WO2019167843A1

WO2019167843A1 - Motor

Info

Publication number: WO2019167843A1
Application number: PCT/JP2019/006856
Authority: WO
Inventors: 雄策吉田; 梅田　智之; 藤原　英雄; 尚石田; 中島　拓
Original assignee: 日本電産株式会社
Priority date: 2018-02-28
Filing date: 2019-02-22
Publication date: 2019-09-06
Also published as: CN111771318A

Abstract

This motor is provided with: a rotor that is rotatable about the center axis extending in the vertical direction; a stator that has a plurality of coils and that is located radially outside the rotor; and a bus bar unit that is provided on the upper side of the stator. The rotor has a shaft that extends along the center axis, and has a sensor magnet that is located at an upper end portion of the shaft. The bus bar unit has a bus bar that is connected to the coils, a magnetic member that is formed from a magnetic material, and a bus bar holder that extends along a flat surface orthogonal to the center axis so as to support the magnetic member and the bus bar. The bus bar holder is provided with a center hole through which the shaft is inserted. The magnetic member has a cylindrical part that extends in the axial direction along the inner circumferential surface of the center hole. The cylindrical part at least partially overlaps the sensor magnet in the axial direction.

Description

motor

The present invention relates to a motor.

An electromechanically integrated motor that detects the rotor position using a sensor magnet and a sensor is known. Japanese Laid-Open Patent Publication No. 2006-158059 discloses a structure in which the position detection accuracy is improved by attaching a back yoke to a bracket for holding a bearing to block magnetic noise generated from other than the sensor magnet. .

Japanese Unexamined Patent Publication No. 2006-158059

In the structure described in Japanese Patent Application Laid-Open No. 2006-158059, since the back yoke is provided, the number of parts is increased, and the manufacturing process is complicated accordingly.

In view of the above problems, one aspect of the present invention is to provide a motor with reduced manufacturing cost while suppressing magnetic noise from affecting the sensor.

A motor according to an aspect of the present invention includes a rotor that can rotate around a central axis that extends in the vertical direction, a stator that has a plurality of coils and is positioned on the outer side in the radial direction of the rotor, Is provided. The rotor has a shaft extending along the central axis, and a sensor magnet located at the upper end of the shaft. The bus bar unit includes a bus bar connected to the coil, a magnetic member made of a magnetic material, and a bus bar holder that extends along a plane orthogonal to the central axis and supports the bus bar and the magnetic member. The bus bar holder is provided with a central hole into which the shaft is inserted. The magnetic member has a cylindrical portion extending in the axial direction along the inner peripheral surface of the central hole. At least a part of the cylindrical portion overlaps the sensor magnet in the axial direction.

According to one aspect of the present invention, there is provided a motor with reduced manufacturing costs while suppressing magnetic noise from affecting the sensor.

FIG. 1 is a schematic cross-sectional view of a motor according to an embodiment. FIG. 2 is a perspective view of the phase bus bar unit according to the embodiment. FIG. 3 is a plan view of a phase bus bar unit according to an embodiment.

Hereinafter, a bus bar unit and a motor according to an embodiment of the present invention will be described with reference to the drawings. In the following drawings, in order to make each configuration easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

Each figure shows the Z-axis as appropriate. The Z-axis direction in each figure is a direction parallel to the central axis J shown in FIG. In the following description, the positive side (+ Z side) in the Z-axis direction is referred to as “upper side”, and the negative side (−Z side) in the Z-axis direction is referred to as “lower side”. The upper side and the lower side are directions used for explanation only, and do not limit the actual positional relationship and direction. Unless otherwise specified, the direction parallel to the central axis J (Z-axis direction) is simply referred to as “axial direction” or “vertical direction”, and the radial direction around the central axis J is simply referred to as “radial direction”. The circumferential direction around the central axis J, that is, the circumference of the central axis J is simply referred to as “circumferential direction”. Furthermore, in the following description, “plan view” means a state viewed from the axial direction.

<Motor>
FIG. 1 is a schematic cross-sectional view of the motor 1.
A control device (external device) 9 is connected to the motor 1. The control device 9 supplies power to the motor 1 via the control terminal 9a and controls the rotation of the motor 1.

The motor 1 includes a rotor 3, a stator 4, a housing 2, a bearing holder 5, an upper bearing (bearing) 6A, a lower bearing (bearing) 6B, a neutral point bus bar unit 10, and a phase bus bar unit. (Bus bar unit) 20.

The rotor 3 is rotatable around a central axis J extending in the vertical direction. The rotor 3 includes a shaft 3a, a rotor core 3b, a rotor magnet 3c, a sensor magnet 3d, and a sensor magnet mounting member 3e.

The shaft 3a extends along the central axis J. The shaft 3a is rotatably supported around the central axis J by the upper bearing 6A and the lower bearing 6B. The rotor core 3b is fixed to the outer peripheral surface of the shaft 3a. The rotor magnet 3c is fixed to the outer peripheral surface of the rotor core 3b.

The sensor magnet 3d is fixed to the upper end of the shaft 3a. That is, the sensor magnet 3d is located at the upper end of the shaft 3a. Fixing holes 3aa extending along the axial direction are provided on the upper end surface of the shaft 3a. The sensor magnet 3d is provided with a fixing hole 3da penetrating along the axial direction. The sensor magnet attachment member 3e is a bar extending along the axial direction. The sensor magnet attachment member 3e is fitted into the fixing hole 3aa of the shaft 3a and the fixing hole 3da of the sensor magnet 3d. Thereby, the sensor magnet attachment member 3e fixes the shaft 3a and the sensor magnet 3d to each other.

The sensor magnet 3d rotates around the central axis J together with the shaft 3a. The sensor magnet 3d faces the rotation sensor 9b provided in the control device 9 in the axial direction. That is, the sensor magnet 3d is located immediately below the rotation sensor 9b. The rotation sensor 9b is mounted on the lower surface of a circuit board (not shown) of the control device 9. The rotation sensor 9b measures the rotation angle of the rotor 3 from the change in magnetic flux of the sensor magnet 3d.

The stator 4 is annularly arranged around the central axis J. The stator 4 is located on the radially outer side of the rotor 3. The stator 4 is opposed to the rotor 3 in the radial direction through a gap. The stator 4 surrounds the outer side of the rotor 3 in the radial direction. The stator 4 is fixed to the inner peripheral surface of the housing 2. The stator 4 includes an annular stator core 4a, a pair of insulators 4b mounted on the stator core 4a from above and below, and a coil 7 wound around the stator core 4a via the insulator 4b.

The plurality of coils 7 of the present embodiment constitute a three-phase circuit of a plurality of systems (two systems in the present embodiment). In each system, the U-phase, V-phase, and W-phase coils 7 are Y-connected. The stator 4 of this embodiment is provided with 12 coils 7. A coil wire 7a extends from each coil 7. Among the 12 coil wires 7 a, 6 coil wires 7 a are connected to the phase bus bar 21 of the phase bus bar unit 20. The other six coil wires 7 a are connected to the neutral point bus bar 11 of the neutral point bus bar unit 10.

The housing 2 has a cylindrical shape that opens upward (+ Z side). The housing 2 accommodates the rotor 3, the stator 4 and the bearing holder 5. The housing 2 has a cylindrical part 2a and a bottom part 2b. The cylindrical portion 2a surrounds the stator 4 from the outside in the radial direction. The bottom 2b is located at the lower end of the cylinder 2a. A lower bearing holding portion 2c that holds the lower bearing 6B is provided in the center of the bottom portion 2b in plan view.

The bearing holder 5 is located above the stator 4. The bearing holder 5 is located between the phase bus bar unit 20 and the neutral point bus bar unit 10 in the axial direction. That is, the bearing holder 5 is located between the phase bus bar unit 20 and the stator 4. The bearing holder 5 is made of metal. The bearing holder 5 is held on the inner peripheral surface of the housing 2.

The bearing holder 5 has an upper bearing holding portion 5a. The upper bearing holding portion 5a holds the upper bearing 6A. The bearing holder 5 rotatably supports the shaft 3a via the upper bearing 6A. The upper bearing holding portion 5 a is located at the center of the bearing holder 5 in plan view. The upper bearing holding portion 5a includes a holding cylinder portion 5aa extending in the axial direction around the central axis J, and an upper end protruding portion 5ab extending radially inward from the upper end of the holding cylinder portion 5aa. The upper end protrusion 5ab positions the upper bearing 6A in the vertical direction. A hole 5c penetrating in the axial direction is provided in the center of the upper end protrusion 5ab in plan view. The hole 5c allows the shaft 3a to pass inside.

The bearing holder 5 is provided with a coil wire passage hole 5d and a screw hole 5f penetrating in the vertical direction. The coil wire 7a that is drawn from the coil 7 and connected to the phase bus bar unit 20 passes through the coil wire passage hole 5d. A fixing screw 8 for fixing the phase bus bar unit 20 to the bearing holder 5 is inserted into the screw hole 5f.

The neutral point bus bar unit 10 is located above the stator 4. The neutral point bus bar unit 10 includes a neutral point bus bar holder 12 and a plurality (two in this embodiment) of neutral point bus bars 11. The neutral point bus bar holder 12 holds the neutral point bus bar 11. In the present embodiment, the neutral point bus bar unit 10 is provided with a pair of neutral point bus bars 11.

The neutral point bus bar holder 12 extends along a plane orthogonal to the central axis J. The neutral point bus bar holder 12 has a leg portion 12a. The leg portion 12a extends downward along the axial direction. The lower end of the leg portion 12a is in contact with the upper surface of the stator core 4a. Moreover, the neutral point bus-bar holder 12 has the support part 12b. The support portion 12b extends upward along the axial direction. The support portion 12 b surrounds the coil wire 7 a and suppresses the coil wire 7 a from contacting the coil wire passage hole 5 d of the bearing holder 5.

Each neutral point bus bar 11 has three coil wire connecting portions 11a. Neutral point bus bar 11 is connected to coil wire 7a at coil wire connecting portion 11a. The neutral point bus bar 11 connects the coil wires 7a extending from different coils 7 to constitute a neutral point of the three-phase circuit.

(Phase bus bar unit)
The phase bus bar unit 20 is located above the stator 4 and the bearing holder 5. The phase bus bar unit 20 is provided between the coil wire 7 a drawn up to the upper side of the bearing holder 5 and the control device 9 so as to electrically connect them.

FIG. 2 is a perspective view of the phase bus bar unit 20. FIG. 3 is a plan view of the phase bus bar unit 20.
As shown in FIG. 2, the phase bus bar unit 20 includes a plurality (six in this embodiment) of phase bus bars (bus bars) 21, a bus bar holder 30, a pair of terminal receiving members 40, and a reinforcing member (magnetic). Member) 50.

The phase bus bar 21 includes a bus bar main body part 22, a coil wire connection part 24, and an external connection terminal 27. In the present embodiment, the bus bar main body portion 22 and the coil wire connection portion 24 are a single member. The external connection terminal 27 is a separate member from the bus bar main body 22 and is connected to the bus bar main body 22. The external connection terminal 27 and the bus bar main body 22 may be a single member.

Each part of the bus bar for phase 21 is plate-shaped and is formed by press working. The phase bus bar 21 is processed in the bus bar main body portion 22 such that the axial direction is the plate thickness direction. The phase bus bar 21 is processed so that the direction perpendicular to the axial direction is the plate thickness direction in the coil wire connection portion 24 and the external connection terminal 27.

As shown in FIG. 3, the phase bus bar 21 is embedded in the holder main body 31 of the bus bar holder 30. That is, the bus bar holder 30 is manufactured by insert molding for embedding the phase bus bar 21.

The bus bar main body 22 extends linearly along a plane orthogonal to the axial direction. A terminal connection portion 22 a is provided at one end of the bus bar main body portion 22. In addition, a coil wire connecting portion 24 is connected to the other end of the bus bar main body portion 22.

The coil wire connecting portion 24 is connected to the coil wire 7a. The coil wire connection unit 24 holds the coil wire 7a. The planar view shape of the coil wire connecting portion 24 is a substantially U-shape opening outward in the radial direction.

The terminal connection unit 22 a holds the external connection terminal 27. The terminal connection portion 22a is provided with an insertion hole 22aa penetrating in the axial direction. The external connection terminal 27 is press-fitted into the insertion hole 22aa from below. Thereby, the phase bus bar 21 and the external connection terminal 27 are mechanically and electrically connected. The terminal connection portion 22a and the external connection terminal 27 may be connected to each other by a welding method such as laser welding.

As shown in FIG. 2, the external connection terminal 27 extends along the axial direction. The external connection terminal 27 of the present embodiment is provided with a slit 27a extending downward from the upper end portion. The control terminal 9a of the control device 9 is inserted into the slit 27a. As a result, the control device 9 is connected to the motor 1 via the external connection terminal 27.

As shown in FIG. 3, a plurality (six in this embodiment) of bus bars 21 are classified into a first bus bar group 28 and a second bus bar group 29. Each of the first bus bar group 28 and the second bus bar group 29 includes a plurality of (three in this embodiment) phase bus bars 21. That is, the phase bus bar unit 20 includes a plurality of phase bus bars 21, and the plurality of phase bus bars 21 are classified into a plurality of bus bar groups (a first bus bar group 28 and a second bus bar group 29).

The phase bus bars 21 belonging to the first bus bar group 28 and the second bus bar group 29 are respectively connected to coils 7 of different systems. The three coils connected to the three phase bus bars 21 of the first bus bar group 28 constitute a three-phase circuit of one system, and the three coils connected to the three phase bus bars 21 of the second bus bar group 29. The coil constitutes a three-phase circuit of another system. First bus bar group 28 and second bus bar group 29 include a U-phase bus bar, a V-phase bus bar, and a W-phase bus bar, respectively. That is, the three-phase bus bars 21 of the first bus bar group 28 and the second bus bar group 29 are connected to the U-phase, V-phase, and W-phase coils 7, respectively.

The first bus bar group 28 and the second bus bar group 29 are arranged side by side in the circumferential direction. In addition, the phase bus bar 21 of the first bus bar group 28 and the phase bus bar 21 of the second bus bar group 29 are arranged to be pointed around the central axis J. In the first bus bar group 28 and the second bus bar group 29, the in-phase bus bars 21 have the same shape. For this reason, in the bus bar unit 20 for phases, the number of parts can be reduced.

The phase bus bars 21 included in the first bus bar group 28 and the second bus bar group 29 are arranged in the bus bar main body 22 so as to overlap each other in the radial direction. That is, in the first bus bar group 28 and the second bus bar group 29, the bus bar main body portions 22 of the three phase bus bars 21 are arranged side by side in the radial direction. For this reason, it is suppressed that the area | region where the bus bar 21 for phases is arrange | positioned seeing from an axial direction expands in the circumferential direction. Thereby, the length of the bus bar main-body part 22 can be shortened, the material cost required for the phase bus bar 21 can be suppressed, the cost can be reduced, and the phase bus bar unit 20 can be reduced in weight.

As shown in FIG. 1, the bus bar holder 30 is provided on the upper side (one side in the axial direction) of the stator. The bus bar holder 30 extends along a plane orthogonal to the central axis J. The bus bar holder 30 is made of a resin material.

The bus bar holder 30 includes a holder main body portion 31, a cylindrical portion 33, and a plurality (six in this embodiment) of square tube portions 37.

The holder main body 31 extends along a plane orthogonal to the central axis J. The holder main body 31 has an upper surface 31a facing the upper side (one side in the axial direction) and a lower surface 31b facing the lower side (the other side in the axial direction). A phase bus bar 21 and a reinforcing member 50 are embedded in the holder body 31. Thereby, the bus bar holder 30 supports the phase bus bar 21 and the reinforcing member 50. Further, the bus bar holder 30 is reinforced by the phase bus bar 21 and the reinforcing member 50.

The holder main body 31 is provided with a central hole 35 centered on the central axis J. That is, the bus bar holder 30 is provided with a central hole 35. The central hole 35 penetrates in the axial direction. The central hole 35 is circular when viewed from the axial direction. The central hole 35 allows the shaft 3a to pass inside.

As shown in FIG. 3, the holder main body 31 has a pair of bus bar embedded regions 31 A and a pair of reinforcing member embedded regions 31 B around the central hole 35. The bus bar embedded regions 31A and the reinforcing member embedded regions 31B are alternately arranged along the circumferential direction.

The bus bar body 22 of the phase bus bar 21 is embedded in the pair of bus bar embedded regions 31A. The pair of bus bar embedded regions 31 A are arranged on opposite sides in the radial direction with the central hole 35 therebetween as viewed from the axial direction. Of the pair of bus bar embedded regions 31A, one of the three phase bus bars 21 belonging to the first bus bar group 28 is embedded, and the other one of the three phase bus bars 21 belonging to the second bus bar group 29 is embedded. Therefore, the first bus bar group 28 and the second bus bar group 29 are arranged on the opposite sides in the radial direction with the central hole 35 therebetween as viewed from the axial direction.

In the pair of reinforcing member embedding regions 31B, a pair of radially extending portions 54b of the reinforcing member 50 described later is embedded. The pair of reinforcing member embedding regions 31B are arranged on the opposite sides in the radial direction with the central hole 35 therebetween as viewed from the axial direction.

The holder main body 31 is reinforced by the phase bus bar 21 in the bus bar embedded region 31A. Further, the holder main body 31 is reinforced by the reinforcing member 50 in the reinforcing member embedded region 31B.

As shown in FIG. 1, the cylindrical portion 33 extends along the axial direction from the periphery of the central hole 35 of the holder main body portion 31. In the present embodiment, the cylindrical portion 33 extends upward and downward with respect to the holder main body portion 31.

The outer peripheral surface of the cylindrical portion 33 is circular when viewed from the axial direction. Further, the inner peripheral surface of the cylindrical portion 33 coincides with the inner peripheral surface of the central hole 35 when viewed from the axial direction. On the lower side of the holder main body 31, the outer peripheral surface of the cylindrical portion 33 fits into a hole 5 c provided in the bearing holder 5. Accordingly, the phase bus bar unit 20 is positioned in the radial direction.

As shown in FIG. 2, the rectangular tube portion 37 extends upward from the upper surface 31 a of the holder main body portion 31. The rectangular tube portion 37 is a rectangular tube that is rectangular when viewed from the axial direction. The same number (ie, six) of the rectangular tube portions 37 as the external connection terminals 27 provided in the phase bus bar unit 20 are provided in the bus bar holder 30. Inside the rectangular tube portion 37, a terminal passage hole 37a penetrating along the axial direction is provided. The terminal passage hole 37 a surrounds the external connection terminal 27. Thereby, the rectangular tube part 37 protects the external connection terminal 27.

The terminal receiving member 40 has a plate shape extending along a plane orthogonal to the axial direction. The terminal receiving member 40 is fixed to the lower surface 31 b of the holder main body 31. One of the pair of terminal receiving members 40 is located below the three terminal connecting portions 22 a of the first bus bar group 28. One of the pair of terminal receiving members 40 is located below the three terminal connection portions 22 a of the second bus bar group 29.

The terminal receiving member 40 is in contact with the lower end portion of the external connection terminal 27 on a backup surface (not shown) facing upward. When the external connection terminal 27 is connected to the control device 9, it receives a downward stress from the control terminal 9 a of the control device 9. The terminal receiving member 40 supports the external connection terminal 27 on the backup surface, and suppresses the external connection terminal 27 from being detached from the insertion hole 22aa of the phase bus bar 21.

As shown in FIG. 1, at least a part of the reinforcing member 50 is embedded in the bus bar holder 30. That is, the bus bar holder 30 is manufactured by insert molding in which the reinforcing member 50 is embedded. The reinforcing member 50 is made of a metal material and reinforces the bus bar holder 30. The reinforcing member 50 is made of a magnetic material.

The reinforcing member 50 includes a cylindrical portion 51, a flat plate portion 54, a pair of bent portions 53, and a pair of fixed portions 52. The reinforcing member 50 is embedded in the bus bar holder 30 in part of the cylindrical portion 51 and the flat plate portion 54.

The cylindrical portion 51 extends in a cylindrical shape along the axial direction. The cylindrical portion 51 surrounds the central axis J. Therefore, the reinforcing member 50 extends in the axial direction along the inner peripheral surface of the central hole 35 provided in the bus bar holder 30. In the present embodiment, the cylindrical portion 51 has a cylindrical shape. However, the cylindrical portion 51 is not limited to a circular shape in plan view, and may be a square tube having a rectangular shape in plan view.

The upper end portion of the shaft 3a is disposed inside the cylindrical portion 51. A sensor magnet 3d fixed to the upper end portion of the shaft 3a is disposed inside the cylindrical portion 51. That is, the cylindrical part 51 surrounds the sensor magnet 3d from the outside in the radial direction.

In the phase bus bar unit 20, an alternating current flows through the phase bus bar 21 disposed around the central hole 35. For this reason, a magnetic field is generated around the phase bus bar 21 due to a change in the current flowing through the phase bus bar 21. As described above, the magnetic field generated from the sensor magnet 3d is detected by the rotation sensor 9b provided in the control device 9, and used for measurement of the rotation angle by the rotation sensor 9b. For this reason, the magnetic flux of the sensor magnet 3d may be affected by the magnetic field generated from the phase bus bar 21 and may affect the measurement of the rotation angle by the rotation sensor 9b. According to the present embodiment, the reinforcing member 50 is made of a magnetic material, and surrounds the sensor magnet 3 d in the cylindrical portion 51. For this reason, the cylindrical part 51 functions as a magnetic shield. That is, the cylindrical part 51 suppresses the magnetic noise from the outside of the cylindrical part 51 from affecting the magnetic flux of the sensor magnet 3 d located inside the cylindrical part 51. As a result, the measurement accuracy of the rotation angle by the rotation sensor 9b can be improved, and the highly reliable motor 1 can be configured.

In this embodiment, the phase bus bar 21 has an external connection terminal 27 extending upward with respect to the bus bar holder 30. For this reason, the magnetic field generated by the external connection terminal 27 tends to affect the measurement accuracy of the rotation angle in the rotation sensor 9b located above the sensor magnet 3d. According to this embodiment, the cylindrical part 51 shields between the external connection terminal 27 and the sensor magnet 3d. For this reason, it can suppress that the magnetic field produced from the external connection terminal 27 influences the inner side of the cylindrical part 51, and can raise the measurement precision of the rotation angle by the rotation sensor 9b.

In the present embodiment, the upper end of the cylindrical portion 51 is located above the upper end of the sensor magnet 3d. Therefore, according to this embodiment, it can suppress that the magnetic flux which goes upwards from the upper end of the sensor magnet 3d is influenced by the magnetic field produced from the phase bus bar 21. Moreover, the lower end of the cylindrical part 51 is located below the lower end of the sensor magnet 3d. Therefore, according to this embodiment, it can suppress that the magnetic flux which comes out from the upper end of the sensor magnet 3d and enters the inside of the sensor magnet 3d from the lower end is influenced by the magnetic field generated from the phase bus bar 21. In addition, in this embodiment, the case where the cylindrical part 51 encloses the full length of the axial direction of the sensor magnet 3d was illustrated. However, if at least a part of the cylindrical portion 51 overlaps the sensor magnet 3d in the axial direction, magnetic noise from the outside of the cylindrical portion 51 is prevented from affecting the magnetic flux of the sensor magnet 3d. It is possible to achieve a certain effect of increasing the measurement accuracy of the rotation sensor 9b.

The cylindrical part 51 is embedded in the cylindrical part 33 of the bus bar holder 30. The bus bar holder 30 is made of a resin material in order to ensure insulation between the phase bus bars 21. For this reason, the bus bar holder 30 has a lower strength than the metal material. Moreover, since the central hole 35 through which the central axis J passes is provided in the bus bar holder 30, the strength around the central hole 35 is low. According to the present embodiment, the cylindrical portion 51 surrounding the central hole 35 is embedded inside the bus bar holder 30, thereby reinforcing the periphery of the central hole 35 of the bus bar holder 30 and applying stress to the bus bar holder 30. Even if it exists, damage to the bus bar holder 30 can be suppressed.

According to the present embodiment, the cylindrical portion 33 that functions as a magnetic shield is embedded in the bus bar holder 30. For this reason, the bus bar holder 30 and the cylindrical portion 33 can be handled as a single component. According to this embodiment, compared with the case where a bus-bar holder and a magnetic shield are provided as separate parts, the cost concerning an assembly process etc. can be reduced and the motor 1 can be manufactured at low cost.

The flat plate portion 54 extends in the radial direction from the cylindrical portion 51 along a plane orthogonal to the central axis J. As shown in FIG. 3, the flat plate portion 54 includes an annular portion 54 a that surrounds the central hole 35 and a pair of radially extending portions 54 b that extend radially outward from the annular portion 54 a.

The flat plate portion 54 is embedded in the holder main body portion 31 except for the radially outer end portion of the radially extending portion 54b. That is, at least a part of the flat plate portion 54 is embedded in the holder main body portion 31 of the bus bar holder 30. Thereby, the flat plate part 54 reinforces the holder main body part 31. The fixed portion 52 is connected to the radially outer edge portion of the radially extending portion 54 b via the bent portion 53.

The pair of radially extending portions 54b extend along the radial direction. The radially extending portion 54 b is located between the first bus bar group 28 and the second bus bar group 29 in the circumferential direction. That is, the radially extending portion 54b extends in the radial direction between the bus bar groups adjacent in the circumferential direction.

In the present embodiment, the plurality of phase bus bars 21 are classified into a first bus bar group 28 and a second bus bar group 29, and are arranged firmly for each bus bar group. Each phase bus bar 21 is embedded in a bus bar embedded region 31 A of the holder main body 31. The holder main body 31 is reinforced by the phase bus bar 21 in the bus bar embedded region 31A. On the other hand, the radially extending portion 54 b is embedded in the reinforcing member embedded region 31 B of the holder main body portion 31. The reinforcing member embedded region 31B is located between the bus bar embedded regions 31A in the circumferential direction. Accordingly, the radially extending portion 54b reinforces the region between the pair of bus bar embedded regions 31A (that is, the reinforcing member embedded region 31B). According to the present embodiment, the plurality of bus bar groups and the radially extending portions 54 b are alternately embedded in the circumferential direction in the holder main body portion 31. Thereby, the whole area | region of the circumferential direction of the holder main-body part 31 is reinforced, and damage to the bus-bar holder 30 can be suppressed effectively. Also, the phase bus bar 21 and the reinforcing member 50, which are metal materials, have higher heat conduction characteristics than the holder main body portion 31, which is a resin material. When the holder body 31 is provided with a region in which the metal material is embedded and a region in which the metal material is not embedded, the cooling efficiency differs depending on the region. easy. According to the present embodiment, since the metal material is embedded in the entire region in the circumferential direction of the holder main body 31, it is possible to suppress warping during the molding of the holder main body 31.

The annular portion 54 a extends annularly along the outer peripheral surface of the tubular portion 51. The annular portion 54 a is connected to the outer peripheral surface of the cylindrical portion 51. The annular portion 54 a surrounds the central hole 35 of the bus bar holder 30. Since the annular portion 54 a is embedded in the holder main body portion 31, the periphery of the central hole 35 of the bus bar holder 30 is reinforced. Thereby, even if it is a case where stress is added to the bus-bar holder 30, damage to the bus-bar holder 30 is suppressed.

The annular portion 54a is located between the pair of radially extending portions 54b and connects the pair of radially extending portions 54b to each other. That is, the plurality (two in the present embodiment) of radially extending portions 54b are connected to each other via the annular portion 54a. Thereby, the rigidity of the plurality of radially extending portions 54b can be increased by the annular portion 54a. As a result, the reinforcing effect of the holder body 31 by the radially extending portion 54b can be enhanced.

In the present embodiment, the flat plate portion 54 is arranged at a position different from the phase bus bar 21 when viewed from the axial direction. That is, the flat plate portion 54 and the phase bus bar 21 do not overlap in the axial direction. The holder main body 31 is reinforced by the flat plate portion 54 and the phase bus bar 21. By providing the flat plate portion 54 and the phase bus bar 21 at positions different from each other when viewed in the axial direction, the flat plate portion 54 is not excessively embedded in the holder main body portion 31. For this reason, the intensity | strength of the bus bar holder 30 whole can be improved with sufficient balance, suppressing the weight of the bus bar unit 20 for phases.

As shown in FIG. 1, the bent portion 53 and the fixing portion 52 are not embedded in the bus bar holder 30. That is, the bent portion 53 and the fixing portion 52 are exposed from the bus bar holder 30. The bent portion 53 is located at the radially outer end portion of the radially extending portion 54 b of the flat plate portion 54. The bent portion 53 connects the flat plate portion 54 and the fixed portion 52. The bent portion 53 is bent downward with respect to the flat plate portion 54. On the other hand, the fixing portion 52 extends in a plate shape along a plane orthogonal to the central axis J. By providing the bent portion 53 between the flat plate portion 54 and the fixed portion 52, the fixed portion 52 is disposed below the flat plate portion 54.

The lower surface of the fixing portion 52 contacts the upper surface of the bearing holder 5. The fixing portion 52 is provided with a through hole 52a penetrating in the axial direction. A fixing screw 8 for fixing the phase bus bar unit 20 to the bearing holder 5 is inserted into the through hole 52a. Accordingly, the phase bus bar unit 20 is fixed to other components (in the present embodiment, the bearing holder 5) in the fixing portion 52.

Since the bus bar holder 30 is made of a resin material, if the bus bar holder 30 is directly fixed to another component (for example, the bearing holder 5), the bus bar holder 30 may be damaged by the fastening force at the time of fixing. is there. According to the present embodiment, the phase bus bar unit 20 is fixed to the bearing holder 5 at the fixing portion 52 that reinforces the bus bar holder 30. Since the reinforcing member 50 reinforces the bearing holder 5, it has a higher strength than the resin material constituting the bearing holder 5. In particular, in the present embodiment, the reinforcing member 50 is made of a metal material. For this reason, when fixing the bus bar unit 20 for phases to the bearing holder 5, it can suppress that a part of bus bar unit 20 for phases is damaged.

According to the present embodiment, the reinforcing member 50 that reinforces the bus bar holder 30 has the fixing portion 52. That is, the reinforcing member 50 has a function of reinforcing the bus bar holder 30 and a function of fixing the phase bus bar unit 20 to other members. For this reason, compared with the case where a bus-bar unit has a bus-bar holder and a fixing member, it can suppress that a number of parts increases. As a result, not only the manufacturing cost of components can be suppressed, but also the management costs of components accompanying an increase in the number of components can be suppressed, and the motor 1 can be manufactured at low cost.

In the present embodiment, the case where the fixing portion 52 is fixed to the bearing holder 5 is illustrated, but the fixing portion 52 may be fixed to components other than the phase bus bar unit 20 constituting the motor 1. For example, the fixing portion 52 may be fixed to the stator 4. Further, in the present embodiment, the case where the fixing portion 52 is fixed to another component by the fixing screw 8 is exemplified, but the fixing portion 52 and the other component may be fixed by other means. For example, the fixing part 52 may be fixed to other parts by caulking.

In the present embodiment, the description has been given on the assumption that the reinforcing member 50 is made of a metal material. However, the reinforcing member 50 may be made of other materials as long as the cylindrical portion 51 is made of a magnetic material and the fixing portion 52 is made of a material having higher strength than the bus bar holder 30.

In the present embodiment, the case where the present invention is applied to the phase bus bar unit 20 has been described. However, the bus bar unit to which the configuration of the present invention is applied may be a bus bar unit having a neutral point bus bar. That is, the bus bar provided in the bus bar unit may be a neutral point bus bar or a phase bus bar as long as it is connected to the coil.

Although one embodiment of the present invention has been described above, each configuration and combination thereof in the embodiment is an example, and addition, omission, replacement, and others of the configuration are within a range not departing from the gist of the present invention. Can be changed. Further, the present invention is not limited by the embodiment.

DESCRIPTION OF SYMBOLS 1 ... Motor, 3 ... Rotor, 3a ... Shaft, 3d ... Sensor magnet, 4 ... Stator, 5 ... Bearing holder, 6A ... Upper bearing (bearing), 7 ... Coil, 20 ... Phase busbar unit (busbar unit), 21 ... Bus bar (bus bar), 27 .. external connection terminal, 30... Bus bar holder, 35... Central hole, 50 .. reinforcing member (magnetic member), 51. ... flat plate part, 54a ... annular part, 54b ... radially extending part, J ... central axis

Claims

A rotor rotatable around a central axis extending in the vertical direction;
A stator having a plurality of coils and positioned radially outside the rotor;
A bus bar unit provided on the upper side of the stator,
The rotor is
A shaft extending along the central axis;
A sensor magnet located at the upper end of the shaft,
The bus bar unit is
A bus bar connected to the coil;
A magnetic member made of a magnetic material;
A bus bar holder that extends along a plane orthogonal to the central axis and supports the bus bar and the magnetic member;
The bus bar holder is provided with a central hole into which the shaft is inserted,
The magnetic member has a cylindrical portion extending in the axial direction along the inner peripheral surface of the central hole,
A motor in which at least a part of the cylindrical portion overlaps the sensor magnet in the axial direction.
The magnetic member has a flat plate portion extending in a radial direction along a plane orthogonal to the central axis from the cylindrical portion,
The motor according to claim 1, wherein at least a part of the flat plate portion is embedded in the bus bar holder.
The motor according to claim 2, wherein the flat plate portion is disposed at a position different from the bus bar as viewed in the axial direction.
The bus bar unit has a plurality of the bus bars,
The plurality of bus bars are classified into a plurality of bus bar groups,
The plurality of bus bar groups are arranged side by side in the circumferential direction,
4. The motor according to claim 2, wherein the flat plate portion includes a plurality of radially extending portions extending in a radial direction between the bus bar groups adjacent in the circumferential direction.
The flat plate portion has an annular portion extending annularly along the outer peripheral surface of the cylindrical portion,
The motor according to claim 4, wherein the plurality of radially extending portions are connected to each other via the annular portion.
The motor according to any one of claims 1 to 5, wherein at least a part of the bus bar is embedded in the bus bar holder.
The bus bar has an external connection terminal extending along the axial direction,
The motor according to any one of claims 1 to 6, wherein the cylindrical portion shields between the external connection terminal and the sensor magnet.
The motor according to any one of claims 1 to 7, wherein an upper end of the cylindrical portion is located above an upper end of the sensor magnet.
The motor according to any one of claims 1 to 8, wherein a lower end of the cylindrical portion is located below a lower end of the sensor magnet.