阅读说明：本技术 电动机 (Electric motor ) 是由 服部宏之 北山武志 于 2019-07-25 设计创作，主要内容包括：提供一种能够抑制磁轭变形的电动机。电动机具备：旋转轴构件,能够以轴线为中心进行旋转；转子,具有设置于旋转轴构件的圆环状的转子芯及设置于转子芯的磁铁；定子,具有相对于转子芯在径向上隔开间隔而配置的圆环状的定子芯及卷绕于定子芯的定子线圈,径向是与旋转轴构件的轴线方向正交的方向；圆筒状的磁轭,包住转子及定子,相对于定子芯的相对的位置关系确定；及壳体构件,具有与磁轭的外周面对向且在轴线方向上延伸的侧壁部,磁轭固定于壳体构件。(Provided is a motor capable of suppressing deformation of a yoke. The motor is provided with: a rotation shaft member rotatable about an axis; a rotor having an annular rotor core provided on the rotating shaft member and a magnet provided on the rotor core; a stator having an annular stator core arranged at a radial distance from the rotor core and a stator coil wound around the stator core, the radial direction being a direction orthogonal to the axial direction of the rotating shaft member; a cylindrical yoke that surrounds the rotor and the stator and has a predetermined relative positional relationship with respect to the stator core; and a housing member having a side wall portion that faces the outer peripheral surface of the yoke and extends in the axial direction, the yoke being fixed to the housing member.)

1. An electric motor, comprising:

a rotation shaft member rotatable about an axis;

a rotor having an annular rotor core provided on the rotation shaft member and a magnet provided on the rotor core;

a stator having an annular stator core disposed at an interval in a radial direction from the rotor core, the radial direction being a direction orthogonal to an axial direction of the rotating shaft member, and a stator coil wound around the stator core;

a cylindrical yoke that surrounds the rotor and the stator and has a predetermined relative positional relationship with the stator core; and

and a housing member having a side wall portion that faces the outer peripheral surface of the yoke and extends in the axial direction, the yoke being fixed to the housing member.

2. The motor according to claim 1,

the side wall portion is formed in a cylindrical shape,

the yoke is press-fitted to the side wall portion.

3. The motor according to claim 1 or 2,

the housing member has a pair of end wall portions extending in the radial direction and opposed to each other with the yoke interposed therebetween in the axial direction,

the yoke is fixed to the pair of end wall portions.

4. The motor according to claim 3,

the magnetic yoke has a coupling member for coupling the magnetic yoke to the pair of end wall portions.

5. The motor according to claim 3 or 4,

the housing member is supported by the rotating shaft member via a bearing.

6. The motor according to any one of claims 1 to 5,

the stator core is fixed to the housing member.

7. The motor according to claim 6,

an opening is formed in a part of an outer peripheral surface of the yoke,

fixing the stator core with the housing member at a position corresponding to the opening.

8. The motor according to any one of claims 1 to 7,

the housing member covers the outer peripheral surface of the yoke and both end surfaces in the axial direction.

Technical Field

The present invention relates to an electric motor.

Background

Patent document 1 discloses an electric motor including: a rotor having an annular rotor core provided on a shaft; a stator having an annular stator core disposed at a radial interval from the rotor core; and a cylindrical yoke (field yoke) surrounding the rotor and the stator. In this motor, the outer peripheral portion of the stator core is press-fitted into the inner peripheral portion of the yoke, and the stator core is fixed to the yoke.

Disclosure of Invention

Problems to be solved by the invention

However, in the motor disclosed in patent document 1, when the motor is operated, the yoke may be deformed by a force such as a torque reaction force directly acting from the outer peripheral portion of the stator core to the inner peripheral portion of the yoke.

The present invention has been made in view of the above problems, and an object thereof is to provide a motor capable of suppressing deformation of a yoke.

Means for solving the problems

In order to solve the above problems and achieve the object, a motor according to the present invention includes: a rotation shaft member rotatable about an axis; a rotor having an annular rotor core provided on the rotation shaft member and a magnet provided on the rotor core; a stator having an annular stator core disposed at an interval in a radial direction from the rotor core, the radial direction being a direction orthogonal to an axial direction of the rotating shaft member, and a stator coil wound around the stator core; a cylindrical yoke that surrounds the rotor and the stator and has a predetermined relative positional relationship with the stator core; and a housing member having a side wall portion facing the outer peripheral surface of the yoke and extending in the axial direction, the yoke being fixed to the housing member.

In the above aspect, the side wall portion may be cylindrical, and the yoke may be press-fitted into the side wall portion.

This can reinforce the yoke with the side wall portion of the case member, thereby suppressing deformation of the yoke.

In the above aspect, the housing member may have a pair of end wall portions extending in the radial direction and facing each other with the yoke interposed therebetween in the axial direction, and the yoke may be fixed to the pair of end wall portions.

Thus, the yoke can be reinforced by the pair of end wall portions of the case member, and deformation of the yoke can be suppressed.

In the above aspect, a coupling member may be provided to couple the yoke and the pair of end wall portions.

Thus, the yoke and the pair of end wall portions are coupled by the coupling member, and the yoke is reinforced by the end wall portion of the case member, thereby suppressing deformation of the yoke.

In the above aspect, the housing member may be supported by the rotating shaft member via a bearing.

This suppresses the force in the radial direction from the bearing from directly acting on the yoke, and suppresses the yoke from deforming.

In the above aspect, the stator core may be fixed to the housing member.

This suppresses the force from the stator core from directly acting on the yoke, and suppresses deformation of the yoke.

In the above aspect, an opening may be formed in a part of an outer peripheral surface of the yoke, and the stator core and the housing member may be fixed at a position corresponding to the opening.

This suppresses the force from the stator core from directly acting on the yoke, and suppresses deformation of the yoke.

In the above aspect, the housing member may cover the outer peripheral surface and both axial end surfaces of the yoke.

Thereby, the yoke can be effectively protected by the case member.

Effects of the invention

In the motor of the present invention, the yoke is fixed to a case member having a side wall portion that faces the outer peripheral surface of the yoke and extends in the axial direction, and the yoke is reinforced by the case member. Thus, the motor of the present invention has the following effects: even if a force is directly applied from the stator core to the yoke at the radially outer side of the stator core, the yoke can be suppressed from being deformed.

Drawings

Fig. 1 is a sectional view of a motor according to embodiment 1.

Fig. 2 is a view of the yoke as viewed from the axial direction.

Fig. 3 is a sectional view of the motor of embodiment 2.

Detailed Description

Hereinafter, embodiments of the motor according to the present invention will be described. The present invention is not limited to the embodiment.

(embodiment mode 1)

Fig. 1 is a sectional view of a motor 1 according to embodiment 1. As shown in fig. 1, a motor 1 according to embodiment 1 includes a shaft 2, a rotor 3, a stator 4, a yoke 5, a field coil 6, a housing 7, and the like.

The shaft 2 is a metal rotary shaft member that is long in the axial direction. In the following description, the "axial direction" is defined as the axial direction (longitudinal direction) of the shaft 2. The rotor 3 includes a rotor core 31, a magnet 32, a field core 33, and the like. The rotor core 31 is formed in a cylindrical shape by laminating a plurality of electromagnetic steel plates in the axial direction of the shaft 2. Since rotor core 31 has a gap between the electromagnetic steel plates in the axial direction, the magnetic resistance in the axial direction is larger than the magnetic resistance in the radial direction and the circumferential direction, which are directions orthogonal to the axial direction of rotor core 31. Therefore, in the rotor core 31, the magnetic flux is hard to flow in the axial direction, and the magnetic flux is easy to flow in the radial direction and the circumferential direction.

Magnet 32 is embedded inside rotor core 31 and extends in the axial direction of rotor core 31. Both end surfaces of the magnet 32 in the axial direction are substantially coplanar with both end surfaces of the rotor core 31 in the axial direction, respectively. Further, 4 magnets 32 are arranged at intervals of 90 ° [ ° ] in the circumferential direction of rotor core 31.

The field core 33 is formed in a cylindrical shape from a magnetic material, is provided on the inner periphery of the rotor core 31, and is fixed to the shaft 2 so as to be rotatable together with the shaft 2. Both axial end surfaces of the field core 33 are substantially coplanar with both axial end surfaces of the rotor core 31. The magnetic resistance in the axial direction of the field core 33 is smaller than the magnetic resistance in the axial direction of the rotor core 31. Therefore, the magnetic flux flows more easily in the axial direction in the field core 33 than in the rotor core 31.

The stator 4 includes a cylindrical stator core 41 disposed at a predetermined interval radially outward of the rotor core 31, and a stator coil 42 wound around the stator core 41. The stator core 41 is formed by laminating a plurality of electromagnetic steel plates in the axial direction. Since stator core 417 has a gap between electromagnetic steel plates in the axial direction, the magnetic resistance in the axial direction is larger than the magnetic resistance in the radial direction and the circumferential direction. Therefore, in the stator core 41, the magnetic flux is hard to flow in the axial direction, and the magnetic flux is easy to flow in the radial direction and the circumferential direction.

The yoke 5 is made of a magnetic material, and as shown in fig. 1, includes a pair of end wall portions 51A, 51B, an outer wall portion 52, and a pair of inner wall portions 53(53A, 53B), and encloses the rotor 3 and the stator 4. The pair of end wall portions 51A, 51B are annular and are disposed at positions separated from both end portions of the rotor 3 and the stator 4 in the axial direction. The outer wall portion 52 extends axially outward of the coil end 421 of the stator 4, and is formed in a cylindrical shape so as to be continuous with the radially outer peripheral edge portions of the end wall portions 51A and 51B. The pair of inner side walls 53A, 53B are formed in a cylindrical shape so as to be continuous with the radially inner peripheral edge portions of the respective end wall portions 51A, 51B, and are arranged at predetermined intervals from both end portions of the rotor 3 in the axial direction. The inner wall portions 53A and 53B are arranged at predetermined intervals from the shaft 2 in the radial direction.

Fig. 2 is a view of the yoke 5 as viewed from the axial direction. Notch portions 511 are formed in the radial outer peripheral edge portions of the end wall portions 51A, 51B of the yoke 5 at intervals of 120 ° in the circumferential direction. Of the pair of end wall portions 51A, 51B, the 3 cutout portions 511 formed in the end wall portion 51A and the 3 cutout portions 511 formed in the end wall portion 51B are located at positions overlapping in the circumferential direction when viewed from the axial direction. Further, an opening 521 (see fig. 1) extending in the axial direction is formed in the outer wall portion 52 so that the notches 511 of the pair of end wall portions 51A and 51B are connected to each other in the axial direction. Further, through holes 512 are formed in the end wall portions 51A and 51B at positions shifted by 180 ° in the circumferential direction with respect to the notch portions 511.

The excitation coil 6 is provided on the surface of each end wall portion 51A, 51B on the rotor 3 side in the axial direction. The field coil 6 forms a magnetic path between the yoke 5 and the rotor core 31, thereby controlling the magnetic flux between the rotor core 31 and the stator core 41.

As shown in fig. 1, the housing 7 is composed of a pair of end wall portions 71A, 71B, an outer wall portion 72, and a pair of inner wall portions 73A, 73B, and houses the rotor 3, the stator 4, and the yoke 5 therein. Further, the yoke 5 is fixed to the case 7. The case 7 covers the outer peripheral surface and both end surfaces in the axial direction of the yoke 5, and the yoke 5 can be effectively protected by the case 7, but an opening through which the yoke 5 is exposed to the outside may be provided in a part of the case 7. The pair of end wall portions 71A, 71B are annular and are disposed so as to face each other in the axial direction with the pair of end wall portions 51A, 51B of the yoke 5 interposed therebetween. Further, bolt holes 711 into which bolts 10A and 10B as coupling members are inserted are opened in the end wall portions 71A and 71B at positions corresponding to the through holes 512 opened in the end wall portions 51A and 51B of the yoke 5.

In motor 1 according to embodiment 1, outer wall portion 52 of yoke 5 is press-fitted into the inner periphery of outer wall portion 72 of case 7, and outer wall portion 52 of yoke 5 is fixed to outer wall portion 72 of case 7. Thereby, the outer side wall portion 52 of the yoke 5 is supported and reinforced by the outer side wall portion 72 of the case 7. In motor 1 according to embodiment 1, bolts 10A and 10B are inserted into bolt holes 711 provided in end wall portions 71A and 71B of case 7 and through holes 512 provided in end wall portions 51A and 51B of yoke 5, and end wall portions 71A and 71B of case 7 and end wall portions 51A and 51B of yoke 5 are fixed by bolt fastening. Thereby, end wall portions 51A, 51B of yoke 5 are supported and reinforced by end wall portions 71A, 71B of case 7.

As a method of fixing the yoke 5 to the housing 7, any mechanical fixing method such as press fitting, bolt fastening, shrink fitting, and caulking may be used. When the yoke 5 is fixed to the housing 7, it is preferable to use a positioning structure of the yoke 5 with respect to the housing 7 by a locking pin or the like.

The outer wall portion 72 is formed in a cylindrical shape so as to be continuous with the outer peripheral edge portions of the end wall portions 71A and 71B. A projection 721 that projects radially inward and has one end side continuous with the end wall portions 71A and 71B in the axial direction and the other end side contactable with the stator core 41 is provided at a position corresponding to an opening 521 formed in the outer wall portion 52 of the yoke 5 in the inner peripheral surface of the outer wall portion 72. The projection 721 has a bolt hole 722 into which the bolt 11 is inserted, which is opened in the axial direction at a position communicating with the through hole 411 provided in the stator core 41 and penetrating in the axial direction.

In motor 1 according to embodiment 1, stator core 41 is not fixed to yoke 5, and stator core 41 is fixed to case 7. In the motor 1 according to embodiment 1, the bolts 11 are inserted into the through holes 411 provided in the stator core 41 and the bolt holes 722 provided in the protrusions 721 of the housing 7, and the stator core 41 and the outer wall portion 72 of the housing 7 are fixed by bolt fastening. Accordingly, since the stator core 41 is directly fixed to the housing 7 without passing through the yoke 5, the torque reaction force from the stator 4 during operation of the motor 1 does not directly enter the yoke 5. This prevents deformation of the yoke 5 caused by the direct action of the torque reaction force on the yoke 5. Further, since the stator core 41 is directly fixed to the housing 7 without the yoke 5, it is possible to prevent the yoke 5 from being deformed by stress at the time of coupling that may occur when the yoke 5 and the stator 4 are directly fixed by press-fitting or the like.

The pair of inner wall portions 73A and 73B of the housing 7 are respectively connected to radially inner peripheral portions of the end wall portions 71A and 71B to form a cylindrical shape, and are arranged at predetermined intervals from both end portions of the rotor 3 in the axial direction. The inner wall portions 73A and 73B are arranged at predetermined intervals in the radial direction with respect to the inner wall portions 53A and 53B of the yoke 5 and the shaft 2. At this time, the predetermined interval between the inner wall portions 73A and 73B and the shaft 2 is wider than the predetermined interval between the inner wall portions 73A and 73B and the inner wall portions 53A and 53B of the yoke 5. Ball bearings 8A and 8B are provided on the inner peripheries of the inner side walls 73A and 73B, respectively, and the shaft 2 and the housing 7 inserted through the ball bearings 8A and 8B are rotatable relative to each other by the ball bearings 8A and 8B. Further, seal members 9A and 9B of different shapes, which are inserted through the shaft 2 and seal the space between the inner wall portions 73A and 73B and the shaft 2, are provided on the outer sides in the axial direction of the ball bearings 8A and 8B, respectively.

In the motor 1 according to embodiment 1, since the housing 7 is supported by the shaft 2 via the ball bearings 8A and 8B, the radial force from the ball bearings 8A and 8B does not directly enter the yoke 5 when the motor 1 is operated. This prevents the yoke 5 from being deformed by the force in the radial direction from the ball bearings 8A and 8B directly entering the yoke 5.

As described above, in the motor 1 according to embodiment 1, it is possible to prevent the yoke 5 from being damaged or deformed due to the direct force acting on the yoke 5. This ensures the reliability of the yoke 5, and suppresses deterioration of loss due to strain in the yoke 5. In addition, since the yoke 5 can be prevented from being deformed by force, the insulating performance can be maintained. The gap between rotor core 31 and yoke 5 is stable in size, and the excitation effect can be stabilized. Further, since the cores of the stator 4 and the rotor 3 are drawn out through the housing 7, the gap between the stator 4 and the rotor 3 is stable in size, and the torque output from the motor 1 can be stabilized. Further, since the stator 4 is fixed to the housing 7 separately from the yoke 5, the stator 4 can be easily assembled to the housing 7.

In embodiment 1, the inner rotor type motor 1 in which the rotor 3 is disposed radially inside the stator 4 has been described, but the outer rotor type motor 1 in which the rotor 3 is disposed radially outside the stator 4 may be used.

(embodiment mode 2)

Next, a motor 1 according to embodiment 2 of the present invention will be described. Note that, in the motor 1 according to embodiment 2, portions common to the motor 1 according to embodiment 1 are appropriately omitted from description.

Fig. 3 is a sectional view of the motor of embodiment 2. Fig. 3 shows a radial half of the motor 1 bounded by the axis of the shaft 2. In the motor 1 according to embodiment 2, the housing 7 that houses the rotor 3, the stator 4, and the yoke 5 is configured by a pair of annular end wall portions 71A and 71B and a cylindrical outer wall portion 72, and does not have the inner wall portions 73A and 73B of the housing 7 of the motor 1 according to embodiment 1. In the motor 1 according to embodiment 2, as shown in fig. 3, ball bearings 8A and 8B are provided on the inner peripheries of the inner side walls 53A and 53B of the yoke 5, respectively, and the ball bearings 8A and 8B are supported by the yoke 5. Therefore, when the motor 1 is operated, the radial force from the ball bearings 8A and 8B directly acts on the yoke 5.

On the other hand, in the motor 1 of embodiment 2, as in the motor 1 of embodiment 1, the bolts 10A and 10B are inserted through the bolt holes 711 provided in the end wall portions 71A and 71B of the housing 7 and the through holes 512 provided in the end wall portions 51A and 51B of the yoke 5, and the end wall portions 71A and 71B of the housing 7 and the end wall portions 51A and 51B of the yoke 5 are fixed by bolt fastening. End wall portions 51A and 51B of yoke 5 are thereby supported by end wall portions 71A and 71B of case 7, and yoke 5 is reinforced by case 7. Thus, even if the radial force from the ball bearings 8A and 8B is directly applied to the yoke 5 during the operation of the motor 1, the yoke 5 can be prevented from being deformed.

Description of the reference symbols

1 electric motor

2 axle

3 rotor

4 stator

5 magnetic yoke

6 excitation coil

7 casing

8A, 8B ball bearing

9A, 9B seal member

10A, 10B bolt

11 bolt

31 rotor core

32 magnet

33 excitation core

41 stator core

42 stator coil

52 outer side wall part

51A, 51B end wall portions

53A, 53B inner wall part

72 outer side wall part

71A, 71B end wall portions

73A, 73B inner wall part

411 through hole

421 coil end

511 notch part

512 through hole

711 bolt hole

722 bolt holes.