Stator of rotary electric machine

Abstract

To reduce the axial size of a yoke in a stator.SOLUTION: The jumper wire 32 of the coil 28 of each phase extends such that directions from one to the other of the two winding portions 30 forming the coil set 33 are all the same direction in the circumferential direction of the yoke 24, the winding start side lead wire 34 of the coil 28 of each phase is drawn out from the winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24 among the plurality of teeth 25, and the winding start side lead wire 34 or the winding end side lead wire 35 of each coil set 33 is electrically connected to each other to form a neutral point.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] For example, as disclosed in Patent Document 1, a stator of a rotating electric machine includes a stator core and three-phase coils. The stator core has a cylindrical yoke and a plurality of teeth. The plurality of teeth are arranged at intervals in the circumferential direction of the yoke. Each tooth extends from the peripheral surface of the yoke in the radial direction of the yoke. The coil of each phase has a plurality of winding portions formed by winding a winding around the teeth in a concentrated winding manner. The winding portions are connected in series via crossover wires, which are part of the winding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-213343 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the crossover wires of the coils of each phase may overlap in the axial direction of the yoke, resulting in a location where three crossover wires overlap in the axial direction of the yoke. As a result, there is a risk that the size of the stator in the axial direction of the yoke may increase. Therefore, it is desirable to reduce the size of the stator in the axial direction of the yoke. [Means for solving the problem]

[0005] The stator of a rotating electric machine that solves the above-mentioned problems is a stator of a rotating electric machine that includes three-phase coils, a cylindrical yoke, and a stator core having a plurality of teeth that are spaced apart in the circumferential direction of the yoke and extend radially from the circumferential surface of the yoke, wherein the coils of each phase have four or more winding sections formed by winding a winding around every other tooth in the circumferential direction among the plurality of teeth in a concentrated winding manner, and two of the four or more winding sections that are separated by two teeth in the circumferential direction among the four or more winding sections are connected in series via crossover wires that are part of the windings, and the plurality of coil sets are connected in parallel, and the coils of each phase have In this configuration, a winding start side lead wire, which is part of the winding, is drawn out from one of the two winding sections that form the coil group, and a winding end side lead wire, which is part of the winding, is drawn out from the other of the two winding sections that form the coil group, the jumper wires of the coils of each phase extend so that the directions from one to the other of the two winding sections that form the coil group are all the same in the circumferential direction, and the winding start side lead wires of the coils of each phase are drawn out from winding sections that are wound around teeth that are located every other tooth in the circumferential direction among the plurality of teeth, and the winding start side lead wires of each coil group or the winding end side lead wires of each coil group are electrically connected to each other to form a neutral point.

[0006] As described above, each phase coil has four or more winding sections formed by winding a wire around every other tooth in the circumferential direction of the yoke using concentrated winding. Each phase coil has a plurality of coil sets, each of which has two winding sections, separated by two teeth in the circumferential direction of the yoke, connected in series via a crossover wire that is part of the winding. Each phase coil is configured by connecting multiple coil sets in parallel. In each phase coil configured in this manner, the crossover wires of each phase coil extend in the same direction from one of the two winding sections forming the coil set to the other in the circumferential direction of the yoke. The winding start lead wire of each phase coil is drawn out from the winding section wound around every other tooth in the circumferential direction of the yoke. The winding start lead wires of each coil set or the winding end lead wires of each coil set are electrically connected to each other to form a neutral point. This allows the number of overlapping crossover wires of each phase coil in the axial direction of the yoke to be at most two, preventing the existence of a location where three crossover wires overlap in the axial direction of the yoke, thereby enabling the stator to be made more compact in the axial direction of the yoke.

[0007] In the stator of the above-described rotating electric machine, the winding-end lead wires of the coil sets may be electrically connected to each other to form a neutral point. The winding start portion of the winding part is fixed as the winding is wound around the teeth. Therefore, there is no need to separately fix the lead wire on the winding start side to prevent the winding start portion of the winding part from loosening. On the other hand, to prevent the winding end portion of the winding part from loosening, it is necessary to fix the lead wire on the winding end side.

[0008] Generally, a winding has a conductor and a coating applied to the outer periphery of the conductor. When the winding is fixed to the locking part, it is considered to cover the outer periphery of the coating with an insulating material in advance to prevent the coating from breaking and exposing the conductor.

[0009] On the other hand, consider a case where a neutral point is formed by electrically connecting lead wires, which are part of the windings drawn from the windings of the coils of each phase. In this case, the lead wires of the coils of each phase that form the neutral point must be insulated when connecting the lead wires of the coils of each phase to form the neutral point, so it is considered to cover the outer side of the coating of the lead wire with an insulating material in advance.

[0010] Therefore, in a configuration in which the end-of-winding side lead wire is the neutral point and has an insulating member, this is preferable because the insulating member required for connecting the neutral point can also be used as the insulating member when fixing to the locking portion.

[0011] In this case, if the lead wire at the start of winding is a lead wire that forms the neutral point, the outer periphery of the coating of the lead wire at the start of winding must be covered with an insulating material in advance. Furthermore, the outer periphery of the coating of the lead wire at the end of winding must also be covered with an insulating material in advance because the lead wire must be fixed to the locking portion. Therefore, the outer periphery of the coating of both the lead wire at the start of winding and the lead wire at the end of winding must be covered with an insulating material, which makes the configuration complicated.

[0012] Therefore, the neutral point is formed by electrically connecting the end-of-winding lead wires of each coil group. This eliminates the need to pre-coat the outer periphery of the coating of the start-of-winding lead wire of each coil group with an insulating material; it is sufficient to pre-coat the outer periphery of the coating of the end-of-winding lead wire of each coil group with an insulating material. Therefore, since there is no need to pre-coat the outer periphery of the coating of both the start-of-winding lead wire and the end-of-winding lead wire of each coil group with an insulating material, a complicated configuration can be avoided. As a result, the axial size of the yoke in the stator can be reduced without complicating the configuration.

[0013] In the stator of the rotating electric machine, the winding-start side lead wires of the coil sets may be electrically connected to each other to form a neutral point. The end-of-winding side lead wire is only drawn out from the end-of-winding side of the winding part, and is therefore unlikely to come into contact with other parts of the winding part. On the other hand, the start-of-winding side lead wire is likely to come into contact with the end-of-winding side of the winding part when drawn out from the winding part.

[0014] Here, when a voltage is applied to each coil group by power supply, the voltage applied to the winding part downstream in the power supply direction of the two winding parts that form the coil group is lower than the voltage applied to the winding part upstream in the power supply direction. In other words, the voltage applied to the winding part closer to the neutral point is lower than the voltage applied to the winding part upstream in the power supply direction of the two winding parts that form the coil group. According to the inventor's verification, approximately 20% to 30% of the total voltage applied to each coil group is applied to the winding part closest to the neutral point, and the remaining approximately 70% to 80% is applied to the winding part upstream in the power supply direction. Therefore, if the winding start side leads of each coil group are electrically connected to each other to form a neutral point, the voltage applied to the winding part from which the winding start side leads are drawn is lower than the voltage applied to the winding part from which the winding end side leads are drawn. Therefore, the winding start side leads of each coil group are electrically connected to each other to form a neutral point. This allows the potential difference between the lead-out wire on the winding start side and the winding end side of the winding unit to be kept small, even if the lead-out wire on the winding start side comes into contact with the winding end side of the winding unit when being drawn out from the winding unit, thereby improving the dielectric strength of the coil and improving the reliability of the stator of the rotating electric machine.

[0015] In the stator of the above-mentioned rotating electric machine, the stator core has a first core end face which is an end face located on one end side of the yoke in the axial direction, and the jumper wires of the coils of each phase are pulled out to the first core end face side and extend in the circumferential direction while passing outside the first core end face in the axial direction.

[0016] For example, consider a case where the crossover wire of one of the three phase coils is pulled out to the second core end face, which is the end face of the stator core located at the other end of the yoke in the axial direction, and extends circumferentially around the yoke while passing outside the second core end face in the axial direction of the yoke. In this case, the number of turns of the winding of the winding part constituting one of the three phase coils is different from the number of turns of the winding of the winding parts constituting the other phase coils, which may result in an unstable magnetic balance of the entire stator and poor motor performance. Therefore, the crossover wire of each phase coil is pulled out to the first core end face, and extends circumferentially around the yoke while passing outside the first core end face in the axial direction of the yoke. This allows the number of turns of the winding of the winding parts constituting the coils of each phase to be the same, which stabilizes the magnetic balance of the entire stator and improves motor performance.

[0017] The stator of the above-described rotating electric machine further comprises an insulator that is disposed opposite the first core end face and that insulates between the coil and the first core end face, the insulator having a cylindrical insulator base that is positioned so as to overlap the yoke in the axial direction, and two jumper wire accommodating grooves that are arranged side by side in the axial direction of the insulator base and extend in the circumferential direction are formed on the peripheral surface of the insulator base, one of the two jumper wire accommodating grooves accommodating the jumper wire of one coil set and guiding it in the circumferential direction, and the other of the two jumper wire accommodating grooves accommodating the jumper wire of the coil set of the winding section from which the winding-start-side lead wire of the one coil set is drawn out and the winding section that is located every other winding section in the circumferential direction, and guiding it in the circumferential direction.

[0018] This allows the jumper wires of each coil set to be accommodated in the jumper wire receiving grooves and guided circumferentially around the yoke. Therefore, the jumper wires of each coil set can be extended circumferentially around the yoke while maintaining insulation between the overlapping jumper wires of each coil set in the axial direction of the yoke. Consider, for example, a case where the jumper wires of each coil set overlap in the axial direction of the yoke, resulting in three overlapping jumper wires in the axial direction of the yoke. In such a case, it is not necessary to form three jumper wire receiving grooves on the outer peripheral surface of the insulator base, each of which is arranged side by side in the axial direction of the insulator base and extends circumferentially around the yoke. This allows the axial length of the insulator base to be shortened. As a result, the axial size of the insulator base can be reduced. This allows the stator yoke to be reduced in the axial direction.

[0019] In the stator of the above-mentioned rotating electric machine, the stator core preferably has a second core end face, which is an end face located on the other axial end side of the yoke, and the winding start side lead wire and the winding end side lead wire of the coil of each phase are preferably drawn out to the second core end face side.

[0020] According to this, the winding start side lead wire and the winding end side lead wire of the coil of each phase are drawn to the end face side of the second core and electrically connected to each other to form a neutral point or to the power feed side. This prevents the jumper wire from interfering with the work of connecting the winding start side lead wire and the winding end side lead wire of the coil of each phase to the neutral point or to the power feed side. Therefore, the work of connecting the winding start side lead wire and the winding end side lead wire of the coil of each phase to the neutral point or to the power feed side can be performed smoothly. [Effects of the Invention]

[0021] According to this invention, it is possible to reduce the size of the yoke in the stator in the axial direction. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view showing a rotating electric machine according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing the stator core and two insulators. [Figure 3] FIG. 3 is a perspective view of the stator. [Figure 4] FIG. 4 is a perspective view of the stator. [Figure 5] FIG. 5 is a schematic diagram showing the relationship between the insulators, teeth, and windings in an expanded view. [Figure 6] FIG. 6 is a cross-sectional view of the winding. [Figure 7] FIG. 7 is a cross-sectional view of the lead wire at the winding end side. [Figure 8] FIG. 8 is a perspective view showing a state in which the lead wires on the winding end side are bound and fixed. [Figure 9] FIG. 9 is a schematic diagram showing an expanded relationship between the insulators, teeth, and windings in the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, one embodiment of a stator for a rotating electrical machine will be described with reference to FIGS. <Basic configuration of a rotating electric machine> As shown in FIG. 1 , a rotating electric machine 10 includes a stator 11 and a rotor 12. The stator 11 is cylindrical. The rotor 12 is disposed inside the stator 11. The rotor 12 includes a cylindrical rotor core 13 and a plurality of permanent magnets (not shown) embedded in the rotor core 13. The rotor core 13 is fixed to a rotating shaft 14. The rotor core 13 is configured to be rotatable integrally with the rotating shaft 14.

[0024] As shown in FIGS. 1 and 2 , the stator 11 includes a stator core 23. The stator core 23 includes a yoke 24 and a plurality of teeth 25. The yoke 24 is cylindrical. The plurality of teeth 25 extend radially from an inner circumferential surface 24a, which is the circumferential surface of the yoke 24. The plurality of teeth 25 are arranged at intervals in the circumferential direction of the yoke 24. The plurality of teeth 25 are arranged at equal intervals in the circumferential direction of the yoke 24. The circumferential direction of the yoke 24 is also the circumferential direction of the stator core 23. Each tooth 25 extends from the inner circumferential surface 24a of the yoke 24 toward the axis of the stator core 23. In this embodiment, the stator core 23 has 12 teeth 25. The number of teeth 25 is not particularly limited, but is a multiple of three.

[0025] As shown in Fig. 2, both end faces of the yoke 24 located in the axial direction are flat. Both end faces of each tooth 25 located in the axial direction of the yoke 24 are flat. The axial length of the yoke 24 is the same as the axial length of each tooth 25. The end face of the yoke 24 located on one side in the axial direction is located on the same plane as the end face of each tooth 25 located on one side in the axial direction of the yoke 24. The end face of the yoke 24 located on the other side in the axial direction is located on the same plane as the end face of each tooth 25 located on the other side in the axial direction of the yoke 24.

[0026] The end face of the yoke 24 located on one side in the axial direction and the end faces of each tooth 25 located on one side in the axial direction of the yoke 24 form a first core end face 23a, which is an end face of the stator core 23 located on one side in the axial direction of the yoke 24. The end face of the yoke 24 located on the other side in the axial direction and the end face of each tooth 25 located on the other side in the axial direction of the yoke 24 form a second core end face 23b, which is an end face of the stator core 23 located on the other side in the axial direction of the yoke 24. Therefore, the stator core 23 has the first core end face 23a, which is an end face located on one end side in the axial direction of the yoke 24, and the second core end face 23b, which is an end face located on the other end side in the axial direction of the yoke 24.

[0027] 1 and 2, each tooth 25 has a tooth extension portion 26 and a tooth flange portion 27. The tooth extension portion 26 is a thin plate extending from the inner circumferential surface 24a of the yoke 24. The tooth extension portion 26 extends from the first core end face 23a to the second core end face 23b of the stator core 23. The tooth flange portions 27 protrude from the ends of the tooth extension portions 26 opposite the yoke 24 to both sides in the circumferential direction of the yoke 24.

[0028] 1, the stator 11 includes three-phase coils 28. In the following description, the coils 28 of each phase may be referred to as a "U-phase coil 28U," a "V-phase coil 28V," and a "W-phase coil 28W," respectively.

[0029] 3 and 4, the stator 11 has a first coil end 281 and a second coil end 282. The first coil end 281 is a part of the coil 28 and protrudes from the first core end face 23a. The second coil end 282 is a part of the coil 28 and protrudes from the second core end face 23b.

[0030] <Insulator> 2, the stator 11 includes two insulators 50. Each insulator 50 is cylindrical. Each insulator 50 is made of, for example, a resin material. Each insulator 50 insulates the coil 28 from the stator core 23.

[0031] Each insulator 50 has an insulator base 51 and a plurality of insulator teeth 52. The insulator base 51 is cylindrical. Each insulator 50 is disposed relative to the stator core 23 with the axis of the insulator base 51 coinciding with the axis of the yoke 24. The insulator base 51 is disposed at a position overlapping the yoke 24 in the axial direction of the yoke 24. The circumferential direction of the insulator base 51 coincides with the circumferential direction of the yoke 24.

[0032] One of the two insulators 50 is disposed opposite the first core end face 23a of the stator core 23 while in contact with the first core end face 23a. The other of the two insulators 50 is disposed opposite the second core end face 23b of the stator core 23 while in contact with the second core end face 23b. The outer diameter of the insulator base 51 is smaller than the outer diameter of the yoke 24. The inner diameter of the insulator base 51 is the same as the inner diameter of the yoke 24.

[0033] Each insulator tooth 52 extends from the inner circumferential surface 51a of the insulator base 51 in the radial direction of the insulator base 51. The multiple insulator teeth 52 are arranged at intervals in the circumferential direction of the insulator base 51. The multiple insulator teeth 52 are arranged at equal intervals in the circumferential direction of the insulator base 51. Each insulator tooth 52 extends from the inner circumferential surface 51a of the insulator base 51 toward the axis of the insulator base 51. In this embodiment, the insulator 50 has 12 insulator teeth 52. The number of insulator teeth 52 is the same as the number of teeth 25 of the stator core 23.

[0034] Each insulator tooth 52 has an insulator extension 53 and an insulator flange 54. The insulator extension 53 is columnar and extends from the inner circumferential surface 51a of the insulator base 51. The circumferential width of each insulator extension 53 of the insulator base 51 is the same as the circumferential width of each tooth extension 26 of the yoke 24. Each insulator extension 53 is in contact with each tooth 25. The insulator flange 54 protrudes along the insulator base 51 from the end of the insulator extension 53 opposite the insulator base 51.

[0035] 3, of the two insulators 50, the insulator 50 arranged opposite the first core end face 23a of the stator core 23 insulates between the first coil end 281 and the first core end face 23a. Therefore, one of the two insulators 50 insulates between the coil 28 and the first core end face 23a.

[0036] 4, of the two insulators 50, the insulator 50 arranged opposite the second core end face 23b of the stator core 23 insulates between the second coil end 282 and the second core end face 23b. Therefore, the other of the two insulators 50 insulates between the coil 28 and the second core end face 23b.

[0037] <Crossover wire accommodation groove> As shown in FIG. 2 , two crossover wire accommodating grooves 61 are formed in the outer peripheral surface, which is the peripheral surface of the insulator base 51 of one of the two insulators 50. The two crossover wire accommodating grooves 61 are arranged side by side in the axial direction of the insulator base 51. Each crossover wire accommodating groove 61 extends in the circumferential direction of the yoke 24. Each crossover wire accommodating groove 61 extends around the entire outer peripheral surface of the insulator base 51. Each crossover wire accommodating groove 61 does not penetrate the insulator base 51.

[0038] In the following description, of the two crossover wire accommodating grooves 61, the crossover wire accommodating groove 61 that is located farther from the stator core 23 may be referred to as the "first crossover wire accommodating groove 611." Furthermore, of the two crossover wire accommodating grooves 61, the crossover wire accommodating groove 61 that is located closer to the stator core 23 may be referred to as the "second crossover wire accommodating groove 612."

[0039] 5, six first through grooves 62 and six second through grooves 63 are formed in the insulator base 51 of one of the two insulators 50. Each of the first through grooves 62 and each of the second through grooves 63 penetrates the insulator base 51 in the radial direction. The total number of the first through grooves 62 and each of the second through grooves 63 matches the number of the teeth 25. Each of the first through grooves 62 and each of the second through grooves 63 extends in the axial direction of the insulator base 51 from an end face 51e located on the opposite side of the insulator base 51 from the stator core 23.

[0040] The length of each first through groove 62 from the end face 51e of the insulator base 51 is shorter than the length of each second through groove 63 from the end face 51e of the insulator base 51. Each first through groove 62 communicates with the first crossover wire accommodating groove 611. Each first through groove 62 divides the first crossover wire accommodating groove 611 in the circumferential direction of the insulator base 51. Each second through groove 63 traverses the first crossover wire accommodating groove 611 and communicates with the second crossover wire accommodating groove 612. Each second through groove 63 divides the first crossover wire accommodating groove 611 and the second crossover wire accommodating groove 612 in the circumferential direction of the insulator base 51.

[0041] 2, when viewed in the axial direction of the insulator base 51, each of the first through grooves 62 and each of the second through grooves 63 overlaps with each of the insulator extension portions 53 in the radial direction of the insulator base 51. As shown in Fig. 5, when viewed in the radial direction of the insulator base 51, each of the first through grooves 62 and each of the second through grooves 63 is disposed on the axis L1 of each of the teeth 25. In this way, each of the first through grooves 62 and each of the second through grooves 63 is disposed at a position corresponding to each of the teeth 25 in the circumferential direction of the insulator base 51.

[0042] The two first through grooves 62 are adjacent to each other in the circumferential direction of the insulator base 51. The two second through grooves 63 are adjacent to each other in the circumferential direction of the insulator base 51. The two first through grooves 62 adjacent to each other in the circumferential direction of the insulator base 51 and the two second through grooves 63 adjacent to each other in the circumferential direction of the insulator base 51 are arranged alternately in the circumferential direction of the insulator base 51.

[0043] <Coils for each phase> U-phase coil 28U, V-phase coil 28V, and W-phase coil 28W each have four winding portions 30. Each winding portion 30 is formed by winding wire 31 in a concentrated manner so as to collectively surround each tooth extension portion 26 and each insulator extension portion 53 of each insulator 50. For convenience of illustration, FIG. 5 does not show the state in which wire 31 is wound around each insulator extension portion 53 of each insulator 50. FIG. 5 also schematically shows only the state in which wire 31 is wound around tooth 25.

[0044] In the following description, the four winding portions 30 of the U-phase coil 28U may be referred to as the "first winding portion U1," the "second winding portion U2," the "third winding portion U3," and the "fourth winding portion U4." Furthermore, the four winding portions 30 of the V-phase coil 28V may be referred to as the "first winding portion V1," the "second winding portion V2," the "third winding portion V3," and the "fourth winding portion V4." Furthermore, the four winding portions 30 of the W-phase coil 28W may be referred to as the "first winding portion W1," the "second winding portion W2," the "third winding portion W3," and the "fourth winding portion W4."

[0045] The first winding portion U1, the second winding portion U2, the third winding portion U3, and the fourth winding portion U4 are each formed by winding the wire 31 in a concentrated manner around every other tooth 25 among the plurality of teeth 25 in the circumferential direction of the yoke 24. The first winding portion U1, the second winding portion U2, the third winding portion U3, and the fourth winding portion U4 are arranged in this order in the circumferential direction of the yoke 24 with two teeth 25 between them.

[0046] The first winding portion V1, the second winding portion V2, the third winding portion V3, and the fourth winding portion V4 are each formed by winding the winding 31 in a concentrated manner around every other tooth 25 among the plurality of teeth 25 in the circumferential direction of the yoke 24. The first winding portion V1, the second winding portion V2, the third winding portion V3, and the fourth winding portion V4 are arranged in this order in the circumferential direction of the yoke 24 with two teeth 25 between them.

[0047] The first winding portion W1, the second winding portion W2, the third winding portion W3, and the fourth winding portion W4 are each formed by winding the wire 31 in a concentrated manner around every other tooth 25 among the plurality of teeth 25 in the circumferential direction of the yoke 24. The first winding portion W1, the second winding portion W2, the third winding portion W3, and the fourth winding portion W4 are arranged in this order in the circumferential direction of the yoke 24 with two teeth 25 between them.

[0048] In this way, the coil 28 of each phase has four winding sections 30 formed by winding the winding 31 in a concentrated manner around every other tooth 25 among the multiple teeth 25 in the circumferential direction of the yoke 24.

[0049] Each phase coil 28 has two crossover wires 32. The crossover wires 32 are part of the windings 31. In the following description, the two crossover wires 32 of the U-phase coil 28U may be referred to as the "first crossover wire Ucw1" and the "second crossover wire Ucw2." The two crossover wires 32 of the V-phase coil 28V may be referred to as the "first crossover wire Vcw1" and the "second crossover wire Vcw2." The two crossover wires 32 of the W-phase coil 28W may be referred to as the "first crossover wire Wcw1" and the "second crossover wire Wcw2."

[0050] The U-phase coil 28U has a first coil set Ug1 in which a first winding portion U1 and a second winding portion U2, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a first crossover wire Ucw1. The U-phase coil 28U also has a second coil set Ug2 in which a third winding portion U3 and a fourth winding portion U4, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a second crossover wire Ucw2. The U-phase coil 28U is configured by connecting the first coil set Ug1 and the second coil set Ug2 in parallel.

[0051] The V-phase coil 28V has a first coil set Vg1 in which a first winding portion V1 and a second winding portion V2, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a first crossover wire Vcw1. The V-phase coil 28V also has a second coil set Vg2 in which a third winding portion V3 and a fourth winding portion V4, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a second crossover wire Vcw2. The V-phase coil 28V is configured by connecting the first coil set Vg1 and the second coil set Vg2 in parallel.

[0052] The W-phase coil 28W has a first coil set Wg1 in which a first winding portion W1 and a second winding portion W2, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a first crossover wire Wcw1. The W-phase coil 28W also has a second coil set Wg2 in which a third winding portion W3 and a fourth winding portion W4, which are two winding portions 30 that are spaced apart by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a second crossover wire Wcw2. The W-phase coil 28W is configured by connecting the first coil set Wg1 and the second coil set Wg2 in parallel.

[0053] In the following description, the first coil group Ug1, the second coil group Ug2, the first coil group Vg1, the second coil group Vg2, the first coil group Wg1, and the second coil group Wg2 may be simply referred to as "coil group 33."

[0054] In this way, the coil 28 of each phase has two coil sets 33 in which two of the four winding sections 30, which exist in the circumferential direction of the yoke 24 with two teeth 25 between them, are connected in series via crossover wires 32. The coil 28 of each phase is configured by connecting two coil sets 33 in parallel.

[0055] In the U-phase coil 28U, a first winding-start lead Usw1, which is part of the winding 31, is drawn out from the first winding portion U1 that forms the first coil group Ug1. In addition, in the U-phase coil 28U, a first winding-end lead Uew1, which is part of the winding 31, is drawn out from the second winding portion U2 that forms the first coil group Ug1.

[0056] In the U-phase coil 28U, a second winding start lead Usw2, which is part of the winding 31, is drawn out from the third winding portion U3 that forms the second coil group Ug2. In addition, in the U-phase coil 28U, a second winding end lead Uew2, which is part of the winding 31, is drawn out from the fourth winding portion U4 that forms the second coil group Ug2.

[0057] In the V-phase coil 28V, a first winding-start lead Vsw1, which is part of the winding 31, is led out from the first winding portion V1 that forms the first coil group Vg1. In addition, in the V-phase coil 28V, a first winding-end lead Vew1, which is part of the winding 31, is led out from the second winding portion V2 that forms the first coil group Vg1.

[0058] In the V-phase coil 28V, a second winding-start lead Vsw2, which is part of the winding 31, is led out from the third winding portion V3 that forms the second coil group Vg2. In addition, in the V-phase coil 28V, a second winding-end lead Vew2, which is part of the winding 31, is led out from the fourth winding portion V4 that forms the second coil group Vg2.

[0059] In the W-phase coil 28W, a first winding-start lead-out wire Wsw1, which is part of the winding 31, is drawn out from the first winding portion W1 that forms the first coil group Wg1. In addition, in the W-phase coil 28W, a first winding-end lead-out wire Wew1, which is part of the winding 31, is drawn out from the second winding portion W2 that forms the first coil group Wg1.

[0060] In the W-phase coil 28W, a second winding-start lead-out wire Wsw2, which is part of the winding 31, is drawn out from the third winding portion W3 that forms the second coil group Wg2. In addition, in the W-phase coil 28W, a second winding-end lead-out wire Wew2, which is part of the winding 31, is drawn out from the fourth winding portion W4 that forms the second coil group Wg2.

[0061] In the following description, the first winding start side lead Usw1, the second winding start side lead Usw2, the first winding start side lead Vsw1, the second winding start side lead Vsw2, the first winding start side lead Wsw1, and the second winding start side lead Wsw2 may be simply referred to as "winding start side lead 34." In the following description, the first winding end side lead Uew1, the second winding end side lead Uew2, the first winding end side lead Vew1, the second winding end side lead Vew2, the first winding end side lead Wew1, and the second winding end side lead Wew2 may be simply referred to as "winding end side lead 35."

[0062] In this way, in the coil 28 of each phase, a winding start side lead wire 34 is drawn out from one of the two winding sections 30 that form the coil set 33, and a winding end side lead wire 35 is drawn out from the other of the two winding sections 30 that form the coil set 33.

[0063] The first winding portion V1 is a winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24, among the plurality of teeth 25, with respect to the first winding portion U1. The first winding portion W1 is a winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24, among the plurality of teeth 25, with respect to the first winding portion V1. The third winding portion U3 is a winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24, among the plurality of teeth 25, with respect to the first winding portion W1. The third winding portion V3 is a winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24, among the plurality of teeth 25, with respect to the third winding portion U3. The third winding portion W3 is a winding portion 30 wound around every other tooth 25 in the circumferential direction of the yoke 24 among the plurality of teeth 25 with respect to the third winding portion V3.

[0064] Therefore, the first winding-start side lead Usw1, the second winding-start side lead Usw2, the first winding-start side lead Vsw1, the second winding-start side lead Vsw2, the first winding-start side lead Wsw1, and the second winding-start side lead Wsw2 are each led out from winding portions 30 wound around every other tooth 25 of the multiple teeth 25 in the circumferential direction of the yoke 24. In this way, the winding-start side leads 34 of the coils 28 of each phase are each led out from winding portions 30 wound around every other tooth 25 of the multiple teeth 25 in the circumferential direction of the yoke 24.

[0065] The first coil group Ug1 is a coil group 33 of the first winding portion U1 that exists every other coil group in the circumferential direction of the yoke 24 and is connected to the third winding portion W3 from which the winding-start lead-out Wsw2 of the second coil group Wg2, which is one coil group 33, is led out. The first coil group Vg1 is a coil group 33 of the first winding portion V1 that exists every other coil group in the circumferential direction of the yoke 24 and is connected to the first winding portion U1 from which the winding-start lead-out Usw1 of the first coil group Ug1, which is one coil group 33, is led out. The first coil group Wg1 is a coil group 33 of the first winding portion V1 that exists every other coil group in the circumferential direction of the yoke 24 and is connected to the first winding portion W1 from which the winding-start lead-out Vsw1 of the first coil group Vg1, which is one coil group 33, is led out. The second coil group Ug2 is a coil group 33 of the third winding portion U3 that exists every other coil group in the circumferential direction of the yoke 24, and is located between the first winding portion W1 and the first coil group Wg1, which is one of the coil groups 33, and from which the winding-start-side lead-out Wsw1 of the first coil group Wg1 is led out. The second coil group Vg2 is a coil group 33 of the third winding portion V3 that exists every other coil group in the circumferential direction of the yoke 24, and from which the winding-start-side lead-out Usw2 of the second coil group Ug2, which is one of the coil groups 33, is led out. The second coil group Wg2 is a coil group 33 of the third winding portion V3 that exists every other coil group in the circumferential direction of the yoke 24, and is located between the third winding portion V3 and the third winding portion W3 that exists every other coil group in the circumferential direction of the yoke 24, and from which the winding-start-side lead-out Vsw2 of the second coil group Vg2, which is one of the coil groups 33, is led out.

[0066] The axis L1 of the tooth 25 around which the winding 31 forming the first winding portion U1 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the first winding portion U1 is wound.

[0067] The axis L1 of the tooth 25 around which the winding 31 forming the second winding portion U2 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the second winding portion U2 is wound.

[0068] The first crossover wire Ucw1 is drawn from the first winding portion U1 toward the first core end face 23a and is drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the first through groove 62. The first crossover wire Ucw1 drawn out from the first through groove 62 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the first crossover wire accommodating groove 611. The first crossover wire Ucw1 accommodated in the first crossover wire accommodating groove 611 extends in the circumferential direction of the yoke 24 while crossing the two second through grooves 63 and is connected to the second winding portion U2 through the next first through groove 62.

[0069] The axis L1 of the tooth 25 around which the winding 31 forming the first winding portion V1 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the first winding portion V1 is wound.

[0070] The axis L1 of the tooth 25 around which the winding 31 forming the second winding portion V2 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the second winding portion V2 is wound.

[0071] The first crossover wire Vcw1 is drawn from the first winding portion V1 toward the first core end face 23a and then drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the second through groove 63. The first crossover wire Vcw1 drawn out from the second through groove 63 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the second crossover wire accommodating groove 612. The first crossover wire Vcw1 accommodated in the second crossover wire accommodating groove 612 extends in the circumferential direction of the yoke 24 and is connected to the second winding portion V2 through the next second through groove 63.

[0072] The axis L1 of the tooth 25 around which the winding 31 forming the first winding portion W1 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the first winding portion W1 is wound.

[0073] The axis L1 of the tooth 25 around which the winding 31 forming the second winding portion W2 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the second winding portion W2 is wound.

[0074] The first crossover wire Wcw1 is drawn from the first winding portion W1 toward the first core end face 23a and is drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the first through groove 62. The first crossover wire Wcw1 drawn out from the first through groove 62 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the first crossover wire accommodating groove 611. The first crossover wire Wcw1 accommodated in the first crossover wire accommodating groove 611 extends in the circumferential direction of the yoke 24 while crossing the two second through grooves 63 and is connected to the second winding portion W2 through the next first through groove 62.

[0075] The axis L1 of the tooth 25 around which the winding 31 forming the third winding portion U3 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the third winding portion U3 is wound.

[0076] The axis L1 of the tooth 25 around which the winding 31 forming the fourth winding portion U4 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the fourth winding portion U4 is wound.

[0077] The second crossover wire Ucw2 is drawn from the third winding portion U3 toward the first core end face 23a and is drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the second through groove 63. The second crossover wire Ucw2 drawn out from the second through groove 63 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the second crossover wire accommodating groove 612. The second crossover wire Ucw2 accommodated in the second crossover wire accommodating groove 612 extends in the circumferential direction of the yoke 24 and is connected to the fourth winding portion U4 through the next second through groove 63.

[0078] The axis L1 of the tooth 25 around which the winding 31 forming the third winding portion V3 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the third winding portion V3 is wound.

[0079] The axis L1 of the tooth 25 around which the winding 31 forming the fourth winding portion V4 is wound passes through one of the six first through grooves 62 when viewed from the radial direction of the insulator base 51. Therefore, one of the six first through grooves 62 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the fourth winding portion V4 is wound.

[0080] The second crossover wire Vcw2 is drawn from the third winding portion V3 toward the first core end face 23a and drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the first through groove 62. The second crossover wire Vcw2 drawn out from the first through groove 62 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the first crossover wire accommodating groove 611. The first crossover wire Vcw2 accommodated in the first crossover wire accommodating groove 611 extends in the circumferential direction of the yoke 24 while crossing the two second through grooves 63 and is connected to the fourth winding portion V4 through the next first through groove 62.

[0081] The axis L1 of the tooth 25 around which the winding 31 forming the third winding portion W3 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the winding 31 forming the third winding portion W3 is wound.

[0082] The axis L1 of the tooth 25 around which the wire 31 forming the fourth winding portion W4 is wound passes through one of the six second through grooves 63 when viewed from the radial direction of the insulator base 51. Therefore, one of the six second through grooves 63 is disposed at a position corresponding to the tooth 25 around which the wire 31 forming the fourth winding portion W4 is wound.

[0083] The second crossover wire Wcw2 is drawn from the third winding portion W3 toward the first core end face 23a and is drawn outward in the radial direction of the yoke 24 beyond the insulator base portion 51 through the second through groove 63. The second crossover wire Wcw2 drawn out from the second through groove 63 is then bent to one side in the circumferential direction of the yoke 24 and accommodated in the second crossover wire accommodating groove 612. The second crossover wire Wcw2 accommodated in the second crossover wire accommodating groove 612 extends in the circumferential direction of the yoke 24 and is connected to the fourth winding portion W4 through the next second through groove 63.

[0084] In this way, the crossover wires 32 of the coils 28 of each phase extend such that the direction from one to the other of the two winding portions 30 that form the coil set 33 is the same in the circumferential direction of the yoke 24. The crossover wires 32 of the coils 28 of each phase are drawn out toward the first core end face 23a and extend in the circumferential direction of the yoke 24 while passing outside the first core end face 23a in the axial direction of the yoke 24. One of the two crossover wire accommodating grooves 61 accommodates and guides the crossover wires 32 of one coil set 33 in the circumferential direction of the yoke 24. The other of the two crossover wire accommodating grooves 61 accommodates and guides in the circumferential direction of the yoke 24 the winding portion 30 from which the winding-start-side lead wire 34 of one coil set 33 is drawn out and the crossover wires 32 of the coil sets 33 of the winding portions 30 that are present every other winding portion 30 in the circumferential direction of the yoke 24.

[0085] When accommodated in the first jumper wire accommodating groove 611, the first jumper wire Ucw1 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the first winding portion V1 is wound. Furthermore, when accommodated in the first jumper wire accommodating groove 611, the first jumper wire Ucw1 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the fourth winding portion W4 is wound.

[0086] In the first jumper wire Ucw1, the section from the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the first winding section V1 is wound, to the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the second winding section U2 is wound, overlaps with the first jumper wire Vcw1 in the axial direction of the yoke 24.

[0087] In the first jumper wire Ucw1, the section from the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the first winding section U1 is wound, to the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the first winding section V1 is wound, overlaps with the second jumper wire Wcw2 in the axial direction of the yoke 24.

[0088] When accommodated in the first jumper wire accommodating groove 611, the first jumper wire Wcw1 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the second winding portion V2 is wound. Furthermore, when accommodated in the first jumper wire accommodating groove 611, the first jumper wire Wcw1 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the third winding portion U3 is wound.

[0089] In the first crossover wire Wcw1, the portion from the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the first winding section W1 is wound, to the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the second winding section V2 is wound, overlaps with the first crossover wire Vcw1 in the axial direction of the yoke 24.

[0090] In the first jumper wire Wcw1, the section from the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the third winding section U3 is wound, to the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the second winding section W2 is wound, overlaps with the second jumper wire Ucw2 in the axial direction of the yoke 24.

[0091] When accommodated in the first jumper wire accommodating groove 611, the second jumper wire Vcw2 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the fourth winding portion U4 is wound. Furthermore, when accommodated in the first jumper wire accommodating groove 611, the second jumper wire Vcw2 extends in the circumferential direction of the yoke 24 while crossing the second through groove 63 that is disposed in a position corresponding to the tooth 25 around which the winding 31 that forms the third winding portion W3 is wound.

[0092] In the second jumper wire Vcw2, the section from the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the third winding section V3 is wound, to the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the fourth winding section U4 is wound, overlaps with the second jumper wire Ucw2 in the axial direction of the yoke 24.

[0093] In the second jumper wire Vcw2, the section from the second through groove 63, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the third winding section W3 is wound, to the first through groove 62, which is located at a position corresponding to the tooth 25 around which the winding 31 forming the fourth winding section V4 is wound, overlaps with the second jumper wire Wcw2 in the axial direction of the yoke 24.

[0094] In this way, the number of overlaps in the crossover wires 32 of the coils 28 of each phase in the axial direction of the yoke 24 is a maximum of two. In the U-phase coil 28U, the first winding-start side lead Usw1 and the second winding-start side lead Usw2 are drawn out toward the second core end face 23b and electrically connected in parallel to a connection terminal 41 housed in the cluster block 40. In the V-phase coil 28V, the first winding-start side lead Vsw1 and the second winding-start side lead Vsw2 are drawn out toward the second core end face 23b and electrically connected in parallel to a connection terminal 41 housed in the cluster block 40. In the W-phase coil 28W, the first winding-start side lead Wsw1 and the second winding-start side lead Wsw2 are drawn out toward the second core end face 23b and electrically connected in parallel to a connection terminal 41 housed in the cluster block 40. The connection terminal 41 is electrically connected to a power source 42, which is the power supply side. Therefore, the winding-start side lead wires 34 of the coils 28 of each phase are drawn out toward the second core end face 23b and connected in parallel to the power supply side. In this way, the winding-start side lead wires 34 of the coils 28 of each phase are drawn out toward the second core end face 23b.

[0095] The first winding end lead Uew1, the second winding end lead Uew2, the first winding end lead Vew1, the second winding end lead Vew2, the first winding end lead Wew1, and the second winding end lead Wew2 are drawn out toward the second core end face 23b. In this way, the winding end lead 35 of the coil 28 of each phase is drawn out toward the second core end face 23b.

[0096] The first winding end-side lead-out Uew1, the second winding end-side lead-out Uew2, the first winding end-side lead-out Vew1, the second winding end-side lead-out Vew2, the first winding end-side lead-out Wew1, and the second winding end-side lead-out Wew2 are electrically connected to each other to form a neutral point. In this way, the winding end-side leads 35 of each coil set 33 are electrically connected to each other to form a neutral point.

[0097] 6, the winding 31 has a conductor 31a and a coating 31b applied to the outer periphery of the conductor 31a. The coating 31b is, for example, an enamel coating. 7, the lead-out wire 35 at the winding end side has an insulating member 31c that covers the outer periphery of the coating 31b. Thus, the lead-out wire 35 at the winding end side has a conductor 31a, the coating 31b, and the insulating member 31c. The insulating member 31c is made of a tubular resin.

[0098] As shown in FIG. 2, the other of the two insulators 50 has an insulator base 51 provided with six locking portions 55. 8, each locking portion 55 is configured to be able to entangle and fix the winding-end lead wire 35 of the coil 28 of each phase. By being entangled and fixed to each locking portion 55, each winding-end lead wire 35 is fixed to the insulator base 51 in a state in which tension is applied. In this way, the winding-end lead wire 35 is fixed in a state in which tension is applied.

[0099] [Operation of the embodiment] Next, the operation of this embodiment will be described. An input current from the power supply 42 flows to the winding-start lead wire 34 of the coil 28 of each phase via each connection terminal 41. In this way, the input current flows through the coil 28 of each phase, causing the rotor 12 and the rotating shaft 14 to rotate integrally.

[0100] [Effects of the embodiment] The above embodiment can provide the following effects. (1) The coil 28 of each phase has four winding portions 30 formed by winding a winding 31 in a concentrated manner around every other tooth 25 among the multiple teeth 25 in the circumferential direction of the yoke 24. The coil 28 of each phase has two coil sets 33 in which two of the four winding portions 30, which are separated by two teeth 25 in the circumferential direction of the yoke 24, are connected in series via a crossover wire 32 that is part of the winding 31. The coil 28 of each phase is configured by connecting two coil sets 33 in parallel. In the coil 28 of each phase configured in this manner, the crossover wires 32 of the coil 28 of each phase extend in the same direction in the circumferential direction of the yoke 24 from one of the two winding portions 30 to the other that form the coil set 33. The winding-start lead-out wires 34 of the coils 28 of each phase are respectively drawn out from winding portions 30 wound around every other tooth 25 of the multiple teeth 25 in the circumferential direction of the yoke 24. The winding-end lead-out wires 35 of each coil group 33 are electrically connected to each other to form a neutral point. This allows the number of overlapping jumper wires 32 of the coils 28 of each phase in the axial direction of the yoke 24 to be a maximum of two, preventing the existence of a location where three jumper wires 32 overlap in the axial direction of the yoke 24. This allows the stator 11 to be made smaller in the axial direction of the yoke 24.

[0101] (2) The winding start side portion of the winding portion 30 is fixed as the winding wire 31 is wound around the teeth 25. Therefore, there is no need to separately fix the winding start side lead wire 34 to prevent the winding start side portion of the winding portion 30 from loosening. On the other hand, in order to prevent the winding end side portion of the winding portion 30 from loosening, it is necessary to fix the winding end side lead wire 35.

[0102] Generally, winding 31 has conductor 31a and coating 31b applied to the outer periphery of conductor 31a. When winding 31 is fixed to locking portion 55, it is considered to cover the outer periphery of coating 31b with insulating member 31c in advance to prevent coating 31b of winding 31 from being torn and conductor 31a from being exposed.

[0103] On the other hand, consider a case where a neutral point is formed by electrically connecting together lead wires, which are part of the windings 31 drawn from the winding portions 30 of the coils 28 of each phase. In this case, the lead wires of the coils 28 of each phase that form the neutral point need to be insulated when connecting the lead wires of the coils 28 of each phase to each other at the neutral point, so it is considered that the outer periphery of the coating 31b of the lead wire is covered in advance with an insulating member 31c.

[0104] Therefore, in a configuration in which the end-of-winding side lead wire 35 is the neutral point and the end-of-winding side lead wire 35 has an insulating member 31c, this is preferable because the insulating member 31c required for neutral point connection can also be used as the insulating member 31c when fixing to the locking portion 55.

[0105] In this case, if the start-side lead-wire 34 is a lead-wire that forms the neutral point, it is necessary to cover the outer periphery of the coating 31b of the start-side lead-wire 34 with the insulating member 31c in advance. Furthermore, since the end-side lead-wire 35 must be fixed to the locking portion 55, it is also necessary to cover the outer periphery of the coating 31b of the end-side lead-wire 35 with the insulating member 31c in advance. Therefore, it is necessary to cover the outer periphery of the coating 31b of both the start-side lead-wire 34 and the end-side lead-wire 35 with the insulating member 31c, which complicates the configuration.

[0106] Therefore, the neutral point is formed by electrically connecting the winding-end leads 35 of each coil group 33 to each other. This eliminates the need to cover the outer periphery of the coating 31b of the winding-start lead 34 of each coil group 33 with the insulating member 31c in advance; it is sufficient to cover the outer periphery of the coating 31b of the winding-end lead 35 of each coil group 33 with the insulating member 31c in advance. Therefore, since it is not necessary to cover the outer periphery of the coating 31b of both the winding-start lead 34 and the winding-end lead 35 of each coil group 33 with the insulating member 31c, a complicated configuration can be avoided. As a result, the axial size of the yoke 24 in the stator 11 can be reduced without complicating the configuration.

[0107] (3) For example, consider a case where the crossover wire 32 of the coil 28 of one of the three phases is pulled out toward the second core end face 23b and extends circumferentially around the yoke 24 while passing outside the second core end face 23b in the axial direction of the yoke 24. In this case, the number of turns of the winding 31 of the winding portion 30 constituting the coil 28 of one of the three phases is different from the number of turns of the winding 31 of the winding portion 30 constituting the coil 28 of the other phases. This may cause the magnetic balance of the stator 11 as a whole to become unstable, resulting in deterioration of motor characteristics. Therefore, the crossover wire 32 of the coil 28 of each phase is pulled out toward the first core end face 23a and extends circumferentially around the yoke 24 while passing outside the first core end face 23a in the axial direction of the yoke 24. This allows the number of turns of the winding 31 of the winding portion 30 constituting the coil 28 of each phase to be the same, thereby stabilizing the magnetic balance of the stator 11 as a whole and improving motor characteristics.

[0108] (4) The jumper wires 32 of each coil set 33 are accommodated in the jumper wire receiving grooves 61 and guided in the circumferential direction of the yoke 24. Therefore, the jumper wires 32 of each coil set 33 can extend in the circumferential direction of the yoke 24 while ensuring insulation between the jumper wires 32 of each coil set 33 that overlap in the axial direction of the yoke 24. Consider, for example, a case where the jumper wires 32 of each coil set 33 overlap in the axial direction of the yoke 24, resulting in a location where three jumper wires 32 overlap in the axial direction of the yoke 24. As in such a case, it is not necessary to form three jumper wire receiving grooves 61 arranged side by side in the axial direction of the insulator base 51 and extending in the circumferential direction of the yoke 24 on the outer circumferential surface of the insulator base 51. This allows the axial length of the insulator base 51 to be shortened. As a result, the axial size of the insulator base 51 in the insulator 50 can be reduced. This allows the axial size of the yoke 24 in the stator 11 to be reduced.

[0109] (5) The winding start side lead-out wire 34 and the winding end side lead-out wire 35 of the coil 28 of each phase are drawn out toward the second core end surface 23b and electrically connected to each other to form a neutral point or to the power feed side. This prevents the jumper wire 32 from interfering with the work of connecting the winding start side lead-out wire 34 and the winding end side lead-out wire 35 of the coil 28 of each phase to the neutral point or to the power feed side. This allows the work of connecting the winding start side lead-out wire 34 and the winding end side lead-out wire 35 of the coil 28 of each phase to the neutral point or to the power feed side to be performed smoothly.

[0110] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0111] 9, the neutral point may be formed by electrically connecting the winding-start side lead wires 34 of each coil set 33 to each other. In short, it is sufficient that the winding-start side lead wires 34 of each coil set 33 or the winding-end side lead wires 35 of each coil set 33 are electrically connected to each other to form the neutral point.

[0112] Because the end-of-winding lead wire 35 is only pulled out from the end-of-winding portion of the winding unit 30, it is unlikely to come into contact with other portions of the winding unit 30. On the other hand, the start-of-winding lead wire 34 is likely to come into contact with the end-of-winding portion of the winding unit 30 when it is pulled out from the winding unit 30.

[0113] When a voltage is applied to each coil group 33 by power supply, the voltage applied to the winding group 30 downstream in the power supply direction of the two winding groups 30 that form the coil group 33 is smaller than the voltage applied to the winding group 30 upstream in the power supply direction. In other words, of the two winding groups 30 that form the coil group 33, the voltage applied to the winding group 30 closer to the neutral point is smaller. Therefore, if the winding-start-side leads 34 of each coil group 33 are electrically connected to each other to form a neutral point, the voltage applied to the winding group 30 from which the winding-start-side leads 34 are led out is smaller than the voltage applied to the winding group 30 from which the winding-end-side leads 35 are led out. Therefore, the winding-start-side leads 34 of each coil group 33 are electrically connected to each other to form a neutral point. This makes it possible to keep small the potential difference between the winding-start side lead-out wire 34 and the winding-end side part of the winding part 30, even if the winding-start side lead-out wire 34 comes into contact with the winding-end side part of the winding part 30 when being drawn out from the winding part 30. As a result, it is possible to improve the dielectric strength of the coil 28, and to improve the reliability of the stator 11 of the rotating electric machine 10.

[0114] In the embodiment, for example, the crossover wire 32 of the coil 28 of one of the three phases may be drawn out toward the second core end face 23b and extend in the circumferential direction of the yoke 24 while passing outside the second core end face 23b in the axial direction of the yoke 24. Even in this case, it is sufficient that the crossover wires 32 of the coils 28 of each phase extend in the same direction in the circumferential direction of the yoke 24 from one to the other of the two winding portions 30 that form the coil set 33.

[0115] In the above embodiment, the winding-end lead wires 35 of the coils 28 of each phase may be drawn to the first core end surface 23a and electrically connected to each other. In the above embodiment, the winding-start side lead wires 34 of the coils 28 of each phase may be drawn out to the first core end surface 23a and connected in parallel to each other.

[0116] In the embodiment, the coil 28 of each phase may have four or more winding portions 30. In other words, the coil 28 of each phase may have a plurality of coil sets 33 in which two winding portions 30, among the four or more winding portions 30, that are present in the circumferential direction of the yoke 24 with two teeth 25 between them are connected in series via crossover wires 32, and the plurality of coil sets 33 are connected in parallel to each other.

[0117] In the above embodiment, the rotor 12 is disposed inside the stator 11. However, the stator 11 may be disposed inside a cylindrical rotor 12. In this case, the teeth 25 extend radially outward from the outer peripheral surface of the yoke 24. In short, it is sufficient that the teeth 25 extend radially from the outer peripheral surface of the yoke 24. When the stator 11 is disposed inside the rotor 12, two crossover wire accommodating grooves 61 are formed in the inner peripheral surface 51a of the insulator base 51. In short, it is sufficient that two crossover wire accommodating grooves 61 are formed in the peripheral surface of the insulator base 51.

[0118] In the embodiment, no tension may be applied to the end-of-winding lead wires 35 fixed to the locking portions 55. The key is that the end-of-winding lead wires 35 are fixed to the locking portions 55 so that the end-of-winding portion of the winding portion 30 does not loosen.

[0119] [Note] The technical ideas that can be understood from the above-described embodiment and modifications will be described below. <Appendix 1> Three-phase coils and A stator for a rotating electric machine comprising: a cylindrical yoke; and a stator core having a plurality of teeth arranged at intervals in a circumferential direction of the yoke and extending from a peripheral surface of the yoke in a radial direction of the yoke, The coil of each phase has four or more winding sections formed by winding a winding around every other tooth among the plurality of teeth in the circumferential direction using concentrated winding, and has a plurality of coil sets in which two of the winding sections that are present between two of the teeth in the circumferential direction among the four or more winding sections are connected in series via crossover wires that are part of the winding, and the plurality of coil sets are connected in parallel, In each of the phase coils, a winding-start side lead wire, which is part of the winding, is drawn out from one of the two winding portions that form the coil set, and a winding-end side lead wire, which is part of the winding, is drawn out from the other of the two winding portions that form the coil set, the crossover wires of the coils of each phase extend such that the directions from one to the other of the two winding portions forming the coil set are all the same in the circumferential direction, the winding-start-side lead wire of each phase coil is drawn out from a winding portion wound around every other tooth in the circumferential direction among the plurality of teeth, A stator for a rotating electric machine, characterized in that the winding start side lead wires of each of the coil groups or the winding end side lead wires of each of the coil groups are electrically connected to each other to form a neutral point.

[0120] <Appendix 2> The stator of the rotating electric machine according to <Appendix 1>, wherein the winding end side lead wires of the respective coil groups are electrically connected to each other to form a neutral point.

[0121] <Appendix 3> The stator of the rotating electric machine according to <Appendix 1>, wherein the winding-start side lead wires of the respective coil groups are electrically connected to each other to form a neutral point.

[0122] <Appendix 4> the stator core has a first core end surface that is an end surface located on one end side in the axial direction of the yoke, The stator of a rotating electric machine according to any one of <Appendix 1> to <Appendix 3>, characterized in that the crossover wires of the coils of each phase are drawn out to the first core end face side and extend in the circumferential direction while passing outside the first core end face in the axial direction.

[0123] <Appendix 5> an insulator disposed opposite the first core end face and insulating the coil from the first core end face; the insulator has a cylindrical insulator base portion disposed at a position overlapping the yoke in the axial direction, Two crossover wire accommodating grooves are formed on the peripheral surface of the insulator base portion, the crossover wire accommodating grooves being arranged side by side in the axial direction of the insulator base portion and extending in the circumferential direction, The stator of a rotating electric machine described in <Appendix 4>, characterized in that one of the two crossover wire accommodating grooves accommodates and guides in the circumferential direction the crossover wire of one coil set, and the other of the two crossover wire accommodating grooves accommodates and guides in the circumferential direction the crossover wire of a coil set of a winding section from which the winding-start-side lead-out wire of the one coil set is pulled out and of every other winding section in the circumferential direction.

[0124] <Appendix 6> the stator core has a second core end surface that is an end surface located on the other end side of the yoke in the axial direction, The stator of a rotating electric machine described in <Appendix 4> or <Appendix 5>, characterized in that the winding start side lead wire and the winding end side lead wire of the coil of each phase are drawn out to the end face side of the second core. [Explanation of symbols]

[0125] 10...rotating electric machine, 11...stator, 23...stator core, 23a...first core end face, 23b...second core end face, 24...yoke, 24a...inner peripheral surface which is the peripheral surface, 25...teeth, 28...coil, 30...winding portion, 31...winding, 32...crossover wire, 33...coil set, 34...winding start side lead wire, 35...winding end side lead wire, 50...insulator, 51...insulator base, 61...crossover wire accommodating groove.

Claims

1. A three-phase coil, A stator for a rotating electric machine comprising: a cylindrical yoke; and a stator core having a plurality of teeth arranged at intervals in a circumferential direction of the yoke and extending from a peripheral surface of the yoke in a radial direction of the yoke, The coil of each phase has four or more winding sections formed by winding a winding around every other tooth among the plurality of teeth in the circumferential direction using concentrated winding, and has a plurality of coil sets in which two of the four or more winding sections that are separated by two teeth in the circumferential direction are connected in series via crossover wires that are part of the winding, and the plurality of coil sets are connected in parallel to each other, In each of the phase coils, a winding-start side lead wire, which is a part of the winding, is drawn out from one of the two winding portions that form the coil set, and a winding-end side lead wire, which is a part of the winding, is drawn out from the other of the two winding portions that form the coil set, the crossover wires of the coils of each phase extend such that the directions from one to the other of the two winding portions forming the coil set are all the same in the circumferential direction, the winding-start-side lead wire of each phase coil is drawn out from a winding portion wound around every other tooth in the circumferential direction among the plurality of teeth, A stator for a rotating electric machine, characterized in that the winding start side lead wires of each of the coil groups or the winding end side lead wires of each of the coil groups are electrically connected to each other to form a neutral point.

2. 2. The stator of claim 1, wherein the winding end lead wires of the coil sets are electrically connected to each other to form a neutral point.

3. 2. The stator of claim 1, wherein the winding-start side lead wires of the coil sets are electrically connected to each other to form a neutral point.

4. the stator core has a first core end surface that is an end surface located on one end side in the axial direction of the yoke, A stator for a rotating electric machine according to any one of claims 1 to 3, characterized in that the crossover wires of the coils of each phase are pulled out to the first core end face side and extend in the circumferential direction while passing outside the first core end face in the axial direction.

5. an insulator disposed opposite the first core end face and insulating the coil from the first core end face; the insulator has a cylindrical insulator base portion disposed at a position overlapping the yoke in the axial direction, Two crossover wire accommodating grooves are formed on the peripheral surface of the insulator base portion, the crossover wire accommodating grooves being arranged side by side in the axial direction of the insulator base portion and extending in the circumferential direction, 5. The stator of claim 4, wherein one of the two jumper wire accommodating grooves accommodates and guides in the circumferential direction the jumper wire of one coil set, and the other of the two jumper wire accommodating grooves accommodates and guides in the circumferential direction the jumper wire of a coil set of a winding section from which the winding-start-side lead wire of the one coil set is pulled out and a winding section that exists every other winding section in the circumferential direction.

6. the stator core has a second core end surface that is an end surface located on the other end side of the yoke in the axial direction, 5. The stator of claim 4, wherein the winding start side lead wire and the winding end side lead wire of the coil of each phase are led out to an end face side of the second core.

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