Electric motor stator

Abstract

To provide a motor stator capable of further increasing a space factor.SOLUTION: An electric motor stator includes a core 10 and a coil 20A. The core 10 includes a core back 11 and a plurality of teeth 12, and a slot 13 is formed between two adjacent teeth 12. The core back 11 includes a slot forming surface 11a. In a cross section perpendicular to an axial direction, a plurality of conductor wires 21a, 21b, 21c, 21d, and 21e is accommodated in the slot 13 in parallel along a radial direction. A circumferential dimension of each of the plurality of conductor wires is smaller as the conductor wire is located radially inward. Of the plurality of conductor wires, the conductor wire 21a closest to the slot forming surface 11a has an opposing surface 21a1 opposing the slot forming surface 11a, and in the cross section, a distance between the opposing surface 21a1 and the slot forming surface 11a is constant.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric motor stator. [Background technology]

[0002] Patent Document 1 discloses a stator. The stator has a coil and an annular stator member. The stator member has a plurality of teeth arranged in an annular shape. A coil is attached to each tooth. The coil is an edgewise coil having a helical structure formed of a strip-shaped flat conductor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7170345 Summary of the Invention [Problem to be solved by the invention]

[0004] A slot is formed between the two teeth of the stator. The slot is surrounded by the mutually facing side surfaces of the two teeth and the inner peripheral surface of the core back. In a cross section perpendicular to the rotation axis, a plurality of flat conductors are accommodated in the slot in parallel along the radial direction.

[0005] Each of the flat conductors has a rectangular cross-sectional shape. Meanwhile, the inner peripheral surface of the core back is formed into a cylindrical surface. Therefore, the distance between the flat conductor located at the outermost position in the radial direction among the flat conductors and the inner peripheral surface of the core back varies depending on the circumferential position. Therefore, the distance between the flat conductor located at the outermost position and the inner peripheral surface of the core back becomes longer than necessary depending on the circumferential position. Therefore, there was room for further increasing the space factor of the above stator. Here, the space factor refers to the proportion of the cross section of the slot that is occupied by the conductor.

[0006] The present invention has been made in order to solve the above-mentioned problems, and has an object to provide an electric motor stator capable of further increasing the space factor. [Means for solving the problem]

[0007] an electric motor stator according to the present invention includes an annular core and a coil attached to the core, the core having a core back and a plurality of teeth protruding from the core back in a radial direction of the core, a slot is formed between two adjacent teeth among the plurality of teeth, a width of the slot in the circumferential direction of the core narrows toward the inside in the radial direction, the core back has a slot-forming surface facing the slot, in a cross section perpendicular to an axial direction of the core, a plurality of conductor wires that are part of the coil are accommodated in the slot in parallel along the radial direction, when a dimension of each of the plurality of conductor wires along the circumferential direction in the cross section is defined as a circumferential dimension of each of the plurality of conductor wires, the circumferential dimension of each of the plurality of conductor wires is smaller as the circumferential dimension of the conductor wire located inner in the radial direction, and among the plurality of conductor wires, the conductor wire closest to the slot-forming surface in the radial direction has an opposing surface that faces the slot-forming surface, and in the cross section, a distance between the opposing surface and the slot-forming surface is constant. Effect of the Invention

[0008] According to the present invention, the space factor can be further increased. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a configuration of an electric motor stator according to a first embodiment. [Diagram 2] 1 is a cross-sectional view showing a configuration of an electric motor stator according to a first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view showing a configuration of an electric motor stator according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Embodiment 1 An electric motor stator according to a first embodiment will be described. FIG. 1 is a perspective view showing the configuration of the electric motor stator according to the present embodiment. FIG. 2 is a cross-sectional view showing the configuration of the electric motor stator according to the present embodiment. FIG. 2 shows the configuration for one slot in a cross section perpendicular to the axial direction of a core 10. The electric motor stator according to the present embodiment is combined with an electric motor rotor (not shown) to form an inner rotor type electric motor. The electric motor stator according to the present embodiment is arranged on the outer periphery of the electric motor rotor.

[0011] As shown in Fig. 1 and Fig. 2, the electric motor stator has a core 10 and a plurality of coils attached to the core 10. The core 10 has an overall annular shape. Each of the plurality of coils has a substantially similar configuration. Three of the plurality of coils, coils 20A, 20B, and 20C, are shown in Fig. 1.

[0012] In the following description, the direction along the central axis of core 10 may be referred to as the "axial direction of core 10" or simply as the "axial direction." In a cross section perpendicular to the axial direction, the direction along the circumference centered on the central axis of core 10 may be referred to as the "circumferential direction of core 10" or simply as the "circumferential direction." In the same cross section, the direction along the radius of core 10 may be referred to as the "radial direction of core 10" or simply as the "radial direction."

[0013] The core 10 has a core back 11 and a plurality of teeth 12. The core back 11 has an annular shape. The core back 11 has a slot forming surface 11a. The slot forming surface 11a faces a slot 13 described later. In this embodiment, the slot forming surface 11a is a concave curved surface formed into a cylindrical surface. However, the slot forming surface 11a may be formed into a flat surface.

[0014] Each of the teeth 12 protrudes inward from the core back 11 in the radial direction of the core 10. Each tooth 12 has one side surface 12a and the other side surface 12b. Both the side surface 12a and the side surface 12b are formed in a flat shape. The side surface 12a of each tooth 12 faces the side surface 12b of the adjacent tooth 12.

[0015] Flanges 12c, 12d are formed at the tip of each tooth 12 in the protruding direction. Flange 12c protrudes to one side along the circumferential direction of core 10 from a portion of the tip of each tooth 12 closer to side surface 12a. Flange 12d protrudes to the other side along the circumferential direction of core 10 from a portion of the tip of each tooth 12 closer to side surface 12b. Flange 12c of each tooth 12 and flange 12d of an adjacent tooth 12 face each other with a gap therebetween.

[0016] Each of the coils 20A, 20B, and 20C has a helical structure. When each of the coils 20A, 20B, and 20C is viewed along its respective helical axis, each of the coils 20A, 20B, and 20C is formed in a generally rectangular frame shape. Each of the coils 20A, 20B, and 20C is formed, for example, using a 3D printer. Each of the coils 20A, 20B, and 20C is attached to the corresponding tooth 12 so as to form a concentrated winding. Each of the coils 20A, 20B, and 20C is insulated from the core 10 by an insulator (not shown).

[0017] A slot 13 is formed between two adjacent teeth 12 among the multiple teeth 12. The slot 13 is surrounded by a slot forming surface 11a of the core back 11, a side surface portion 12a and a flange portion 12c of one tooth 12, and a side surface portion 12b and a flange portion 12d of the other tooth 12.

[0018] The width of the slot 13 in the circumferential direction of the core 10 becomes narrower toward the inside in the radial direction of the core 10. That is, the width W2 of the slot 13 in the portion close to the flanges 12c and 12d is narrower than the width W1 of the slot 13 in the portion close to the slot forming surface 11a (W2 <W1)。

[0019] Four corners 13a, 13b, 13c, and 13d are formed on the inner surface of the slot 13. The corner 13a is formed between the slot forming surface 11a and the side surface 12a of one of the teeth 12. The corner 13b is formed between the slot forming surface 11a and the side surface 12b of the other tooth 12. The corner 13c is formed between the side surface 12a of one of the teeth 12 and the flange 12c of the tooth 12. The corner 13d is formed between the side surface 12b of the other tooth 12 and the flange 12d of the tooth 12. In the cross section shown in FIG. 2, the corners 13a, 13b, 13c, and 13d are all rounded.

[0020] A plurality of conductor wires 21a, 21b, 21c, 21d, and 21e that are part of coil 20A, and a plurality of conductor wires 21f, 21g, 21h, 21i, and 21j that are part of coil 20B are housed in slot 13. In the cross section shown in FIG. 2, the overall contour shape of conductor wires 21a, 21b, 21c, 21d, 21e, 21f, 21g, 21h, 21i, and 21j is generally similar to the shape of slot 13.

[0021] The conductor wires 21a, 21b, 21c, 21d, and 21e are arranged in parallel in this order from the outside along the radial direction of the core 10. Each of the conductor wires 21a, 21b, 21c, 21d, and 21e has a generally rectangular cross-sectional shape. A gap between two adjacent conductor wires among the conductor wires 21a, 21b, 21c, 21d, and 21e is filled with an insulating material (not shown).

[0022] The conductor wires 21f, 21g, 21h, 21i, and 21j are arranged in parallel in this order from the outside along the radial direction of the core 10. Each of the conductor wires 21f, 21g, 21h, 21i, and 21j has a generally rectangular cross-sectional shape. A gap between two adjacent conductor wires among the conductor wires 21f, 21g, 21h, 21i, and 21j is filled with an insulating material (not shown).

[0023] In the slot 13, the set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j are adjacent to each other in the circumferential direction of the core 10. The set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j are symmetrical to each other. An insulating member (not shown) is filled in the gap between the set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j.

[0024] The configuration of the set of conductor wires 21a, 21b, 21c, 21d, and 21e will be described below, but the set of conductor wires 21f, 21g, 21h, 21i, and 21j also has a similar configuration. The dimension of each of the conductor wires 21a, 21b, 21c, 21d, and 21e along the circumferential direction of the core 10 is defined as the circumferential dimension of each of the conductor wires. In this case, the circumferential dimensions of the conductor wires 21a, 21b, 21c, 21d, and 21e are smaller as the circumferential dimensions of the conductor wires located radially inside the core 10. That is, the circumferential dimension Wa of the conductor wire 21a, the circumferential dimension Wb of the conductor wire 21b, the circumferential dimension Wc of the conductor wire 21c, the circumferential dimension Wd of the conductor wire 21d, and the circumferential dimension We of the conductor wire 21e satisfy the relationship Wa>Wb>Wc>Wd>We.

[0025] For each of the conductor lines 21a, 21b, 21c, 21d, and 21e, the dimension along the radial direction of the core 10 is defined as the radial dimension of each conductor line. At this time, the radial dimensions of the conductor lines 21a, 21b, 21c, 21d, and 21e are larger as the conductor lines are located more inward in the radial direction of the core 10. That is, the radial dimension Ra of the conductor line 21a, the radial dimension Rb of the conductor line 21b, the radial dimension Rc of the conductor line 21c, the radial dimension Rd of the conductor line 21d, and the radial dimension Re of the conductor line 21e satisfy the relationship Ra < Rb < Rc < Rd < Re.

[0026] In the present embodiment, since the coil 20A is formed using a 3D printer, the conductor lines 21a, 21b, 21c, 21d, and 21e having the above-described relationships of the circumferential dimensions and the radial dimensions can be easily formed. The cross-sectional areas of the respective conductor lines 21a, 21b, 21c, 21d, and 21e are equal.

[0027] The conductor line 21a is the conductor line that is closest to the slot formation surface 11a in the radial direction of the core 10 among the conductor lines 21a, 21b, 21c, 21d, and 21e. Further, the conductor line 21a is the conductor line located at the outer peripheral end in the radial direction of the core 10 among the conductor lines 21a, 21b, 21c, 21d, and 21e.

[0028] The conductor line 21a has a facing surface 21a1 that faces the slot formation surface 11a. In the cross-section shown in FIG. 2, the facing surface 21a1 has a shape following the shape of the slot formation surface 11a. In the present embodiment, since the slot formation surface 11a is formed in a cylindrical surface shape, the facing surface 21a1 is formed in a cylindrical surface shape. Thereby, in the cross-section shown in FIG. 2, the distance between the facing surface 21a1 and the slot formation surface 11a is constant.

[0029] When the slot formation surface 11a is formed in a planar shape, it is desirable that the facing surface 21a1 is formed in a planar shape parallel to the slot formation surface 11a. Thereby, the distance between the facing surface 21a1 and the slot formation surface 11a can be made constant.

[0030] Conductor wire 21a has corner 21a2 facing corner 13a. In the cross section shown in Fig. 2, corner 21a2 has a shape following the shape of corner 13a. That is, corner 21a2 is chamfered to have a rounded edge corresponding to the roundness of corner 13a. As a result, in the cross section shown in Fig. 2, the distance between corner 21a2 and corner 13a is constant.

[0031] Of the conductor wires 21a, 21b, 21c, 21d, and 21e, the conductor wire 21e is the farthest from the slot forming surface 11a in the radial direction of the core 10. Moreover, of the conductor wires 21a, 21b, 21c, 21d, and 21e, the conductor wire 21e is the conductor wire located at the inner circumferential end in the radial direction of the core 10.

[0032] Conductor wire 21e has corner 21e2 facing corner 13c. In the cross section shown in Fig. 2, corner 21e2 has a shape following the shape of corner 13c. That is, corner 21e2 is chamfered with a radius corresponding to the roundness of corner 13c. As a result, in the cross section shown in Fig. 2, the distance between corner 21e2 and corner 13c is constant.

[0033] As described above, the electric motor stator according to the present embodiment includes an annular core 10 and a coil 20A attached to the core 10. The core 10 includes a core back 11 and a plurality of teeth 12. The plurality of teeth 12 protrude from the core back 11 along the radial direction of the core 10. A slot 13 is formed between two adjacent teeth 12 among the plurality of teeth 12. The width of the slot 13 in the circumferential direction of the core 10 becomes narrower toward the inside in the radial direction. The core back 11 has a slot forming surface 11a facing the slot 13. In a cross section perpendicular to the axial direction of the core 10, a plurality of conductor wires 21a, 21b, 21c, 21d, and 21e that are part of the coil 20A are accommodated in the slot 13 in parallel along the radial direction.

[0034] In the above cross section, the dimensions of the conductor wires 21a, 21b, 21c, 21d, and 21e along the circumferential direction are defined as circumferential dimensions Wa, Wb, Wc, Wd, and We of the conductor wires 21a, 21b, 21c, 21d, and 21e. The circumferential dimensions Wa, Wb, Wc, Wd, and We of the conductor wires 21a, 21b, 21c, 21d, and 21e are smaller as the conductor wires are positioned radially inward. Among the conductor wires 21a, 21b, 21c, 21d, and 21e, the conductor wire 21a that is closest to the slot-forming surface 11a in the radial direction has an opposing surface 21a1 that faces the slot-forming surface 11a. In the above cross section, the distance between the opposing surface 21a1 and the slot-forming surface 11a is constant.

[0035] This configuration ensures a necessary distance between the opposing surface 21a1 and the slot forming surface 11a while preventing the distance from becoming longer than necessary, thereby further increasing the space factor of the motor stator.

[0036] In the electric motor stator according to the present embodiment, of the multiple conductor wires 21a, 21b, 21c, 21d, and 21e, conductor wire 21a located at one end in the radial direction has corner 21a2 facing corner 13a of the inner surface of slot 13. Conductor wire 21e located at the other end in the radial direction has corner 21e2 facing corner 13c of the inner surface of slot 13. In the above cross section, corner 21a2 has a shape following the shape of corner 13a, and corner 21e2 has a shape following the shape of corner 13c.

[0037] This configuration can ensure the necessary distance between the corner 21a2 and the corner 13a, and between the corner 21e2 and the corner 13c, while preventing the distance from becoming longer than necessary, thereby further increasing the space factor of the motor stator.

[0038] In the above cross section of the motor stator according to the present embodiment, the radial dimensions of each of the conductor wires 21a, 21b, 21c, 21d, and 21e are defined as radial dimensions Ra, Rb, Rc, Rd, and Re of the conductor wires 21a, 21b, 21c, 21d, and 21e, respectively. The radial dimensions Ra, Rb, Rc, Rd, and Re of the conductor wires 21a, 21b, 21c, 21d, and 21e are larger for the conductor wires located radially more inward.

[0039] With this configuration, even if the circumferential dimensions of the conductor wires 21a, 21b, 21c, 21d, and 21e are smaller toward the inside in the radial direction, the cross-sectional areas of the conductor wires 21a, 21b, 21c, 21d, and 21e can be made closer to each other. Therefore, when a current is passed through the coil 20A, the current densities of the conductor wires 21a, 21b, 21c, 21d, and 21e in the cross section can be made closer to each other.

[0040] In the cross section of the motor stator according to the present embodiment, the conductor wires 21a, 21b, 21c, 21d, and 21e have the same cross-sectional area. With this configuration, the current densities of the conductor wires 21a, 21b, 21c, 21d, and 21e in the cross section can be made equal.

[0041] Embodiment 2 An electric motor stator according to a second embodiment will be described. Fig. 3 is a cross-sectional view showing the configuration of the electric motor stator according to this embodiment. Fig. 3 shows the configuration for one slot in a cross section perpendicular to the axial direction of core 10. The electric motor stator according to this embodiment is combined with an electric motor rotor (not shown) to form an outer rotor type electric motor. The electric motor stator according to this embodiment is disposed on the inner peripheral side of the electric motor rotor.

[0042] As shown in Fig. 3, each of the teeth 12 protrudes outward from the core back 11 in the radial direction of the core 10. The core back 11 has a slot forming surface 11a. In this embodiment, the slot forming surface 11a is a convex curved surface formed into a cylindrical surface. However, the slot forming surface 11a may be formed into a flat surface.

[0043] A slot 13 is formed between two adjacent teeth 12 among the multiple teeth 12. The slot 13 is surrounded by a slot forming surface 11a of the core back 11, a side surface portion 12a and a flange portion 12c of one tooth 12, and a side surface portion 12b and a flange portion 12d of the other tooth 12.

[0044] The width of the slot 13 in the circumferential direction of the core 10 becomes narrower toward the inside in the radial direction of the core 10. That is, the width W2 of the slot 13 in the portion close to the slot forming surface 11a is narrower than the width W1 of the slot 13 in the portion close to the flange portions 12c and 12d (W2 <W1)。

[0045] Four corners 13a, 13b, 13c, and 13d are formed on the inner surface of the slot 13. The corner 13a is formed between the slot forming surface 11a and the side surface 12a of one of the teeth 12. The corner 13b is formed between the slot forming surface 11a and the side surface 12b of the other tooth 12. The corner 13c is formed between the side surface 12a of one of the teeth 12 and the flange portion 12c of the tooth 12. The corner 13d is formed between the side surface 12b of the other tooth 12 and the flange portion 12d of the tooth 12. In the cross section shown in FIG. 3, the corners 13a, 13b, 13c, and 13d are all rounded.

[0046] A plurality of conductor wires 21a, 21b, 21c, 21d, and 21e that are part of coil 20A, and a plurality of conductor wires 21f, 21g, 21h, 21i, and 21j that are part of coil 20B are housed in slot 13. In the cross section shown in FIG.

[0047] The conductor wires 21a, 21b, 21c, 21d, and 21e are arranged in parallel in this order from the outside along the radial direction of the core 10. Each of the conductor wires 21a, 21b, 21c, 21d, and 21e has a generally rectangular cross-sectional shape. A gap between two adjacent conductor wires among the conductor wires 21a, 21b, 21c, 21d, and 21e is filled with an insulating material (not shown).

[0048] The conductor wires 21f, 21g, 21h, 21i, and 21j are arranged in parallel in this order from the outside along the radial direction of the core 10. Each of the conductor wires 21f, 21g, 21h, 21i, and 21j has a generally rectangular cross-sectional shape. A gap between two adjacent conductor wires among the conductor wires 21f, 21g, 21h, 21i, and 21j is filled with an insulating material (not shown).

[0049] In the slot 13, the set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j are adjacent to each other in the circumferential direction of the core 10. The set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j are symmetrical to each other. An insulating member (not shown) is filled in the gap between the set of conductor wires 21a, 21b, 21c, 21d, and 21e and the set of conductor wires 21f, 21g, 21h, 21i, and 21j.

[0050] The configuration of the set of conductor lines 21a, 21b, 21c, 21d, and 21e will be described below. The set of conductor lines 21f, 21g, 21h, 21i, and 21j has the same configuration. The circumferential dimensions of the conductor lines 21a, 21b, 21c, 21d, and 21e are smaller than those of the conductor lines located on the inner side in the radial direction of the core 10. That is, the circumferential dimension Wa of the conductor line 21a, the circumferential dimension Wb of the conductor line 21b, the circumferential dimension Wc of the conductor line 21c, the circumferential dimension Wd of the conductor line 21d, and the circumferential dimension We of the conductor line 21e satisfy the relationship Wa > Wb > Wc > Wd > We.

[0051] The radial dimensions of the conductor lines 21a, 21b, 21c, 21d, and 21e are larger than those of the conductor lines located on the inner side in the radial direction of the core 10. That is, the radial dimension Ra of the conductor line 21a, the radial dimension Rb of the conductor line 21b, the radial dimension Rc of the conductor line 21c, the radial dimension Rd of the conductor line 21d, and the radial dimension Re of the conductor line 21e satisfy the relationship Ra < Rb < Rc < Rd < Re.

[0052] In the present embodiment, since the coil 20A is formed using a 3D printer, the conductor lines 21a, 21b, 21c, 21d, and 21e having the above-described relationships of the circumferential dimensions and the radial dimensions can be easily formed. The cross-sectional areas of the respective conductor lines 21a, 21b, 21c, 21d, and 21e are equal.

[0053] The conductor line 21e is the conductor line that is closest to the slot formation surface 11a in the radial direction of the core 10 among the conductor lines 21a, 21b, 21c, 21d, and 21e. Further, the conductor line 21e is the conductor line located at the inner peripheral end in the radial direction of the core 10 among the conductor lines 21a, 21b, 21c, 21d, and 21e.

[0054] The conductor wire 21e has an opposing surface 21e1 that faces the slot-forming surface 11a. In the cross section shown in FIG. 3, the opposing surface 21e1 has a shape that matches the shape of the slot-forming surface 11a. In this embodiment, since the slot-forming surface 11a is formed into a cylindrical surface, the opposing surface 21e1 is also formed into a cylindrical surface. As a result, in the cross section shown in FIG. 3, the distance between the opposing surface 21e1 and the slot-forming surface 11a is constant.

[0055] When the slot forming surface 11a is formed in a flat shape, it is preferable that the opposing surface 21e1 is formed in a flat shape parallel to the slot forming surface 11a, so that the distance between the opposing surface 21e1 and the slot forming surface 11a can be made constant.

[0056] Conductor wire 21e has corner 21e2 facing corner 13a. In the cross section shown in Fig. 3, corner 21e2 has a shape following the shape of corner 13a. That is, corner 21e2 is chamfered to have a rounded edge corresponding to the roundness of corner 13a. As a result, the distance between corner 21e2 and corner 13a is constant in the cross section shown in Fig. 3.

[0057] Of the conductor wires 21a, 21b, 21c, 21d, and 21e, the conductor wire 21a is the conductor wire that is farthest from the slot forming surface 11a in the radial direction of the core 10. Moreover, of the conductor wires 21a, 21b, 21c, 21d, and 21e, the conductor wire 21a is the conductor wire that is located at the outer circumferential end in the radial direction of the core 10.

[0058] Conductor wire 21a has corner 21a2 facing corner 13c. In the cross section shown in Fig. 3, corner 21a2 has a shape following the shape of corner 13c. That is, corner 21a2 is chamfered to have a rounded edge corresponding to the roundness of corner 13c. As a result, the distance between corner 21a2 and corner 13c is constant in the cross section shown in Fig. 3.

[0059] According to this embodiment, the same effects as those of the first embodiment can be obtained. [Explanation of symbols]

[0060] 10 core, 11 core back, 11a slot forming surface, 12 teeth, 12a, 12b side portions, 12c, 12d flange portions, 13 slots, 13a, 13b, 13c, 13d corner portions, 20A, 20B, 20C coils, 21a conductor wire, 21a1 opposing surface, 21a2 corner portion, 21b, 21c, 21d, 21e conductor wire, 21e1 opposing surface, 21e2 corner portion, 21f, 21g, 21h, 21i, 21j conductor wires, Ra, Rb, Rc, Rd, Re radial dimensions, W1, W2 widths, Wa, Wb, Wc, Wd, We circumferential dimensions.

Claims

1. A toric core (10); A coil (20A) attached to the core; Equipped with The core has a core back (11) and a plurality of teeth (12) protruding from the core back along a radial direction of the core, A slot (13) is formed between two adjacent teeth among the plurality of teeth, A width of the slot in the circumferential direction of the core is narrowed toward the inside in the radial direction, The core back has a slot forming surface (11a) facing the slot, In a cross section perpendicular to the axial direction of the core, a plurality of conductor wires (21 a, 21 b, ...) that are part of the coil are housed in the slots in parallel along the radial direction, When the dimension of each of the plurality of conductor wires in the cross section along the circumferential direction is defined as the circumferential dimension (Wa, Wb, . . . ) of each of the plurality of conductor wires, a circumferential dimension of each of the plurality of conductor wires is smaller toward the inside in the radial direction, Among the plurality of conductor wires, the conductor wire closest to the slot forming surface in the radial direction has an opposing surface (21a1) opposing the slot forming surface, An electric motor stator, wherein the distance between the opposing surface and the slot forming surface is constant in the cross section.

2. Among the plurality of conductor wires, the conductor wires (21a, 21e) located at both ends in the radial direction have corners (21a2, 21e2) facing corners (13a, 13c) of the inner surface of the slot, 2. The electric motor stator according to claim 1, wherein in the cross section, the corner portion has a shape conforming to a shape of the corner portion.

3. When the dimension of each of the plurality of conductor wires in the cross section along the radial direction is defined as the radial dimension (Ra, Rb, ...) of each of the plurality of conductor wires, 3. The electric motor stator according to claim 1, wherein a radial dimension of each of the plurality of conductor wires is greater toward the inside in the radial direction.

4. 3. The electric motor stator according to claim 1, wherein the cross-sectional areas of the plurality of conductor wires are equal in the cross section.

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