阅读说明：本技术 电枢 (Armature ) 是由 铃木工 于 2020-03-06 设计创作，主要内容包括：公开了一种电枢。定子包括具有连接沿周向方向间隔开的两个绝缘体(32)的引导部分(32a)的连接绝缘体构件(73),以及通过引导部分(32a)引导并连接两个线圈(33)的跳线(41g、51h、51j)。连接绝缘体构件(73)包括下层绝缘体构件(74)、中间层绝缘体构件(75)和上层绝缘体构件(76)。下层绝缘体构件(74)的引导部分(32a)具有下层弧形连接部(74b),中间层绝缘体构件(75)具有中间层弧形连接部(75b),并且上层绝缘体构件(76)的引导部分(32a)具有上层弧形连接部(76b)。中间层弧形连接部被布置成在轴向方向上相对于下层弧形连接部在上方,并且上层弧形连接部被布置成在径向方向上相对于中间层弧形连接部在外侧。(An armature is disclosed. The stator includes a connecting insulator member (73) having a guide portion (32a) connecting two insulators (32) spaced apart in a circumferential direction, and jumper wires (41g, 51h, 51j) that guide and connect two coils (33) through the guide portion (32 a). The connecting insulator member (73) includes a lower insulator member (74), an intermediate insulator member (75), and an upper insulator member (76). The guide portion (32a) of the lower insulator member (74) has a lower arc-shaped connecting portion (74b), the intermediate insulator member (75) has an intermediate arc-shaped connecting portion (75b), and the guide portion (32a) of the upper insulator member (76) has an upper arc-shaped connecting portion (76 b). The intermediate layer arc connecting portion is arranged above with respect to the lower layer arc connecting portion in the axial direction, and the upper layer arc connecting portion is arranged outside with respect to the intermediate layer arc connecting portion in the radial direction.)

1. An armature, comprising:

a plurality of core component members (31d) having teeth (31b) extending in a radial direction and arranged side by side in a circumferential direction;

a connecting insulator member (73) having an insulator (32) covering the teeth and a guide portion (32a) configured to connect two insulators spaced apart in a circumferential direction;

a coil (33) wound around the teeth via the insulator; and

a jumper (41g, 41h, 41j, 51g, 51h, 51j) guided by the guide portion to connect the two coils, wherein,

the connecting insulator member includes a lower insulator member (74), an intermediate insulator member (75), and an upper insulator member (76) assembled in an axial direction,

the guide portion of the lower insulator member includes a lower arcuate connecting portion (74b) having an arcuate shape when viewed from the axial direction, the guide portion of the intermediate insulator member includes an intermediate arcuate connecting portion (75b) having an arcuate shape when viewed from the axial direction, and the guide portion of the upper insulator member includes an upper arcuate connecting portion (76b) having an arcuate shape when viewed from the axial direction, and

the intermediate layer arc connecting portion is arranged above with respect to the lower layer arc connecting portion in the axial direction, and the upper layer arc connecting portion is arranged outside with respect to the intermediate layer arc connecting portion in the radial direction.

2. The armature of claim 1,

the leading portion of the intermediate layer insulator member includes an intermediate layer extension (75a) extending from a radially inner side of the insulator to the inner side in a radial direction and connecting the intermediate layer arc-shaped connecting portions, and

the upper layer arcuate connection includes a thinned portion (76e) to increase space on the middle layer extension at a circumferential location facing the middle layer extension.

3. The armature of claim 2,

the thinned portion is a through hole (76e) that penetrates in the axial direction.

4. The armature of claim 2,

the upper layer arc-shaped connecting portion includes a protruding portion (76f) protruding outward in the radial direction at a circumferential position corresponding to the thinned portion.

5. The armature of any of claims 1 to 4,

the leading portion of the middle tier insulator member has a middle tier extension extending radially inward from the insulator and connected to the middle tier arcuate connection portion, and

a guide recess (75c) for guiding the jumper in a radial direction is formed on the intermediate layer extension.

6. The armature of any of claims 1 to 4,

an arc-shaped wall portion (77) protruding in the axial direction is formed on a radially inner side of at least one of the intermediate layer arc-shaped connection portion and the upper layer arc-shaped connection portion so as to guide the jumper wire along an outer surface of the arc-shaped wall portion in the radial direction, and a restricting protrusion (77a) is formed, the restricting protrusion (77a) protruding outward in the radial direction so as to restrict movement of the jumper wire in the axial direction.

7. The armature of any of claims 1 to 4,

the armature is a stator (30), and a rotor (20) is provided on a radially inner side of the stator.

Technical Field

The present invention relates to an armature.

Background

Conventionally, in a stator as an armature of an electric motor, a plurality of core constituent members having teeth extending inward in a radial direction are arranged in a circumferential direction, and a coil is wound around the teeth via an insulator (for example, see patent document 1). The stator includes a connection insulator member having two insulators spaced apart in a circumferential direction and a guide portion connecting them, and a jumper wire connecting two coils is guided by the guide portion. Further, the connecting insulator member includes a lower insulator member, an intermediate insulator member, and an upper insulator member assembled in the axial direction. The leading portion of each of the insulator members includes a lower layer arc-shaped connecting portion, an intermediate layer arc-shaped connecting portion, and an upper layer arc-shaped connecting portion each having an arc shape as viewed from the axial direction. The intermediate layer arc-shaped connection portion is arranged parallel to the lower layer arc-shaped connection portion in the radial direction, and the upper layer arc-shaped connection portion is arranged above the intermediate layer arc-shaped connection portion in the axial direction. Therefore, while suppressing the enlargement of the guide portion in the radial direction, the enlargement in the axial direction is suppressed (see fig. 23 of patent document 1).

Disclosure of Invention

However, in the stator described above, for example, the intermediate-layer arc connecting portion is arranged in parallel with the inner side in the radial direction of the lower-layer arc connecting portion. Therefore, it is difficult to form the intermediate layer inwardly extending portion that extends inwardly from the insulator in the radial direction and is connected to the intermediate layer arc connecting portion so as not to interfere with the upper layer arc connecting portion and the lower layer arc connecting portion. Therefore, it is difficult to realize guide portions in which the guide portions do not interfere with each other.

The present invention is proposed to solve the above-described problems, and an object of the present invention is to provide an armature in which guide portions that do not interfere with each other can be easily realized.

The armature includes: a plurality of core constituent members having teeth extending in a radial direction and arranged side by side in a circumferential direction; a connecting insulator member having an insulator covering the teeth and a guide portion configured to connect two insulators spaced apart in a circumferential direction; a coil wound around the teeth via an insulator; and a jumper guided by the guide portion to connect the two coils. The connecting insulator member includes a lower insulator member, an intermediate insulator member, and an upper insulator member assembled in an axial direction. The guide portion of the lower insulator member includes a lower arcuate connecting portion having an arcuate shape when viewed from the axial direction, the guide portion of the intermediate insulator member includes an intermediate arcuate connecting portion having an arcuate shape when viewed from the axial direction, and the guide portion of the upper insulator member includes an upper arcuate connecting portion having an arcuate shape when viewed from the axial direction. The intermediate layer arc connecting portion is arranged above with respect to the lower layer arc connecting portion in the axial direction, and the upper layer arc connecting portion is arranged outside with respect to the intermediate layer arc connecting portion in the radial direction.

According to the above structure, the intermediate layer arc-shaped connection portion is arranged parallel upward in the axial direction with respect to the lower layer arc-shaped connection portion, and the upper layer arc-shaped connection portion is arranged parallel outward in the radial direction with respect to the intermediate layer arc-shaped connection portion. Therefore, the guide portions can be easily implemented so that the guide portions do not interfere with each other.

Drawings

Fig. 1 is a schematic configuration diagram of an electric brake system including a motor according to an embodiment;

FIG. 2 is a schematic plan view of a stator in the same embodiment;

FIG. 3 is a perspective view of a stator in an embodiment;

FIG. 4 is a perspective view of a stator in an embodiment;

fig. 5 is a partially exploded perspective view of a stator in an embodiment;

fig. 6 is a partially exploded perspective view of a stator in an embodiment;

fig. 7 is a sectional view showing a part of a stator in the embodiment;

fig. 8 is a sectional view showing a part of a stator in the embodiment;

fig. 9 is a sectional view showing a part of a stator in another embodiment; and

fig. 10 is a sectional view showing a part of a stator in another embodiment.

Detailed Description

Hereinafter, embodiments of a motor including a stator as an armature will be described with reference to the drawings. In the drawings, a part of the structure may be enlarged or simplified for convenience of explanation. Also, the size ratio of each portion may be different from the actual one.

As shown in fig. 1, the motor 10 is used for an electric brake system. The electric brake system includes: a hydraulic unit 11 that adjusts a hydraulic pressure of the brake fluid; a motor 10 connected to the hydraulic unit 11 and driving the hydraulic unit 11; and an EDU (electric drive unit) 12 that controls the drive of the motor 10. In the brake system of the present embodiment, the hydraulic unit 11 is interposed between the EDU 12 and the motor 10. The motor 10 and the EDU 12 are electrically connected through a through hole 11b provided in a housing 11a of the hydraulic unit 11.

The motor 10 of the present embodiment includes a rotor 20 and a stator 30. As shown in fig. 1, the rotor 20 is disposed inside the stator 30 in the radial direction, and has a rotor core 21, a magnet (not shown) disposed on the rotor core 21, and a rotary shaft 22 disposed at the radial center of the rotor core 21. One end of the rotary shaft 22 in the axial direction is directly or indirectly connected to the gear 11c in the hydraulic unit 11. As a result, when the rotary shaft 22 is rotationally driven, the gear 11c in the hydraulic unit 11 is driven to adjust the hydraulic pressure of the brake fluid.

As shown in fig. 2 and 3, the stator 30 includes a stator core 31, an insulator 32 (not shown in fig. 2) of the stator core 31, and a coil 33.

The stator core 31 has a substantially annular portion 31a and a plurality of teeth 31b extending radially inward from the annular portion 31 a. In the present embodiment, for example, twelve teeth 31b are provided. The coil 33 is wound around each of the teeth 31b with an insulator 32, and the insulator 32 covers and is located between the teeth 31 b. For example, the coil 33 is wound in a concentrated manner.

The coil 33 includes a first three-phase winding 40 electrically connected to a first inverter circuit 12a provided in the EDU 12 and a second three-phase winding 50 electrically connected to a second inverter circuit 12b provided in the EDU 12. That is, in the present embodiment, the first inverter circuit 12a and the second inverter circuit 12b constituting two system (a plurality of systems) in the EDU 12 are provided, and the first inverter circuit 12a and the second inverter circuit 12b supply current to each of the three-phase windings 40 and 50.

As shown in fig. 2, the first three-phase winding 40 has a plurality of three-phase windings 41a to 41f, and three-phase alternating currents having a phase difference of 120 degrees are supplied from the first inverter circuit 12a to the plurality of three-phase windings 41a to 41 f. The plurality of three-phase windings 41a to 41f include a U + phase winding 41a, a U-phase winding 41b, a V + phase winding 41c, a V-phase winding 41d, a W + phase winding 41e, and a W-phase winding 41 f.

As shown in fig. 2, the second three-phase winding 50 has a plurality of three-phase windings 51a to 51f, and three-phase alternating current having a phase difference of 120 degrees is supplied from the second inverter circuit 12b to the plurality of three-phase windings 51a to 51 f. The plurality of three-phase windings 51a to 51f include an X + phase winding 51a, an X-phase winding 51b, a Y + phase winding 51c, a Y-phase winding 51d, a Z + phase winding 51e, and a Z-phase winding 51 f.

For example, the coil 33 of the present embodiment is wound around each tooth 31b in the order of the W-phase winding 41f, the V + phase winding 41c, the Y + phase winding 51c, the X-phase winding 51b, the U-phase winding 41b, the W + phase winding 41e, the Z + phase winding 51e, the Y-phase winding 51d, the V-phase winding 41d, the U + phase winding 41a, the X + phase winding 51a, and the Z-phase winding 51 f. Therefore, all the coils 33 of the present embodiment have a different phase from the coils 33 adjacent in the circumferential direction.

The U + phase winding 41a and the U-phase winding 41b are wound on the teeth 31b provided at positions different by 150 degrees in the circumferential direction. The V + phase winding 41c and the V-phase winding 41d are wound on the teeth 31b provided at positions different by 150 degrees in the circumferential direction. The teeth 31b wound by the W + phase winding 41e and the teeth 31b wound by the W-phase winding 41f are provided at positions different by 150 degrees in the circumferential direction.

The teeth 31b wound by the X + phase winding 51a and the teeth 31b wound by the X-phase winding 51b are provided at positions different by 150 degrees in the circumferential direction. The teeth 31b wound with the Y + phase winding 51c and the teeth 31b wound with the Y-phase winding 51d are disposed at positions different by 150 degrees in the circumferential direction. The teeth 31b wound by the Z + phase winding 51e and the teeth 31b wound by the Z-phase winding 51f are provided at positions different by 150 degrees in the circumferential direction.

The U + phase winding 41a and the U-phase winding 41b are connected by a jumper wire 41 g. The V + phase winding 41c and the V-phase winding 41d are connected by a jumper wire 41 h. The W + phase winding 41e and the W-phase winding 41f are connected by a jumper wire 41 j. The X + phase winding 51a and the X-phase winding 51b are connected by a jumper wire 51 g. The Y + phase winding 51c and the Y-phase winding 51d are connected by a jumper wire 51 h. The Z + phase winding 51e and the Z-phase winding 51f are connected by a jumper wire 51 j. The jumper wires 41g, 41h, 41j, 51g, 51h, 51j are provided on the other end side in the axial direction of the stator core 31 and on the side not facing the hydraulic unit 11 (the lower side in fig. 1). As schematically shown in fig. 2, these jumper wires are provided under the guide of a guide portion 32a (see fig. 4) of a connection insulator 32 to be described later. The jumper wire 41j connecting the W + phase winding 41e and the W-phase winding 41f and the jumper wire 51j connecting the Z + phase winding 51e and the Z-phase winding 51f are routed outward in the radial direction with respect to the other jumper wires 41g, 41h, 51g, 51h, and thus are longer than the other jumper wires 41g, 41h, 51g, 51 h.

The first three-phase winding 40 of the present embodiment is connected to the first inverter circuit 12a by delta connection. The second three-phase winding 50 is connected to the second inverter circuit 12b by a delta connection.

More specifically, the terminal line 33a of the U + phase winding 41a is connected to the U terminal of the first inverter circuit 12a together with the terminal line 33a of the W-phase winding 41 f. The terminal line 33a of the U-phase winding 41b is connected to the V terminal of the first inverter circuit 12a together with the terminal line 33a of the V + phase winding 41 c. The terminal line 33a of the W + phase winding 41e is connected to the W terminal of the first inverter circuit 12a together with the terminal line 33a of the V-phase winding 41 d.

The terminal line 33a of the X + phase winding 51a is connected to the X terminal of the second inverter circuit 12b together with the terminal line 33a of the Z-phase winding 51 f. The terminal line 33a of the X-phase winding 51b is connected to the Y terminal of the second inverter circuit 12b together with the terminal line 33a of the Y + phase winding 51 c. The terminal line 33a of the Z + phase winding 51e is connected to the Z terminal of the second inverter circuit 12b together with the terminal line 33a of the Y-phase winding 51 d. In addition, for each phase, jumper wires 41g, 41h, 41j, 51g, 51h, 51j connect the opposite-side ends of the coil 33 to the above-described terminal wire 33 a.

As shown in fig. 1, in the stator 30, a guide member 60 is provided on a side surface of the hydraulic unit 11, i.e., on one side in the axial direction of the stator core 31.

The guide member 60 guides the terminal wire 33a of the coil 33 drawn out from the coil 33 to one side in the axial direction, and further guides it to the EDU 12. The guide member 60 includes a guide body 61 and a pull-out guide 62 for pulling out.

As shown in fig. 3, the guide body 61 is formed in a substantially disc shape having a plurality of steps in the axial direction, and includes a plurality of notches 63 extending from the radially outer side to the radially inner side and penetrating in the axial direction. The terminal wire 33a of the coil 33 passes through the notch 63 in the axial direction, is drawn out to one side of the guide body 61 in the axial direction, and is bent in the circumferential direction and extends along the step of the guide body 61. The terminal wire 33a is guided to a part of the guide body 61 in the circumferential direction.

The pull-out guide 62 is configured to have a long columnar shape in the axial direction, and is fixed to a part in the circumferential direction of the guide body 61. Then, the terminal wire 33a guided to a part of the guide body 61 in the circumferential direction passes through the inside of the pull-out guide 62 and is drawn out to one side in the axial direction. As described above, the terminal line 33a is connected to the first inverter circuit 12a and the second inverter circuit 12 b.

Here, the stator core 31 of the present embodiment has a structure in which the annular portion 31a is divided for each tooth 31 b. The core constituting member 31d includes a tooth 31b extending radially inward and a pair of core extending portions 31c extending circumferentially from radially outer ends of both sides of the tooth 31 b. The plurality of core constituting members 31d are arranged side by side in the circumferential direction. Specifically, in the present embodiment, the core extension portions 31c of twelve core constituting members 31d are arranged in the circumferential direction to form an annular shape, and the core extension portions 31c adjacent to each other in the circumferential direction are welded to form the stator core 31. In a state before the core constituent members 31d are arranged side by side in the circumferential direction, the coil 33 is wound on the teeth 31b via the insulator 32.

As shown in fig. 3 to 6, the insulator 32 of the present embodiment includes a first insulator 71 assembled from one axial side (upper side in fig. 3 and lower side in fig. 4 to 6) of the core constituting member 31d and a second insulator 72 assembled from the other axial side (lower side in fig. 3 and upper side in fig. 4 to 6) of the core constituting member 31 d. The two second insulators 72 are connected by the above-described guide portion 32a, and the second insulators 72 and the guide portion 32a constitute a connecting insulator member 73. The guide portion 32a connects the second insulators 72 spaced apart by 150 degrees in the circumferential direction.

As shown in fig. 5 and 6, the connecting insulator member 73 includes a lower insulator member 74, an intermediate insulator member 75, and an upper insulator member 76 assembled in the axial direction. That is, in a state where the insulator 32 is assembled to the core constituting member 31d and the coil 33 is wound, the lower insulator member 74, the intermediate insulator member 75, and the upper insulator member 76 are assembled in order from the upper side in the order of the lower insulator member 74, the intermediate insulator member 75, and the upper insulator member 76, with the side surface provided with the guide portion 32a facing upward. Also, a pair of lower-layer insulator members 74, intermediate-layer insulator members 75, and upper-layer insulator members 76 are provided and assembled in a paired state in the axial direction.

The guide portion 32a of the lower insulator member 74 includes a lower extension portion 74a extending radially from the radially inner side to the inner side of the insulator 32 and a lower arc-shaped connecting portion 74b connecting the lower extension portion 74 a. The lower-layer arc-shaped connecting portion 74b is formed in an arc shape when viewed from the axial direction, and is substantially circular in a state where the two lower-layer insulator members 74 are arranged to form a pair.

The lead portion 32a of the intermediate layer insulator member 75 includes an intermediate layer extension portion 75a extending from the radially inner side of the insulator 32 to the inner side in the radial direction and an intermediate layer arc-shaped connecting portion 75b connecting the intermediate layer extension portion 75 a. The intermediate layer arc-shaped connecting portion 75b is formed in an arc shape as viewed from the axial direction, and is substantially circular in a state where the two intermediate layer insulator members 75 are arranged to form a pair.

The guide portion 32a of the upper-layer insulator member 76 includes an upper-layer extension portion 76a extending from the radially inner side of the insulator 32 to the inner side in the radial direction and an upper-layer arc-shaped connecting portion 76b connecting the upper-layer extension portion 76 a. The upper-layer arc-shaped connecting portion 76b is formed in an arc shape as viewed from the axial direction, and is substantially circular in a state where the two upper-layer insulator members 76 are arranged to form a pair.

Arc-shaped wall portions 77 that project in the axial direction are formed on the radially inner sides of the lower layer arc-shaped connecting portion 74b, the intermediate layer arc-shaped connecting portion 75b, and the upper layer arc-shaped connecting portion 76 b. The jumper wires 41g, 41h, 41j, 51g, 51h, 51j are guided along the outer surface of the arc-shaped wall portion 77 in the radial direction.

In addition, as shown in fig. 6, guide recesses 74c, 75c, 76c for guiding the jumpers 41g, 41h, 41j, 51g, 51h, 51j in the radial direction are formed on the lower layer extension portion 74a, the intermediate layer extension portion 75a, and the upper layer extension portion 76a, respectively. The guide concave portions 74c, 75c, 76c of the present embodiment are inclined toward the inside in the radial direction and in the circumferential direction on the lower layer arc connecting portion 74b, the intermediate layer arc connecting portion 75b, and the upper layer arc connecting portion 76b sides. Further, protrusions 74d, 75d, 76d are provided on the lower layer extension 74a, the middle layer extension 75a, and the upper layer extension 76a, respectively, to prevent deviation from the guide recesses 74c, 75c, and 76c of the jumpers 41g, 41h, 41j, 51g, 51h, and 51 j.

As shown in fig. 7, the intermediate layer arc connecting portion 75b is arranged above with respect to the lower layer arc connecting portion 74b in the axial direction, and the upper layer arc connecting portion 76b is arranged outside with respect to the intermediate layer arc connecting portion 75b in the radial direction.

As shown in fig. 6 and 8, the upper layer arc-shaped connecting portion 76b has a plurality of through holes 76e at circumferential positions facing the intermediate layer extended portion 75 a. With this structure, the space above the intermediate layer extension portion 75a is increased, and the via hole 76e functions as a thinned portion. The through hole 76e penetrates in the axial direction.

As shown in fig. 6, the upper layer arc-shaped connecting portion 76b has a protrusion portion 76f that protrudes outward in the radial direction at a circumferential position corresponding to the through hole 76 e.

Next, a method for manufacturing the stator 30 formed as described above and its function will be described.

First, the insulator 32, specifically, the connecting insulator member 73 including the first insulator 71 and the second insulator 72 is assembled to the core constituting member 31 d. After that, the coil 33 is wound on the teeth 31b via the insulator 32. Then, jumper wires 41g, 41h, 41j, 51g, 51h, 51j as winding ends of the coil 33 are arranged along the guide portion 32a, and the coil 33 is wound around the other tooth 31b connected via the insulator 32 by the guide portion 32 a.

As shown in fig. 5, a lower core unit 81 having a pair of lower insulator members 74, an intermediate core unit 82 having a pair of intermediate insulator members 75, and an upper core unit 83 having a pair of upper insulator members 76 are manufactured, and the core units 81, 82, and 83 are assembled in the axial direction. At this time, as shown in fig. 7, the intermediate layer arc connecting portions 75b are arranged in parallel at the same radial position of the lower layer arc connecting portions 74b in the axial direction, and the upper layer arc connecting portions 76b are arranged radially outward of the intermediate layer arc connecting portions 75b at the same axial position. And, the stator core 31 is manufactured by welding the core extending portions 31c adjacent in the circumferential direction.

Then, as shown in fig. 3, the guide body 61 of the guide member 60 is assembled to one side in the axial direction of the stator core 31, and the terminal wire 33a of the coil 33 is drawn out from the notch 63 to one side in the axial direction. Further, the terminal wires 33a of the coil 33 are bent in the circumferential direction and drawn out from a portion in the circumferential direction to one side in the axial direction of the pull-out guide 62 through the pull-out guide 62, thereby completing the manufacture of the stator 30.

Next, the effects of the present embodiment are described below.

(1) The middle layer arc connecting portion 75b is arranged parallel upward in the axial direction with respect to the lower layer arc connecting portion 74b, and the upper layer arc connecting portion 76b is arranged parallel outward in the radial direction with respect to the lower layer arc connecting portion. Therefore, the increase of the guide portions 32a in the radial direction and in the axial direction can be suppressed, and the guide portions 32a can be easily realized so that the guide portions 32a do not interfere with each other. In other words, in arrangements other than the present embodiment, it is difficult to realize guide portions that do not interfere with each other due to a complicated shape or the like of the guide portions. However, in the present embodiment, since the shape is simple, the guide portions 32a that do not interfere with each other can be realized.

(2) The upper layer arc-shaped connecting portion 76b has a plurality of through holes 76e at circumferential positions facing the intermediate layer extension portion 75 a. With this structure, the space above the intermediate layer extension portion 75a is increased, and the via hole 76e functions as a thinned portion. Therefore, interference between the jumper wires 41h and 51h arranged on the intermediate layer extension portion 75a and the upper layer arc-shaped connection portion 76b can be avoided while suppressing an increase in the overall axial dimension.

(3) The upper-layer arc-shaped connecting portion 76b has a projection portion 76f projecting outward in the radial direction at a circumferential position corresponding to the through hole 76 e. Therefore, by compensating for the rigidity of the upper layer arc-shaped connection portion 76b that is lowered by providing the through hole 76e, the rigidity of the upper layer arc-shaped connection portion 76b can be ensured.

(4) Guide recesses 75c for guiding the jumper wires 41h, 51h radially inward are formed on the intermediate layer extension portion 75 a. Therefore, positioning of the jumper wires 41h, 51h becomes easy, and interference between the jumper wires 41h, 51h and the upper-layer arc-shaped connection portion 76b can be avoided while suppressing an increase in the overall axial dimension.

The above embodiment may be modified as follows. The above-described embodiment and the following modifications can be implemented in combination with each other as long as there is no technical contradiction.

In the above embodiment, the restricting protrusion may be formed at the front end of at least one of the arc-shaped wall portions 77 of the intermediate layer arc-shaped connecting portion 75b and the upper layer arc-shaped connecting portion 76b, and protrudes radially outward so as to restrict the movement of the jumper wires 41h, 51h, 41j, 51j in the axial direction.

Specifically, for example, as shown in fig. 9 and 10, a restricting protrusion 77a protruding radially outward may be formed at the front end of the arc wall portion 77 of the intermediate layer arc-shaped connecting portion 75b and the upper layer arc-shaped connecting portion 76 b. In the above embodiment, the jumper wires 41h, 51h, 41j, 51j are prevented from jumping out in the axial direction. In addition, since the intermediate layer arc-shaped connection portion 75b and the upper layer arc-shaped connection portion 76b are located above the lower layer arc-shaped connection portion 74b, even if the restricting protrusion is not provided, the movement of the jumper wire in the axial direction is restricted. In the example shown in fig. 9, a part of the jumper wire 51j guided on the upper layer arc connection portion 76b enters the inside of the through hole 76 e. While the restricting projection 77a is provided, an increase in the axial dimension can be suppressed.

In the above embodiment, the upper layer arc-shaped connecting portion 76b has the through hole 76e as the thinned portion. However, the thinned portion may be provided at a position facing the intermediate layer extension portion 75a in the circumferential direction to enlarge the space above the intermediate layer extension portion 75 a. For example, a reduced thickness portion that is thinner than other portions without passing through may be employed as the thinned portion. In addition, the upper layer arc-shaped connecting portion 76b having no thinned portion may be employed.

In the above embodiment, the upper-layer arc-shaped connecting portion 76b has the protruding portion 76f protruding outward in the radial direction at the circumferential position corresponding to the through hole 76 e. However, a structure without the projection 76f may be adopted.

In the above embodiment, the guide recesses 74c, 75c, 76c for guiding the jump wires 41g, 41h, 41j, 51g, 51h, 51j in the radial direction are formed on the lower layer extension portion 74a, the intermediate layer extension portion 75a, and the upper layer extension portion 76a, respectively. However, the guide recesses 74c, 75c, and 76c may be omitted.

In the above embodiment, the stator 30 having twelve teeth 31b is disclosed, but a stator having a number other than the number of teeth 31b may be employed.

In the above embodiment, the stator 30 in the inner rotor type brushless motor is implemented as an armature, but may be implemented in other armatures. For example, the present disclosure may be implemented in a stator as an armature in an outer rotor type brushless motor, or in a rotor as an armature in a brushed motor.