Manufacturing method of stator of rotary electric machine

Abstract

To provide a manufacturing method of a stator of a rotary electric machine capable of simplifying assembly work of the stator using a coil of a flat wire.SOLUTION: Provided is a manufacturing method of a stator of a rotary electric machine and the stator comprises: a first stator core in which a plurality of teeth is radially disposed at an outer peripheral side of a cylindrical body; and an annular second stator core of which the inner periphery is abutted with outer peripheral side ends of the teeth. In a first step, a coil segment including a coil part, which is formed by bending a flat wire in a loop shape, is inserted from an outer peripheral side of the first stator core in a radial direction in such a manner that the flat wire is disposed between the teeth. In a second step, the second stator core is inserted to an outer periphery of the first stator core, to which the coil segment is inserted, in an axial direction, and the first stator core and the second stator core are coupled.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a stator for a rotating electrical machine. [Background technology]

[0002] 2. Description of the Related Art Conventionally, various stators have been proposed that have a structure in which a stator core is divided in the radial direction and an annular outer diameter portion is attached to the outer periphery of an inner diameter portion having teeth. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-126984 [Patent Document 2] Patent Publication No. 2021-136717 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve the coil space factor in the slot, a coil made of rectangular wire may be applied to the stator. In manufacturing a stator using a coil made of rectangular wire, for example, a U-shaped coil component is inserted into the slot from the axial direction of the stator to avoid interference with the flange portion formed on the teeth. After the coil component is inserted into the slot, it is welded, and the coil connected by welding is subsequently subjected to post-processing such as powder coating. Therefore, there is room for improvement in that the assembly work of the stator is complicated.

[0005] The present invention has been made in consideration of the above circumstances, and provides a manufacturing method for a stator for a rotating electric machine that can simplify the assembly work of a stator using a coil of rectangular wire. [Means for solving the problem]

[0006] One aspect is a method for manufacturing a stator for a rotating electric machine, the stator comprising a first stator core having a plurality of teeth arranged radially on the outer periphery of a cylindrical body, and an annular second stator core whose inner periphery abuts the outer periphery ends of the teeth. In a first step, a coil segment having a coil portion formed by bending a rectangular wire into a loop is inserted radially from the outer periphery of the first stator core so that the rectangular wire is arranged between the teeth. In a second step, the second stator core is inserted axially around the outer periphery of the first stator core after the coil segment is inserted, and the first stator core and the second stator core are joined together.

[0007] In the above-described method for manufacturing a stator, the coil segment may be formed from a single rectangular wire and have a plurality of coil portions that are circumferentially spaced apart and connected by jumper portions. In the above-described method for manufacturing a stator, the rotating electric machine may have a rotor disposed on the inner periphery of the stator, and the coil portion may face the rotor across the cylindrical body in the radial direction. In the above-described method for manufacturing a stator, a radial width of the cylindrical body may be smaller than a radial width of the second stator core. Effect of the Invention

[0008] According to one aspect, it is possible to provide a manufacturing method for a stator for a rotating electric machine that can simplify the assembly work of a stator using a coil of rectangular wire. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a rotating electric machine according to an embodiment of the present invention; [Diagram 2] 11A to 11C are diagrams showing a process of arranging coil segments on a first stator core. [Diagram 3] 5A to 5C are diagrams showing a process of joining the first stator core and the second stator core. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiments, in order to make the description easier to understand, structures and elements other than the main parts of the present invention will be described in a simplified or omitted manner. In addition, in the drawings, the same elements are given the same reference numerals. Note that the shapes, dimensions, etc. of each element shown in the drawings are shown only for illustrative purposes, and do not represent the actual shapes, dimensions, etc.

[0011] In the following description, the direction parallel to the extension direction of the rotation axis Ax is referred to as the axial direction, the circumferential direction centered on the rotation axis Ax is simply referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax is simply referred to as the radial direction. In the following description, "extending in the axial direction" includes not only the case of extending strictly in the axial direction, but also the case of extending in a direction tilted by less than 45° with respect to the axial direction. In addition, "extending in the radial direction" includes not only the case of extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction, but also the case of extending in a direction tilted by less than 45° with respect to the radial direction. In addition, "parallel" includes not only the case of being strictly parallel, but also the case of being tilted by an angle of less than 45° with respect to each other.

[0012] FIG. 1 is a diagram showing an example of a rotating electric machine according to the present embodiment. As shown in Fig. 1, a rotating electric machine 1 of this embodiment is, for example, an inner rotor type motor for an electric vehicle, and has a rotor 2, a shaft 3, and a stator 4. In Fig. 1, the extension direction (axial direction) of a rotation axis Ax of the rotating electric machine 1 is perpendicular to the plane of the drawing.

[0013] The rotor 2 has an overall cylindrical shape and may be, for example, any of an embedded magnet type rotor, a surface magnet type rotor, a squirrel-cage type rotor, a wound type rotor, etc. A shaft 3 is fitted into the center of the rotor 2 so as to penetrate the iron core along the rotation axis Ax. The shaft 3 of the rotor 2 is supported by a bearing (not shown).

[0014] The stator 4 is arranged concentrically around the rotor 2 with a small air gap between them. The overall shape of the stator 4 is cylindrical, and U-, V-, and W-phase coils 12 are wound around it. The coils 12 for each phase are each made of rectangular wire, and are arranged around the circumferential direction of the stator 4 with the U-, V-, and W-phase coils shifted from each other.

[0015] The iron core of the stator 4 is divided into two in the radial direction, and includes a first stator core 13 on the inner periphery side and an annular second stator core 14 on the outer periphery side. The first stator core 13 and the second stator core 14 are each formed, for example, by laminating punched silicon steel plates in an insulated state in the axial direction.

[0016] 2(a) and (b), the first stator core 13 has an annular bridging portion 13a and a plurality of teeth 13b. The annular bridging portion 13a is an example of a cylindrical body, and is formed in a ring shape whose inner periphery faces the outer periphery of the rotor 2, and serves to hold each of the teeth 13b on the inner periphery.

[0017] Each of the teeth 13b extends a predetermined length in the radial direction from the outer periphery of the annular bridging portion 13a. The teeth 13b of the first stator core 13 are arranged radially around the rotation axis Ax and are comb-shaped at equal intervals on the outer periphery of the annular bridging portion 13a. A positioning protrusion 13d for positioning the second stator core 14 is formed on the outer periphery end of some of the teeth 13b.

[0018] Slots 13c for accommodating coils 12 are formed between the teeth 13b of the first stator core 13. Each slot 13c of the first stator core 13 is open on both axial ends and on the outer circumferential side.

[0019] The second stator core 14 functions as a yoke portion of the stator 4. The inner circumference of the second stator core 14 is formed to a size that allows it to abut against the outer circumferential end of the teeth portion 13b of the first stator core 13. The radial width of the second stator core 14 is set to be sufficiently larger than the radial width of the annular bridging portion 13a. In addition, the inner circumference of the second stator core 14 is formed with positioning grooves 14a that engage with the protrusions 13d at positions corresponding to the protrusions 13d of the teeth portion 13b. The grooves 14a each extend in the axial direction.

[0020] 1, the magnetic field of the stator 4 is switched in sequence by controlling the current of the coils 12 of each phase, thereby forming a rotating magnetic field in the stator 4. Then, the rotor 2 and the shaft 3 rotate about the rotation axis Ax due to the attractive or repulsive force with the magnetic field of the rotor 2.

[0021] In addition, in the rotating electric machine 1 of this embodiment, the annular bridging portion 13a is disposed on the inner periphery side of the stator 4, and no openings communicating with the slots 13c are formed on the inner periphery side of the stator 4. That is, the coil 12 faces the rotor 2 across the annular bridging portion 13a in the radial direction. Therefore, in this embodiment, the annular bridging portion 13a can increase the number of magnetic fluxes interlinked with the coil 12. Furthermore, the annular bridging portion 13a also serves the function of making the inner periphery surface of the stator 4 uniform in the circumferential direction to suppress windage loss of the rotating electric machine 1. As a result, in the rotating electric machine 1 of this embodiment, torque ripple can be suppressed without reducing the torque of the rotating electric machine 1.

[0022] Hereinafter, a procedure for assembling the stator 4 of this embodiment will be described with reference to FIGS. First, the coils 12 of each phase are arranged on the first stator core 13. In arranging the coils 12, a plurality of coil segments 12a using rectangular wire are prepared for each phase.

[0023] The coil segment 12a is formed by bending a single rectangular wire, and has a plurality of coil portions 12a1 and a crossover portion 12a2 spaced apart in the circumferential direction, as shown in FIG. 2(a). Each coil portion 12a1 is formed by bending a rectangular wire into a loop shape at a predetermined slot pitch. The crossover portion 12a2 connects the plurality of coil portions 12a1 in the circumferential direction. FIG. 2(a) shows the coil segment 12a constituting a part of the U-phase coil 12, and the remaining coil segments of the U-phase and the coil segments of the V-phase and W-phase are not shown.

[0024] 2(a) and (b), the coils 12 of each phase are arranged by radially inserting the coil segments 12a from the outer periphery into the slots 13c of the first stator core 13 so that the rectangular wire is arranged between the teeth 13b. Because the outer periphery of each slot 13c of the first stator core 13 is open, an operator can easily insert the coil segments 12a into the slots 13c without interfering with the teeth 13b, and the rectangular wire coils 12 can be arranged in each slot 13c with a high space factor.

[0025] Next, after the coil 12 is arranged on the first stator core 13, the second stator core 14 is inserted and attached axially onto the outer periphery of the first stator core 13 with the projections 13d and grooves 14a aligned as shown in Fig. 3. In Fig. 3, the second stator core 14 inserted axially is indicated by a dashed line. In this way, the first stator core 13 with the coil 12 arranged thereon and the second stator core 14 are joined together to form the stator 4. Thereafter, the rotor 2 is disposed on the inner periphery of the stator 4, thereby completing the manufacture of the rotating electric machine 1 shown in FIG.

[0026] As described above, in assembling the stator 4 in this embodiment, the loop-shaped coil portion 12a1 can be used when arranging the coil 12 in the first stator core 13. Therefore, in this embodiment, it is possible to omit the work of inserting divided coil components into the slots 13c and then welding the coil components together to form one coil 12, and the troublesome post-treatment including powder coating of the connection portion, etc. This simplifies the assembly work of the stator 4.

[0027] Furthermore, in this embodiment, by inserting one coil segment 12a into the first stator core 13, the coil portions 12a1 can be simultaneously arranged at a plurality of locations in the circumferential direction of the first stator core 13.

[0028] The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

[0029] For example, in the above embodiment, the rotating electric machine 1 is a motor, but the rotating electric machine 1 may be a generator. Also, the rotating electric machine of the above embodiment is not limited to use in an electric vehicle, and may be used for other purposes. In addition, in the above embodiment, a configuration example has been shown in which the protrusions of teeth portion 13b are engaged with the grooves of second stator core 14, but a configuration in which protrusions are formed on second stator core 14 and engaged with the grooves of teeth portion 13b may also be used.

[0030] In addition, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0031] Reference Signs List 1... rotating electric machine, 2... rotor, 3... shaft, 4... stator, 12... coil, 12a... coil segment, 12a1... coil portion, 12a2... bridge portion, 13... first stator core, 13a... annular bridging portion, 13b... teeth portion, 13c... slot, 13d... projection, 14... second stator core, 14a... groove

Claims

1. A method for manufacturing a stator for a rotating electric machine, comprising the steps of: the stator includes a first stator core having a plurality of teeth radially arranged on an outer periphery of a cylindrical body, and an annular second stator core whose inner periphery abuts on outer periphery ends of the teeth, A first step of inserting a coil segment having a coil portion formed by bending a rectangular wire into a loop shape from an outer periphery side of the first stator core in a radial direction such that the rectangular wire is disposed between the teeth portions; and a second step of axially inserting the second stator core onto the outer periphery of the first stator core after the coil segments have been inserted, thereby joining the first stator core and the second stator core together. A method for manufacturing a stator.

2. The coil segment is formed from a single rectangular wire, and has a plurality of the coil sections that are arranged at intervals in the circumferential direction and connected by jumper sections. A method for manufacturing a stator according to claim 1 .

3. the rotating electric machine has a rotor that is disposed on an inner circumferential side of the stator, The coil portion faces the rotor across the cylindrical body in the radial direction. A method for manufacturing a stator according to claim 1 .

4. The radial width of the cylindrical body is smaller than the radial width of the second stator core. A method for manufacturing a stator according to claim 1 .

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