 25,325 ... sensor Magnet, 30 ... stator, 40, 240, 340 ... bearing holder, 41a ... holder through hole, 52, 352 ... second bearing (bearing), J ... central shaft

Claims (6)

A rotor that can rotate around the central axis and
A stator located on the radial outer side of the rotor and
A housing that houses the rotor and holds the stator,
Bearings that rotatably support the rotor and
A bearing holder fixed to the housing and holding the bearing,
With
The rotor
A rotor body with a rotor core and a rotor magnet,
With the sensor magnet
Have,
The bearing holder is located on one side of the rotor body in the axial direction.
A motor in which at least a part of the sensor magnet is located between the rotor body and the bearing holder in the axial direction. The motor according to claim 1, wherein at least a part of the sensor magnet is located between the rotor core and the bearing holder in the axial direction. The housing has an opening that opens on one side in the axial direction.
The motor according to claim 1 or 2, wherein the bearing holder covers the opening from one side in the axial direction. The motor according to any one of claims 1 to 3, wherein the sensor magnet is directly or indirectly fixed to the rotor core. The bearing holder is a magnetic member having a holder through hole that penetrates the bearing holder in the axial direction and is made of a magnetic material.
The motor according to any one of claims 1 to 4, wherein the holder through hole overlaps a part of the sensor magnet when viewed along the axial direction. The motor according to any one of claims 1 to 4, wherein the bearing holder is a non-magnetic member made of a non-magnetic material and covers one side of the entire sensor magnet in the axial direction.

Images