Stator

Abstract

This stator is configured such that: in a plurality of adjacent coil end parts, one and the other circumferential-direction inclined parts do not overlap each other in the axial direction, and the side surfaces on the circumferential direction side are adjacent to each other so as to face each other; and in the plurality of adjacent coil end parts, the lower surface of the circumferential-direction inclined part of one coil end part and the end part on the axial-direction inclined part side of a crank part of the other coil end part do not overlap each other in the axial direction and are adjacent to each other in the circumferential direction.

Description

Stator

[0001] The present invention relates to a stator.

[0002] A stator has been known in the art, and is described in, for example, Japanese Patent Application Laid-Open No. 2014-225974.

[0003] Japanese Patent Application Publication No. 2014-225974 discloses a stator for a rotating electric machine including an annular stator core with a plurality of slots and coils inserted into the slots. In Japanese Patent Application Publication No. 2014-225974, at least one axial end of the stator core, the coils are arranged such that crossover sections connecting the radially inner portion of one slot to the radially outer portion of another slot overlap in the circumferential direction and as viewed from the axial direction, thereby forming a coil end section. Furthermore, the crossover sections are twisted so that they cross in the radial direction to prevent interference between the coils.

[0004] JP 2014-225974 A

[0005] In the stator core of JP 2014-225974 A, the coil end portions (coils) are twisted and processed so as to intersect when viewed from the radial direction, resulting in a complex shape.

[0006] Furthermore, although not disclosed in JP 2014-225974 A, when coil end portions are formed by twisting, the complex shape of the coil end portions makes processing difficult, so the dimensions are set larger in advance to take into account shape variations. After processing, the coil end portions are then pressure-molded to reduce their axial length. However, pressure molding places excessive loads on the coil end portions. Therefore, it is desirable to suppress interference between coil end portions without twisting, and to reduce the axial length of the coil end portions without pressure molding.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a stator that can suppress interference between coil end portions and can suppress an increase in the axial length of the coil end portions without performing pressure molding.

[0008] In order to achieve the above object, a stator in one aspect of the present invention comprises a stator core, and a coil made of a rectangular wire, which is inserted into the stator core and includes a plurality of coil end portions that extend and protrude axially outward from an end face of the stator core, wherein the plurality of coil end portions are provided on the stator core side and have axially inclined portions that are inclined axially outward with respect to the end face of the stator core and extend circumferentially, a circumferential inclined portion that is inclined circumferentially with respect to the axially inclined portion when viewed from the axial direction and extends radially outward, and a crank portion that is configured to connect the axially inclined portion and the circumferential inclined portion and curves axially outward, wherein in adjacent plurality of coil end portions, one and the other circumferential inclined portions do not overlap with each other in the axial direction and the circumferential side surfaces are adjacent and face each other, and in adjacent plurality of coil end portions, the lower surface of the circumferential inclined portion of one coil end portion and the end of the crank portion of the other coil end portion on the axially inclined portion side do not overlap with each other in the axial direction but are adjacent to each other in the circumferential direction.

[0009] In one aspect of the present invention, the stator includes an axially inclined portion, a circumferentially inclined portion, and a crank portion, as described above. The axial length can be adjusted using the axially inclined portion and the circumferentially inclined portion, while the crank portion allows the coil end portions to be positioned so as not to interfere with each other. Furthermore, in adjacent coil end portions, the circumferentially inclined portions of one coil end portion and the other circumferentially inclined portion are adjacent and face each other, allowing the adjacent coil end portions to be positioned without interference along the circumferential direction. This eliminates the need to twist the coil end portions. Furthermore, in adjacent coil end portions, the lower surface of the circumferentially inclined portion of one coil end portion and the end of the crank portion of the other coil end portion on the axially inclined portion side do not overlap in the axial direction and are adjacent in the circumferential direction. This allows the coil end portions to be positioned so as not to overlap in the axial direction, and the crank portion can be positioned lower, preventing the axial length of the coil end portions from increasing. As a result, interference between the coil end portions can be prevented, and the axial length of the coil end portions can be prevented from increasing without pressure molding. Here, "adjacent" means that the two coil end portions are not in contact with each other but are located close to each other.

[0010] In the stator according to the aforementioned aspect, the axial length from the end face of the stator core to the circumferentially inclined portion is preferably greater than the axial length from the end face of the stator core to another portion of the coil end portion.

[0011] With this configuration, the axial length from the end face of the stator core to the circumferential inclined portion is the maximum value of the axial length from the end face of the stator core to the coil end portion, so by arranging the circumferential inclined portions along the circumferential direction, it is possible to easily prevent the axial length from becoming too large.

[0012] In this case, the circumferentially inclined portion is preferably configured to extend along the direction in which the end face of the stator core extends.

[0013] With this configuration, the circumferentially inclined portion, which has the maximum axial length from the end face of the stator core to the coil end portion, can be positioned horizontally in the radial direction, thereby effectively preventing the axial length of the coil end portion from becoming too large.

[0014] In the stator according to the above aspect, preferably, the coil end portion further includes a connection portion connecting the axially inclined portion and the crank portion, and the connection portion is configured to be inclined radially outward with respect to the axially inclined portion when viewed from the axial direction.

[0015] With this configuration, the connecting portions are tilted radially outward, thereby preventing contact with adjacent coil end portions. Furthermore, because the connecting portions can tilt the coil end portions radially outward before they are tilted axially by the crank portion, there is no need to tilt the crank portion radially outward, which prevents the crank portion from becoming complicated in structure.

[0016] In the stator according to the above aspect, the following configuration is also possible.

[0017] (Additional Item 1) In the stator according to the above aspect, the coil is configured by joining a plurality of segment coils, each of which includes an axially inclined portion and a circumferentially inclined portion.

[0018] With this configuration, the coil is constructed by joining multiple segment coils that include axially inclined portions and circumferentially inclined portions, so the coil can be easily constructed while preventing the axial length from becoming too large.

[0019] (Additional Item 2) In the stator according to the above aspect, the plurality of circumferential inclined portions are arranged so that the circumferential side surfaces thereof face and adjoin each other without being twisted.

[0020] With this configuration, the coil can be formed without twisting the multiple circumferentially inclined portions, which prevents the process of forming the coil end portions from becoming complicated.

[0021] 1 is a perspective view showing a stator in the first embodiment. FIG. 2 is a top view of a stator in the first embodiment. FIG. 3 is a perspective view showing a segment coil in the first embodiment. FIG. 4 is a top view showing a segment coil in the first embodiment. FIG. 5 is a top view showing an enlarged portion of the segment coil. FIG. 6 is a view of a portion of the segment coil from the radial direction. FIG. 7 is a perspective view showing a stator in the second embodiment. FIG. 8 is a top view of a stator in the second embodiment. FIG. 9 is a perspective view showing a segment coil in the second embodiment. FIG. 10 is a circuit diagram showing the wiring configuration of the coil in the second embodiment. FIG. 11 is a view of the segment coil in the second embodiment from the radial direction. FIG. 12 is a top view showing an enlarged portion of the segment coil in the second embodiment.

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] First Embodiment The configuration of a stator according to a first embodiment will be described with reference to FIGS. 1 to 6. FIG.

[0024] (Overall Configuration of Stator) The stator 100 shown in FIG. 1 constitutes part of a rotating electric machine (not shown) together with a rotor (not shown) arranged on the R1 side of the stator 100 so as to face the stator 100. The rotating electric machine is, for example, a motor, a generator, or a motor / generator. The stator 100 has a cylindrical shape. A hole through which the rotor is inserted is formed in the center of the stator 100. In the following description, the radial direction of the stator 100 is defined as the R direction, the circumferential direction of the stator 100 is defined as the C direction, and the axial direction in which the rotor is inserted into the stator 100 is defined as the Z direction.

[0025] The stator 100 includes a stator core 1 and a coil 2. The stator 100 is a three-phase AC stator.

[0026] The stator core 1 has a cylindrical shape with a central axis (not shown) along the Z direction. The stator core 1 is formed by stacking a plurality of electromagnetic steel plates (for example, silicon steel plates) in the Z direction.

[0027] The stator core 1 is provided with a plurality of slots 11, which are grooves extending in the Z direction. A coil 2, which is made up of a plurality of segment coils 20, is inserted into the slots 11.

[0028] As shown in Figure 2, the coil 2 is formed by joining multiple segment coils 20. The multiple segment coils 20 that make up the coil 2 are made of rectangular wire. As an example, the multiple segment coils 20 are made of copper wire. The coil 2 is configured to generate magnetic flux when supplied with three-phase AC power from a power supply unit (not shown). The segment coils 20 are arranged (wound) along the circumferential direction of the stator core 1 by moving back and forth in the Z direction through the slot portion 11. The coil 2 is formed by winding the joined multiple segment coils 20 two or more times along the circumferential direction of the stator core 1.

[0029] The plurality of segment coils 20 include a U-shaped segment coil 20 and an I-shaped segment coil 20.

[0030] The U-shaped segment coil 20 includes a pair of slot insertion portions 20a that are inserted into the slot portions 11 of the stator core 1, and a coil end portion 20b that connects the pair of slot insertion portions 20a. The U-shaped segment coil 20 includes an axially inclined portion 21 and a circumferentially inclined portion 22. The multiple segment coils 20 are arranged adjacent to each other. Here, in this specification, "adjacent" means that the two coil end portions are not in contact with each other but are located close to each other.

[0031] When inserted into the stator core 1, the U-shaped segment coil 20 has its coil end portion 20b exposed from one end face in the Z direction of the stator core 1, and both end portions 20c, which are not connected by the coil end portions 20b of the segment coil 20, exposed from the other end face in the Z direction of the stator core 1. The pair of slot insertion portions 20a is configured so that both end portions 20c are inserted across different slot portions 11. Furthermore, the end portions 20c of the multiple segment coils 20 exposed from the other end face in the Z direction of the stator core 1 are connected to each other to form one coil 2.

[0032] In one coil 2 shown in FIG. 2 , an I-shaped segment coil 20 is joined to a U-shaped segment coil 20 at both circumferential ends. The I-shaped coil forms a terminal portion. In this embodiment, two segment coils 20 are inserted into one slot 11. Two coils 2 are arranged for each of the U, V, and W phases of the three-phase AC. Each coil 2 for each phase has one end protruding from the outer peripheral surface of the stator core 1 and the other end not protruding from the outer peripheral surface of the stator core 1. Two coils 2 are arranged for each phase, and one end is connected to another component. Two coils 2 are arranged for each phase, and the other end is connected to an intermediate connecting wire connecting the U, V, and W phases. The terminal portion may be arranged on one axial side of the stator core 1 where the joints of the U-shaped segment coils 20 are provided, or on the other axial side of the stator core 1 where the coil end portions 20b are formed.

[0033] 3 and 4, the coil end portion 20b has an axially inclined portion 21, a circumferentially inclined portion 22, a crank portion 23, and a connecting portion 24. The coil end portion 20b also includes a second end portion 25 connected to the circumferentially inclined portion 22.

[0034] The segment coils 20 extend in the axial direction from the axial end face of the stator core 1, and then are inclined axially outward by the axially inclined portions 21. After being inclined axially outward by the axially inclined portions 21, they are inclined radially outward by the connection portions 24. They are inclined axially outward by the crank portions 23, and extend along the end face of the stator core 1 by the circumferential inclined portions 22. They are curved radially outward from the circumferential inclined portion 22 by the other end side portion 25 and inclined axially inward, and then extend axially toward the end face of the stator core 1 along the axial direction.

[0035] As shown in Figures 5 and 6, the axially inclined portion 21 is provided on the stator core 1 side. The axially inclined portion 21 is rectangular when viewed in the axial and circumferential directions. The axially inclined portion 21 is inclined axially outward with respect to the end face of the stator core 1. The segment coil 20 extends axially outward from the stator core 1 and is then inclined axially outward by the axially inclined portion 21. The axially inclined portion 21 extends along the circumferential direction. In Figure 6, the end face of the stator core 1 is simplified and shown by a dashed line.

[0036] The axially inclined portions 21 of the multiple segment coils 20 are arranged along the inner circumference of the stator core 1. The axially inclined portions 21 of adjacent segment coils 20 are arranged so as to face each other in the axial direction. Note that the axially inclined portions 21 of adjacent segment coils 20 do not need to face the entire upper surface of one segment coil 20 and the entire lower surface of the other segment coil 20; it is sufficient that a portion of the upper surface of one segment coil 20 faces a portion of the lower surface of the other segment coil 20. The axially inclined portions 21 of adjacent segment coils 20 are arranged offset in the circumferential direction.

[0037] The circumferential inclined portion 22 has a rectangular shape when viewed in the axial and circumferential directions. When viewed in the axial direction, the circumferential inclined portion 22 is inclined in the circumferential direction with respect to the axial inclined portion 21. The circumferential inclined portion 22 is inclined to such an extent that it does not come into contact with adjacent segment coils 20 in the circumferential direction. The circumferential inclined portion 22 extends radially outward. The circumferential inclined portion 22 is configured to extend along the direction in which the end face of the stator core 1 extends. In other words, the circumferential inclined portion 22 extends along the radial direction. The circumferential inclined portion 22 is formed approximately horizontal when viewed in the radial direction. Preferably, the circumferential inclined portion 22 is configured to extend parallel to the end face of the stator core 1.

[0038] In adjacent coil end portions 20b, the circumferential inclined portions 22 on one side and the other side are adjacent and do not overlap with each other in the axial direction, and the circumferential side surfaces 22a face each other. In adjacent coil end portions 20b, the circumferential inclined portions 22 on one side and the other side are formed so that their axial lengths from the end face of the stator core 1 are approximately the same. Although the circumferential inclined portions 22 on one side and the other side extend along the circumferential direction, they do not need to be parallel to each other, and one may be inclined relative to the other. Furthermore, the circumferential side surfaces 22a of the circumferential inclined portions 22 on the one side and the other side do not need to face each other entirely; they may face each other partially. The circumferential inclined portions 22 are arranged so that the circumferential side surfaces 22a face each other and are adjacent to each other without twisting.

[0039] The axial length from the end face of the stator core 1 to the circumferential inclined portion 22 is configured to be longer than the axial length from the end face of the stator core 1 to other parts of the coil end portion 20b. In other words, the longest part of the axial length from the end face of the stator core 1 to the segment coil 20 is included in the circumferential inclined portion 22. When the circumferential inclined portion 22 is approximately parallel to the end face of the stator core 1, the entire circumferential inclined portion 22 becomes the longest part of the axial length from the end face of the stator core 1 to the segment coil 20, and when the circumferential inclined portion 22 is not parallel to the end face of the stator core 1, only a part of the circumferential inclined portion 22 becomes the longest part of the axial length from the end face of the stator core 1 to the segment coil 20.

[0040] The crank portion 23 is configured to connect between the axially inclined portion 21 and the circumferentially inclined portion 22. The crank portion 23 is curved axially outward. The crank portion 23 includes a first curved portion 23a that curves axially outward and a second curved portion 23b that curves axially inward, and has an S-shape when viewed radially.

[0041] In adjacent coil end portions 20b, the lower surface 22b of the circumferentially inclined portion 22 of one coil end portion 20b and the end portion 23c of the crank portion 23 of the other coil end portion 20b on the axially inclined portion 21 side are configured so as not to overlap in the axial direction but to be adjacent in the circumferential direction. The end portion 23c of the crank portion 23 on the axially inclined portion 21 side refers to the boundary between the crank portion 23 and the connection portion 24. Also, "adjacent in the circumferential direction" refers to being close to each other even if they are not in contact in the circumferential direction. Furthermore, the relationship in axial length when adjacent in the circumferential direction is not limited to the case where the axial length from the end face of the stator core 1 to the lower surface of the circumferentially inclined portion 22 of one coil end portion 20b is the same as the axial length from the end face of the stator core 1 to the end portion of the crank portion 23 on the inclined portion side of the other coil end portion 20b, and may be slightly different. The crank portion 23 configures adjacent segment coils 20 so that the spacing between them increases with increasing distance from the stator core 1 side.

[0042] As shown in FIGS. 5 and 6 , the connection portion 24 is configured to connect the axially inclined portion 21 and the crank portion 23. The connection portion 24 is configured to be inclined axially outward with respect to the end face of the stator core 1, similar to the axially inclined portion 21, when viewed from the circumferential direction. In FIG. 4 , the connection portion 24 and the axially inclined portion 21 are inclined at the same angle with respect to the end face of the stator core 1. In another example, the inclination angle of the connection portion with respect to the end face of the stator core is different from the inclination angle of the axially inclined portion with respect to the end face of the stator core. The connection portion 24 is configured to be inclined radially outward with respect to the axially inclined portion 21 when viewed from the axial direction. The connection portion 24 has a fan-like shape including a pair of arc-shaped portions 24 a that curve radially inward when viewed from the axial direction, and a pair of straight portions 24 b that connect the pair of arc-shaped portions 24 a. The pair of straight portions 24 b are configured to connect to the axially inclined portion 21 and the crank portion 23, respectively.

[0043] The stator 100 is formed by laminating electromagnetic steel sheets to form the stator core 1, and then inserting multiple segment coils 20. The multiple segment coils 20 are inserted into the slots to form the coil end portions 20b. At this time, the segment coils 20 are inserted into the slot portions 11 without being twisted. The inserted segment coils 20 are joined together to form the coil 2.

[0044] (Effects of First Embodiment) In the first embodiment, the following effects can be obtained.

[0045] In the first embodiment, as described above, in the adjacent coil end portions 20b, the circumferentially inclined portions 22 of one coil end portion 20b and the crank portion 23 of the other coil end portion 20b are configured so that they do not overlap with each other in the axial direction and their circumferential side surfaces face each other and are adjacent to each other, and in the adjacent coil end portions 20b, the lower surface of the circumferentially inclined portion 22 of one coil end portion 20b and the end portion of the crank portion 23 of the other coil end portion 20b on the axially inclined portion 21 side do not overlap with each other in the axial direction and are adjacent to each other in the circumferential direction. Thus, by having the axially inclined portion 21, the circumferentially inclined portion 22, and the crank portion 23, the axial length can be adjusted by the axially inclined portion 21 and the circumferentially inclined portion 22, and the crank portion 23 can be used to arrange the coil end portions 20b so that they do not interfere with each other. Furthermore, in the adjacent coil end portions 20b, the circumferentially inclined portions 22 of the one coil end portion 20b and the crank portion 23 do not overlap with each other in the axial direction and their circumferential side surfaces face each other and are adjacent to each other, so that the adjacent coil end portions 20b can be arranged so that they do not interfere with each other in the circumferential direction. Therefore, there is no need to twist the coil end portions 20b. Furthermore, in adjacent coil end portions 20b, the lower surface 22b of the circumferentially inclined portion 22 of one coil end portion 20b and the end portion 23c of the crank portion 23 of the other coil end portion 20b on the axially inclined portion 21 side do not overlap in the axial direction and are adjacent to each other in the circumferential direction. This allows the multiple coil end portions 20b to be arranged so that they do not overlap in the axial direction, and the position of the crank portion 23 can be lowered, thereby preventing the axial length of the coil end portions 20b from becoming too long. As a result, interference between the coil end portions 20b can be prevented, and the axial length of the coil end portions 20b can be prevented from becoming too long without performing pressure molding.

[0046] Furthermore, in the first embodiment, as described above, the axial length from the end face of the stator core 1 to the circumferential inclined portions 22 is greater than the axial length from the end face of the stator core 1 to other portions of the coil end portions 20b. As a result, the axial length from the end face of the stator core 1 to the circumferential inclined portions 22 is the maximum value of the axial length from the end face of the stator core 1 to the coil end portions 20b. Therefore, by arranging the circumferential inclined portions 22 along the circumferential direction, it is possible to easily prevent the axial length from becoming too large.

[0047] Furthermore, in the first embodiment, as described above, the circumferential inclined portion 22 is configured to extend along the direction in which the end face of the stator core 1 extends. This allows the circumferential inclined portion 22, which has the longest axial length from the end face of the stator core 1 to the coil end portion 20b, to be arranged horizontally in the radial direction, effectively preventing the axial length of the coil end portion 20b from becoming too large.

[0048] Furthermore, in the first embodiment, as described above, the coil end portions 20b further include connection portions 24 that connect the axially inclined portions 21 and the crank portions 23, and the connection portions 24 are configured to be inclined radially outward relative to the axially inclined portions 21 when viewed in the axial direction. This makes it possible to prevent the connection portions 24 from being inclined radially outward from contacting adjacent coil end portions 20b. Furthermore, because the connection portions 24 can incline the coil end portions 20b radially outward before they are inclined axially by the crank portions 23, there is no need to incline the crank portions 23 radially outward, and this makes it possible to prevent the structure of the crank portions 23 from becoming complicated.

[0049] Furthermore, in the first embodiment, as described above, the coil 2 is configured by joining a plurality of segment coils 20, each including an axially inclined portion 21 and a circumferentially inclined portion 22. As a result, the coil 2 is configured by joining a plurality of segment coils 20, each including an axially inclined portion 21 and a circumferentially inclined portion 22, and therefore the coil 2 can be easily configured while preventing the axial length from becoming too large.

[0050] In the first embodiment, as described above, the multiple circumferentially inclined portions 22 are arranged so that their circumferential side surfaces face each other and are adjacent to each other without being twisted. This allows the coil 2 to be formed without twisting the multiple circumferentially inclined portions 22, thereby preventing the process of forming the coil end portions 20b from becoming complicated.

[0051] Second Embodiment

[0052] The configuration of the stator according to the second embodiment will be described with reference to FIGS.

[0053] (Overall Configuration of Stator) The stator 200 shown in Figures 7 and 8 constitutes part of a rotating electric machine (not shown) together with a rotor (not shown) arranged on the R1 side of the stator 200 so as to face the stator 200. The rotating electric machine is, for example, a motor, a generator, or a motor / generator. The stator 200 has a cylindrical shape. A hole through which the rotor is inserted is formed in the center of the stator 200. In the following description, the radial direction of the stator 200 is defined as the R direction, the circumferential direction of the stator 200 is defined as the C direction, and the axial direction in which the rotor is inserted into the stator 200 is defined as the Z direction.

[0054] The stator 200 includes a stator core 201 and a coil 202. The stator 200 is a three-phase AC stator.

[0055] The stator core 201 has a cylindrical shape with a central axis (not shown) along the Z direction. The stator core 201 is formed by stacking a plurality of electromagnetic steel plates (for example, silicon steel plates) in the Z direction.

[0056] The stator core 201 is provided with a plurality of slots 211, which are grooves extending in the Z direction. Coils 202, each made up of a plurality of segment coils 220, are inserted into the slots 211. The slots 211 are arranged along the circumferential direction on the end surface of the stator core 201.

[0057] The coil 202 is formed by joining a plurality of segment coils 220. The plurality of segment coils 220 that make up the coil 202 are made of rectangular wire. As an example, the plurality of segment coils 220 are made of copper wire. The coil 202 is configured to generate magnetic flux when supplied with three-phase AC power from a power supply unit (not shown). The segment coils 220 are arranged (wound) along the circumferential direction of the stator core 201 by moving back and forth through the slots 211 in the Z direction.

[0058] The plurality of segment coils 220 include a U-shaped segment coil 220 and an I-shaped segment coil 220 .

[0059] As shown in Figure 9, the U-shaped segment coil 220 includes a pair of slot-accommodated portions 220a that are inserted into the slots 211 of the stator core 201, and a coil end portion 220b that connects the pair of slot-accommodated portions 220a. The multiple segment coils 220 are arranged adjacent to each other. Here, in this specification, "adjacent" means that the two coil end portions are not in contact with each other but are located close to each other.

[0060] 7 and 8, when inserted into the stator core 201, the U-shaped segment coil 220 has its coil end portion 220b exposed from one end face in the Z direction of the stator core 201, and both end portions 220c of the segment coil 220 that are not connected by the coil end portion 220b are exposed from the other end face in the Z direction of the stator core 201. The pair of slot accommodating portions 220a are configured so that both end portions 220c are inserted across different slots 211. Furthermore, the end portions 220c of the multiple segment coils 220 exposed from the other end face in the Z direction of the stator core 201 are connected to each other to form one coil 202.

[0061] 8, one coil 202 has a U-shaped segment coil 220 and an I-shaped segment coil 220 joined to both ends in the circumferential direction. The I-shaped coil forms a connection end.

[0062] As shown in FIG. 10 , the coils 202 are three-phase coils including a U-phase coil 202U, a V-phase coil 202V, and a W-phase coil 202W. Two sets of coils 202 are arranged for each of the U-phase, V-phase, and W-phase. The coils 202 are connected in a three-phase Y-connection. The coils 202 are provided with multiple neutral points N. The U-phase coil 202U is provided with two neutral point connection ends NtU and two power line connection ends PtU. The V-phase coil 202V is provided with two neutral point connection ends NtV and two power line connection ends PtV. The W-phase coil 202W is provided with two neutral point connection ends NtW and two power line connection ends PtW. The power line connection terminals PtU, PtV and PtW and the neutral point connection terminals NtU, NtV and NtW are arranged on the other axial side (Z2 side) opposite to one side (Z1 side) of the stator core 201 where the connection portion of the U-shaped segment coil 220 is provided.

[0063] 9, the coil end portion 220b has a slot-side inclined portion 221, a circumferential inclined portion 222, and a crank portion 223. The coil end portion 220b also includes a second end portion 224 connected to the circumferential inclined portion 222.

[0064] The slot-side inclined portions 221 cause the segment coil 220 to incline with respect to the end face of the stator core 201 and incline in a direction away from the end face of the stator core 201 and in a direction intersecting the axial direction. The slot-side inclined portions 221 also cause the segment coil 220 to incline in the tangential and normal directions. The crank portions 223 cause the segment coil 220 to incline with respect to the end face of the stator core 201 and incline in a direction away from the end face of the stator core 201 and in a direction intersecting the axial direction, and the circumferential inclined portions 222 cause the segment coil 220 to extend along the end face of the stator core 201. The other-end portion 224 from the circumferential inclined portion 222 causes the segment coil 220 to incline with respect to the end face of the stator core 201, curves in a direction away from the end face of the stator core 201 and in a direction intersecting the axial direction, and inclines with respect to the end face of the stator core 201. The segment coil 220 then inclines in a direction approaching the end face of the stator core 201 and in a direction intersecting the axial direction, and then extends axially toward the end face of the stator core 201.

[0065] As shown in Figure 8, the tangential direction is the direction along the extension of a tangent that abuts on one point on the inner circumferential surface of stator core 201. The tangential direction includes a direction perpendicular to the radial direction of stator core 201 and a direction that is not perpendicular to the radial direction but intersects with it. The normal direction side includes the normal direction in the strict sense, which is a direction perpendicular to the tangential direction, and a direction that is not perpendicular to the tangential direction but intersects with it. The normal direction side includes the same direction as the radial direction.

[0066] 11 and 12, the slot-side inclined portion 221 has a connecting portion 221a, a tangential inclined portion 221b, and a normal-side inclined portion 221c. The slot-side inclined portion 221 is formed in a pentagonal shape when viewed in the axial direction. However, the slot-side inclined portion may have a polygonal shape other than a pentagonal shape or a triangular shape.

[0067] The connection portion 221a is connected to the slot-accommodated portion 220a. The connection portion 221a is curved in a tangential direction relative to the axial direction. After the segment coil 220 extends along the axial direction via the slot-accommodated portion 220a, the connection portion 221a inclines in a tangential direction to the inner circumferential surface 212 of the stator core 201. The connection portion 221a has an arc shape that protrudes circumferentially when viewed in the radial direction. The inner circumferential surface 212 of the stator core 201 is a surface that forms (surrounds) the hole through which the rotor is inserted.

[0068] The tangentially inclined portion 221b is connected to the connection portion 221a. When viewed in the axial direction, the tangentially inclined portion 221b extends in a tangential direction of the stator core 201 relative to the stator core 201. As an example, the tangential direction is the tangential direction of the inner circumferential surface 212 of the stator core 201. When viewed in the radial direction, the tangentially inclined portion 221b extends outward in the axial direction (extending in a direction away from the stator core 201). When viewed in the axial direction, the tangentially inclined portion 221b extends outward in the radial direction. In circumferentially adjacent segment coils 220, a portion of the lower surface of one tangentially inclined portion 221b and a portion of the upper surface of the other tangentially inclined portion 221b overlap when viewed in the axial direction. Note that the overlapping portion is the portion on the side connected to the connection portion 221a. When viewed in the axial direction, the slot side inclined portion 221 has an exposed portion 221e that does not overlap with other adjacent slot side inclined portions 221, and the slot side inclined portion 221 has an overlapping portion 221f that overlaps with other adjacent slot side inclined portions 221.

[0069] In the axial view, the area A1 of the exposed portion 221e is larger than the area A2 of the overlapping portion 221f. Therefore, adjacent slot-side inclined portions 221 have little overlap in the axial direction. Note that in FIG. 6, the area A1 of the exposed portion 221e and the area A2 of the overlapping portion 221f are indicated by different hatching. The overlapping portion 221f is indicated by a dashed line. The exposed portion 221e is a portion formed by combining a portion of the tangential inclined portion 221b and the normal-side inclined portion 221c. The overlapping portion 221f is the remaining portion of the tangential inclined portion 221b. In the axial view, the exposed portion 221e has a polygonal shape, including a quadrangular shape and a pentagonal shape, but excluding a triangular shape. The overlapping portion 221f is formed in a triangular shape in the axial view.

[0070] The exposed portion 221e is configured such that the width W increases radially outward when viewed in the axial direction. Specifically, the width W of the normal-side inclined portion 221c is greater than the width W of the tangential inclined portion 221b. The width W refers to the length in the radial direction.

[0071] The normal-side inclined portion 221c is positioned radially outward of the tangential-side inclined portion 221b when viewed in the axial direction. The normal-side inclined portion 221c is inclined toward the normal direction that intersects with the direction in which the tangential-side inclined portion 221b extends. In circumferentially adjacent segment coils 220, the normal-side inclined portions 221c do not overlap with each other in the axial direction when viewed in the axial direction. Furthermore, in circumferentially adjacent segment coils 220, one normal-side inclined portion 221c is positioned radially outward of the other normal-side inclined portion 221c.

[0072] The slot-side inclined portion 221 further includes a bent portion 221d. The bent portion 221d is located between the tangential inclined portion 221b and the normal-side inclined portion 221c. The bent portion 221d bends the slot-side inclined portion 221 radially inward, changing the extension direction of the slot-side inclined portion 221 toward the normal direction. In circumferentially adjacent segment coils 220, the bent portions 221d do not overlap in the axial direction when viewed in the axial direction. Furthermore, in circumferentially adjacent segment coils 220, one bent portion 221d is located radially outward of the other bent portion 221d. The bent portion 221d is formed linearly when viewed in the axial direction. Note that in Figure 6, for convenience, the boundaries between the tangential inclined portion 221b, the bent portion 221d, and the normal-side inclined portion 221c are indicated by dashed lines. The tangential inclined portion 221b, the bent portion 221d, and the normal inclined portion 221c are integrally formed as one member.

[0073] When viewed in the axial direction, the area of ​​the tangential inclined portion 221 b is larger than the area of ​​the normal inclined portion 221 c, which is also larger than the area of ​​the bent portion 221 d.

[0074] When viewed in the axial direction, adjacent slot-side inclined portions 221 are arranged so that the inner peripheral surface 221g of one slot-side inclined portion 221 and the inner peripheral surface 221g of the other slot-side inclined portion 221 overlap in the radial direction rather than being arranged in an arc shape along the circumferential direction. When viewed in the axial direction, the inner peripheral surfaces 221g that overlap along the circumferential direction are the inner peripheral surfaces of the tangential inclined portions 221b. When viewed in the axial direction, adjacent tangential inclined portions 221b appear to intersect and form corners, so when viewed in the axial direction, the inner peripheral side of coil 202 appears to have a polygonal shape with the same number of corners as the number of segment coils 220.

[0075] The circumferential inclined portion 222 has a rectangular shape when viewed in the axial and circumferential directions. When viewed in the axial direction, the circumferential inclined portion 222 extends toward the normal direction and also extends radially outward. The circumferential inclined portion 222 is inclined to such an extent that it does not come into contact with adjacent segment coils 220 in the circumferential direction. The circumferential inclined portion 222 is configured to extend along the direction in which the end face of the stator core 201 extends. In other words, the circumferential inclined portion 222 extends along the radial direction. The circumferential inclined portion 222 is formed approximately horizontally when viewed in the radial direction. Preferably, the circumferential inclined portion 222 is configured to extend parallel to the end face of the stator core 201.

[0076] In adjacent coil end portions 220b, the circumferential inclined portions 222 on one side and the circumferential side surfaces 222a on the other side do not overlap with each other in the axial direction, and the circumferential side surfaces 222a do not face each other. In adjacent coil end portions 220b, the circumferential inclined portions 222 on one side and the circumferential side surfaces 222a on the other side are formed so that their axial lengths from the end face of the stator core 201 are approximately the same. Although the circumferential inclined portions 222 on one side and the circumferential side surfaces 222a on the other side extend along the circumferential direction, they do not need to be parallel to each other, and one may be inclined relative to the other. Furthermore, the circumferential side surfaces 222a of the circumferential inclined portions 222 on one side and the circumferential side surfaces 222a on the other side do not need to face each other entirely, as long as they face each other partially. The circumferential inclined portions 222 are arranged so that the circumferential side surfaces 222a face each other adjacently without twisting.

[0077] The crank portion 223 is configured to connect the slot-side inclined portion 221 and the circumferential inclined portion 222. The crank portion 223 is curved outward in the axial direction. The crank portion 223 includes a first curved portion 223a that curves outward in the axial direction and a second curved portion 223b that curves inward in the axial direction, and is S-shaped when viewed radially. The crank portions 223 of adjacent coil end portions 220b do not overlap with each other in the axial direction or the circumferential direction. The adjacent coil end portions 220b are arranged such that the crank portion 223 and the circumferential inclined portion 222 face each other in the circumferential direction.

[0078] As shown in Figure 8, the other end portion 224 is connected to the circumferentially inclined portion 222. When viewed from the radial direction, the other end portion 224 is inclined in the opposite direction to the slot-side inclined portion 221. More specifically, it is inclined with respect to the axial direction so as to approach the end face of the stator core 201. In addition, of the pair of slot-accommodated portions 220a of the segment coil 220, the other end portion 224 is connected to a slot-accommodated portion 220a that is different from the slot-accommodated portion 220a to which the slot-side inclined portion 221 is connected.

[0079] 12 , in an axial view, the circumferential inclined portion 222, the normal-side inclined portion 221c, and the crank portion 223 extend linearly in the same radially outward direction. Therefore, in an axial view, the extension directions of the circumferential inclined portion 222, the normal-side inclined portion 221c, and the crank portion 223 are radially outward and normal. Therefore, in an axial view, the segment coil 220 is inclined in the tangential direction by the tangential inclined portion 221b, and is inclined toward the normal direction by the circumferential inclined portion 222, the normal-side inclined portion 221c, and the crank portion 223.

[0080] In the adjacent coil end portions 220b, the adjacent segment coils 220 are configured so that the circumferential spacing G increases with increasing distance from the stator core 201. In detail, the spacing G between the slot-side inclined portion 221 of one of the adjacent coil end portions 220b facing each other and the circumferential inclined portion 222 of the other of the adjacent coil end portions 220b facing each other is smallest, and the spacing G between the other end-side portion 224 of one of the adjacent coil end portions 220b facing each other is largest.

[0081] Stator 200 is formed by laminating electromagnetic steel sheets to form stator core 201, and then inserting multiple segment coils 220. Inserting multiple segment coils 220 into slots 211 forms coil end portions 220b. At this time, segment coils 220 are inserted into slots 211 without being twisted. Coil 202 is formed by joining the inserted segment coils 220 together. Coil 202 is formed by bending segment coil 220 to form connection portion 221a and crank portion 223, bending in the tangential direction to form tangentially inclined portion 221b, and bending in the normal direction to form normal-side inclined portion 221c.

[0082] (Effects of Second Embodiment) In the second embodiment, the following effects can be obtained.

[0083] In the second embodiment, as described above, the multiple coil end portions 220b include a connecting portion 221a connected to the slot-accommodating portion 220a and a slot-side inclined portion 221 having a tangentially inclined portion 221b that extends tangentially to the inner circumferential surface of the stator core 201 relative to the stator core 201 and extends axially outward when viewed in the axial direction. Since the slot-side inclined portion 221 of the coil end portion 220b of the segment coil 220 has the tangentially inclined portion 221b, when processing the segment coil 220, it is only necessary to bend the segment coil 220 in the tangential direction of the stator core 201, and therefore there is no need to form the coil end portion 220b of the segment coil 220 into an arc shape along the inner circumferential surface of the stator core 201. As a result, it is possible to easily process the portion of the segment coil 220 corresponding to the coil end portion 220b.

[0084] In the second embodiment, as described above, the slot-side inclined portion 221 is disposed radially outward of the tangential inclined portion 221b in the axial view and further includes a normal-side inclined portion 221c that is inclined toward the normal direction intersecting the direction of extension of the tangential inclined portion 221b. This allows the normal-side inclined portion 221c to incline the segment coil 220 toward the normal direction, allowing adjacent segment coils 220 to be arranged side by side in the circumferential direction. This prevents adjacent segment coils 220 from overlapping in the axial direction, thereby increasing the axial length.

[0085] In the second embodiment, as described above, when viewed in the axial direction, the area A1 of the exposed portion 221e of the slot-side inclined portion 221 that does not overlap with another adjacent slot-side inclined portion 221 is larger than the area A2 of the overlapping portion 221f of the slot-side inclined portion 221 that overlaps with another slot-side inclined portion 221. As a result, the area of ​​the slot-side inclined portion 221 that is in contact with the outside air is increased, and heat generated by passing a current through the coil 202 can be efficiently dissipated.

[0086] In the second embodiment, as described above, the exposed portion 221e is configured so that the width W increases radially outward when viewed in the axial direction. This increases the width W radially outward, which allows heat to be dissipated more easily from the radially outer side than from the radially inner side. As a result, heat is more easily transferred from the inner periphery of the stator core 201 to the radially outer side, where heat dissipation is easier, and the inner periphery of the stator core 201 can be prevented from becoming too hot.

[0087] In the second embodiment, as described above, when viewed in the axial direction, adjacent slot-side inclined portions 221 are arranged so that the inner peripheral surface 221g of one slot-side inclined portion 221 overlaps the inner peripheral surface 221g of the other slot-side inclined portion 221 in the radial direction, rather than being arranged in an arc shape along the circumferential direction. This eliminates the need to form and arrange adjacent slot-side inclined portions 221 in an arc shape, and instead allows the slot-side inclined portions 221 to be arranged side by side in the radial direction, making it easier to process the portion corresponding to the coil end portion 220b of the segment coil 220.

[0088] In the second embodiment, as described above, the coil end portion 220b includes a circumferentially inclined portion 222 that extends along the end face of the stator core 201 and is inclined radially outward relative to the circumferential direction in an axial view, and a crank portion 223 that connects the circumferentially inclined portion 222 and the slot-side inclined portion 221 and is curved axially outward in a radial view. This allows the circumferentially inclined portion 222 and the crank portion 223 to incline the segment coil 220 in the radial and axial directions, allowing adjacent segment coils 220 to be arranged so that they do not overlap in the radial and axial directions. This prevents the axial and radial lengths of the entire coil 202 from increasing due to overlapping of the segment coils 220.

[0089] In the second embodiment, as described above, the circumferential inclined portion 222, the normal-side inclined portion 221c, and the crank portion 223 extend linearly in the same radially outward direction when viewed in the axial direction. This eliminates the need to bend or twist the segment coil 220, making it even easier to process the portion of the segment coil 220 corresponding to the coil end portion 220b.

[0090] [Modifications] The above-described embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the above-described embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0091] For example, in the first embodiment, the segment coil includes a connecting portion, but the present invention is not limited to this. In the present invention, the segment coil may not include a connecting portion, and the axially inclined portion and the crank portion may be directly connected.

[0092] In the first embodiment, the crank portion is S-shaped, but the present invention is not limited to this. In the present invention, the crank portion may be fan-shaped when viewed from the radial direction. In this case, at least one of the axially inclined portion and the circumferentially inclined portion may have a curved portion.

[0093] In the first embodiment, the axial length from the end face of the stator core to the circumferentially inclined portion is greater than the axial length from the end face of the stator core to other portions of the coil end portion, but the present invention is not limited to this. In the present invention, the axial length from the end face of the stator core to the crank portion may be greater than the axial length from the end face of the stator core to the circumferentially inclined portion.

[0094] In addition, in the first embodiment, an example was shown in which the stator core is a three-phase AC stator, but the present invention is not limited to this, and the present invention may also be a single-phase AC stator.

[0095] In the second embodiment, the slot-side inclined portion includes a normal-side inclined portion, but the present invention is not limited to this. In the present invention, the slot-side inclined portion does not have to include a normal-side inclined portion.

[0096] In the second embodiment, the connecting portion is curved, but the present invention is not limited to this. In the present invention, the connecting portion may be inclined linearly. In this case, the connecting portion may be inclined in the tangential direction.

[0097] In the second embodiment, the area of ​​the exposed portion is larger than the area of ​​the overlapping portion when viewed in the axial direction, but the present invention is not limited to this. In the present invention, the area of ​​the exposed portion may be equal to or smaller than the area of ​​the overlapping portion.

[0098] In the second embodiment, the exposed portion is configured so that its width increases radially outward as viewed in the axial direction, but the present invention is not limited to this. In the present invention, the width of the exposed portion does not need to change or may decrease radially outward as viewed in the axial direction.

[0099] In the second embodiment, the bent portion is formed linearly when viewed in the axial direction, but the present invention is not limited to this. In the present invention, the bent portion may be formed to be curved or bent when viewed in the axial direction.

[0100] In the second embodiment, the area of ​​the tangentially inclined portion is larger than the area of ​​the normal-side inclined portion when viewed in the axial direction, but the present invention is not limited to this. In the present invention, the area of ​​the tangentially inclined portion when viewed in the axial direction may be smaller than the area of ​​the normal-side inclined portion.

[0101] In the second embodiment, the area of ​​the normal-side inclined portion is larger than the area of ​​the bent portion when viewed in the axial direction, but the present invention is not limited to this. In the present invention, the area of ​​the normal-side inclined portion when viewed in the axial direction may be smaller than the area of ​​the bent portion.

[0102] In the second embodiment, the stator core is a three-phase AC stator, but the present invention is not limited to this. In the present invention, a single-phase AC stator may be used.

[0103] 1: stator core, 2: coil, 20b: coil end portion, 21: axially inclined portion, 22: circumferentially inclined portion, 23: crank portion, 24: connection portion, 100: stator, 201: stator core, 202: coil, 211: slot, 220: segment coil, 220a: slot-accommodated portion, 220b: coil end portion, 221: slot-side inclined portion, 221a: connection portion, 221b: tangentially inclined portion, 221c: normal-side inclined portion, 221e: exposed portion, 221f: overlapping portion, 200: stator

Claims

1. A stator comprising: a stator core; and a coil made of rectangular wire, the coil being inserted through the stator core and including a plurality of coil end portions that extend and protrude axially outward from an end face of the stator core, wherein the plurality of coil end portions have: an axially inclined portion that is provided on the stator core side and inclined axially outward with respect to the end face of the stator core, and extends circumferentially; a circumferentially inclined portion that, when viewed from the axial direction, inclined circumferentially with respect to the axially inclined portion and extends radially outward; and a crank portion that is configured to connect the axially inclined portion and the circumferentially inclined portion, and curves axially outward; wherein, in the plurality of adjacent coil end portions, the circumferentially inclined portions of one and the other do not overlap with each other in the axial direction, and the circumferential side surfaces of the circumferentially inclined portions are adjacent and face each other; and, in the plurality of adjacent coil end portions, the underside of the circumferentially inclined portion of one of the coil end portions and the end of the crank portion of the other of the coil end portions on the axially inclined portion side do not overlap with each other in the axial direction, but are adjacent to each other in the circumferential direction.

2. A stator according to claim 1, wherein the axial length from the end face of the stator core to the circumferentially inclined portion is greater than the axial length from the end face of the stator core to the other portion of the coil end portion.

3. A stator according to claim 2, wherein the circumferentially inclined portion is configured to extend along the direction in which the end face of the stator core extends.

4. A stator according to claim 1, wherein the coil end portion further includes a connecting portion that connects the axially inclined portion and the crank portion, and the connecting portion is configured to be inclined radially outward relative to the axially inclined portion when viewed from the axial direction.

5. A stator comprising: a stator core including slots; a coil formed by joining together a plurality of U-shaped segment coils made of rectangular wire, the coil including a slot accommodating portion inserted into the slot and a plurality of coil end portions extending axially outward from the end face of the stator core, wherein the plurality of coil end portions include a connection portion connected to the slot accommodating portion and a slot-side inclined portion that extends tangentially to the stator core relative to the stator core when viewed in the axial direction and also extends axially outward.

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