Stator

Abstract

To provide a stator capable of, when a plurality of coils are disposed in one phase, connecting a first-turn coil and a second-turn coil while suppressing an increase in the total radial direction length of the coils.SOLUTION: A stator 100 includes a stator core 1, and a coil 2 that is inserted into the stator core 1 and is formed by connecting a plurality of segment coils 20 each formed of a rectangular wire and having a U-like shape. Two sets of the coils 2 are disposed in the same phase. Each of the two sets of coils is wound around the stator core 1 in two turns and has a crossover portion 21a for connecting the first and second turns. The crossover portions 21a of the two sets of the coils 2 in the same phase are arranged so as to overlap each other in a radial direction when viewed from the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a stator, and more particularly to a stator including a coil and a stator core. [Background technology]

[0002] BACKGROUND ART Conventionally, a stator including a coil and a stator core is known (for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a stator including a coil and a stator core. In Patent Document 1, the coils include a U-phase coil, a V-phase coil, and a W-phase coil, with four coils provided for each phase. Furthermore, each phase coil has four power line connection ends and four neutral point connection ends. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-140708 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not disclosed in Patent Document 1, conventionally, a coil may be wound around the stator for each phase in two turns. In this case, a coil having a power line connection end is wound around the stator as the first turn, and a coil having a neutral point connection end is wound around the stator as the second turn, connecting the coil of the first turn to the coil of the second turn. Alternatively, the coils of the first turn and the coils of the second turn may be arranged radially so as not to overlap in the axial direction, and the connecting portions connecting the coils of the first turn and the coils of the second turn may be arranged radially. However, when multiple coils (first turn coils and second turn coils) are provided for one phase in this manner, multiple connecting portions are arranged radially according to the number of coils, which creates a problem in that the radial length of the entire coil increases.

[0006] 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, when multiple coils are provided in one phase, is capable of connecting the first and second winding coils while preventing the radial length of the entire coil from increasing. [Means for solving the problem]

[0007] In order to achieve the above object, a stator in one aspect of the present invention comprises a stator core, and a coil inserted into the stator core, made of flat wire and consisting of a plurality of U-shaped segment coils connected together, wherein the coils are provided in two sets for the same phase, and each of the two sets of coils is wound around the stator core two times and includes a bridge portion connecting the first and second turns, and the bridge portions of the two sets of coils for the same phase are arranged so that their radial positions overlap when viewed from the axial direction.

[0008] In a stator according to one aspect of the present invention, as described above, each of the two sets of coils is wound around the stator core two times and includes a transition portion connecting the first and second transition portions, and the transition portions of the two sets of coils of the same phase are arranged so that their radial positions overlap when viewed from the axial direction. Because the transition portions of the two sets of coils overlap in the radial direction, the radial size can be reduced compared to when two transition portions are arranged along the radial direction. As a result, when multiple coils are provided in one phase, the first and second transition coils can be connected while preventing the radial length of the entire coil from increasing.

[0009] In the stator according to the aforementioned aspect, preferably, two sets of coils are provided for each of a plurality of phases, and the crossover portions of the coils of different phases are arranged to be shifted in the circumferential direction.

[0010] By configuring in this manner, the transition portions of different phases can be arranged circumferentially offset, so that the radial positions of the transition portions of different phases can be aligned, thereby further preventing the radial length from increasing.

[0011] In this case, preferably, two sets of coils are provided corresponding to the first, second and third phases that make up the three phases, and the first phase transition portion, the second phase transition portion and the third phase transition portion are arranged offset along the circumferential direction and are arranged so that their axial positions overlap each other when viewed from the radial direction.

[0012] With this configuration, the first-phase transition portions, the second-phase transition portions, and the third-phase transition portions are arranged circumferentially offset, thereby aligning their radial positions and preventing an increase in radial length. Also, the first-phase transition portions, the second-phase transition portions, and the third-phase transition portions are arranged so that their axial positions overlap one another when viewed radially, aligning their axial positions and preventing an increase in axial length.

[0013] In the stator according to the aforementioned aspect, the transition portion is preferably arranged to protrude radially inward as viewed from the axial direction.

[0014] With this configuration, since the transition portion protrudes radially inward, the segment coils other than the transition portion arranged on the end face of the stator core can be arranged on the inner side of the stator core, thereby preventing the coils from spreading radially outward.

[0015] In the stator according to the above aspect, the following configuration is also possible.

[0016] (Additional note 1) In the stator according to the above aspect, the transition portion includes a first portion extending circumferentially, a second portion located axially outward from the first portion and extending circumferentially, and an inclined portion connecting the first portion and the second portion and inclined relative to the radial direction, and has a Z-shape when viewed axially.

[0017] With this configuration, the radial positions of the first and second portions of the transition section are different, so that the segment coils arranged on the inner periphery of the other segment coils arranged on the end face of the stator core and the first portion can be arranged circumferentially, and the segment coils arranged on the outer periphery and the second portion can be arranged circumferentially. As a result, the transition section can be arranged so as not to interfere with other coils while preventing the radial length from increasing.

[0018] (Additional note 2) In this case, the transition portions of different phases adjacent in the circumferential direction are arranged such that the first portion of one phase and the second portion of the other phase are shifted along the radial direction, and the first portion of one phase and the first portion of the other phase are shifted along the circumferential direction.

[0019] This configuration allows the first and second portions of the transition portions of different phases to be arranged circumferentially, and also allows the transition portions of different phases to be aligned in the radial direction, thereby preventing the radial length from increasing and allowing multiple transition portions of different phases to be arranged.

[0020] (Additional note 3) In the stator according to the above aspect, the transition portion is disposed at the innermost position in the radial direction when viewed from the axial direction.

[0021] By configuring it in this manner, the transition section can be positioned at the innermost side, so that it does not overlap with the segment coils arranged on the end face of the stator core in the axial direction, and the coils can be prevented from expanding radially outward and becoming larger. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view showing a stator in the embodiment. [Figure 2] FIG. 2 is a top view of the stator according to the embodiment. [Figure 3] FIG. 2 is an oblique view showing a segment coil in an embodiment. [Figure 4] FIG. 2 is a circuit diagram showing a coil connection configuration in the embodiment. [Figure 5] 10A and 10B are diagrams for explaining the arrangement of segment coils in an embodiment. [Figure 6] FIG. 10 is a view of the transition portion as seen from the radial direction. [Figure 7] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] The configuration of a stator 100 according to an embodiment will be described with reference to FIGS.

[0025] (Overall configuration of the stator) The stator 100 shown in FIG. 1 constitutes a part of a rotating electric machine (not shown) together with a rotor (not shown) disposed on the inner circumferential surface 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.

[0026] The stator 100 includes a stator core 1 and a coil 2. The stator 100 is a three-phase AC stator having a U phase, a V phase, and a W phase. The U phase, the V phase, and the W phase are examples of the "first phase," the "second phase," and the "third phase" respectively described in the claims.

[0027] 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.

[0028] The stator core 1 is provided with a plurality of slots 11, which are grooves extending in the Z direction. A coil 2 consisting of a plurality of segment coils 20 is inserted into the slots 11. The slots 11 are provided between the teeth 12. In this embodiment, the slots 11 are provided in 48 locations.

[0029] As shown in FIG. 2, the coil 2 is formed by connecting a plurality of segment coils 20. The plurality of segment coils 20 constituting the coil 2 are made of rectangular wire. The plurality of segment coils 20 are made of copper wire, for example. 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 through the slot portion 11 in the Z direction. The coil 2 is formed by winding the connected plurality of segment coils 20 two or more times along the circumferential direction of the stator core 1. The coil 2 in the first turn and the coil 2 in the second turn are connected. In this embodiment, a coil 2 wound two times will be described as an example. A coil 2 in which the first turn and the second turn are connected is defined as one set of coils 2.

[0030] The plurality of segment coils 20 include a U-shaped segment coil 20 and an I-shaped segment coil 20.

[0031] As shown in FIG. 3, 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.

[0032] 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 ends not connected by the coil end portion 20b of the segment coil 20 are exposed from the other end face in the Z direction of the stator core 1. The pair of slot insertion portions 20a are configured so that both ends are inserted across different slot portions 11. Furthermore, the ends 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.

[0033] 2, one coil 2 has a U-shaped segment coil 20 and an I-shaped segment coil 20 connected to both ends in the circumferential direction. The I-shaped segment coil 20 forms a terminal portion. In this embodiment, two sets of segment coils 20 are inserted into one slot portion 11.

[0034] As shown in FIG. 4, the coils 2 are three-phase coils including a U-phase coil 2U, a V-phase coil 2V, and a W-phase coil 2W. Two sets of coils 2 are arranged for each of the U-phase, V-phase, and W-phase. The coils 2 are connected by a three-phase Y connection. The coils 2 are provided with multiple neutral points N. The U-phase coil 2U is provided with two neutral point connection ends NtU and two power line connection ends PtU. The V-phase coil 2V is provided with two neutral point connection ends NtV and two power line connection ends PtV. The W-phase coil 2W is provided with two neutral point connection ends NtW and two power line connection ends PtW. The power line connection ends PtU, PtV and PtW and the neutral point connection ends NtU, NtV and NtW are arranged on the other axial side (Z1 side) opposite to one side (Z2 side) of the stator core 1 where the connection portion of the U-shaped segment coil 20 is provided.

[0035] As shown in Fig. 6, each of the two sets of coils 2 is wound around the stator core 1 two times and includes a transition portion 21, a transition portion 22, and a transition portion 23 that connect the first and second turns. The transition portions 21, 22, and 23 are disposed at the innermost radial positions when viewed from the axial direction. The transition portions 21, 22, and 23 are disposed so as to protrude radially inward when viewed from the axial direction. Specifically, they protrude so as not to come into contact with the rotor and rotor shaft that are inserted into the stator core 1.

[0036] 1 and 5, a case where the coil 2 is wound around the stator core 1 twice will be described. In FIG. 5, the first set of segment coils 20 is indicated by solid lines, and the second set of segment coils 20 is indicated by dashed lines. The teeth 12 are indicated by rectangles, and slots 11 are provided between the teeth 12. The numbers between the teeth 12 indicate the slot 11 numbers. The slots 11 are numbered from the first to the left, connecting from the left end to the right end. In FIG. 5, the cylindrical stator core 1 is shown in plan view, with the upper ends of the teeth 12 representing the Z1-side end face of the stator core 1 and the lower ends representing the Z2-side end face of the stator core 1. In FIG. 5, the connections between the segment coils 20 are indicated by black rectangles.

[0037] The U-phase coil 2U will be described as an example. The starting point S1 of the first turn of the segment coils 20 constituting the first set of U-phase coils is one end of the I-shaped segment coil 20 inserted into the tenth slot 11. The other end of the I-shaped segment coil 20 inserted into the tenth slot 11 is connected to the U-shaped segment coil 20 inserted into the fourth slot 11. The connection is located on the Z2 side of the stator core 1. The segment coil 20 inserted into the fourth slot 11 is also inserted into the 46th slot 11. The segment coils 20 inserted into the 40th and 34th slots 11 are connected to the segment coils 20 inserted into the fourth and 46th slots 11. The segment coils 20 are connected in the same manner and inserted into the 28th, 22nd, and 16th slots 11, in that order. In FIG. 5, the middle part is omitted, as it is assumed to continue to I.

[0038] One end of the segment coil 20 inserted into the 16th slot 11 is inserted into the 11th slot 11. One end of the segment coil 20 inserted into the 16th slot 11 and the 11th slot 11 is connected to the segment coil 20 inserted into the 17th slot 11 and the 23rd slot 11. The segment coil 20 inserted into the 11th slot 11 and the 16th slot 11 form the first set of crossover portions 21a for the U phase. One end of the segment coil 20 inserted into the 11th slot 11 is the end point of the first turn. One end of the segment coil 20 inserted into the 17th slot 11 is the start point S2 of the second turn. In the first turn, the segment coil 20 is wound in the C1 direction (from left to right on the paper).

[0039] The other end of the segment coil 20 inserted through the 17th slot 11 and the 23rd slot 11 advances in the C2 direction and is connected to the segment coil 20 inserted through the 29th slot 11 and the 35th slot 11. Subsequently, the segment coils 20 are connected in the same manner and inserted through the 41st slot 11 and the 47th slot 11. Note that in FIG. 5, the intermediate portion is omitted as it continues to II. The U-shaped segment coil 20 inserted through the 41st slot 11 and the 47th slot 11 is connected to the I-shaped segment coil 20 inserted through the 5th slot 11, and the other end of the I-shaped segment coil 20 becomes the end point S3 of the second turn. In the second turn, the segment coil 20 is wound in the C2 direction (from right to left on the paper).

[0040] The starting point S4 of the first turn of the segment coils 20 constituting the second set of U-phase coils is one end of the I-shaped segment coil 20 inserted into the 11th slot 11. The other end of the I-shaped segment coil 20 inserted into the 11th slot 11 is connected to the U-shaped segment coil 20 inserted into the 5th slot 11. The connection is located on the Z2 side of the stator core 1. The segment coil 20 inserted into the 5th slot 11 is also inserted into the 47th slot 11. The segment coils 20 inserted into the 5th and 47th slots 11 are connected to the segment coils 20 inserted into the 41st and 35th slots 11. The segment coils 20 are connected in the same manner and inserted into the 29th, 23rd, 17th, and 10th slots 11 in that order. In FIG. 5, the middle part is omitted as it continues to III. One end of the segment coil 20 inserted into the 17th slot 11 is inserted into the 10th slot 11 and connected to the segment coils 20 inserted into the 16th and 22nd slots 11. The segment coils 20 inserted into the 10th and 17th slots 11 form the first set of crossover sections 21a for U phase. One end of the segment coil 20 inserted into the 10th slot 11 is the end point of the first turn. One end of the segment coil 20 inserted into the 16th slot 11, which is connected to one end of the segment coil 20 inserted into the 10th slot 11, is the start point S5 of the second turn. In the first turn, the segment coil 20 is wound in the C1 direction (from left to right on the paper).

[0041] The other end of the segment coil 20 inserted through the 16th slot 11 and the 22nd slot 11 advances in the C2 direction and is connected to the segment coil 20 inserted through the 28th slot 11 and the 34th slot 11. Subsequently, the segment coils 20 are connected in the same manner, and are inserted through the 40th slot 11 and the 46th slot 11 in that order. Note that in FIG. 5, the intermediate portion is omitted, as it is assumed to be continued from IV. The U-shaped segment coil 20 inserted through the 40th slot 11 and the 46th slot 11 is connected to one end of the I-shaped segment coil 20 inserted through the 4th slot 11, and the other end of the I-shaped segment coil 20 is the end point S6 of the second turn. In the second turn, the segment coil 20 is wound in the C2 direction (from left to right on the paper). As described above, the segment coils 20 in the first and second sets are inserted into the same slots 11, resulting in two segment coils 20 being inserted into one slot 11. Additionally, the crossover portion 21a of the first set and the crossover portion 21b of the second set overlap in the axial direction. While the U-phase coil 2U has been described above, the same applies to the V-phase coil 2V and the W-phase coil 2W.

[0042] The U-phase coil 2U, the V-phase coil 2V, and the W-phase coil 2W are inserted into different slots 11 and are not inserted into the same slot 11. In this embodiment, the V-phase coil 2V is inserted into the slot 11 four slots 11 away from the slot 11 into which the U-phase coil 2U is inserted. Furthermore, the W-phase coil 2W is inserted into the slot 11 four slots 11 away from the slot 11 into which the V-phase coil 2V is inserted. The coils 2 of each phase are inserted into 16 slots 11.

[0043] 5 and 7, the crossover portions of the two sets of coils 2 of the same phase are arranged so that their radial positions overlap when viewed from the axial direction. The crossover portions of the two sets of coils 2 of the same phase are arranged so that their radial positions completely overlap when viewed from the axial direction.

[0044] In the case of the U phase, the crossover portion 21a of the first set of coils 2 is arranged to connect the 11th slot portion 11 and the 16th slot portion 11, and the crossover portion 21b of the second set of coils 2 is arranged to connect the 10th slot portion 11 and the 17th slot portion 11. Therefore, the crossover portion 21b of the second set has a longer circumferential length than the crossover portion 21a of the first set, and is arranged on the Z1 side so as to straddle the crossover portion 21a of the first set. When viewed in the axial direction, the crossover portion 21a of the first set is hidden by the crossover portion 21b of the second set.

[0045] In the case of the V-phase, the crossover portion 22a of the first set of coils 2 is arranged to connect the seventh slot portion 11 and the twelfth slot portion 11, and the crossover portion 22b of the second set of coils 2 is arranged to connect the sixth slot portion 11 and the thirteenth slot portion 11. Therefore, the crossover portion 22b of the second set has a longer circumferential length than the crossover portion 22a of the first set, and is arranged on the Z1 side so as to straddle the crossover portion 22a of the first set. When viewed in the axial direction, the crossover portion 22a of the first set is hidden by the crossover portion 22b of the second set.

[0046] In the case of the W-phase, the crossover portion 23a of the first set of coils 2 is arranged to connect the third slot portion 11 and the eighth slot portion 11, and the crossover portion 23b of the second set of coils 2 is arranged to connect the second slot portion 11 and the ninth slot portion 11. Therefore, the crossover portion 23b of the second set has a longer circumferential length than the crossover portion 23a of the first set, and is arranged on the Z1 side so as to straddle the crossover portion 23a of the first set. When viewed in the axial direction, the crossover portion 23a of the first set is hidden by the crossover portion 23b of the second set.

[0047] As shown in Figures 5 and 6, the crossover portions 21 (22, 23) of the coils 2 of different phases are arranged with a circumferential offset. Furthermore, the U-phase crossover portion 21, the V-phase crossover portion 22, and the W-phase crossover portion 23 are arranged with a circumferential offset and are arranged so that their axial positions overlap one another when viewed from the radial direction. Specifically, the V-phase crossover portion 22 in both the first and second sets is inserted into a slot portion 11 that is shifted by four slots in the C1 direction from the slot portion 11 through which the U-phase crossover portion 21 is inserted. Furthermore, the W-phase crossover portion 22 in both the first and second sets is inserted into a slot portion 11 that is shifted by four slots in the C1 direction from the slot portion 11 through which the V-phase crossover portion 22 is inserted.

[0048] As shown in FIG. 7, the transition portion 21b (22b, 23b) includes a first portion 211b (221b, 231b), a second portion 212b (222b, 232b), and an inclined portion 213b (223b, 233b). The first portion 211b (221b, 231b) extends along the circumferential direction. The second portion 212b (222b, 232b) is located axially outward of the first portion 211b (221b, 231b) and extends along the circumferential direction. The inclined portion 213b (223b, 233b) is inclined with respect to the radial direction and the axial direction and connects the first portion 211b (221b, 231b) and the second portion 212b (222b, 232b). The transition portion 21b (22b, 23b) has a Z-shape when viewed in the axial direction.

[0049] The first portion 211b (221b, 231b) and the second portion 212b (222b, 232b) may have the same or different circumferential lengths. The first portion 211b (221b, 231b) and the second portion 212b (222b, 232b) have the same axial lengths. Note that while FIG. 7 shows the transition portion 21b, the transition portion 22b, and the transition portion 23b, the transition portion 21a, the transition portion 22a, and the transition portion 23a also have the same shape.

[0050] The transition portions 21b (22b, 23b) of different phases that are adjacent in the circumferential direction are arranged such that the first portion 211b (221b, 231b) of one phase and the second portion 212b (222b, 232b) of the other phase are shifted along the radial direction, and the first portion 211b (221b, 231b) of one phase and the first portion 211b (221b, 231b) of the other phase are shifted along the circumferential direction.

[0051] Specifically, the U-phase first portion 211b and the V-phase second portion 222b are arranged with a radial offset, and the U-phase first portion 211b and the V-phase first portion 221b are arranged with a circumferential offset. Furthermore, the V-phase first portion 221b and the W-phase second portion 232b are arranged with a radial offset, and the V-phase first portion 221b and the W-phase first portion 231b are arranged with a circumferential offset. As a result, the U-phase first portion 211b, the V-phase first portion 221b, and the W-phase first portion 231b are arranged side by side in the circumferential direction. Furthermore, the U-phase second portion 212b, the V-phase second portion 222b, and the W-phase second portion 232b are also arranged in the circumferential direction. As a result, the radial positions of U-phase transition portion 21b, V-phase transition portion 22b, and W-phase transition portion 23b are the same. Note that while Fig. 7 shows transition portion 21b, transition portion 22b, and transition portion 23b, the same applies to transition portion 21a, transition portion 22a, and transition portion 23a.

[0052] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0053] In this embodiment, as described above, the stator 100 comprises a stator core 1 and coils 2 inserted into the stator core 1 and formed by connecting a plurality of U-shaped segment coils 20 made of flat wire, and two sets of coils 2 are provided for the same phase, and each of the two sets of coils 2 is wound around the stator core 1 for two turns and includes a crossover portion 21a (22a, 23a, 21b, 22b, 23b) connecting the first turn and the second turn, and the crossover portions 21a (22a, 23a, 21b, 22b, 23b) of the two sets of coils 2 for the same phase are arranged so that their radial positions overlap when viewed from the axial direction. As a result, the crossover portions 21a (22a, 23a, 21b, 22b, 23b) of the two sets of coils 2 overlap in the radial direction, making it possible to reduce the radial size compared to when two crossover portions 21a (22a, 23a, 21b, 22b, 23b) are arranged side by side along the radial direction. As a result, when multiple coils 2 are provided in one phase, it is possible to connect the coils 2 of the first turn and the coils 2 of the second turn while preventing the radial length of the entire coils 2 from increasing.

[0054] In this embodiment, as described above, two sets of coils 2 are provided for each of a plurality of phases, and the crossover portions 21a (22a, 23a, 21b, 22b, 23b) of the coils 2 of different phases are arranged with a circumferential offset. By arranging the crossover portions 21a (22a, 23a, 21b, 22b, 23b) of different phases with a circumferential offset, the radial positions of the crossover portions 21a (22a, 23a, 21b, 22b, 23b) of different phases can be aligned, thereby further preventing the radial length from increasing.

[0055] In this embodiment, as described above, two sets of coils 2 are provided corresponding to the first, second and third phases that make up the three phases, and the first phase transition portions 21a (22a, 23a, 21b, 22b, 23b), the second phase transition portions 21a (22a, 23a, 21b, 22b, 23b), and the third phase transition portions 21a (22a, 23a, 21b, 22b, 23b) are arranged with a circumferential offset and are arranged so that their axial positions overlap each other when viewed from the radial direction. As a result, the first phase transition portions 21a (22a, 23a, 21b, 22b, 23b), the second phase transition portions 21a (22a, 23a, 21b, 22b, 23b), and the third phase transition portions 21a (22a, 23a, 21b, 22b, 23b) are arranged offset in the circumferential direction, which allows their radial positions to be aligned, thereby preventing the radial length from becoming too large. Furthermore, the first phase transition portions 21a (22a, 23a, 21b, 22b, 23b), the second phase transition portions 21a (22a, 23a, 21b, 22b, 23b), and the third phase transition portions 21a (22a, 23a, 21b, 22b, 23b) are arranged so that their axial positions overlap each other when viewed from the radial direction, thereby aligning the axial positions and preventing the axial length from becoming too large.

[0056] In this embodiment, as described above, the transition portions 21a (22a, 23a, 21b, 22b, 23b) are arranged so as to protrude radially inward when viewed from the axial direction. As a result, the transition portions 21a (22a, 23a, 21b, 22b, 23b) protrude radially inward, so that the segment coils 20 of the transition portions 21a (22a, 23a, 21b, 22b, 23b) arranged on the end faces of the stator core 1 can be arranged on the inner circumferential side of the stator core 1, thereby preventing the coils 2 from spreading radially outward.

[0057] In this embodiment, as described above, the transition portion 21a (22a, 23a, 21b, 22b, 23b) includes a first portion 211b (221b, 231b) extending circumferentially, a second portion 212b (222b, 232b) located axially outward of the first portion 211b (221b, 231b) and extending circumferentially, and an inclined portion 213b (223b, 233b) connecting the first portion 211b (221b, 231b) and the second portion 212b (222b, 232b) and arranged at an angle relative to the radial direction, and has a Z-shape when viewed axially. As a result, the radial positions of the first portion 211b (221b, 231b) and the second portion 212b (222b, 232b) of the transition portion 21a (22a, 23a, 21b, 22b, 23b) are different, so that the segment coil 20 arranged on the inner periphery of the other segment coils 20 arranged on the end face of the stator core 1 and the first portion 211b (221b, 231b) can be arranged along the circumferential direction, and the segment coil 20 arranged on the outer periphery and the second portion 212b (222b, 232b) can be arranged along the circumferential direction. As a result, the transition portion 21a (22a, 23a, 21b, 22b, 23b) can be arranged so as not to interfere with the other coils 2 while preventing the radial length from becoming too large.

[0058] In this embodiment, as described above, the transition portions 21a (22a, 23a, 21b, 22b, 23b) of different phases adjacent to each other in the circumferential direction are arranged such that the first portion 211b (221b, 231b) of one phase and the second portion 212b (222b, 232b) of the other phase are shifted along the radial direction, and the first portion 211b (221b, 231b) of one phase and the first portion 211b (221b, 231b) of the other phase are shifted along the circumferential direction. This allows the first portions 211b (221b, 231b) and the second portions 212b (222b, 232b) of the transition portions 21a (22a, 23a, 21b, 22b, 23b) of different phases to be arranged in the circumferential direction, and also allows the radial positions of the transition portions 21a (22a, 23a, 21b, 22b, 23b) of different phases to be aligned. As a result, it is possible to arrange multiple transition portions 21a (22a, 23a, 21b, 22b, 23b) of different phases while preventing the radial length from increasing.

[0059] In this embodiment, as described above, the transition portions 21a (22a, 23a, 21b, 22b, 23b) are arranged at the innermost radial positions when viewed from the axial direction. By arranging the transition portions 21a (22a, 23a, 21b, 22b, 23b) at the innermost positions, the transition portions 21a (22a, 23a, 21b, 22b, 23b) can be arranged so as not to overlap with the segment coils 20 arranged on the end faces of the stator core 1 in the axial direction, and the coils 2 can be prevented from expanding radially outward.

[0060] [Variations] 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 defined by the claims rather than the description of the above-described embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0061] For example, in the above 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.

[0062] In the above embodiment, two sets of coils are provided for the same phase, but the present invention is not limited to this. In the present invention, more than two sets of coils may be provided.

[0063] In the above embodiment, the crossover portions of the two sets of coils of the same phase are arranged so that their radial positions completely overlap when viewed from the axial direction, but the present invention is not limited to this. In the present invention, the crossover portions of the two sets of coils of the same phase may be arranged so that their radial positions partially overlap when viewed from the axial direction.

[0064] In the above embodiment, the coil is wound around the stator core two times, but the present invention is not limited to this. In the present invention, the coil may be wound around the stator three or more times. In this case, in addition to a bridge portion connecting the first and second turns, a bridge portion connecting the second and third turns is provided.

[0065] In the above embodiment, the first-phase transition portion, the second-phase transition portion, and the third-phase transition portion are arranged so that their axial positions overlap one another when viewed from the radial direction, but the present invention is not limited to this. In the present invention, the first-phase transition portion, the second-phase transition portion, and the third-phase transition portion may be arranged so that their axial positions differ when viewed from the radial direction.

[0066] In the above embodiment, the first-phase transition portion, the second-phase transition portion, and the third-phase transition portion are arranged side by side in the circumferential direction, but the present invention is not limited to this. In the present invention, the first-phase transition portion, the second-phase transition portion, and the third-phase transition portion may be located at different radial positions. In this case, the first portion of one of the transition portions of the different phases and the second portion of the other may be arranged along the circumferential direction.

[0067] In the above embodiment, the transition portion is disposed so as to protrude radially inward as viewed from the axial direction, but the present invention is not limited to this. In the present invention, the transition portion may be disposed along the inner circumferential surface of the stator core so as not to protrude radially inward as viewed from the axial direction.

[0068] In the above embodiment, the transition portion is disposed at the innermost position in the radial direction as viewed from the axial direction, but the present invention is not limited to this. In the present invention, the transition portion may be disposed at the inner or outer position in the radial direction as viewed from the axial direction. [Explanation of symbols]

[0069] 1: stator core, 2: coil, 20: segment coil, 21 (21a, 21b), 22 (22a, 22b), 23 (23a, 23b): transition section, 100: stator

Claims

1. A stator core; a coil that is inserted into the stator core, is made of a rectangular wire, and is configured by connecting a plurality of U-shaped segment coils together; Two sets of the coils are provided for the same phase, Each of the two sets of coils is wound around the stator core two times and includes a bridge portion connecting the first and second turns, The stator, wherein the crossover portions of the two sets of coils of the same phase are arranged so as to overlap in radial positions when viewed from the axial direction.

2. The two sets of coils are provided for each of a plurality of phases, The stator according to claim 1 , wherein the transition portions of the coils of different phases are arranged to be offset in the circumferential direction.

3. the two sets of coils are provided corresponding to a first phase, a second phase, and a third phase that constitute three phases, 3. The stator according to claim 2, wherein the transition portion of the first phase, the transition portion of the second phase, and the transition portion of the third phase are arranged to be offset from one another in the circumferential direction and to overlap one another in the axial direction when viewed from the radial direction.

4. The stator according to claim 1 , wherein the transition portion is disposed so as to protrude radially inward when viewed from the axial direction.

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