CN117914048A - Rotary electric machine - Google Patents

Abstract

The invention provides a rotating electrical machine capable of preventing poor formation of an insulator. The second insulator includes: a second core end surface coating portion that covers the other axial end surface of the core body (21); and a second skirt portion extending from the second core end surface coating portion toward the axial center of the core body (21). The second skirt includes: a core side surface coating part (66) which covers the inner peripheral surface of the core body (21); and a tooth side surface coating part (72) for coating the circumferential side surface (28 b) of the tooth body (28). A side thick portion (91) and a center thick portion (92) which are thicker than the wall thickness of the core side surface coating portion (66) are formed on the core side surface coating portion (66). Each thick portion (91, 92) is formed over the entire axial direction of the core side surface coating portion (66).

Description

Rotary electric machine

Technical Field

The present invention relates to a rotating electrical machine.

Background

As the rotary electric machine, for example, an electric motor is cited. The electric motor includes, for example: a stator around which a coil is wound; and a rotor rotatably provided with respect to the stator and having a permanent magnet. The stator is formed of a magnetic body. The stator has an annular core body and teeth protruding radially from the core body. The coil is wound from the insulator to the tooth. The insulator is formed of a resin having insulating properties. Insulation of the teeth from the coil is achieved by an insulator.

With this structure, when the coil is energized, a magnetic field is formed in the tooth. A magnetic attraction force or a repulsive force is generated between the magnetic field and the permanent magnet, and the rotor continuously rotates.

The insulator is often divided in the axial direction so as to surround the tooth portion, and is attached from both sides in the axial direction of the core body. Each insulator is integrally formed with a core end face coating portion (annular portion) that covers an axial end face of the core body, and a skirt portion (projection) that extends from the core end face coating portion toward an axial center of the core body. The skirt portion covers the periphery of the tooth portion and the peripheral surface of the core body. In the case of injection molding such an insulator with a resin, for example, a molten resin is injected from the core end face coating portion.

[ Prior Art literature ]

[ Patent literature ]

[ Patent document 1] Japanese patent laid-open No. 2018-7427

Disclosure of Invention

[ Problem to be solved by the invention ]

However, in the above-described conventional art, in the structure in which the skirt portion extends from the core end surface coating portion, it is difficult for the molten resin to spread over the entire skirt portion. Therefore, there is a possibility that molding failure of the insulator may occur.

Accordingly, the present invention provides a rotary electric machine capable of preventing defective molding of an insulator.

[ Means of solving the problems ]

In order to solve the problem, in a first embodiment of the present invention, a rotary electric machine includes: a stator core having an annular core body and a plurality of teeth protruding radially from the core body; two insulators which are installed on the stator core from two axial sides and made of resin; and a coil wound from an insulator to the tooth, the insulator including: a core end surface coating portion that covers an axial end surface of the core body; and a skirt portion extending from the core end face cladding portion toward an axial center of the core body, the skirt portion including: a core side surface coating portion covering the peripheral surface of the core body; and a tooth side surface coating portion that covers a circumferential side surface of the tooth, wherein a plurality of thick wall portions that are thicker than a wall of the core side surface coating portion are formed in the core side surface coating portion, and the thick wall portions are formed throughout an axial direction of the core side surface coating portion.

Thus, by effectively forming the thick portion instead of simply forming the thick portion, the molten resin can be spread over the entire skirt portion. Therefore, poor molding of the insulator can be prevented.

In a second embodiment of the present invention, according to the rotating electrical machine of the first embodiment, the plurality of teeth protrude from the core body toward the radial inside, the thick wall portion is formed with three, the thick wall portion has: the wall thickness of the side thick-wall portion changes so as to gradually protrude from the central thick-wall portion side toward the circumferential outside and the wall thickness of the central thick-wall portion changes so as to gradually protrude from the circumferential both sides of the central thick-wall portion toward the circumferential center and the outside.

With this configuration, the molten resin can be reliably spread over the entire skirt portion. The winding space of the coil is not obstructed by the thick portion. Therefore, the space factor of the coil can be prevented from being reduced.

In a third embodiment of the present invention, the rotating electrical machine according to the first or second embodiment, wherein the tooth portion has a tooth portion body extending in a radial direction, and a flange portion extending in a circumferential direction from a radially inner end of the tooth portion body, and the insulator has a flange side surface coating portion protruding from a radial end of the tooth portion side surface coating portion and covering an outer peripheral surface of the flange portion, and the central thick-wall portion is disposed between the flange portion and the flange side surface coating portion adjacent in the circumferential direction as viewed in the radial direction.

With this structure, the coil is not easily arranged between the flange portion and the flange side surface coating portion adjacent to each other in the circumferential direction when viewed in the radial direction. By disposing the central thick portion at such a position, the space factor of the coil can be reliably prevented from being lowered.

In a fourth embodiment of the present invention, the rotating electrical machine according to any one of the first to third embodiments, wherein a wall thickness of the core side surface coating portion other than the thick wall portion and a wall thickness of the tooth side surface coating portion are the same.

With this configuration, the skirt portion can be set to two different wall thickness modes. Thus, the shape of the skirt portion can be simplified as much as possible.

In a fifth embodiment of the present invention, the rotating electrical machine according to any one of the first to third embodiments, the core side surface coating portion has: two first side coating portions extending from a circumferential center between the tooth side coating portions adjacent in a circumferential direction toward the tooth side coating portions; and two second side surface coating portions which extend from the first side surface coating portions toward the tooth portion side surface coating portions in a bending manner, are connected to the tooth portion side surface coating portions, wherein an angle between the two first side surface coating portions is larger than an angle between the first side surface coating portions and the second side surface coating portions, and a connecting portion of the first side surface coating portions and the second side surface coating portions is located on a straight line parallel to the circumferential side surface of the tooth portion body and passing through the circumferential end portion of the flange side surface coating portion, and the side thick wall portion is formed at an end portion of the first side surface coating portion on the second side surface coating portion side.

With this configuration, the thick portions can be arranged in an appropriate number at appropriate positions. Thus, the molten resin can be effectively spread over the entire skirt portion to the maximum extent with a small number of thick portions. Therefore, poor molding of the insulator can be prevented.

[ Effect of the invention ]

According to the present invention, poor molding of the insulator can be prevented.

Drawings

Fig. 1 is a perspective view of a motor with a speed reducer according to an embodiment of the present invention.

Fig. 2 is a sectional view taken along line II-II of fig. 1.

Fig. 3 is a perspective view of a stator in an embodiment of the present invention.

Fig. 4 is a plan view of the stator in the embodiment of the present invention as viewed from the axial direction, showing a state in which the terminal bracket is removed.

Fig. 5 is a partially enlarged plan view of the stator core in the embodiment of the present invention as viewed from the axial direction.

Fig. 6 is a perspective view of an insulator in an embodiment of the invention.

Fig. 7 is a perspective view of the first insulator in the embodiment of the present invention as viewed from above.

Fig. 8 is a perspective view of the second insulator in the embodiment of the present invention as seen from below.

Fig. 9 is a perspective view of the second insulator in the embodiment of the present invention as viewed from above.

Fig. 10 is a partially enlarged plan view of the second insulator mounted to the stator core in the embodiment of the present invention as viewed from the first insulator side.

[ Description of symbols ]

1: Motor with speed reducer

2: Electric motor

3: Speed reducing unit

4: Controller for controlling a power supply

5: Motor shell

6: First motor housing

6A: an opening part

7: Second motor housing

7A: an opening part

8: Stator

9: Rotor

10: Bottom part

10A: through hole

11: Connector with a plurality of connectors

16: Outer flange part

17: Outer flange part

19: An inner peripheral surface

19A: first perimeter

19B: a second peripheral surface

20: Stator core

20P: electromagnetic steel sheet

21: Core body

21A: an end surface

21B: another end face

22: Tooth part

22A: specific tooth

23: Fixing part

23A: bolt insertion hole

24: Coil

24A: end portion

25: Bolt

26: Insulator

27: Groove(s)

28: Tooth body

28A: front end of tooth

28B: circumferential side face

29: Flange part

31: Shaft

32: Rotor core

32A: magnet cover

40: Gear box

40A: an opening part

40B: side wall

40C: bottom wall

41: Worm speed reducing mechanism

42: Gear housing part

43: An opening part

44: Worm shaft

45: Worm wheel

46: Bearing

47: Bearing

48: Output shaft

48A: spline

49: Bearing boss

50: Magnetic detection element

51: Controller substrate

52: Convex rib

53: Cover for vehicle

61: First insulator (insulator)

62: Second insulator (insulator)

63: Core body cladding

64: Tooth coating part

64A: specific tooth coating part

65: First core end surface coating part (core end surface coating part)

65A: abutment surface

66: Core side cladding

66A: first side covering part

66B: second side surface coating part

66C: connecting part

66D: front end part

66E: central connection part

67: Outer wall portion

68: Introduction slit

69: Extraction slit

70: Coil accommodating recess

71: Tooth end surface coating part

72: Tooth side surface coating part

72A: long tooth side surface coating part

72B: short tooth side surface coating part

73: Flange side cladding

73A: circumferential end portion

74: Inner wall portion

77: Coil lead-out part

78: Coil guiding recess

78A: coil holding claw

79: First skirt portion (skirt portion)

79A: front end part

79B: outer side surface

82A: press-in convex part

82B: press-in convex part

83: Outer wall portion

85: Terminal support

86: Terminal for connecting a plurality of terminals

87: Bracket body

87A: terminal accommodating recess

88: Cover part

88A: end face mask part

88B: outer Zhou Zhao part

88C: cut-out portion

91: Side thick wall part

91A: inner side surface

91B: inclined surface

92: Central thick wall part

92A: inner side surface

93: Concave part

93A: bottom surface

93B: side surface

262: Second insulator

264: Tooth coating part

265: Second core end surface coating part (core end surface coating part)

265A: abutment surface

279: Second skirt portion (skirt portion)

279A: front end part

C1: axis of rotation

C2: circumferential center

And C3: circumferential center

G: injection gate mark

O: gap of

L1: length of

L2: length of

S: straight line

T1: wall thickness

T2: wall thickness

Θ1: angle of

Θ2: angle of

Θ3: angle of

Θ4: angle of

Detailed Description

Next, embodiments of the present invention will be described based on the drawings.

Motor with speed reducer

Fig. 1 is a perspective view of a motor 1 with a speed reducer. Fig. 2 is a sectional view taken along line II-II of fig. 1.

The motor 1 with a speed reducer is used as a drive source of a wiper device for a vehicle, for example.

As shown in fig. 1 and 2, the motor 1 with a speed reducer includes an electric motor 2, a speed reduction unit 3 that reduces the rotation of the electric motor 2 and outputs the reduced rotation, and a controller 4 that controls the driving of the electric motor 2.

In the following description, the term "axial direction" refers to a direction parallel to the central axis of the shaft 31 of the electric motor 2 (the rotation axis C1 of the electric motor 2). In the case of simply referred to as "circumferential direction", it means the circumferential direction (rotational direction) of the shaft 31. In the case of simply referred to as "radial direction", the radial direction of the shaft 31 orthogonal to the axial direction and the circumferential direction is referred to.

< Electric Motor >)

The electric motor 2 includes: a motor housing 5; a cylindrical stator 8 accommodated in the motor case 5; and a rotor 9 disposed radially inward of the stator 8 and rotatably provided with respect to the stator 8. The electric motor 2 is a so-called brushless motor that does not require a brush when supplying electric power to the stator 8.

Motor housing

The motor case 5 is made of a material having excellent heat dissipation properties such as aluminum alloy. The motor housing 5 includes a first motor housing 6 and a second motor housing 7 which are formed so as to be separable in the axial direction. The first motor housing 6 and the second motor housing 7 are formed in a bottomed cylinder shape, respectively.

The bottom 10 of the first motor housing 6 is integrally formed with the gear box 40 of the reduction unit 3. At the radial center of the bottom 10, a through hole 10a through which the shaft 31 of the electric motor 2 can be inserted is formed. An outer flange 16 and an outer flange 17 extending radially outward are formed in the openings 6a and 7a of the first motor case 6 and the second motor case 7, respectively. The outer flange portions 16 and 17 are abutted against each other, and the first motor housing 6 and the second motor housing 7 are integrated by bolts 25. The motor housing 5 has an internal space enclosed by the first motor housing 6 and the second motor housing 7, and a stator 8 and a rotor 9 are accommodated in the internal space.

< Rotor >)

The rotor 9 is rotatably disposed inside the stator 8 in the radial direction through a minute gap. The rotor 9 includes a shaft 31, a cylindrical rotor core 32 fitted and fixed to the shaft 31, a plurality of magnets not shown assembled on the outer peripheral portion of the rotor core 32, and a magnet cover 32a covering the rotor core 32 from above the magnets.

The shaft 31 is integrally formed with a worm shaft 44 constituting the speed reducing portion 3. However, the worm shaft 44 is not limited thereto, and may be formed separately from the shaft 31 and connected to an end of the shaft 31. The shaft 31 and the worm shaft 44 are rotatably supported by the gear case 40 via a bearing 46 and a bearing 47. The shaft 31 and the worm shaft 44 rotate about the rotation axis C1. Further, ferrite magnets are used as the magnets, for example. However, the present invention is not limited thereto, and a neodymium bond magnet, a neodymium sintered magnet, or the like can be applied to the magnet.

< Speed reduction portion >)

The speed reducing section 3 includes: a gear case 40 integrated with the motor housing 5; and a worm reduction mechanism 41 housed in the gear case 40. The gear case 40 is formed of a metal material having excellent heat dissipation properties such as an aluminum alloy. The gear case 40 is formed in a box shape having an opening 40a on one surface. The gear case 40 has a gear housing portion 42 that houses the worm reduction mechanism 41 therein. Further, in the side wall 40b of the gear case 40, an opening 43 is formed at a portion where the first motor housing 6 is integrally formed, the through hole 10a of the first motor housing 6 and the gear housing 42 are communicated.

A cylindrical bearing boss 49 is formed to protrude from the bottom wall 40c of the gear case 40. The bearing boss 49 rotatably supports the output shaft 48 of the worm reduction mechanism 41, and a sliding bearing, not shown, is disposed on the inner peripheral side. An O-ring, not shown, is attached to the inner peripheral surface of the distal end portion of the bearing boss 49. Further, a plurality of ribs 52 for securing rigidity are provided on the outer peripheral surface of the bearing boss 49.

The worm reduction mechanism 41 accommodated in the gear accommodating portion 42 includes: a worm shaft 44 integrally formed with the shaft 31 of the rotor 9; and a worm wheel 45 engaged with the worm shaft 44. Both axial ends of the worm shaft 44 are rotatably supported by the gear case 40 about the rotation axis C1 via bearings 46 and 47. The worm wheel 45 is coaxially and integrally provided with an output shaft 48 of the electric motor 2. The worm wheel 45 and the output shaft 48 are disposed such that their rotation axes are orthogonal to the rotation axis C1 of the worm shaft 44 (the shaft 31 of the electric motor 2). The output shaft 48 protrudes to the outside via a bearing boss 49 of the gear case 40. A spline 48a that can be connected to an object to be driven by a motor is formed at the protruding tip of the output shaft 48.

Further, a sensor magnet, not shown, is provided in the worm wheel 45. The sensor magnet detects a position by a magnetic detection element 50 described later provided in the controller 4. That is, the rotational position of the worm wheel 45 is detected by the magnetic detection element 50 of the controller 4.

Controller

The controller 4 has a controller substrate 51 on which the magnetic detection element 50 is mounted. The controller board 51 is disposed in the opening 40a of the gear case 40 so that the magnetic detection element 50 faces the sensor magnet of the worm wheel 45. The opening 40a of the gear case 40 is closed by a cover 53.

The controller board 51 is electrically connected to a coil 24 of the stator 8, which will be described later. Further, terminals of the connector 11 (see fig. 1) provided in the cover 53 are electrically connected to the controller board 51. The controller board 51 is provided with a power module (not shown) including a switching element such as a field effect Transistor (FIELD EFFECT Transistor, FET) for controlling a drive voltage supplied to the coil 24, a capacitor (not shown) for smoothing a voltage, and the like, in addition to the magnetic detection element 50.

Stator and terminal bracket

Fig. 3 is a perspective view of the stator 8. Fig. 4 is a plan view of the stator 8 as seen from the axial direction, showing a state in which the terminal holder 85 is removed.

As shown in fig. 3 and 4, the stator 8 includes: a cylindrical stator core 20 having a central axis coincident with the rotation axis C1; an insulator 26 mounted to the stator core 20; and a plurality of coils 24 of a three-phase (U-phase, V-phase, W-phase) structure wound from the insulator 26 to the stator core 20.

A terminal bracket 85 is provided on the stator core 20. The terminal holder 85 is integrally formed with a terminal 86, a holder body 87 holding the terminal 86, and a cover 88 covering one axial end of the stator core 20. The terminals 86 are connected to the distal end portions 24a of the coils 24 of the respective phases, and are connected to connectors, not shown, extending from the controller board 51.

The cover 88 is integrally formed with: an annular end face cover portion 88a disposed opposite to each other in the axial direction of the stator core 20, and an outer peripheral cover portion 88b extending from the outer peripheral edge of the end face cover portion 88a toward the stator core 20 side and covering the insulator 26 from the radial outside.

The bracket body 87 is formed to stand from a part of the end face cover 88a toward the opposite side to the stator core 20. The end cover portion 88a and the outer peripheral cover portion 88b have cut portions 88c in a cut-away form at portions corresponding to the holder body 87.

The holder body 87 is formed in a rectangular parallelepiped shape which is long in the axial direction and the circumferential direction. A connector, not shown, extending from the controller board 51 is attached to the holder body 87. Three terminal accommodating recesses 87a aligned in the longitudinal direction as viewed from the axial direction are formed in the holder body 87. The terminal 86 is accommodated and held in the terminal accommodating recess 87a. The terminals 86 are connected to connectors, not shown, extending from the controller board 51.

Fig. 5 is a partially enlarged plan view of the stator core 20 as viewed from the axial direction. Fig. 5 illustrates only a first insulator 61 described later, which is mounted on the insulator 26 of the stator core 20. Fig. 5 shows the stator core 20 as viewed from the side of a second insulator 62, which will be described later, among the insulators 26.

As shown in fig. 3 to 5, the stator core 20 is formed by laminating a plurality of electromagnetic steel plates 20 p. However, the present invention is not limited thereto, and for example, the stator core 20 may be formed by press molding soft magnetic powder.

The stator core 20 has: the core member includes a cylindrical core body 21, a plurality of (six in the present first embodiment) teeth 22 protruding radially inward from an inner peripheral surface 19 of the core body 21, and two fixing portions 23 integrally formed on an outer peripheral surface of the core body 21.

The inner peripheral surface 19 of the core body 21 is not circular arc-shaped but slightly polygonal. That is, the inner peripheral surface 19 of the core body 21 has: two first peripheral surfaces 19a extending from a circumferential center C2 between circumferentially adjacent teeth 22 toward the teeth 22; and two second peripheral surfaces 19b extending further from the first peripheral surface 19a toward the tooth portion 22 and connected to the root portion of the tooth portion 22. The angle θ1 between the two first peripheral surfaces 19a is larger than the angle θ2 between the first peripheral surface 19a and the second peripheral surface 19 b.

The tooth 22 includes: a tooth body 28 protruding radially from the inner peripheral surface 19 of the core body 21; and a flange portion 29 integrally formed with a tooth tip portion 28a, which is a radially inner end of the tooth body 28 opposite to the core body 21. The two circumferential sides 28b of the tooth body 28 are parallel and parallel with respect to the radial direction. The coil 24 is wound from the insulator 26 to the dental body 28.

The flange portion 29 extends in the circumferential direction. The inner peripheral surface of the flange 29 is formed along a circle centered on the rotation axis C1. Between the teeth 22 adjacent in the circumferential direction, a groove 27 having a dovetail shape as viewed in the axial direction is formed by the inner peripheral surface of the core body 21, the circumferential side surface 28b of the tooth body 28, and the outer peripheral surface of the flange 29.

The fixing portions 23 protrude radially outward from the outer peripheral surface of the core body 21 and are disposed at 180 ° intervals in the circumferential direction. The fixing portion 23 is formed with a bolt insertion hole 23a penetrating in the axial direction.

According to this structure, the outer peripheral surface of the core body 21 is fitted and accommodated in the inner peripheral surface of the first motor case 6. Then, a self-tapping screw, not shown, is inserted into the bolt insertion hole 23a of the fixing portion 23, and the self-tapping screw is screwed into the bottom portion 10 of the first motor housing 6, whereby the stator core 20 is fastened and fixed to the first motor housing 6. The second motor housing 7 is fitted over the stator core 20 thus fixed. The second motor housing 7 is fixed to the first motor housing 6.

< Insulator >)

Fig. 6 is a perspective view of the insulator 26. Fig. 6 shows the insulator 26 in a state of being attached to the stator core 20.

The insulator 26 is used to insulate the stator core 20 from the coil 24, and is injection molded from a resin having insulation properties.

As shown in fig. 6, the insulator 26 is formed so as to be divided into two in the axial direction so as to be attached from both sides in the axial direction of the stator core 20. That is, the insulator 26 includes: a first insulator 61 mounted from one (upper in fig. 5) side in the axial direction of the stator core 20, and a second insulator 62 mounted from the other (lower in fig. 5) side in the axial direction of the stator core 20.

Hereinafter, for the sake of understanding, the description will be given with the first insulator 61 side set up as the upper side and the second insulator 62 side set down as the lower side (the same applies to the second embodiment below).

< First insulator >)

First, the first insulator 61 is explained based on fig. 5 to 7.

Fig. 7 is a perspective view of the first insulator 61 from above.

As shown in fig. 5 to 7, the first insulator 61 is integrally formed with a core body coating portion 63 that covers the core body 21 and a tooth coating portion 64 that covers the tooth 22. The core body coating portion 63 includes: an annular first core end surface coating portion 65 covering the axial one end surface 21a of the core body 21; a core side surface coating portion 66 protruding downward from an abutment surface 65a of the first core end surface coating portion 65 with the core body 21; and a cylindrical outer wall portion 67 protruding upward from the contact surface 65a of the first core end surface coating portion 65.

The core side surface coating portion 66 is disposed on the inner peripheral edge of the first core end surface coating portion 65. The core side surface coating portion 66 is formed along the inner peripheral surface 19 of the core body 21 and covers the inner peripheral surface 19. The core side surface coating portion 66 is slightly formed in a polygonal shape so as to correspond to the shape of the inner peripheral surface 19 of the core main body 21. That is, the core side surface coating portion 66 has: two first side coating portions 66a extending from a circumferential center C3 between the tooth coating portions 64 adjacent in the circumferential direction toward the tooth coating portions 64; and two second side coating portions 66b extending further from the first side coating portion 66a toward the tooth coating portion 64 and connected to the tooth coating portion 64. Hereinafter, the connection portion (circumferential center C3) of the two first side cover portions 66a is sometimes referred to as a center connection portion 66e.

The angle θ3 between the two first side coating portions 66a (the angle of the central connecting portion 66 e) is the same as the angle θ1 between the two first peripheral surfaces 19 a. The angle θ4 between the first side surface coating portion 66a and the second side surface coating portion 66b is the same as the angle θ2 between the first peripheral surface 19a and the second peripheral surface 19 b. That is, the angle θ3 between the two first side cladding portions 66a is greater than the angle θ4 between the first side cladding portions 66a and the second side cladding portions 66 b.

The connection portion 66c between the first side surface coating portion 66a and the second side surface coating portion 66b is located on a straight line S that is parallel to the circumferential side surface 28b of the tooth body 28 and passes through a circumferential end 73a of a flange side surface coating portion 73 described later.

The outer wall portion 67 is disposed near the outer periphery of the first core end surface coating portion 65. An outer peripheral cover portion 88b of the terminal holder 85 is disposed radially outward of the outer wall portion 67.

At the outer wall 67, a lead-in slit 68 and a lead-out slit 69 are formed at positions corresponding to the tooth coating portions 64, respectively.

The introduction slit 68 is used to introduce the coil 24 from the radially outer side to the radially inner side of the outer wall portion 67. The lead slit 69 serves to lead the coil 24 from the radially inner side to the radially outer side of the outer wall portion 67.

The coil lead-out portion 77 is integrally formed at the root of a tooth covering portion 64A (hereinafter, the tooth covering portion 64A is referred to as a specific tooth covering portion 64A) covering a specific tooth 22A (see fig. 4, hereinafter, the tooth 22A is referred to as the specific tooth 22A) among the plurality of teeth 22 in the first core end surface covering portion 65 and the outer wall portion 67.

The coil lead-out portion 77 is a portion that leads out the end portion 24a (see fig. 3 and 4) of the coil 24 of each phase to the upper side. The terminal holder 85 is disposed such that the cut-out portion 88c of the terminal holder 85 is fitted into the coil lead-out portion 77. That is, the terminals 86 of the terminal holder 85 are arranged directly above the coil lead-out portion 77.

The coil lead portion 77 includes a plurality of (for example, three for the coil 24 of the first embodiment) coil guide recesses 78 for restricting lead portions of the end portions 24a of the coils 24 of each phase. The coil guide recesses 78 are arranged in a circumferential direction so as to be gathered. A coil holding claw 78a protruding in the circumferential direction is integrally formed in each coil guide recess 78. The distal end portions 24a of the coils 24 of the respective phases are led upward through the coil guide recesses 78. The distal end 24a of each of the coils 24 drawn out is guided to the terminal 86 of the terminal bracket 85 while being held by the coil holding claw 78a, and is connected to the terminal 86.

The tooth coating portion 64 includes: the tooth end surface coating portion 71 which extends from the first core end surface coating portion 65 in the surface direction of the first core end surface coating portion 65 and is long in the radial direction, a tooth side surface coating portion 72 which protrudes downward from both circumferential sides (both ends in the short side direction) of the tooth end surface coating portion 71, a flange side surface coating portion 73 which protrudes outward in the circumferential direction from the radially inner side end of the tooth side surface coating portion 72, and an inner wall portion 74 which is joined to the radially inner side end of the tooth end surface coating portion 71 and the upper end of the flange side surface coating portion 73 and extends upward from the upper end of the flange side surface coating portion 73.

The tooth end surface coating portion 71 covers the upper end of the tooth body 28. The tooth side surface coating portion 72 covers the circumferential side surface of the tooth body 28 in the tooth 22. The two tooth side surface coating portions 72 are parallel to correspond to the circumferential side surface 28b of the tooth body 28. The second side coating portion 66b is connected to the radially outer end of the tooth side coating portion 72. The two tooth side surface coating portions 72 are formed of a long tooth side surface coating portion 72a having a length longer than the longest portion in the axial direction, and a short tooth side surface coating portion 72b having a length shorter than the long tooth side surface coating portion 72a in the axial direction. In the following description, the length of the axially longest portion of each of the tooth side surface coating portions 72a, 72b is simply referred to as the axial length of each of the tooth side surface coating portions 72a, 72 b.

The flange side surface coating portion 73 covers the outer peripheral surface of the flange portion 29 in the tooth portion 22.

These tooth side surface coating portions 72 (long tooth side surface coating portions 72a and short tooth side surface coating portions 72 b) and flange side surface coating portions 73 are formed so as to be continuous with the core side surface coating portion 66 of the core main body coating portion 63, and constitute a cylindrical first skirt portion 79 protruding downward from the tooth end surface coating portion 71 and the first core end surface coating portion 65. That is, the first skirt 79 is interposed between the grooves 27 of the stator core 20.

The front end 79a, which is the lower end of the first skirt portion 79, i.e., the front end 66d of the core side surface coating portion 66 is formed obliquely so as to smoothly connect the front end of the long tooth side surface coating portion 72a and the front end of the short tooth side surface coating portion 72 b. That is, the front end 79a of the first skirt portion 79 (the front end 66d of the core side surface coating portion 66) is formed so as to be inclined such that the protruding height from the tooth end surface coating portion 71 and the first core end surface coating portion 65 gradually changes in the circumferential direction. By forming the first insulator 61 obliquely, the first skirt portion 79 is gradually inserted into each tooth portion 22 when the first insulator is attached to the stator core 20. Therefore, the insertion (attachment) of the first insulator 61 to the stator core 20 (tooth 22) is improved.

A pair of press-fitting protrusions 82a and 82b are formed on the outer surface 79b (the tooth side surface coating portion 72, the flange side surface coating portion 73, and the stator core 20 side surface of the core side surface coating portion 66) of the first skirt portion 79, near the tooth side surface coating portion 72 of the core side surface coating portion 66. The pair of press-fitting protrusions 82a, 82b are disposed on both sides in the circumferential direction with the tooth covering portion 64 interposed therebetween. The press-fitting convex portions 82a and 82b are used for press-fitting and mounting when the first insulator 61 is mounted on the stator core 20. The press-fitting convex portions 82a and 82b can prevent the first insulator 61 from falling off the stator core 20.

The pair of press-fitting convex portions 82A, 82b are arranged at equal intervals in the circumferential direction in every other tooth covering portion 64 except for the portion corresponding to the specific tooth 22A. In the first embodiment, since six teeth 22 (tooth coating portions 64) are provided, a pair of press-fitting protrusions 82a and 82b are provided at positions corresponding to three tooth coating portions 64 disposed at equal intervals in the circumferential direction except for a specific tooth coating portion 64A.

In the first insulator 61, an injection gate mark G is formed on the inner peripheral surface of each inner wall 74. The injection gate mark G is a resin injection mark formed at the time of injection molding of the first insulator 61.

< Second insulator >)

Next, the second insulator 62 is explained based on fig. 6, 8 to 10.

Fig. 8 is a perspective view of the second insulator 62 in the insulator 26 as seen from below. Fig. 9 is a perspective view of the second insulator 62 in the insulator 26 as viewed from above. Fig. 10 is a partially enlarged plan view of the second insulator 62 attached to the stator core 20 as viewed from the first insulator 61 side.

As shown in fig. 6 and 8 to 10, the second insulator 62 is substantially line-symmetrical to the first insulator 61 with respect to the axial center (vertical center) of the stator core 20. Thus, the basic structure of the second insulator 62 is substantially the same as that of the first insulator 61. Therefore, in the following description, the same structure as that of the first insulator 61 in the second insulator 62 is denoted by the same name as that of the first insulator 61, and the same reference numerals are given thereto, and the description thereof is omitted. In the second insulator 62, the same structure as the first insulator 61 but different from the first insulator 61 will be described, and the description will be made basically by the same names for the convenience of understanding the description.

That is, the second insulator 62 is integrally formed with the core body covering portion 63 covering the core body 21 and the tooth portion covering portion 264 covering the tooth portion 22. The core body coating portion 63 includes: an annular second core end surface coating portion 265 covering the axial other end surface 21b of the core body 21; a core side surface coating portion 66 protruding upward from an abutment surface 265a of the second core end surface coating portion 265 with the core body 21; and a cylindrical outer wall portion 83 protruding downward from the contact surface 265a of the second core end surface coating portion 265.

The first insulator 61 is different from the second insulator 62 in that the coil lead-out portion 77 is formed in the first core end surface coating portion 65 and the outer wall portion 67 of the first insulator 61, whereas the coil lead-out portion 77 is not formed in the second core end surface coating portion 265 and the outer wall portion 83 of the second insulator 62.

That is, the second core end surface coating portion 265 and the outer wall portion 83 have a simpler structure than the first core end surface coating portion 65 and the outer wall portion 67 of the first insulator 61, and have a uniform shape throughout the entire circumference.

The second skirt portion 279 of the second insulator 62 is formed of the tooth side surface coating portion 72 (the long tooth side surface coating portion 72a and the short tooth side surface coating portion 72 b), the flange side surface coating portion 73, and the core side surface coating portion 66 of the core body coating portion 63. The distal end portion 279a of the second skirt portion 279 is formed so as to extend in the inclined direction of the distal end portion 79a of the first skirt portion 79 of the first insulator 61. Therefore, when the first insulator 61 and the second insulator 62 are attached from both axial sides of the stator core 20, the width of the gap O (see fig. 6) between the front end 79a of the first skirt portion 79 and the front end 279a of the second skirt portion 279, which are abutted against each other, is fixed.

The injection gate mark G of the second insulator 62 is also similar to the first insulator 61. That is, the second insulator 62 has an injection gate mark G formed on the inner peripheral surface of each inner wall 74.

The insulator 26 (the first insulator 61 and the second insulator 62) configured as described above has the coil accommodating recess 70 formed by the second side surface coating portion 66b, the tooth side surface coating portion 72 (the long tooth side surface coating portion 72a and the short tooth side surface coating portion 72 b) and the flange side surface coating portion 73 in the core side surface coating portion 66. The coil 24 wound around each tooth 22 from the insulator 26 is accommodated in the coil accommodating recess 70 (see also fig. 4).

The second skirt portion 279 has a longer length at the axially longest portion than the first skirt portion 79. The axially longest portions of the first skirt portion 79 and the second skirt portion 279 are the long tooth side surface coating portions 72a, respectively. In the following description, the length of the portion of the first skirt portion 79 that is longest in the axial direction is simply referred to as the length of the first skirt portion 79. The length of the second skirt portion 279 at the axially longest portion is simply referred to as the length of the second skirt portion 279.

Two side thick portions 91 and one central thick portion 92 are formed in the core side surface coating portion 66 of the second skirt portion 279.

Two side thick-wall portions 91 are formed at the end portion of the first side coating portion 66a on the second side coating portion 66b side (the end portion on the connecting portion 66c side), respectively. The side thick portion 91 is formed over the entire axial direction of the core side surface coating portion 66.

The inner side surface 91a of the side thick portion 91 is parallel to the outer side surface of the second side surface coating portion 66b constituting the outer side surface of the side thick portion 91. In this way, the portion where the inner side surface 91a is parallel to the outer side surface becomes the maximum thick portion of the side thick portion 91.

An inclined surface 91b is formed on the side of the circumferential center C3 between the tooth coating portions 64 on the inner side surface 91a of the side thick portion 91. The wall thickness of the inclined surface 91b changes so as to gradually protrude radially inward from the circumferential center C3 side between the tooth coating portions 64 toward the second side surface coating portion 66b side (circumferential outside). The thickness is the thickness of the corresponding portion, and is also referred to as the plate thickness.

The central thick portion 92 is formed at the central connecting portion 66e. The center thick portion 92 is formed throughout the axial direction of the core side surface coating portion 66. The inner surface 92a of the central thick portion 92 is formed flat so as to be orthogonal to a radial straight line S2 passing through the central connecting portion 66e when viewed from the axial direction. The outer surfaces of the two first side surface covering portions 66a constituting the outer surface of the central thick portion 92 are curved at the central connecting portion 66e so as to form an angle θ3 (see fig. 5). Accordingly, the wall thickness of the central thick portion 92 changes so as to gradually protrude from both circumferential sides of the central thick portion 92 toward the circumferential center and from the outer side.

The inner surface 92a of the central thick portion 92 is formed between the flange portion 29 and the flange side surface coating portion 73 adjacent in the circumferential direction as viewed in the radial direction. That is, the central thick portion 92 is arranged between the flange portion 29 and the flange side surface coating portion 73 adjacent in the circumferential direction as viewed in the radial direction (see region Ar in fig. 10). The maximum thick portion of the central thick portion 92 is the portion where the central connecting portion 66e is located.

The wall thickness of the maximum thick portion of the central thick portion 92 and the wall thickness of the maximum thick portion of the side thick portion 91 are the same wall thickness T1. The wall thickness of the core side surface coating portion 66 and the wall thickness of the tooth side surface coating portion 72 after the maximum wall thickness portions are removed are the same wall thickness T2. The wall thickness T1 and the wall thickness T2 satisfy the following conditions:

T1＞T2…(1)

in this way, the core side surface coating portion 66 and the tooth side surface coating portion 72 in the second skirt portion 279 are formed by two wall thickness patterns, that is, the wall thickness of the thick wall portion 91 and the thick wall portion 92, and the wall thickness of the other portions.

A recess 93 is formed in the front end portion 279a of the second skirt portion 279 over the two first side surface coating portions 66 a. The recess 93 is formed to be recessed toward the second core end surface coating portion 265 side than the front end portion 279a of the second skirt portion 279. The length L1 from the second core end surface coating portion 265 to the bottom surface 93a of the recess 93 is substantially equal to the length L2 in the axial direction of the short tooth side surface coating portion 72 b.

Both circumferential side surfaces 93b of the recess 93 are formed so as to be inclined such that the circumferential width of the recess 93 gradually increases toward the distal end portion 279 a.

< Formation of first insulator and second insulator >)

Next, the molding of the first insulator 61 and the second insulator 62 will be described. The first insulator 61 and the second insulator 62 are formed by using a mold, not shown, and flowing a molten resin into the mold through a gate, not shown. These insulators 61 and 62 are slightly deformed by shrinkage marks generated by shrinkage of the resin during hardening. In the respective insulators 61 and 62, the deformation amounts of the skirt portions 79 and 279 extending from the respective core end surface coating portions 65 and 265 become large in terms of the structure thereof.

Here, the first insulator 61 has a coil lead-out portion 77, whereas the second insulator 62 does not have the coil lead-out portion 77. The shape of the first insulator 61 is correspondingly complicated by the coil lead-out portion 77, and is thus uneven throughout the entire circumference. In contrast, the shape of the second insulator 62 is simple and uniform throughout the entire circumference. Therefore, the deformation amount of each first skirt portion 79 of the first insulator 61 tends to become uneven, and the deformation amount itself also becomes large. In contrast, the second skirt portions 279 of the second insulator 62 have not only a uniform deformation amount but also a small deformation amount itself. The uniform deformation amount means that the direction of deformation is also uniform.

That is, for example, when the length of the first skirt portion 79 is the same as the length of the second skirt portion 279 (hereinafter, this will be referred to as a conventional product), the first skirt portion 79 is not deformed uniformly with respect to the second skirt portion 279, but is deformed to a large extent. Thus, the length of the second skirt portion 279 is made longer than the length of the first skirt portion 79. Thereby, the deformation amount of the second insulator 62 is larger than the deformation amount of the first insulator 61.

As described above, the deformation amount of each second skirt portion 279 of the second insulator 62 is uniform. Therefore, even in the case where the deformation amount of the second insulator 62 is made larger than the deformation amount of the first insulator 61, the deformation of the second insulator 62 can be suppressed from being distorted as compared with the case where the deformation amount of the first insulator 61 is large.

Next, the fluidity of the resin when forming each insulator 61, 262 will be described. First, as the injection gate mark G is formed on the inner peripheral surface of each inner wall portion 74, the resin flows from the radially inner side to the radially outer side. Then, the resin reaches the root of each skirt portion 79, 279 (the side of each core end surface coating portion 65, 265), and then flows toward the tip end portion 79a, 279 a.

In such injection molding, since the length of the second skirt portion 279 is longer than that of the first skirt portion 79, the fluidity of the resin to the second skirt portion 279 is accordingly deteriorated. However, the core side surface coating portion 66 of the second skirt portion 279 is formed with two side thick-wall portions 91 and one central thick-wall portion 92. In other words, the thick portions 91 and 92 are equally arranged at three positions in the circumferential direction of the core side surface coating portion 66. Therefore, the second skirt portion 279, which is an elongated resin flow path, can sufficiently ensure the filling speed of the resin.

Further, the recess 93 is formed in the front end portion 279a of the second skirt portion 279 over the two first side surface coating portions 66 a. Since the concave portion 93 is formed, the length (length L1) of the first side surface coating portion 66a from the second core end surface coating portion 265 at the portion where the concave portion 93 is formed becomes shorter, and the volume of the second skirt portion 279 decreases. Therefore, the occurrence of underfill (short shot) in the second skirt portion 279 can be prevented at the time of injection molding of the second insulator 262. Further, since the circumferential both side surfaces 93b of the recess 93 are formed obliquely, the flow of the resin toward the tip end portion 279a of the second skirt portion 279 via the recess 93 becomes smooth.

Space factor and insulation of coil with respect to the second insulator

Next, the space factor and insulation of the coil 24 with respect to the second insulator 62 will be described.

As shown in fig. 10, the coil 24 wound around each tooth 22 from the insulator 26 (the first insulator 61 and the second insulator 62) is accommodated in the coil accommodating recess 70.

Here, the two side thick portions 91 formed in the second insulator 62 are disposed at the end portions of the first side covering portion 66a on the second side covering portion 66b side (the end portions of the connecting portion 66c side), respectively. The center thick portion 92 formed in the second insulator 62 is arranged between the flange portion 29 and the flange side surface coating portion 73 adjacent in the circumferential direction when viewed in the radial direction (see region Ar in fig. 10). The side thick portion 91 is located at the most end portion of the coil accommodating recess 70, which is the portion accommodating the coil 24. The portion where the central thick portion 92 is disposed is a portion of the coil housing recess 70 where the coil 24 is not housed. In other words, the portion where the central thick portion 92 is disposed is a portion that does not constitute the coil accommodating recess 70. Therefore, the thick portions 91 and 92 hardly affect the space factor of the coil 24.

In the second insulator 62, recesses 93 are formed in the distal end portion 279a of the second skirt portion 279 over the two first side surface coating portions 66a. By forming the concave portion 93, the inner peripheral surface 19 of the core body 21 is exposed through the formation portion of the concave portion 93. However, the recess 93 is formed in the first side surface coating portion 66a which does not constitute the coil housing recess 70. Therefore, the insulation between the stator core 20 and the coil 24 due to the formation of the concave portion 93 can be prevented from being damaged.

As described above, in the above embodiment, the two side thick portions 91 and the single central thick portion 92 are formed in the core side surface coating portion 66 of the second insulator 62. Therefore, the molten resin can be spread over the entire second skirt portion 279 during injection molding of the second insulator 62. Thus, in particular, the defective formation of the second insulator 62 can be prevented. Specifically, the occurrence of underfill in the second skirt portion 279 at the time of injection molding can be prevented.

The two side thick portions 91 are disposed on both circumferential sides of the core side surface coating portion 66, respectively. A central thick portion 92 is disposed between the two side thick portions 91. An inclined surface 91b is formed on the side of the circumferential center C3 between the tooth coating portions 64 on the inner side surface 91a of the side thick portion 91. The wall thickness of the inclined surface 91b changes so as to gradually protrude radially inward from the circumferential center C3 side between the tooth coating portions 64 toward the second side surface coating portion 66b side (circumferential outside). The wall thickness of the central thick portion 92 changes so as to gradually protrude from both circumferential sides of the central thick portion 92 toward the circumferential center and from the outer side. With this configuration, the molten resin can be reliably spread over the entire second skirt portion 279. The winding space of the coil 24 is not obstructed by the thick portions 91 and 92. Therefore, the space factor of the coil 24 can be prevented from being reduced.

The central thick portion 92 is formed at the central connecting portion 66e. That is, the central thick portion 92 is arranged between the flange portion 29 and the flange side surface coating portion 73 adjacent in the circumferential direction as viewed in the radial direction. In this way, since the central thick portion 92 is disposed at the position where the coil 24 is not accommodated in the coil accommodating recess 70, a reduction in the space factor of the coil 24 can be reliably prevented.

The wall thickness of the maximum thick portion of the central thick portion 92 and the wall thickness of the maximum thick portion of the side thick portion 91 are the same wall thickness T1. The wall thickness of the core side surface coating portion 66 and the wall thickness of the tooth side surface coating portion 72 after the maximum wall thickness portions are removed are the same wall thickness T2. In this way, the core side surface coating portion 66 and the tooth side surface coating portion 72 in the second skirt portion 279 are formed in two wall thickness modes, that is, the wall thickness of the thick portion 91 and the thick portion 92 and the wall thickness of the other portions. Thus, the shape of the second skirt portion 279 may be simplified as much as possible.

The core side surface coating portion 66 formed with the thick portions 91, 92 has: two first side coating portions 66a extending from a circumferential center C3 between the tooth coating portions 64 adjacent in the circumferential direction toward the tooth coating portions 64; and two second side coating portions 66b extending further from the first side coating portion 66a toward the tooth coating portion 64 and connected to the tooth coating portion 64. The angle θ3 between the two first side cladding portions 66a is greater than the angle θ4 between the first side cladding portions 66a and the second side cladding portions 66 b. The connection 66c of the first side coating 66a and the second side coating 66b is located on a straight line S that is parallel to the circumferential side 28b of the tooth body 28 and passes through the circumferential end 73a of the flange side coating 73. The two side thick portions 91 are formed at the end portions of the first side coating portion 66a on the second side coating portion 66b side (the end portions of the connecting portion 66c side), respectively. In addition, a central thick portion 92 is formed at the central connecting portion 66e. In this way, it was found that the thick portion 91 and the thick portion 92 were effectively formed in the core side surface coating portion 66, instead of simply thickening the core side surface coating portion 66. By arranging the thick portions 91 and 92 in an appropriate number at appropriate positions, the molten resin can be effectively distributed to the entire second skirt portion 279 to the maximum extent with fewer thick portions 91 and 92. Thus, the defective formation of the second insulator 62 can be reliably prevented.

In the first insulator 61 having the coil lead-out portion 77, the length of the first skirt portion 79 is made shorter than the length of the second skirt portion 279, whereby the molding accuracy of the first insulator 61 can also be improved.

Since the forming accuracy of each insulator 61, 62 (particularly the second insulator 62) can be improved, the goal 12″ of the sustainable development goal (Sustainable Development Goals, SDGs) dominant in the united nations can be facilitated to ensure a sustainable consumption and production pattern.

Further, when the defective formation of the second insulator 62 is prevented, the space factor of the coil 24 is not affected. Therefore, the torque performance of the electric motor 2 can be improved, and the consumed energy when driving the electric motor 2 can be suppressed. Thus, goal 7", which can contribute to the Sustainable Development Goal (SDGs) dominated by the united nations, ensures that everyone can obtain an inexpensive and reliable sustainable modern energy source.

The present invention is not limited to the above-described embodiments, and various modifications are included in the above-described embodiments without departing from the gist of the present invention.

For example, in the above-described embodiment, the description has been made of the case where the motor 1 with a speed reducer is used as a drive source of a wiper device for a vehicle. However, the present invention is not limited thereto, and the motor 1 with a speed reducer may be applied as various driving devices. Further, only the electric motor 2 having the above-described structure among the motors 1 with speed reducers may be used in various electronic devices.

In the above embodiment, the electric motor 2 is described as an example of the rotary electric machine. However, the present invention is not limited thereto, and the above-described structure may be employed in various rotating electrical machines. For example, as the rotating electrical machine, a generator may be used instead of the electric motor 2.

In the above embodiment, the case where the coil 24 of the stator 8 has a three-phase (U-phase, V-phase, W-phase) structure is described. The number of phases of the coil 24 is not limited to three phases.

In the above embodiment, the description has been made of the case where the stator core 20 includes the cylindrical core body 21 and the plurality of (six) teeth 22 protruding radially inward from the inner peripheral surface 19 of the core body 21. The case where the rotor 9 is disposed radially inward of the stator 8 having such a stator core 20 will be described. However, the stator core 20 is not limited to this, and the teeth 22 may protrude radially outward from the outer peripheral surface of the core body 21. The rotor 9 may be disposed radially outside the stator 8 having such a stator core 20. The number of teeth 22 is not limited to six. The insulator 26 may be formed corresponding to the shape of the stator core 20. The above-described structure can also be employed in such an insulator 26.

In the above-described embodiment, the case where two side thick portions 91 and one central thick portion 92 are formed in the core side surface coating portion 66 of the second insulator 62 is described. However, the thick portions 91 and 92 formed in the core side surface coating portion 66 of the second insulator 62 are not limited to three. The core side surface coating portion 66 may be formed with two or more thick portions 91 and 92. The thick portions 91 and 92 may be formed over the entire axial direction of the core side surface coating portion 66.

In the above-described embodiment, the case where the two side thick portions 91 are formed at the end portions of the first side coating portion 66a on the second side coating portion 66b side (the end portions of the connecting portion 66c side) is described. The case where the central thick portion 92 is formed in the central connecting portion 66e is described. That is, the case where the central thick portion 92 is arranged between the flange portion 29 and the flange side surface coating portion 73 adjacent in the circumferential direction (see the region Ar of fig. 10) when viewed in the radial direction is described. However, the present invention is not limited to this, and the core side surface coating portion 66 may be formed with thick portions 91 and 92. It is desirable that the two side thick portions 91 are disposed on both circumferential sides of the core side surface coating portion 66, respectively. Desirably, a central thick portion 92 is disposed between the two side thick portions 91.

In the above-described embodiment, the case where the core side surface coating portion 66 and the tooth side surface coating portion 72 in the second skirt portion 279 are formed in two wall thickness modes, that is, the wall thickness of the thick portion 91 and the thick portion 92 and the wall thickness of the other portions. However, the core side surface coating portion 66 and the tooth side surface coating portion 72 may be formed of a plurality of patterns of wall thicknesses. The thickness of the thick portions 91, 92 may be thicker than the thickness of the core side surface coating portion 66 other than the portions where these thick portions 91, 92 are formed.

In the above-described embodiment, the case where the thick portions 91 and 92 are formed in the second skirt portion 279 of the second insulator 62 is described. However, the present invention is not limited thereto, and the thick portions 91 and 92 may be formed in the first skirt portion 79 of the first insulator 61.

Claims (5)

1.A rotating electrical machine, characterized by comprising:

A stator core having an annular core body and a plurality of teeth protruding radially from the core body;

two insulators which are installed on the stator core from two axial sides and made of resin; and

A coil wound from the insulator to the tooth portion,

The insulator includes:

a core end surface coating portion that covers an axial end surface of the core body; and

A skirt portion extending from the core end surface coating portion toward an axial center of the core body,

The skirt portion includes:

A core side surface coating portion covering the peripheral surface of the core body; and

A tooth side surface coating part for coating the circumferential side surface of the tooth,

The core side surface coating portion is formed with a plurality of thick wall portions thicker than the wall thickness of the core side surface coating portion,

The thick portion is formed throughout the axial entirety of the core side surface coating portion.

2. A rotary electric machine according to claim 1, characterized in that:

the plurality of teeth protrude from the core body toward a radially inner side,

The thick-walled portion is formed with three,

The thick-walled portion has:

Two side thick-wall parts arranged on both sides in the circumferential direction; and

A central thick-wall portion disposed between the two side thick-wall portions,

The wall thickness of the side thick-wall portion changes so as to gradually protrude from the central thick-wall portion side toward the circumferential outer side and the inner side surface side,

The wall thickness of the central thick-wall portion changes so as to gradually protrude from both circumferential sides of the central thick-wall portion toward the circumferential center and from the outer side surface side.

3. A rotary electric machine according to claim 2, characterized in that:

The tooth has:

A tooth body extending in a radial direction; and

A flange portion extending circumferentially from a radially inner end of the dental portion body,

The insulator has a flange side surface coating portion which protrudes from a radial end portion of the tooth side surface coating portion and covers an outer peripheral surface of the flange portion,

The center thick portion is disposed between the flange portion and the flange side surface coating portion adjacent in the circumferential direction when viewed in the radial direction.

4. A rotary electric machine according to claim 3, characterized in that:

the core side surface coating portions other than the thick wall portion have the same wall thickness as the tooth side surface coating portions.

5. A rotary electric machine according to claim 3 or 4, characterized in that:

The core side cladding has:

Two first side coating portions extending from a circumferential center between the tooth side coating portions adjacent in a circumferential direction toward the tooth side coating portions; and two second side surface coating parts which extend from the first side surface coating parts towards the tooth part side surface coating parts in a bending way and are connected with the tooth part side surface coating parts,

The angle between the two first side cladding portions is larger than the angle between the first side cladding portion and the second side cladding portion,

The connection portion of the first side surface coating portion and the second side surface coating portion is located on a straight line parallel to the circumferential side surface of the dental unit body and passing through the circumferential end portion of the flange side surface coating portion,

The side thick portion is formed at an end portion of the first side surface coating portion on the second side surface coating portion side.