CN111756151A - Motor with a stator having a stator core - Google Patents

Abstract

The invention provides a motor. One embodiment of a motor of the present invention includes: a rotor rotatable about a central axis; a stator having a stator core and a plurality of coils mounted on the stator core, and located radially outside the rotor; a resin housing which accommodates the rotor therein and holds the stator; and a conductive portion electrically connected to the coil. The conductive portion has a portion fitted in the housing on the radially outer side of the stator core.

Description

Motor with a stator having a stator core

Technical Field

The present invention relates to a motor.

Background

A motor in which a stator is housed inside a housing is known. For example, patent document 1 describes a motor for driving a power slide door for an automobile.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-91152

Disclosure of Invention

Problems to be solved by the invention

The motor as described above is required to be further downsized in the axial direction.

In view of the above circumstances, an object of the present invention is to provide a motor having a structure that can be downsized in the axial direction.

Means for solving the problems

One embodiment of a motor of the present invention includes: a rotor rotatable about a central axis; a stator having a stator core and a plurality of coils mounted on the stator core, and located radially outside the rotor; a resin case that accommodates the rotor therein and holds the stator; and a conductive portion electrically connected to the coil. The conductive portion has a portion fitted in the housing on a radially outer side of the stator core.

Effects of the invention

According to one embodiment of the present invention, the motor can be downsized in the axial direction.

Drawings

Fig. 1 is a perspective view showing a motor of embodiment 1.

Fig. 2 is a sectional view showing a part of the motor of embodiment 1, and is a sectional view II-II in fig. 1.

Fig. 3 is a sectional view showing a part of the motor of embodiment 1, and is a partially enlarged view in fig. 2.

Fig. 4 is a perspective sectional view showing a part of the motor of embodiment 1.

Fig. 5 is a sectional view showing a part of the motor of embodiment 1, and is a V-V sectional view in fig. 2.

Fig. 6 is a perspective view showing a part of the motor of embodiment 1.

Fig. 7 is a perspective view showing a part of the motor of embodiment 1.

Fig. 8 is a perspective view showing a part of the motor of embodiment 1.

Fig. 9 is a sectional view showing a part of a motor according to modification 1 of embodiment 1.

Fig. 10 is a sectional view showing a part of a motor according to modification 2 of embodiment 1.

Fig. 11 is a sectional view showing a part of the motor of embodiment 2.

Fig. 12 is a perspective view showing a part of the rotor of embodiment 2.

Description of the reference symbols

1. 101, 201, 301: motor, 10: case, 13 a: stator holding portion, 13 b: bearing holding portion, 20, 120, 320: a rotor, 21: shaft, 22, 122, 322: rotor core, 25, 325: sensor magnet, 30: stator, 31: stator core, 31 a: core back, 31 b: teeth, 33: coil, 33 c: coil lead wire (wiring member), 51, 351: bearing No. 1, 52, 352: bearing No. 2, 60, 360: support member, 61: 1 st tube portion, 62: 2 nd cylinder part, 70: terminal portion, 80: a conductive portion, J: a central axis.

Detailed Description

The Z-axis direction shown in the figures 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 shown in the drawings is parallel to the Z-axis direction and is an imaginary line extending in the vertical direction. In the following description, the axial direction of the central axis J, i.e., the direction parallel to the vertical direction, is simply referred to as the "axial direction", and the radial direction about the central axis J is simply referred to as the "radial direction". The circumferential direction around the central axis J is simply referred to as "circumferential direction". In the present embodiment, the lower side corresponds to one axial side, and the upper side corresponds to the other axial side. The vertical direction, the upper side, and the lower side are only names for describing the relative positional relationship of the respective parts, and the actual arrangement relationship and the like may be an arrangement relationship other than the arrangement relationship and the like indicated by the names.

< embodiment 1 >

The motor 1 of the present embodiment shown in fig. 1 and 2 is mounted on a vehicle. In the present embodiment, the motor 1 is disposed 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 fig. 1 to 3, the motor 1 includes a housing 10, a rotor 20, a stator 30, a bearing holder 40, a 1 st bearing 51, a 2 nd bearing 52, a support member 60, and a conductive portion 80.

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

As shown in fig. 2, the housing 10 internally houses the rotor 20. The housing 10 holds the stator 30, the bearing holder 40, the 1 st bearing 51, the 2 nd bearing 52, the support member 60, and the conductive portion 80. In the present embodiment, the case 10 is made of resin. The housing 10 is molded as a single member by insert molding in which resin is injected into a mold into which the stator 30, the support member 60, and the conductive portion 80 are inserted. Thereby, the stator 30, the support member 60, and the conductive portion 80 are fitted 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 unit 11 holds each unit of the motor 1. The holding portion 11 includes a main body portion 13 and a connector portion 14. In the present embodiment, the body portion 13 is annular with the center axis J as the center. As shown in fig. 2, the main body portion 13 includes a stator holding portion 13a and a bearing holding portion 13 b.

The stator holding portion 13a surrounds the central axis J. In the present embodiment, the stator holding portion 13a is annular with the center axis J as the center. The stator 30 and a part of the support member 60 are fitted into the stator holding portion 13 a. As shown in fig. 4, the stator holding portion 13a has an opening 13h that opens on the upper side. That is, the housing 10 has an opening 13 h. In fig. 4, illustration of the housing 10, the rotor 20, and the bearing holder 40 is omitted.

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

The stator holding portion 13a has a fixing projection 13e and a holding projection 13g on its upper surface. The fixing convex portion 13e and the holding convex portion 13g protrude upward from the upper side of the stator holding portion 13 a. The fixing projection 13e has a cylindrical shape. The retaining protrusion 13g is arcuate and extends in the circumferential direction. As shown in fig. 1, each of the pair of fixing projections 13e and the retaining projection 13g is provided radially across the central axis J. The pair of fixing projections 13e are provided with the center axis J therebetween in the short side direction Y. The pair of holding projections 13g are provided with the center axis J therebetween in the longitudinal direction X. The fixing projection 13e is located between the positions of the pair of retaining projections 13g in the circumferential direction.

As shown in fig. 2, the bearing holding portion 13b holds the 1 st bearing 51. The bearing holding portion 13b is located radially inward of the stator holding portion 13 a. The bearing holding portion 13b extends radially inward from the lower end of the stator holding portion 13 a. The bearing holding portion 13b has a bottom portion 13c and a cylindrical portion 13 d.

The bottom portion 13c extends radially inward from a radially inner edge portion of the lower end portion of the stator holding portion 13 a. In the present embodiment, the bottom portion 13c is annular with the central axis J as the center. The lower surface of the bottom portion 13c and the lower surface of the stator holding portion 13a are continuously connected to each other and are arranged on the same plane perpendicular to the axial direction. As shown in fig. 4, the radially outer edge portion of the bottom portion 13c is continuous with the lower end portions of the plurality of intermediate portions 13 f. That is, a part of the bottom portion 13c connected to the stator holding portion 13a is positioned above a lower end of the insulator 32 described later. Thereby, at least a part of the portion of the bearing holding portion 13b connected to the stator holding portion 13a is positioned above the lower end of the stator 30.

The cylindrical portion 13d protrudes upward from the bottom portion 13 c. In the present embodiment, the cylindrical portion 13d is a cylindrical shape having a center axis J as a center and opening on the upper side. The cylindrical portion 13d is located at a position spaced radially outward from the radially inner edge portion of the bottom portion 13 c. The 1 st bearing 51 is held radially inside the cylindrical portion 13 d.

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

As shown in fig. 1, the mounting portion 12 is a substantially rectangular parallelepiped box shape that is long in the longitudinal direction X. The mounting portion 12 is open on the upper side. The mounting portion 12 surrounds the holding portion 11. The mounting portion 12 is a portion fixed to a power slide door of the vehicle. The mounting portion 12 is fixed to a power slide door of a vehicle by screws, for example. Thereby, the motor 1 is mounted inside the power slide door of the vehicle. In fig. 5, 7, and 8, the housing 10 is not shown.

The rotor 20 is rotatable about the central axis J. As shown in fig. 2, the rotor 20 is housed inside the casing 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 constitute a rotor body 20 a. That is, the rotor 20 includes a rotor body 20a, and the rotor body 20a includes a rotor core 22 and a rotor magnet 23.

The shaft 21 extends along the central axis J. In the present embodiment, the shaft portion 21 is a columnar shape extending in the axial direction with the 1 st center axis J1 as the center. The upper end of the shaft 21 protrudes 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 coupled to a power slide door of the vehicle. The lower end of the shaft 21 is located above the lower surface of the housing 10. The end of the lower side of the shaft 21 is located radially inward of the bottom 13 c.

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 decagonal prism shape with the center axis J as the center. The rotor core 22 has a plurality of magnet support surfaces 22 c. The magnet support surface 22c is a flat surface perpendicular to the radial direction. The plurality of magnet support surfaces 22c are arranged circumferentially at equal intervals. The plurality of magnet bearing surfaces 22c are a plurality of radial outer surfaces of the regular decagonal prism-shaped rotor core 22. The rotor core 22 may have a polygonal columnar shape other than a regular decagonal columnar shape, or may have a columnar shape.

The rotor core 22 has a fixing hole 22d that penetrates the rotor core 22 in the axial direction. The shape of the fixing hole 22d as viewed in the axial direction is a circular shape centered on the central axis J. As shown in fig. 2, the shaft 21 passes through the fixing hole portion 22 d. The shaft 21 is pressed into the fixing hole 22d, for example. Thus, 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 by resin or other members.

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 radially outward of the fixing hole 22 d. The plurality of through holes 22e are arranged circumferentially at equal intervals. For example, 5 through holes 22e are provided. Here, illustration is omitted, and the rotor core 22 is configured by, for example, laminating a plurality of plate members 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 1 st core portion 22a and a 2 nd core portion 22 b. The 1 st core portion 22a is a portion fixed to the outer peripheral surface of the shaft 21. The 2 nd core portion 22b is a portion that protrudes downward from the radially outer end of the 1 st core portion 22 a. The 2 nd core portion 22b is disposed apart from the shaft 21 to the outside in the radial direction, and is in a ring shape surrounding the shaft 21. The radial outer surface of the rotor core 22 is constituted by the radial outer surface of the 1 st core portion 22a and the radial outer surface of the 2 nd core portion 22 b. That is, the magnet support surfaces 22c are respectively configured such that the radially outer side surface of the 1 st core portion 22a and the radially outer side surface of the 2 nd core portion 22b are axially connected. The axial dimension of the 2 nd core portion 22b is smaller than the axial dimension of the 1 st core portion 22 a. As shown in fig. 3, the lower end of the 2 nd core portion 22b is located radially outward of the cylindrical portion 13 d.

As shown in fig. 5 and 6, the rotor magnet 23 has a substantially quadrangular prism shape which 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 so as to be separated from each other in the circumferential direction. In the present embodiment, the plurality of rotor magnets 23 are arranged circumferentially at equal intervals.

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 outward of the 2 nd core portion 22 b. The rotor magnet 23 is located radially inward of a stator core 31 described later. The rotor magnet 23 is directly or indirectly fixed to the rotor core 22. In the present embodiment, the rotor magnet 23 is directly fixed to the rotor core 22 in contact with the radially outer surface of the rotor core 22.

As shown in fig. 5, the plurality of rotor magnets 23 are supported on the plurality of magnet support surfaces 22c from the radially inner side, respectively. The radially inner surface of the rotor magnet 23 is a flat surface perpendicular to the radial direction, and is in contact with the magnet support surface 22 c. More specifically, as shown in fig. 3, the radially inner surface of the rotor magnet 23 contacts a portion below the magnet support surface 22 c.

As shown in fig. 5, the radially outer surface of the rotor magnet 23 is a curved surface that protrudes radially outward. The circumferential central portion of the radially outer surface of the rotor magnet 23 is in contact with the inner circumferential surface of a cylindrical portion 26b of the rotor cover 26, which will be described later. Thereby, the rotor magnet 23 is held in the radial direction in a state of being in contact with the rotor core 22 and the rotor cover 26. The radially outer surface of the rotor magnet 23 is spaced radially inward from the inner peripheral surface of the cylindrical portion 26b as it is spaced circumferentially from the circumferential center portion.

As shown in fig. 3, in the present embodiment, the axial dimension of the rotor magnet 23 is smaller than the axial dimension of the rotor core 22. The axial dimension of the rotor magnet 23 is larger than the axial dimension of the 2 nd core portion 22b, for example. In the present embodiment, the lower end of the rotor magnet 23 is located at the same position in the axial direction as the lower end of the 2 nd core portion 22 b. In the present embodiment, the upper end of the rotor magnet 23 is located above the lower end of the 1 st core portion 22a and the 2 nd core portion 22 b. The upper end of the rotor magnet 23 is located below the upper end of the 1 st core portion 22 a. In the present embodiment, the rotor magnet 23 is fixed to the radially outer surface of the 1 st core portion 22a and the radially outer surface of the 2 nd core portion 22b in a spanning manner.

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

The annular portion 24a is annular surrounding the central axis J. The annular portion 24a is, for example, annular with the center axis J as the center. 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. Thereby, 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. A radially outer corner 24f of the upper end of the annular portion 24a is rounded.

A radially inner edge portion of an upper end portion of the annular portion 24a has a recess 24c recessed downward. As shown in fig. 6, the concave portion 24c is annular with the central axis J as the center. The recess 24c is open radially inward. As shown in fig. 3, the bottom surface of the recess 24c is located at the same position as the upper surface of the rotor core 22 in the axial direction. The bottom surface of the recess 24c is an upward surface of the inner surfaces of the recess 24 c. In the present embodiment, the upper surface of the rotor core 22 is the upper surface of the 1 st core portion 22 a. The radially inner edge of the bottom surface of the recess 24c is connected to the radially outer edge of the upper surface of the rotor core 22.

As shown in fig. 6, the plurality of column portions 24b extend downward from the annular portion 24 a. The plurality of column portions 24b are arranged circumferentially at equal intervals. The plurality of column portions 24b are respectively located between the rotor magnets 23 adjacent in the circumferential direction. The column portions 24b can suppress the rotor magnet 23 from moving in the circumferential direction with respect to the rotor core 22.

The axial dimension of the column 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 disposed at the same position in the axial direction as the lower end of the 2 nd core portion 22b and the lower end of the rotor magnet 23, for example.

As shown in fig. 5, both circumferential side surfaces of the column portion 24b contact the circumferentially adjacent rotor magnets 23. The plurality of column portions 24b are arranged radially outward of the corner portions of the rotor core 22. The radially inner surfaces of the column portions 24b contact radially outer surfaces of the corner portions of the rotor core 22. Thus, the column portions 24b are engaged with the corner portions of the rotor core 22 in the circumferential direction, and the resin portion 24 can be prevented from rotating in the circumferential direction with respect to the rotor core 22. The radially outer surface of the column portion 24b contacts an inner circumferential surface of a cylindrical portion 26b of the rotor cover 26, which will be described later. The radially outer surface of the column portion 24b is shaped to follow the inner peripheral surface of the cylindrical portion 26 b.

The column portion 24b has a column portion main body 24d and a pressing portion 24 e. The pressing portions 24e protrude from the radially outer end of the column main body 24d to both circumferential sides. The pressing portions 24e contact radially outer surfaces of the rotor magnets 23 adjacent to both circumferential sides of the column portion 24 b. Thereby, the pressing portion 24e supports the rotor magnet 23 from the radial outside. Therefore, the rotor magnet 23 can be prevented from moving radially outward relative to the rotor core 22.

As shown in fig. 6, in the present embodiment, the sensor magnet 25 has a ring shape surrounding the central axis J. The sensor magnet 25 is, for example, annular with the center axis J as the center. The sensor magnet 25 is plate-shaped with its plate surface facing in the axial direction. The magnet 13 has a plurality of magnetic poles in the circumferential direction. The sensor magnet 25 is directly or indirectly fixed to the rotor core 22. In the present embodiment, the sensor magnet 25 is fixed to the upper surface of the rotor core 22. Thereby, the sensor magnet 25 is in 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 contacts across the upper surface of the rotor core 22 and the bottom surface of the recess 24 c. The upper surface of the sensor magnet 25 is located 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, for example. The upper surface of the sensor magnet 25 is exposed to the outside of the rotor 20.

The radially outer edge of the sensor magnet 25 faces a radially inward surface of the inner surface of the recess 24c with a gap therebetween. The sensor magnet 25 may be fitted radially inward of the recess 24c by being in contact with a radially inward surface of the inner surface of the recess 24 c. The sensor magnet 25 is fixed to the rotor core 22 and the annular portion 24a by an adhesive or the like, for example.

The sensor magnet 25 is disposed above the rotor magnet 23. In the present embodiment, the radially outer edge portion of the sensor magnet 25 overlaps the radially inner edge portion of the rotor magnet 23 as viewed in the axial direction. That is, in the present embodiment, the rotor magnet 23 and the sensor magnet 25 are at least partially overlapped with each other when viewed in the axial direction. The rotor magnet 23 and the sensor magnet 25 sandwich the annular portion 24a in the axial direction while contacting the annular portion 24 a.

In the present embodiment, the sensor magnet 25 overlaps the 2 nd core portion 22b as viewed in the axial direction. The inner diameter of the sensor magnet 25 is substantially the same as the inner diameter of the 2 nd core portion 22 b. The radially inner edge of the sensor magnet 25 is positioned slightly radially outward of the radially inner edge of the 2 nd core portion 22 b. The magnetic flux M2 of the sensor magnet 25 is detected by the magnetic sensor S1. The magnetic sensor S1 is a hall element such as a hall IC, for example. The rotation of the rotor 20 can be detected by detecting the magnetic flux M2 of the sensor magnet 25 by the magnetic sensor S1. The magnetic sensor S1 may be a magnetoresistive element.

The rotor cover 26 is a nonmagnetic member made of a nonmagnetic material. As shown in fig. 3, the rotor cover 26 has a bottom portion 26a and a cylindrical portion 26 b. The bottom 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 radially outer edge portion of the 2 nd core portion 22b and the rotor magnet 23.

The bottom 26a is, for example, annular with the center axis J as the center. The bottom 26a is plate-shaped with its plate surface facing in the axial direction. The upper surface of the bottom portion 26a contacts the radially outer edge of the lower surface of the rotor core 22 and the lower surface of the rotor magnet 23. Thus, the bottom 26a supports the rotor core 22 and the rotor magnet 23 from below. In the present embodiment, the radially outer edge of the lower surface of the rotor core 22 is the radially outer edge of the lower surface of the 2 nd core portion 22 b. Although not shown here, in the present embodiment, the upper surface of the bottom portion 26a contacts the lower surface of the pillar portion 24 b. Thereby, the bottom portion 26a supports the resin portion 24 from below.

The cylindrical portion 26b extends upward from the radially outer edge portion of the bottom portion 26 a. As shown in fig. 5, the cylindrical portion 26b is, for example, cylindrical with the center axis J as the center. The cylindrical portion 26b is open on the upper side. The cylindrical portion 26b is located radially outward of the rotor magnet 23. The cylindrical 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 of the cylindrical portion 26b is a caulking portion 26c bent inward in the radial direction. The rivet 26c is bent along the curved corner 24 f. The caulking portion 26c contacts 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. This can prevent the rotor cover 26 from coming off the rotor core 22 in the axial direction. In fig. 6, the rotor cover 26 is not shown.

In the present embodiment, the rotor 20 is provided with a magnetic body made of a magnetic material. In the present embodiment, the magnetic body is a rotor core 22. As shown in fig. 3, at least a part of the rotor core 22 as a magnetic body is positioned above the rotor magnet 23 and below the sensor magnet 25. In the present embodiment, the upper portion of the 1 st core portion 22a in the rotor core 22 is positioned above the rotor magnet 23 and below the sensor magnet 25. The upper portion of the 1 st core portion 22a is located radially inward of the annular portion 24 a.

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

The stator core 31 is located radially outward of the rotor magnet 23. The axial dimension of stator core 31 is smaller than the axial dimension of 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 positioned above the lower end of the rotor magnet 23.

The stator core 31 has a core back 31a and a plurality of teeth 31 b. As shown in fig. 5, the core back 31a is annular so as to surround the rotor 20. In the present embodiment, the core back 31a is annular with the center axis J as the center. The core back 31a may have a polygonal ring shape or an elliptical ring shape.

The plurality of teeth 31b extend radially inward from the core back 31 a. The plurality of teeth 31b are arranged at intervals in the circumferential direction. The plurality of teeth 31b are arranged at equal intervals in the circumferential direction over one circumference. For example, 12 teeth 31b are provided. As shown in fig. 4, the radially inner end surfaces of the teeth 31b are exposed on the inner circumferential surface of the stator holding portion 13 a. As shown in fig. 3, the radially inner end surface of the tooth 31b and the radially outer axial portion of the rotor cover 26 located on the rotor magnet 23 are opposed to each other with a gap therebetween in the radial direction.

As shown in fig. 5, in the present embodiment, the stator core 31 is configured by a plurality of stator core segments 31p connected in the circumferential direction. Each of the plurality of stator core segments 31p includes 1 core back segment 31c constituting a part of the core back 31a in the circumferential direction and 1 tooth 31b extending radially inward from the core back segment 31 c. The circumferential ends of the core back pieces 31c are connected to the circumferential ends of the circumferentially adjacent core back pieces 31c in contact with each other. Here, illustration is omitted, and each stator core segment 31p is configured by, for example, laminating a plurality of plate members in the axial direction. The plate member constituting the stator core sheet 31p is, for example, an electromagnetic steel plate.

In addition, the stator core segments 31p may be all single members. The stator core 31 may not have the plurality of stator core segments 31p and may not be divided in the circumferential direction. In this case, the stator core 31 may be formed by laminating a plurality of plate members in the axial direction, or may be a single member.

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

A pair of inner side wall portions 32b, 32c extend in the axial direction from radially inner end portions of the insulator main body portion 32 a. The pair of inner side walls 32b, 32c are plate-shaped with the plate surfaces facing in the radial direction. The inner wall portion 34b extends upward from a radially inner end of the insulator main body portion 32 a. The inner wall portion 32b is located radially outward of the annular portion 24 a. The inner wall portion 32b is located radially between the upper coil end 33a of the coil 33 and the annular portion 24 a. The inner wall portion 32c extends downward from the radially inner end of the insulator body portion 32 a. The lower end of the inner wall portion 32c is located below the upper surface of the bottom portion 13 c. The radially inner surfaces of the inner side walls 32b and 32c are located at the same positions as the radially inner end surfaces of the teeth 31b, for example, in the radial direction. As shown in fig. 4, the radially inner surfaces of the inner wall portions 32b and 32c are exposed on the inner circumferential surface of the stator holding portion 13a, for example.

As shown in fig. 3, a pair of side wall portions 32d, 32e extend in the axial direction from the radially outer end portions of the insulator main body portion 32 a. The outer side wall portion 32d extends upward from a radially outer end of the insulator main body portion 32 a. The outer wall portion 32e extends downward from a radially outer end of the insulator main body portion 32 a. As shown in fig. 7, each of the outer side wall portions 32d has two through grooves 32f that penetrate the outer side 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 side wall portions 32e has two through grooves 32g that penetrate the outer side 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 attached to the stator core 31. In the present embodiment, the plurality of coils 33 are attached to the plurality of teeth 31b via the insulators 32, respectively. For example, 12 coils 33 are provided. As shown in fig. 3, the coil 33 is mounted on the insulator main body portion 32 a. The coil 33 is formed by winding a conductive wire. The plurality of coils 33 are connected by, for example, delta wiring.

The coil 33 has coil ends 33a and 33b projecting in the axial direction from the insulator body portion 32 a. The coil end portion 33a protrudes upward beyond the insulator body portion 32 a. In the present embodiment, the coil end 33a, which is a part of the coil 33, is positioned 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 wall 32b and the upper end of the outer wall 32 d.

When viewed from the radially outer side, the coil end 33a overlaps the rotor 20 at an axial position 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. The coil end portion 33a overlaps the upper portions of the annular portion 24a and the 1 st core portion 22a when viewed from the radially outer side. Thus, in the present embodiment, at least a part of the rotor core 22, which is a magnetic body, is positioned radially inward of the coil end 33a, which is a part of the coil 33.

The coil end portion 33b protrudes downward from the insulator body portion 32 a. The coil end 33b is located below the rotor magnet 23. The coil end 33b overlaps the 1 st bearing 51 when viewed from the radially outer side. The lower end of the coil end 33b is the lower end of the coil 33.

As shown in fig. 8, a coil lead wire 33c is drawn from a part of the plurality of coils 33. The coil lead wire 33c is the same wire as the wire constituting the coil 33. The coil lead wires 33c are drawn from 6 coils 33 out of 12 coils, for example, although not shown here. In fig. 8, only 1 coil lead wire 33c is illustrated, and the illustration of the other coil lead wires 33c is omitted.

As shown in fig. 1 and 2, the bearing holder 40 holds the 2 nd bearing 52. In the present embodiment, the bearing holder 40 is a magnetic member made of a magnetic material. The bearing holder 40 is disposed 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 body 13. As shown in fig. 2, the bearing holder 40 is located on the upper side of the rotor body 20 a. The bearing holder 40 is located on the upper side of the sensor magnet 25. Thus, in the present embodiment, at least a part of the sensor magnet 25 is positioned between the rotor body 20a and the bearing holder 40 in the axial direction.

Therefore, at least a part of the sensor magnet 25 is covered by the bearing holder 40 from the upper side. This can protect the sensor magnet 25 by the bearing holder 40, and can prevent foreign matter generated outside the motor 1 from adhering to the sensor magnet 25. The foreign matter includes, for example, a magnetic body such as iron pieces. A magnetic body such as iron pieces is easily attached to the sensor magnet 25 by magnetic force. Therefore, when a magnetic body such as iron pieces is easily generated outside the motor 1, the effect of protecting the sensor magnet 25 by the bearing holder 40 is particularly effective.

For example, when the sensor magnet 25 is disposed above 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 is likely to be large, and the motor 1 may be large in the axial direction.

In contrast, when at least a part of the sensor magnet 25 is disposed between the rotor body 20a and the bearing holder 40 in the axial direction as in the present embodiment, the sensor magnet 25 can be fixed to the rotor body 20 a. Therefore, the size of the shaft 21 in the axial direction can be easily suppressed, and the size of the motor 1 in the axial direction can be suppressed.

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 a portion where 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 being enlarged in the axial direction.

In addition, 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. This can suppress leakage of the magnetic flux M2 of the sensor magnet 25 to the outside of the motor 1. Therefore, foreign matter such as iron pieces generated outside the motor 1 can be prevented from being attracted to the motor 1 by the magnetic force of the sensor magnet 25.

In the present embodiment, at least a part of the sensor magnet 25 is positioned between the rotor core 22 and the bearing holder 40 in the axial direction. Therefore, the rotor core 22 is easily used as a yoke of the sensor magnet 25, and the magnetic force of the sensor magnet 25 is easily increased. Therefore, the detection accuracy of the magnetic sensor S1 is easily improved. In the present embodiment, the radially 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 housing 10 through the opening 13 h. The bearing holder 40 has a top plate 41, a flange 42, and a holding portion 43. The top plate 41 has a plate surface facing in the axial direction. The top plate 41 is annular with the center axis J as the center. The top plate 41 is located above the rotor core 22 and the sensor magnet 25.

The flange 42 extends radially outward from the radially outer edge of the top plate 41. The flange 42 is a plate with its plate surface facing in the axial direction. The flange 42 is located below the top plate 41. As shown in fig. 1, the flange 42 is, for example, annular with the center axis J as the center. The flange 42 contacts the peripheral edge of the opening 13h in the upper surface of the housing 10. The flange 42 includes an annular flange body 42a and a pair of fixing portions 42b projecting radially outward from the flange body 42 a.

The flange body 42a is fitted radially inward of each of the pair of retaining projections 13 g. The radially outer edge portion of the flange body 42a contacts the radially inner side surfaces of the pair of retaining protrusions 13 g. Thereby, the bearing holder 40 is positioned in the radial direction with respect to the housing 10. The pair of fixing portions 42b are arranged so as to sandwich the center axis J in the radial direction. In the present embodiment, the pair of fixing portions 42b are disposed with the center axis J interposed therebetween in the short direction Y. The fixing portion 42b has a hole 42c through which the fixing protrusion 13e passes. Here, the part of the fixing convex portion 13e protruding upward from the fixing portion 42b through the hole portion 42c is fixed to the upper surface of the fixing portion 42b by, for example, thermal welding or the like, which is not illustrated. Thereby, the bearing holder 40 is fixed to the housing 10.

The holding portion 43 is a cylindrical shape protruding upward from the radially inner edge portion of the top plate portion 41. In the present embodiment, the holding portion 43 is cylindrical with the central axis J as the center. The 2 nd bearing 52 is held radially inside the holding portion 43. In the present embodiment, the holding portion 43 holds the lower end portion of the 2 nd 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 41. The holder through hole 41a axially penetrates the top plate 41. The holder through hole 41a is, for example, an arc shape extending in the circumferential direction. The holder through-hole 41a partially overlaps the sensor magnet 25 when viewed in the axial direction. Therefore, as shown in fig. 3, by disposing the magnetic sensor S1 in the holder through hole 41a, the magnetic sensor S1 can be disposed close to the sensor magnet 25 located below the bearing holder 40. This allows the magnetic flux M2 of the sensor magnet 25 to be detected with high accuracy by the magnetic sensor S1. Therefore, the rotation of the rotor 20 can be detected with high accuracy. In addition, as compared with the case where the magnetic sensor S1 is disposed above the bearing holder 40, it is easier to dispose the entire device on which the magnetic sensor S1 is mounted close 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 downsized in the axial direction.

As shown in fig. 1, the holder through-hole 41a is provided in a portion of the top plate 41 on the other side (+ X side) in the longitudinal direction X. The holder through-hole 41a is provided in a region on the opposite side of a region on which a terminal portion 70 described later is provided, among regions divided in the longitudinal direction X with respect to the central axis J. Therefore, it is possible to suppress interference between the magnetic field generated by the current flowing through the terminal portion 70 and the magnetic sensor S1 provided in the holder through hole 41 a. Therefore, the detection accuracy of the magnetic sensor S1 can be suppressed from being lowered. In the present embodiment, the bearing holder 40 covers, from above, the sensor magnet 25 except for the portion that overlaps with the holder through hole 41a in the axial direction.

As shown in fig. 2, the 1 st bearing 51 and the 2 nd bearing 52 rotatably support the rotor 20. The 1 st bearing 51 rotatably supports a portion of the shaft 21 located below a portion where the rotor core 22 is fixed. The 2 nd bearing 52 rotatably supports a portion of the shaft 21 located above a portion to which the rotor core 22 is fixed. In the present embodiment, the 1 st bearing 51 and the 2 nd bearing 52 are rolling bearings. The 1 st bearing 51 and the 2 nd bearing 52 are, for example, ball bearings.

The 1 st bearing 51 is held by the housing 10. More specifically, the 1 st bearing 51 is held by the bearing holding portion 13 b. The outer ring of the 1 st bearing 51 is fitted radially inside the cylindrical portion 13 d. The outer ring of the 1 st bearing 51 is supported from below by a portion of the bottom portion 13c located radially inward of the cylindrical portion 13 d.

At least a part of the 1 st bearing 51 is located radially inside the stator 30. Therefore, the motor 1 can be downsized in the axial direction compared to the case where the entire 1 st bearing 51 is disposed farther in the axial direction than the stator 30. In the present embodiment, the 1 st bearing 51 is located entirely radially inward of the stator 30. Therefore, the motor 1 can be further downsized in the axial direction. The upper portion of the 1 st bearing 51 is located radially inward of the 2 nd core portion 22 b.

The 2 nd bearing 52 is held on the bearing holder 40. The lower end of the outer ring of the 2 nd bearing 52 is fitted radially inward of the holding portion 43. In the present embodiment, the 2 nd bearing 52 is located above the stator 30. The 2 nd 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, for example, resin. The support member 60 is located radially outward of the stator 30. At least a part of the support member 60 is embedded in the housing 10 radially outside 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 1 st tube portion 61, a 2 nd tube portion 62, a ceiling wall portion 63, a protruding plate portion 64, and a terminal holding portion 65.

The 1 st cylinder portion 61 is located radially outward of the stator core 31. As shown in fig. 5, the 1 st cylinder portion 61 surrounds the stator core 31. In the present embodiment, the 1 st cylinder portion 61 is a cylindrical shape having the central axis J as the center. In the present embodiment, the 1 st tube portion 61 is fitted to the core back portion 31 a. The inner peripheral surface of the 1 st tube portion 61 is in contact with the outer peripheral surface of the core back portion 31 a. As shown in fig. 2, the upper portion 61a of the 1 st cylindrical portion 61 is located radially outward of the stator core 31. The lower portion 61b of the 1 st cylindrical portion 61 is located radially outward of the outer side wall portion 32 e. The lower portion 61b is located radially outward of the coil end 33 b. The lower portion 61b has a smaller outer and inner diameter than the upper portion 61 a.

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 in the circumferential direction. The through hole 61c is arranged at a position radially overlapping the through groove 32g provided in the outer wall portion 32 e.

The 2 nd cylindrical portion 62 is located radially outward of the 1 st cylindrical portion 61. The 2 nd cylindrical portion 62 surrounds the 1 st cylindrical portion 61. More specifically, the 2 nd cylindrical portion 62 is located radially outward of the upper portion 61a of the 1 st cylindrical portion 61, and surrounds the upper portion 61 a. In the present embodiment, the 2 nd cylindrical portion 62 is a cylindrical shape having the central axis J as the center.

As shown in fig. 2, the top wall 63 connects the upper end of the 1 st tube 61 to the upper end of the 2 nd tube 62. In the present embodiment, the top wall 63 has an annular shape with the center axis J as the center. The top wall 63 has a plate surface facing in the axial direction. The upper surface of top wall 63 is located at substantially the same position in the axial direction as the upper surface of stator core 31.

The 1 st cylinder portion 61, the 2 nd cylinder portion 62, and the ceiling wall portion 63 are embedded in the stator holding portion 13 a. The support member 60 is provided with a receiving groove 66 recessed upward and extending in the circumferential direction by the 1 st tube portion 61, the 2 nd tube portion 62, and the ceiling wall portion 63. As shown in fig. 8, the housing groove 66 is annular with the center axis J as the center.

The protruding plate portion 64 protrudes from the lower end of the 2 nd cylindrical portion 62 to one side (X side) in the longitudinal direction X. The protruding plate portion 64 is a plate whose plate surface faces in the axial direction. The protruding plate portion 64 has a substantially rectangular shape.

As shown in fig. 7, the terminal holding portion 65 protrudes upward from the distal end portion of the protruding plate portion 64, i.e., the end portion on one side (X side) in the longitudinal direction X. In the present embodiment, a plurality of terminal holding portions 65 are provided. The plurality of terminal holding portions 65 are arranged at intervals along the short direction Y. For example, 3 terminal holding portions 65 are provided. The terminal holding portions 65 have holding grooves 65a, respectively. The holding groove 65a is open on the upper side and one side in the longitudinal direction X.

The conductive portion 80 is electrically connected to the coil 33. The conductive portion 80 electrically connects the coil 33 to an external power supply not shown. An external power supply, 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 lead wires 33 c. The plurality of terminal portions 70 are portions to be connected to an external power supply not shown. The plurality of terminal portions 70 are held by the terminal holding portions 65, respectively. For example, 3 terminal portions 70 are provided. The terminal portion 70 has a base portion 71, a terminal body portion 72, and a connecting portion 73.

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

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

The coil lead wire 33c is a wiring member for connecting the terminal portion 70 and the coil 33. As shown in fig. 8, the coil lead 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 in the accommodation groove 66. Thereby, at least a part of the conductive portion 80 is positioned between the 1 st cylinder portion 61 and the 2 nd cylinder portion 62 in the radial direction. Inside the housing groove 66, the coil lead wire 33c extends in the circumferential direction to a portion of the housing groove 66 located on one side (the (-X side) in the longitudinal direction X. The coil lead wire 33c extends from a portion of the housing groove 66 located on one side in the longitudinal direction X along a lower side of the protruding plate portion 64 facing one side in the longitudinal direction X, and is connected to the connecting portion 73 of the terminal portion 70.

As shown in fig. 2, the portion of the coil lead wire 33c passing through the housing groove 66 is embedded in the stator holding portion 13a on the radially outer side of the stator core 31. That is, in the present embodiment, the conductive portion 80 has a portion of the coil lead wire 33c passing through the housing groove 66 as a portion embedded in the case 10 on the radial outer side of the stator core 31. By disposing the conductive portion 80 for electrically connecting the coil 33 and the external power supply radially outward of the stator core 31 in this manner, the conductive portion 80 can be prevented from protruding in the axial direction from the stator 30. Therefore, the motor 1 can be downsized in the axial direction. By forming the case 10 from resin and embedding a part of the conductive portion 80 in the case 10, a structure in which a part of the conductive portion 80 can be arranged radially outward of the stator core 31 can be adopted.

In addition, for example, in a structure in which a motor is assembled by inserting a stator into a cylindrical housing, a gap for insulation needs to be provided between an axial wall portion of the housing and an axial direction of the stator. Therefore, the axial dimension of the housing needs to be larger than the axial dimension of the stator to some extent, and there is a limitation in miniaturizing the motor in the axial direction.

In contrast, when 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. This makes it possible to make the axial dimension of the housing 10 holding the stator 30 substantially the same as the axial dimension of the stator 30, thereby achieving a reduction in thickness. Therefore, the motor 1 can be further downsized in the axial direction.

In addition, according to the present embodiment, at least a part of the coil lead wire 33c as a wiring member connecting the terminal portion 70 and the coil 33 is embedded in the case 10 on the outer side in the radial direction of the stator core 31. By disposing at least a part of the wiring member, which tends to increase the overall length of the conductive portion 80, radially outward of the stator core 31 in this manner, it is possible to more easily suppress the conductive portion 80 from protruding in the axial direction than the stator 30. This enables the motor 1 to be further downsized in the axial direction.

In addition, according to the present embodiment, the wiring member connecting the terminal portion 70 and the coil 33 is the coil lead wire 33c led out 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.

In the present embodiment, the support member 60 that supports the conductive portion 80 is provided, and the support member 60 is embedded in the housing 10 on the outer side in the radial direction of the stator core 31. Therefore, even if the wiring member is configured as the coil lead wires 33c, the coil lead wires 33c can be stably led out to the outside in the radial direction of the stator core 31.

Further, according to the present embodiment, the support member 60 includes the 1 st tubular portion 61 and the 2 nd tubular portion 62, and at least a part of the conductive portion 80 is located between the 1 st tubular portion 61 and the 2 nd tubular portion 62 in the radial direction. Therefore, the 1 st cylindrical portion 61 and the 2 nd cylindrical portion 62 can suppress the conductive portion 80 from moving in the radial direction outside the stator core 31. This can prevent the coil lead wires 33c, which are portions of the conductive portions 80 disposed on the outer side in the radial direction of the stator core 31, from moving in the radial direction when the housing 10 is manufactured by pouring resin into a mold. Therefore, the coil lead wires 33c can be prevented from coming into contact with the inner surface of the mold during molding of the case 10. Therefore, the coil lead wires 33c can be prevented from being exposed to the outer surface of the molded case 10.

In addition, according to the present embodiment, the housing 10 has the stator holding portion 13a embedded in the stator 30, and at least a part of the portion of the bearing holding portion 13b connected to the stator holding portion 13a is positioned above the lower end portion of the stator 30. Therefore, even if the axial dimension of the portion of the stator holding portion 13a located on the lower side of the stator 30 is reduced, the axial dimension of the bottom portion 13c, which is the portion of the bearing holding portion 13b connected to the stator holding portion 13a, can be increased. This can ensure the strength of the bearing holding portion 13b and reduce the size of the housing 10 in the axial direction. Therefore, the motor 1 can be further downsized in the axial direction. Further, since at least a part of the bearing holding portion 13b can be disposed radially inward of the stator 30, a configuration in which at least a part of the 1 st bearing 51 is disposed radially inward of the stator 30 can be adopted. This enables the motor 1 to be further downsized in the axial direction.

In addition, 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 is likely to be small. Therefore, the magnetic field generated by the current flowing through the coil 33 interferes with the magnetic field of the sensor magnet 25, and the magnetic sensor S1 may have a reduced accuracy of detecting the magnetic flux M2 of the sensor magnet 25. In particular, the magnetic flux M1 generated from the coil end 33a located above the rotor magnet 23 and below the sensor magnet 25 may flow toward the sensor magnet 25, and may inhibit the detection of the magnetic flux M2 of the sensor magnet 25 by the magnetic sensor S1.

In contrast, according to the present embodiment, the rotor core 22 is provided as a magnetic body portion at least a part of which is positioned 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 drawn to a portion of the rotor core 22 located above the rotor magnet 23 and below the sensor magnet 25. This can suppress the magnetic flux M1 generated from the coil end 33a from flowing into the sensor magnet 25, and can suppress the magnetic flux M1 from interfering with the magnetic flux M2 of the sensor magnet 25. Therefore, the detection accuracy of the magnetic sensor S1 can be suppressed from being lowered.

The magnetic flux passing through the rotor core 22 includes at most a magnetic flux flowing between the stator core 31 and the magnetic flux. Therefore, the magnetic flux M1 flowing from the coil end 33a toward the rotor core 22 easily flows toward the stator core 31 along the main flow of the magnetic flux flowing inside the rotor core 22. Therefore, the magnetic flux M1 flowing from the coil end 33a to the rotor core 22 is less likely to interfere with the sensor magnet 25.

In addition, according to the present embodiment, at least a part of the rotor core 22 as the magnetic body portion is positioned radially inward of the coil end portion 33a as a part of the coil 33. Therefore, the magnetic flux M1 generated from the coil end 33a is easily drawn radially inward and made incident on the rotor core 22. This can further suppress the magnetic flux M1 generated from the coil end 33a from flowing to the sensor magnet 25, and can further suppress a decrease in detection accuracy of the magnetic sensor S1.

In addition, according to the present embodiment, the sensor magnet 25 is in contact with the rotor core 22 as a magnetic body. Therefore, the magnetic flux M1 that attempts to travel from the coil end 33a toward the sensor magnet 25 can be appropriately drawn by the rotor core 22 adjacent to the sensor magnet 25. Therefore, the flow of the magnetic flux M1 to the sensor magnet 25 can be further suppressed. Further, since the rotor core 22 can be used as a 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.

In addition, according to the present embodiment, the entire sensor magnet 25 is located above the coil 33. Therefore, the magnetic flux M1 generated from the coil end 33a can be further suppressed from flowing toward the sensor magnet 25.

In addition, according to the present embodiment, the magnetic body is the rotor core 22. Therefore, it is not necessary to provide another member as the magnetic body portion, and an increase in the number of components of the motor 1 can be suppressed. This can suppress an increase in the manufacturing cost of the motor 1.

Modification 1 of embodiment 1

As shown in fig. 9, in the rotor 120 of the motor 101 of the present modification, the rotor core 122 includes a rotor core main body 122f and a protruding portion 122 g. The rotor core main body 122f has the same shape as the rotor core 22 of the above embodiment. The rotor core main body 122f has the 1 st core portion 22a and the 2 nd core portion 22 b.

The protruding portion 122g protrudes radially outward from the rotor core body 122 f. In the present modification, the projection 122g projects radially outward from the upper end of the 1 st core portion 22 a. The projection 122g is located above the rotor magnet 23 and below the sensor magnet 25. Therefore, as indicated by arrows in fig. 9, the magnetic flux M1 generated from the coil end 33a can be drawn more easily toward the rotor core 122 via the radially outwardly projecting protrusion 122 g. Therefore, the magnetic flux M1 generated from the coil end 33a can be further suppressed from flowing toward the sensor magnet 25, and the detection accuracy of the magnetic sensor S1 can be further suppressed from being degraded.

In the present modification, the radially outer end of the projection 122g is located radially outward of the radially outer edge of the sensor magnet 25. Thus, the rotor core 122 as a magnetic body portion has a portion located radially outward of the sensor magnet 25. Therefore, the protrusion 122g, which is a part of the rotor core 122, can be located closer to the coil end 33a than the sensor magnet 25. This makes it easier to cause the magnetic flux M1 generated from the coil end 33a to flow toward the protrusion 122g, and further suppresses the magnetic flux M1 from flowing toward the sensor magnet 25.

The protruding portion 122g is embedded in the annular portion 24 a. The radially outer end of the projection 122g is located radially inward of the outer peripheral surface of the annular portion 24 a. The projection 122g is located above the rotor magnet 23. The projection 122g is located below the radially outer edge of the sensor magnet 25. The radially inner portion of the projection 122g 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 as a magnetic body portion is positioned between the rotor magnet 23 and the sensor magnet 25 in the axial direction. Therefore, a part of the magnetic body can be disposed relatively close to the coil end 33 a. This makes it easier to draw the magnetic flux M1 generated from the coil end 33a to the magnetic body, and the flow of the magnetic flux M1 through the sensor magnet 25 can be further suppressed.

The protruding portion 122g may be annular surrounding the rotor core main body 122f, or may be provided in plural numbers along the circumferential direction. When the plurality of projections 122g are provided in the circumferential direction, the plurality of projections 122g may be arranged at positions radially inward of the coil ends 33a of the plurality of coils 33, respectively, as viewed in the axial direction.

Modification 2 of embodiment 1

As shown in fig. 10, a bearing holder 240 of a motor 201 of the present modification does not have a holder through-hole 41a unlike the bearing holder 40 of the above 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 nonmagnetic member made of a nonmagnetic material. The bearing holder 240 covers the entire upper side of the sensor magnet 25. Therefore, the entire upper side of the sensor magnet 25 can be protected by the bearing holder 240, and foreign matter generated outside the motor 201 can be further suppressed from adhering to the sensor magnet 25. The bearing holder 240 covers the entire opening 13h of the housing 10 from above. Therefore, the entry of foreign matter into the interior of the housing 10 can be further suppressed.

In the present modification, the magnetic sensor S2 that detects the magnetic flux of the sensor magnet 25 is disposed on the upper surface of the bearing holder 240. More specifically, the magnetic sensor S2 is disposed in a portion of the upper surface of the top plate 241 that overlaps the sensor magnet 25 when viewed in the axial direction. In the present modification, since the bearing holder 240 is a non-magnetic member, the magnetic flux M2 of the sensor magnet 25 positioned below the bearing holder 240 penetrates the bearing holder 240 in the axial direction and flows toward the magnetic sensor S2. Thereby, 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 disposed.

< embodiment 2 >

As shown in fig. 11, a rotor 320 of the motor 301 according to the present embodiment includes a rotor core 322, a rotor magnet 23, a resin portion 324, a magnetic body portion 327, a sensor magnet 325, and a rotor cover 26. The rotor core 322 has the same shape as the 1 st core portion 22a of embodiment 1. The axial dimension of rotor core 322 is the same as the axial dimension of rotor magnet 23. In fig. 12, the rotor cover 26 is not shown.

As shown in fig. 12, the resin portion 324 includes an annular portion 324a, a plurality of column portions 24b, and a plurality of convex portions 324 f. The annular portion 324a is annular with the center axis J as the center. 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 contacts the upper surface of the rotor magnet 23 across the upper surface of the rotor core 322.

As shown in fig. 12, the plurality of protrusions 324f protrude radially inward from the radially inner edge portion of the annular portion 324 a. The plurality of protrusions 324f are arranged circumferentially at equal intervals. The convex portion 324f has a substantially rectangular shape when viewed in the axial direction. For example, 5 protrusions 324f are provided.

Resin portion 324 has groove portion 324c and a plurality of concave portions 324 g. The groove 324c is recessed downward from the upper surface of the annular portion 324 a. The groove portion 324c is annular with the center axis J as the center. The recess 324g is recessed radially inward from a radially inward surface of the inner surface of the groove portion 324 c. The recess 324g is open on the upper side. The plurality of concave portions 324g are provided on the convex portions 324f, respectively.

The magnetic body 327 is a magnetic member made of a magnetic material. In the present embodiment, the magnetic body 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 member different from the rotor core 322. Therefore, without changing the shape of the rotor core 322, at least a part of the magnetic body portion 327 can be easily arranged at an axial position above the rotor magnet 23 and below the sensor magnet 325. This can simplify the shape of the rotor core 322, and can suppress a decrease in detection accuracy of the magnetic sensor S1 by the magnetic body portion 327.

The magnetic body 327 includes a body portion 327a and a plurality of held portions 327 b. The body 327a is annular surrounding the central axis J. More specifically, the body portion 327a is annular with the center axis J as the center. The body portion 327a has a plate surface facing in the axial direction. The body portion 327a is disposed inside the groove portion 324 c. The body portion 327a is fitted in the groove portion 324 c. As shown in fig. 11, the lower surface of the body portion 327a contacts the bottom surface of the groove portion 324 c. The body portion 327a has an axial dimension smaller than that of the groove portion 324 c.

The body portion 327a is located above the rotor core 322 and above the rotor magnet 23. More specifically, the radially outer edge of the body 327a is located above the radially inner edge of the rotor magnet 23. Thereby, the magnetic body 327 and the rotor magnet 23 overlap each other at least partially when viewed in the axial direction.

The plurality of held portions 327b protrude radially inward from the radially inner edge portion of the body portion 327 a. As shown in fig. 12, the plurality of held portions 327b are arranged at equal intervals in the circumferential direction over a range of one circumference. The plurality of held portions 327b are embedded in the plurality of projections 324f, respectively. Thereby, the magnetic body portion 327 is held by the resin portion 324.

The held portion 327b has a substantially rectangular shape when viewed in the axial direction. The held portion 327b has a plate shape with a plate surface facing in the axial direction. The radially inner end surface of the held portion 327b is exposed on the radially inner surface of the convex portion 324 f. 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 through the concave portion 324 g.

The sensor magnet 325 has the same shape as the sensor magnet 25 of embodiment 1. As shown in fig. 11, the sensor magnet 325 is fitted in the groove portion 324c on the upper side of the magnetic body portion 327. The sensor magnet 325 is fixed to an upper surface of the magnetic body 327. The lower surface of the sensor magnet 325 contacts the upper surface of the body 327 a. The inner diameter and the outer diameter of the sensor magnet 325 are the same as those of the body portion 327a, for example. The radially outer edge of the sensor magnet 325 is located at the same position in the radial direction as the radially outer edge of the magnetic body 327, that is, the radially outer edge of the body 327a, for example. The radially outer edge of the sensor magnet 325 is located above the radially inner edge of the rotor magnet 23.

The holding portion 343 of the bearing holder 340 of the present embodiment is cylindrical with the center axis J as the center. The holding portion 343 protrudes downward from the radially inner edge portion of the top plate portion 41. The holding portion 343 is located radially inward of the annular portion 324a, radially inward of the magnetic body portion 327, and radially inward of the sensor magnet 325. In the present embodiment, the holding portion 343 has an outer tubular portion 343a and an inner tubular portion 343 b.

The outer tube portion 343a is cylindrical and extends downward from the radially inner edge of the top plate 41. The radially outer surface of the outer tube section 343a is the radially outer surface of the holding section 343. The inner tube section 343b is cylindrical and extends upward from the lower end of the outer tube section 343a radially inward of the outer tube section 343 a. The radially outer surface of the inner tube portion 343b contacts the radially inner surface of the outer tube portion 343 a. The holding portion 343 holds the 2 nd bearing 352 on the radially inner side. The bearing holder 340 has a support protrusion 344 protruding radially inward from an upper end of the inner tube portion 343 b. The support projection 344 is annular with the center axis J as the center.

As in embodiment 1, at least a part of the 1 st bearing 351 is located radially inward of the stator 30. In the present embodiment, the 1 st bearing 351 is located radially inward of the stator 30 except for the lower end portion. The lower end of the 1 st bearing 351 protrudes downward from the stator 30.

In the present embodiment, at least a part of the 2 nd bearing 352 is located radially inside the stator 30. Thus, in the present embodiment, at least a part of the 1 st bearing 351 and at least a part of the 2 nd bearing 352 are positioned radially inward of the stator 30. Therefore, the motor 301 can be further downsized in the axial direction. In the present embodiment, the 2 nd bearing 352 is located radially inward of the stator 30 except for the upper end portion. The upper end of the 2 nd bearing 352 protrudes upward beyond the stator 30.

The 2 nd bearing 352 is located radially inward of the annular portion 324 a. The 2 nd bearing 352 is located radially inward of the magnetic body 327 and the sensor magnet 325. That is, the sensor magnet 325 is located radially inward of the 2 nd bearing 352. Therefore, the motor 301 can be downsized in the axial direction compared to the case where the sensor magnet 325 is disposed farther away in the axial direction than the 2 nd bearing 352.

The support member 360 of the motor 301 of the present embodiment includes a 1 st support member 360a and a 2 nd support member 360 b. The 1 st support member 360a is the same as the support member 60 of embodiment 1. The 1 st support member 360a has a 1 st tube portion 61, a 2 nd tube portion 62, and a ceiling wall portion 63. The 2 nd support member 360b is coupled to the lower side of the 1 st support member 360 a. The 2 nd support member 360b has a 3 rd tube 367 and a bottom wall 368.

The 3 rd tube 367 is cylindrical around the central axis J. The upper end of the 3 rd tube 367 is connected to the lower end of the 2 nd tube 62. The lower end of the 3 rd tube portion 367 is located at substantially the same position in the axial direction as the lower end of the 1 st tube portion 61. In the present embodiment, the storage groove 366 is formed by the 1 st tube portion 61, the 2 nd tube portion 62, the 3 rd tube portion 367, and the ceiling wall portion 63.

The bottom wall portion 368 protrudes radially inward from the lower end of the 3 rd tube portion 367. The bottom wall portion 368 has an annular shape with the center axis J as the center. The bottom wall portion 368 has a plate shape with a plate surface facing in the axial direction. The radially inner end of the bottom wall portion 368 is radially opposed to the outer peripheral surface of the 1 st cylinder portion 61 with a gap therebetween. The bottom wall portion 368 covers the storage groove 366 from below. Therefore, even if the coil lead wire 33c stored in the storage groove 366 moves downward before the case 10 is manufactured, the coil lead wire 33c can be caught by the bottom wall portion 368. This can prevent the coil lead wire 33c from falling off the support member 360.

The present invention is not limited to the above embodiment, and the following configuration may be adopted. The material of the magnetic body provided in the rotor is not particularly limited as long as it is a magnetic body. The magnetic body may not be located radially inside a part of the coil. For example, in embodiment 2, the entire magnetic body portion 327 may be positioned above the coil end 33 a. The magnetic body may not have a portion located above the rotor magnet and below the sensor magnet.

The sensor magnet is not particularly limited in its arrangement, material, and the like as long as it is provided on the rotor. The sensor magnet may not be in contact with the magnetic body. At least a portion of the sensor magnet may also be located radially inward of the coil. The portion of the sensor magnet located between the rotor body and the bearing holder in the axial direction may not include a portion located between the rotor core and the bearing holder in the axial direction, or may not include a portion located between the rotor magnet and the bearing holder in the axial direction. The sensor magnet may also be fixed directly or indirectly to the shaft. The sensor magnet may be located above the bearing holder. The sensor magnet may be disposed outside the housing. The shape of the sensor magnet is not particularly limited, and may not be annular. The sensor magnet may have a disc shape, for example.

The arrangement, type, and the like of the 1 st bearing and the 2 nd bearing are not particularly limited as long as the rotor is rotatably supported. For example, neither the 1 st bearing nor the 2 nd bearing may be disposed entirely inside the stator in the radial direction. The 1 st and 2 nd bearings may also be sliding bearings.

The shape, structure, and the like of the conductive portion are not particularly limited as long as the conductive portion has a portion embedded in the housing on the outer side in the radial direction of the stator core and electrically connects the coil with an external power supply. For example, the conductive portion may have a bus bar as the wiring member. In this case, the bus bar is embedded in the housing at the radially outer side of the stator core. The wiring member may be a wire or the like. The shape, arrangement, and the like of the support member are not particularly limited as long as the support member can support the conductive portion. For example, the support member may not be disposed radially outward of the stator core. The support member may not be provided.

The use of the motor of the above embodiment is not particularly limited. The motor of the above embodiment may be mounted on a vehicle for applications other than the application for driving the power slide door, or may be mounted on equipment other than the vehicle. In addition, the respective structures described in the present specification can be appropriately combined within a range not contradictory to each other.

Claims (9)

1. A motor, comprising:

a rotor rotatable about a central axis;

a stator having a stator core and a plurality of coils mounted on the stator core, and located radially outside the rotor;

a resin case that houses the rotor therein and holds the stator; and

a conductive portion electrically connected to the coil,

the conductive portion has a portion fitted in the housing on a radially outer side of the stator core.

2. The motor according to claim 1, wherein the conductive portion has:

a terminal portion; and

a wiring member connecting the terminal portion and the coil,

at least a part of the wiring member is fitted into the housing on the outside in the radial direction of the stator core.

3. The motor according to claim 2, wherein the wiring member is a coil lead-out wire led out from the coil.

4. The motor according to any one of claims 1 to 3, further comprising a support member supporting the conductive portion,

at least a part of the support member is fitted into the housing on a radially outer side of the stator core.

5. The motor according to claim 4, wherein the support member has:

a 1 st cylinder portion positioned radially outward of the stator core and surrounding the stator core; and

a 2 nd cylindrical portion located radially outward of the 1 st cylindrical portion and surrounding the 1 st cylindrical portion,

at least a part of the conductive portion is located between the 1 st cylinder and the 2 nd cylinder in a radial direction.

6. The motor according to any one of claims 1 to 5, further having a 1 st bearing rotatably supporting the rotor,

the stator core includes:

an annular core back portion surrounding the rotor; and

a plurality of teeth extending radially inward from the core back and arranged at intervals in a circumferential direction,

the housing has:

a stator holding portion in which the stator is embedded; and

a bearing holding portion extending radially inward from one axial end of the stator holding portion and holding the 1 st bearing,

at least a part of a portion of the bearing holding portion connected to the stator holding portion is located on the other axial side than an end portion on one axial side of the stator,

at least a portion of the 1 st bearing is located radially inward of the stator.

7. The motor of claim 6, further comprising a 2 nd bearing rotatably supporting the rotor,

the rotor has:

a shaft extending along the central axis; and

a rotor core directly or indirectly fixed to an outer peripheral surface of the shaft,

the 1 st bearing rotatably supports a portion of the shaft located on one axial side of a portion to which the rotor core is fixed,

the 2 nd bearing rotatably supports a portion of the shaft located on the other axial side than the portion to which the rotor core is fixed,

at least a portion of the 2 nd bearing is located radially inward of the stator.

8. The motor according to any one of claims 1 to 5, further having a 1 st bearing and a 2 nd bearing that rotatably support the rotor,

the rotor has:

a shaft disposed along the central axis; and

a rotor core directly or indirectly fixed to an outer peripheral surface of the shaft,

the 1 st bearing rotatably supports a portion of the shaft located on one axial side of a portion to which the rotor core is fixed,

the 2 nd bearing rotatably supports a portion of the shaft located on the other axial side than the portion to which the rotor core is fixed,

at least a portion of the 1 st bearing and at least a portion of the 2 nd bearing are located radially inward of the stator.

9. The motor according to claim 7 or 8, wherein the rotor has a sensor magnet directly or indirectly fixed to the rotor core,

the sensor magnet is located radially outward of the 2 nd bearing.

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