Stator

Abstract

This stator comprises: a stator core having a yoke and a plurality of teeth projecting from the yoke; an insulator fixed to the stator core; and a coil wound around the teeth with the insulator therebetween. The insulator has an end insulator fixed to an end of the stator core in the axial direction; and an intermediate insulator disposed closer to the center side of the stator core, as compared to the end insulator in the axial direction. One of the end insulator and the intermediate insulator has a projection part. The other of the end insulator and the intermediate insulator has a recess part into which the projection part fits.

Description

Stator

[0001] The present disclosure relates to a stator.

[0002] In the technical field related to stators, an armature including a divided insulator, as disclosed in Patent Document 1, is known.

[0003] JP 2011-176902 A

[0004] Stators are produced through a process of attaching an insulator to a stator core and a process of winding a coil around the stator core with the insulator interposed therebetween. Before the coil is wound, the insulator may fall off the stator core. If the insulator falls off the stator core during the stator production process, productivity of the stator decreases.

[0005] An object of the present disclosure is to suppress a decrease in productivity of stators.

[0006] According to the present disclosure, there is provided a stator including a stator core having a yoke and a plurality of teeth protruding from the yoke, an insulator fixed to the stator core, and a coil wound around the teeth via the insulator. The insulator includes end insulators fixed to ends of the stator core in the axial direction, and a middle insulator positioned axially closer to the center of the stator core than the end insulators. One of the end insulator and the middle insulator has a protrusion. The other of the end insulator and the middle insulator has a recess into which the protrusion fits.

[0007] According to the present disclosure, a decrease in productivity of the stator is suppressed.

[0008] FIG. 1 is a perspective view showing a stator according to the embodiment. FIG. 2 is a perspective view showing a stator core and an insulator according to the embodiment. FIG. 3 is an exploded perspective view showing a stator core and an insulator according to the embodiment. FIG. 4 is an enlarged view of a portion of the stator according to the embodiment. FIG. 5 is a perspective view showing a split insulator of an upper-end insulator according to the embodiment, as viewed from above. FIG. 6 is a perspective view showing a split insulator of an upper-end insulator according to the embodiment, as viewed from below. FIG. 7 is a view of the split insulator of an upper-end insulator according to the embodiment, as viewed from above. FIG. 8 is a view of the split insulator of an upper-end insulator according to the embodiment, as viewed from a radially inner side. FIG. 9 is a perspective view of a split insulator of an intermediate insulator according to the embodiment, as viewed from above. FIG. 10 is a perspective view of a split insulator of an intermediate insulator according to the embodiment, as viewed from a lower side. FIG. 11 is a view of the split insulator of an intermediate insulator according to the embodiment, as viewed from above. FIG. 12 is a view of the split insulator of an intermediate insulator according to the embodiment, as viewed from a radially inner side. FIG. 13 is a perspective view from above showing a split insulator of a bottom-end insulator according to the embodiment. FIG. 14 is a perspective view from below showing the split insulator of a bottom-end insulator according to the embodiment. FIG. 15 is a view of the split insulator of a bottom-end insulator according to the embodiment, viewed from below. FIG. 16 is a view of the split insulator of a bottom-end insulator according to the embodiment, viewed from the radially inner side. FIG. 17 is a view of a connection structure between an top-end insulator and an intermediate insulator according to the embodiment, viewed from the radially inner side. FIG. 18 is a view of a connection structure between a bottom-end insulator and an intermediate insulator according to the embodiment, viewed from the radially inner side. FIG. 19 is a view of a connection structure between an top-end insulator and an intermediate insulator according to the embodiment, viewed from the top side. FIG. 20 is a view of a portion of a stator according to the embodiment, viewed from the top side. FIG. 21 is a cross-sectional perspective view of a portion of an top-end insulator according to the embodiment. FIG. 22 is a view for explaining the relationship between an top-end insulator, an intermediate insulator, and a bottom-end insulator according to the embodiment.

[0009] Hereinafter, embodiments will be described with reference to the drawings. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] In the embodiment, a direction parallel to the central axis AX of the stator 1 will be referred to as the axial direction, a direction radial from the central axis AX of the stator 1 will be referred to as the radial direction, and a direction circumferentially around the central axis AX of the stator 1 will be referred to as the circumferential direction or the rotational direction.

[0011] A position or direction on one side in the axial direction will be referred to as the upper side or the upper direction, as appropriate, and a position or direction on the other side in the axial direction will be referred to as the lower side or the lower direction, as appropriate. In the radial direction, a position or direction close to the central axis AX of the stator 1 will be referred to as the radially inner side or the inner direction, as appropriate, and a position or direction away from the central axis AX of the stator 1 will be referred to as the radially outer side or the outer direction, as appropriate. A position or direction on one side in the circumferential direction will be referred to as the forward side or the forward direction, as appropriate, and a position or direction on the other side in the circumferential direction will be referred to as the reverse side or the reverse direction, as appropriate.

[0012] [Stator] Fig. 1 is a perspective view showing a stator 1 according to an embodiment. The stator 1 is used in an inner rotor type motor. The stator 1 is disposed around a rotor (not shown). The rotor rotates about a central axis AX. The motor generates a rotational force for driving a hydraulic pump of, for example, an electric hydraulic excavator, which is a type of construction machine.

[0013] The stator 1 includes a stator core 2 , an insulator 3 fixed to the stator core 2 , and a coil 4 attached to the stator core 2 via the insulator 3 .

[0014] Fig. 2 is a perspective view showing the stator core 2 and the insulator 3 according to the embodiment. Fig. 3 is an exploded perspective view showing the stator core 2 and the insulator 3 according to the embodiment.

[0015] The stator core 2 includes a plurality of stacked steel plates. The steel plates are metal plates whose main component is iron. The stator core 2 has an annular yoke 21 and a plurality of teeth 22 that protrude radially inward from the inner peripheral surface of the yoke 21. The yoke 21 is arranged to surround the central axis AX. A plurality of teeth 22 are arranged in the circumferential direction. The plurality of teeth 22 are arranged at equal intervals in the circumferential direction. A slot 23 is provided between each pair of adjacent teeth 22.

[0016] The insulator 3 is disposed so as to cover at least a portion of the surface of the stator core 2. The insulator 3 is an electrically insulating member made of synthetic resin. The insulator 3 is fixed to the stator core 2. The stator core 2 and the coils 4 are electrically insulated by the insulator 3. In this embodiment, the insulator 3 is molded by any molding method, such as injection molding, and then attached to the stator core 2.

[0017] In the embodiment, the insulator 3 is divided in both the axial direction and the circumferential direction. The insulator 3 includes an upper-end insulator 5, an intermediate insulator 6, and a lower-end insulator 7. The upper-end insulator 5, the intermediate insulator 6, and the lower-end insulator 7 are arranged in the axial direction. At least a portion of the upper-end insulator 5 is arranged above the intermediate insulator 6. At least a portion of the lower-end insulator 7 is arranged below the intermediate insulator 6.

[0018] The upper-end insulator 5 is fixed to the upper end of the stator core 2. The lower-end insulator 7 is fixed to the lower end of the stator core 2. The intermediate insulator 6 is arranged closer to the center of the stator core 2 in the axial direction than the upper-end insulator 5. That is, the intermediate insulator 6 is arranged lower than the upper-end insulator 5 in the axial direction. The intermediate insulator 6 is arranged closer to the center of the stator core 2 in the axial direction than the lower-end insulator 7. That is, the intermediate insulator 6 is arranged higher than the lower-end insulator 7 in the axial direction. The upper-end insulator 5 is connected to the upper end of the intermediate insulator 6. The lower-end insulator 7 is connected to the lower end of the intermediate insulator 6.

[0019] The coils 4 are wound around the teeth 22 via the insulators 3. In the embodiment, the coils 15 are wound around the teeth 22 by concentrated winding. A portion of the coils 4 is disposed inside the slots 23. A portion of the coils 4 protrudes upward from the upper end surface of the stator core 2. A portion of the coils 4 protrudes downward from the lower end surface of the stator core 2. In the embodiment, the coils 4 are wound one by one around each tooth 22. That is, one coil 4 is wound around one tooth 22.

[0020] Each of the multiple coils 4 is assigned to one of the U-phase coil, V-phase coil, and W-phase coil. Twelve coils 4 are assigned to the U-phase coil. Twelve coils 4 are assigned to the V-phase coil. Twelve coils 4 are assigned to the W-phase coil.

[0021] A drive current is supplied to the coil 4 via connection terminals 8. The connection terminals 8 include a U-phase connection terminal 8U to which a U-phase drive current is supplied, a V-phase connection terminal 8V to which a V-phase drive current is supplied, and a W-phase connection terminal 8W to which a W-phase drive current is supplied. When a drive current is supplied to the coil 4, a rotating magnetic field is generated between the coil 4 and the rotor, causing the rotor to rotate.

[0022] The coils 4 are connected via crossover wires 9. A plurality of crossover wires 9 are provided. In the example shown in Fig. 1, the crossover wires 9 include a crossover wire 9U, a crossover wire 9V, and a crossover wire 9W.

[0023] FIG. 4 is an enlarged view of a portion of the stator 1 according to the embodiment. As shown in FIGS. 3 and 4 , the upper-end insulator 5 has a yoke opposing portion 50 opposing the yoke 21, and teeth opposing portions 51, 52, and 53 opposing the teeth 22. The yoke opposing portion 50 covers the inner circumferential surface of the yoke 21 facing radially inward. The teeth opposing portion 51 covers the side surfaces of the teeth 22 facing the forward circumferential direction. The teeth opposing portion 52 covers the side surfaces of the teeth 22 facing the reverse circumferential direction. The teeth opposing portion 53 covers the upper surfaces of the teeth 22 facing upward. The teeth opposing portion 53 is arranged to connect the upper end of the teeth opposing portion 51 to the upper end of the teeth opposing portion 52. The teeth opposing portion 51 connected to the end of the teeth opposing portion 53 on the forward circumferential direction is arranged in the slot 23. Teeth opposing portion 52, which is connected to the end of teeth opposing portion 53 on the reverse circumferential side, is arranged in slot 23 adjacent to slot 23 in which teeth opposing portion 51 is arranged. Teeth opposing portion 51, teeth opposing portion 52, and teeth opposing portion 53 are each arranged between teeth 22 and coil 4.

[0024] The upper end insulator 5 also has an outer coil stopper 54 arranged radially outward from the coil 4, and an inner coil stopper 55 arranged radially inward from the coil 4. The outer coil stopper 54 protrudes upward from the radially outer end of the tooth opposing portion 53. The inner coil stopper 55 protrudes upward from the radially inner end of the tooth opposing portion 53. The upper end of the outer coil stopper 54 is positioned higher than the upper end of the inner coil stopper 55. The outer coil stopper 54 supports the coil 4 from the radially outer side. The inner coil stopper 55 supports the coil 4 from the radially inner side.

[0025] The upper end insulator 5 also has a plurality of crossover wire retaining grooves 56 that retain each of the plurality of crossover wires 9. The crossover wire retaining grooves 56 are provided on the outer peripheral surface of the outer coil stop portion 54 that faces radially outward. The crossover wire retaining grooves 56 are formed to extend in the circumferential direction. The plurality of crossover wire retaining grooves 56 are arranged in the axial direction. In this embodiment, three crossover wire retaining grooves 56 are arranged in the axial direction. The crossover wires 9 are arranged inside the crossover wire retaining grooves 56. A crossover wire 9 is arranged in one crossover wire retaining groove 56.

[0026] The intermediate insulator 6 is disposed in the slot 23. The intermediate insulator 6 has a yoke facing portion 60 facing the yoke 21, and teeth facing portions 61 and 62 facing the teeth 22. The yoke facing portion 60 covers the inner peripheral surface of the yoke 21 facing radially inward. The teeth facing portion 61 covers the side surface of the teeth 22 facing the reverse circumferential side. The teeth facing portion 62 covers the side surface of the teeth 22 facing the forward circumferential side. The teeth facing portions 61 and 62 are each disposed between the teeth 22 and the coil 4.

[0027] The lower end insulator 7 has a yoke facing portion 70 facing the yoke 21, and teeth facing portions 71, 72, and 73 facing the teeth 22. The yoke facing portion 70 covers the inner circumferential surface of the yoke 21 facing radially inward. The teeth facing portions 71 cover the side surfaces of the teeth 22 facing the forward circumferential side. The teeth facing portions 72 cover the side surfaces of the teeth 22 facing the reverse circumferential side. The teeth facing portions 73 cover the lower surfaces of the teeth 22 facing downward. The teeth facing portions 73 are arranged to connect the lower ends of the teeth facing portions 71 and 72. The teeth facing portions 71 connected to the end of the teeth facing portion 73 on the forward circumferential side are arranged in the slots 23. Teeth opposing portion 72, which is connected to the end of teeth opposing portion 73 on the reverse circumferential side, is arranged in a slot 23 adjacent to the slot 23 in which teeth opposing portion 71 is arranged. Teeth opposing portion 71, teeth opposing portion 72, and teeth opposing portion 73 are each arranged between teeth 22 and coil 4.

[0028] The lower end insulator 7 also has an outer coil stopper 74 that is positioned radially outward from the coil 4, and an inner coil stopper 75 that is positioned radially inward from the coil 4. The outer coil stopper 74 protrudes downward from the radially outer end of the tooth opposing portion 73. The inner coil stopper 75 protrudes downward from the radially inner end of the tooth opposing portion 73. The position of the lower end of the outer coil stopper 74 is positioned lower than the position of the lower end of the inner coil stopper 75. The outer coil stopper 74 supports the coil 4 from the radially outer side. The inner coil stopper 75 supports the coil 4 from the radially inner side.

[0029] The lower end of the yoke opposing portion 50 is connected to the upper end of the yoke opposing portion 60. The lower end of the teeth opposing portion 51 is connected to the upper end of the teeth opposing portion 62. The lower end of the teeth opposing portion 52 is connected to the upper end of the teeth opposing portion 61. The upper end of the yoke opposing portion 50 is connected to the lower end of the yoke opposing portion 60. The upper end of the teeth opposing portion 71 is connected to the lower end of the teeth opposing portion 62. The upper end of the teeth opposing portion 72 is connected to the lower end of the teeth opposing portion 61.

[0030] Each of the upper end insulator 5, the intermediate insulator 6, and the lower end insulator 7 includes a plurality of segment insulators that are divided in the circumferential direction.

[0031] Fig. 5 is a perspective view from above showing a split insulator of the upper-end insulator 5 according to the embodiment. Fig. 6 is a perspective view from below showing the split insulator of the upper-end insulator 5 according to the embodiment. Fig. 7 is a view of the split insulator of the upper-end insulator 5 according to the embodiment as seen from above. Fig. 8 is a view of the split insulator of the upper-end insulator 5 according to the embodiment as seen from the radially inner side.

[0032] As described above, the upper end insulator 5 includes the yoke opposing portion 50, the tooth opposing portion 51, the tooth opposing portion 52, the tooth opposing portion 53, the outer coil stop portion 54, the inner coil stop portion 55, and the crossover wire retaining groove 56. The tooth opposing portion 51 includes a circumferential opposing portion 51A that covers the side surface of the tooth 22 facing the forward circumferential direction and a radial opposing portion 51B that covers the inner surface of the tooth 22 facing radially inward. The tooth opposing portion 52 includes a circumferential opposing portion 52A that covers the side surface of the tooth 22 facing the reverse circumferential direction and a radial opposing portion 52B that covers the inner surface of the tooth 22 facing radially inward. The radial opposing portion 51B extends from the radially inner end of the circumferential opposing portion 51A to the reverse circumferential direction. The radial opposing portion 52B extends from the radially inner end of the circumferential opposing portion 52A to the forward circumferential direction.

[0033] The upper end insulator 5 also has a protrusion 57 and a protrusion 58. The protrusion 57 protrudes downward from the lower end of the yoke opposing portion 50, the lower end of the teeth opposing portion 51, and the lower end of the teeth opposing portion 52. The thickness of the protrusion 57 is thinner than the thickness of each of the yoke opposing portion 50, the teeth opposing portion 51, and the teeth opposing portion 52. The protrusion 57 has an outer surface 57A. The outer surface 57A is perpendicular to the support surface 57B.

[0034] The protrusion 58 is provided on the yoke opposing portion 50. The protrusion 58 is provided on the inner surface of the yoke opposing portion 50 facing radially inward, so as to extend in the axial direction. The protrusion 58 protrudes radially inward from the inner surface of the yoke opposing portion 50. The upper end of the protrusion 58 extends to the upper end of the upper end insulator 5 (outer coil stopper portion 54). In the axial direction, the position of the upper end of the protrusion 58 and the position of the upper end of the outer coil stopper portion 54 substantially coincide. The lower end of the protrusion 58 extends to the lower end of the upper end insulator 5 (yoke opposing portion 50). In the axial direction, the position of the lower end of the protrusion 58 and the position of the lower end of the yoke opposing portion 50 substantially coincide.

[0035] An insulating paper holding groove 59 is provided in the convex portion 58. The insulating paper holding groove 59 is recessed radially outward from the radially inner end face of the convex portion 58. The insulating paper holding groove 59 is provided to extend in the axial direction. The position of the upper end of the convex portion 58 coincides with the position of the upper end of the insulating paper holding groove 59. The position of the lower end of the convex portion 58 coincides with the position of the lower end of the insulating paper holding groove 59.

[0036] Additionally, an insulating paper holding groove 85 is provided in each of the tooth opposing portions 51 and 52. The insulating paper holding groove 85 is provided in each of the radial opposing portions 51B, which is located at the radially inner end of the tooth opposing portion 51, and the radial opposing portion 52B, which is located at the radially inner end of the tooth opposing portion 52. The insulating paper holding groove 85 is provided to extend in the axial direction in each of the radial opposing portions 51B and 52B.

[0037] Fig. 9 is a perspective view from above showing a split insulator of the intermediate insulator 6 according to the embodiment. Fig. 10 is a perspective view from below showing the split insulator of the intermediate insulator 6 according to the embodiment. Fig. 11 is a view of the split insulator of the intermediate insulator 6 according to the embodiment as seen from above. Fig. 12 is a view of the split insulator of the intermediate insulator 6 according to the embodiment as seen from the radially inner side.

[0038] As described above, the intermediate insulator 6 has the yoke facing portion 60, the teeth facing portion 61, and the teeth facing portion 62. The teeth facing portion 61 includes a circumferential facing portion 61A that covers the side surface of the tooth 22 facing the reverse circumferential side, and a radial facing portion 61B that extends from a radially inner end of the circumferential facing portion 61A to the reverse circumferential side. The teeth facing portion 62 includes a circumferential facing portion 62A that covers the side surface of the tooth 22 facing the forward circumferential side, and a radial facing portion 62B that extends from a radially inner end of the circumferential facing portion 62A to the forward circumferential side.

[0039] The intermediate insulator 6 also has a pair of rod portions 63. The rod portions 63 are provided on the yoke opposing portion 60. The rod portions 63 are provided on the inner surface of the yoke opposing portion 60 facing radially inward, so as to extend in the axial direction. The pair of rod portions 63 are arranged spaced apart from each other in the circumferential direction. The pair of rod portions 63 are provided parallel to each other. The rod portions 63 are fixed to the inner surface of the yoke opposing portion 60. The upper end of the rod portions 63 protrudes upward from the upper end of the yoke opposing portion 60. The lower end of the rod portions 63 protrudes downward from the lower end of the yoke opposing portion 60.

[0040] A recess 64 is provided between a pair of rod portions 63 that protrude upward from the upper end of the yoke opposing portion 60. The recess 64 is defined between the pair of rod portions 63 that protrude upward from the yoke opposing portion 60. A recess 65 is provided between the pair of rod portions 63 that protrude downward from the lower end of the yoke opposing portion 60. The recess 65 is defined between the pair of rod portions 63 that protrude downward from the yoke opposing portion 60.

[0041] The intermediate insulator 6 also has recesses 66. The recesses 66 are recessed downward from the upper end of the yoke opposing portion 60, the upper end of the teeth opposing portion 61, and the upper end of the teeth opposing portion 62. The recesses 66 have an inner surface 66A. The inner surface 66A is perpendicular to the support surface 66B.

[0042] The intermediate insulator 6 also has protrusions 67. The protrusions 67 protrude downward from the lower end of the yoke facing portion 60, the lower end of the teeth facing portion 61, and the lower end of the teeth facing portion 62. The thickness of the protrusions 67 is thinner than the thicknesses of the yoke facing portion 60, the teeth facing portion 61, and the teeth facing portion 62. The protrusions 67 have an outer surface 67A. The outer surface 67A is perpendicular to the support surface 67B.

[0043] An insulating paper holding groove 69 is provided between the pair of rod portions 63. The insulating paper holding groove 69 is defined by the pair of rod portions 63 and the inner surface of the yoke opposing portion 60. The insulating paper holding groove 69 is provided to extend in the axial direction. A recess 64 is provided above the insulating paper holding groove 69. A recess 65 is provided below the insulating paper holding groove 69.

[0044] Additionally, an insulating paper holding groove 86 is provided in each of the tooth opposing portions 51 and 52. The insulating paper holding groove 86 is provided in each of the radial opposing portions 61B, which is located at the radially inner end of the tooth opposing portion 61, and the radial opposing portion 62B, which is located at the radially inner end of the tooth opposing portion 62. The insulating paper holding groove 86 is provided to extend in the axial direction in each of the radial opposing portions 61B and 62B.

[0045] Fig. 13 is a perspective view from above showing the split insulator of the bottom end insulator 7 according to the embodiment. Fig. 14 is a perspective view from below showing the split insulator of the bottom end insulator 7 according to the embodiment. Fig. 15 is a view from below of the split insulator of the bottom end insulator 7 according to the embodiment. Fig. 16 is a view from the radially inner side of the split insulator of the bottom end insulator 7 according to the embodiment.

[0046] As described above, the lower end insulator 7 has a yoke opposing portion 70, a teeth opposing portion 71, a teeth opposing portion 72, a teeth opposing portion 73, an outer coil stop portion 74, and an inner coil stop portion 75. The teeth opposing portion 71 includes a circumferential opposing portion 71A that covers the side surfaces of the teeth 22 facing the forward circumferential direction and a radial opposing portion 71B that covers the inner surfaces of the teeth 22 facing radially inward. The teeth opposing portion 72 includes a circumferential opposing portion 72A that covers the side surfaces of the teeth 22 facing the reverse circumferential direction and a radial opposing portion 72B that covers the inner surfaces of the teeth 22 facing radially inward. The radial opposing portion 71B extends from the radially inner end of the circumferential opposing portion 71A to the reverse circumferential direction. The radial opposing portion 72B extends from the radially inner end of the circumferential opposing portion 72A to the forward circumferential direction.

[0047] The lower end insulator 7 also has a recess 77 and a protrusion 78. The recess 77 is recessed downward from the upper end of the yoke opposing portion 70, the upper end of the teeth opposing portion 71, and the upper end of the teeth opposing portion 72. The recess 77 has an inner surface 77A. The inner surface 77A is perpendicular to the support surface 77B.

[0048] The protrusion 78 is provided on the yoke opposing portion 70. The protrusion 78 is provided on the inner surface of the yoke opposing portion 70 facing radially inward, so as to extend in the axial direction. The protrusion 78 protrudes radially inward from the inner surface of the yoke opposing portion 70. The upper end of the protrusion 78 extends to the upper end of the lower end insulator 7 (yoke opposing portion 70). In the axial direction, the position of the upper end of the protrusion 78 and the position of the upper end of the yoke opposing portion 70 substantially coincide. The lower end of the protrusion 78 extends to the lower end of the lower end insulator 7 (outer coil stop portion 74). In the axial direction, the position of the lower end of the protrusion 78 and the position of the lower end of the yoke opposing portion 70 substantially coincide.

[0049] An insulating paper holding groove 79 is provided in the convex portion 78. The insulating paper holding groove 79 is recessed radially outward from the radially inner end face of the convex portion 78. The insulating paper holding groove 79 is provided to extend in the axial direction. The position of the upper end of the convex portion 78 coincides with the position of the upper end of the insulating paper holding groove 79. The position of the lower end of the convex portion 78 coincides with the position of the lower end of the insulating paper holding groove 79.

[0050] Additionally, an insulating paper holding groove 87 is provided in each of the tooth opposing portions 71 and 72. The insulating paper holding groove 87 is provided in each of the radial opposing portions 71B, which is located at the radially inner end of the tooth opposing portion 71, and the radial opposing portion 72B, which is located at the radially inner end of the tooth opposing portion 72. The insulating paper holding groove 87 is provided to extend in the axial direction in each of the radial opposing portions 71B and 72B.

[0051] Fig. 17 is a view of the connection structure between the upper end insulator 5 and the intermediate insulator 6 according to the embodiment, viewed from the radially inner side. Fig. 18 is a view of the connection structure between the lower end insulator 7 and the intermediate insulator 6 according to the embodiment, viewed from the radially inner side. Each of Fig. 17 and Fig. 18 corresponds to an enlarged view of a part of Fig. 4. Fig. 19 is a view of the connection structure between the upper end insulator 5 and the intermediate insulator 6 according to the embodiment, viewed from the top side.

[0052] The top insulator 5 has a protrusion 58. The middle insulator 6 has a recess 64 into which the protrusion 58 fits. The protrusion 58 is provided on the yoke facing portion 50. The recess 64 is provided on the middle insulator 6. The lower end of the protrusion 58 is inserted into the recess 64 provided on the top end of the middle insulator 6. The protrusion 58 fits into the recess 64, thereby preventing the top insulator 5 and the middle insulator 6 from separating.

[0053] The upper insulator 5 also has a protrusion 57. The intermediate insulator 6 has a recess 66 into which the protrusion 57 fits. The protrusion 57 is provided at least on the teeth facing portions 51 and 52. The recess 66 is provided at least on the teeth facing portions 61 and 52. The lower end of the protrusion 57 provided at the lower end of the upper insulator 5 is inserted into the recess 66 provided at the upper end of the intermediate insulator 6. The lower end of the protrusion 57 contacts the support surface 66B of the recess 66. The outer surface 57A and the inner surface 66A contact each other. By fitting the protrusion 57 into the recess 66, separation between the upper insulator 5 and the intermediate insulator 6 is suppressed.

[0054] 19 , the protrusion 58 is sandwiched between a pair of rod portions 63. The upper ends of the rod portions 63 contact the inner surface of the yoke opposing portion 50, which faces radially inward. The force with which the rod portions 63 sandwich the protrusion 58 and the contact force between the rod portions 63 and the yoke opposing portion 50 suppress separation between the upper end insulator 5 and the intermediate insulator 6.

[0055] The bottom insulator 7 has a protrusion 78. The middle insulator 6 has a recess 65 into which the protrusion 78 fits. The protrusion 78 is provided on the yoke facing portion 70. The recess 65 is provided on the middle insulator 6. The upper end of the protrusion 78 is inserted into the recess 65 provided on the bottom end of the middle insulator 6. The protrusion 78 fits into the recess 65, thereby preventing the bottom insulator 7 and the middle insulator 6 from separating.

[0056] The protrusions 78 are sandwiched between the pair of rod portions 63. The lower ends of the rod portions 63 contact the inner surface of the yoke opposing portion 70, which faces radially inward. The clamping force of the rod portions 63 against the protrusions 78 and the contact force between the rod portions 63 and the yoke opposing portion 70 prevent the lower end insulator 7 and the intermediate insulator 6 from separating from each other.

[0057] The lower-end insulator 7 also has a recess 77. The intermediate insulator 6 has a protrusion 67 that fits into the recess 77. The recess 77 is provided at least on the teeth facing portions 71 and 72. The protrusion 67 is provided at least on the teeth facing portions 61 and 62. The lower end of the protrusion 67 provided at the lower end of the intermediate insulator 6 is inserted into the recess 77 provided at the upper end of the lower-end insulator 7. The lower end of the protrusion 67 contacts the support surface 77B of the recess 77. The outer surface 67A and the inner surface 77A contact each other. By fitting the protrusion 67 into the recess 77, separation between the lower-end insulator 7 and the intermediate insulator 6 is suppressed.

[0058] 17, the width Ga of the insulating paper holding groove 59 is smaller than the width Gb of the recess 64 (insulating paper holding groove 69). As shown in Fig. 18, the width Gc of the insulating paper holding groove 79 is smaller than the width Gb of the recess 64 (insulating paper holding groove 69).

[0059] Fig. 20 is a top view of a portion of the stator 1 according to the embodiment. As shown in Fig. 20, insulating paper 80 is arranged between adjacent coils 4. The radially outer end of the insulating paper 80 is inserted into insulating paper holding groove 59, recess 64, insulating paper holding groove 69, recess 65, and insulating paper holding groove 79. The radially inner end of the insulating paper 80 is inserted into insulating paper holding groove 85, insulating paper holding groove 86, and insulating paper holding groove 87.

[0060] FIG. 21 is a cross-sectional perspective view showing a portion of the upper end insulator 5 according to the embodiment. As described above, three crossover wire holding grooves 56 are provided on the outer peripheral surface of the outer coil stop portion 54. The crossover wire 9 is held by the crossover wire holding grooves 56. The crossover wire holding grooves 56 include a crossover wire holding groove 56A, a crossover wire holding groove 56B, and a crossover wire holding groove 56C. The crossover wire holding groove 56A is provided above the crossover wire holding groove 56B. The crossover wire holding groove 56C is provided above the crossover wire holding groove 56C. The depths of the three crossover wire holding grooves 56 are different from one another. The depth of the crossover wire holding groove 56 refers to the depth of the crossover wire holding groove 56 in the radial direction. In the example shown in FIG. 21 , the crossover wire holding groove 56B is the shallowest, the crossover wire holding groove 56C is the next shallowest, and the crossover wire holding groove 56A is the deepest. For example, by arranging the crossover wire 9U through which a U-phase drive current flows at the back of the crossover wire holding groove 56A, the crossover wire 9V through which a V-phase drive current flows at the back of the crossover wire holding groove 56B, and the crossover wire 9W through which a W-phase drive current flows at the back of the crossover wire holding groove 56C, it is possible to ensure the mutual insulation distance between the three sets of crossover wires 9 (9U, 9V, 9W) even if winding spillage occurs.

[0061] 20 , the upper end insulator 5 has a crossover wire support groove 90 that is provided radially inward of the crossover wire holding groove 56 and supports the crossover wire 9. The crossover wire support groove 90 supports the crossover wire 9 between the coil 4 and the crossover wire holding groove 56.

[0062] 22 is a diagram illustrating the relationship between the upper-end insulator 5, the intermediate insulator 6, and the lower-end insulator 7 according to the embodiment. The dimensions of the split insulators of the upper-end insulator 5 and the lower-end insulator 7 in the circumferential direction are equal. The upper-end insulator 5 and the lower-end insulator 7 each have yoke facing portions 50, 70 facing the yoke 21 and tooth facing portions 51, 52, 53, 71, 72, 73 facing the teeth 22. The coil 4 is wound around the tooth facing portions 51, 52, 53 of the upper-end insulator 5 and the tooth facing portions 71, 72, 73 of the lower-end insulator 7 with the split insulators of the upper-end insulator 5 and the lower-end insulator 7 misaligned in the circumferential direction. That is, the split insulators of the upper-end insulator 5 and the split insulators of the lower-end insulator 7 are fixed by the coil 4 with their circumferential positions (phases) offset from each other. The offset state means that the convex portion 57 (572) of the upper-end insulator 5 is coupled to the concave portion 66 of the intermediate insulator 6, and the concave portion 77 (771) of the lower-end insulator 7 is coupled to the convex portion 67 of the intermediate insulator 6.

[0063] [Manufacturing Method] Next, a manufacturing method of the stator 1 will be described. After the intermediate insulators 6 are placed in the slots 23 of the stator core 2, the upper-end insulators 5 are attached to the upper end of the stator core 2, and the lower-end insulators 7 are attached to the lower end of the stator core 2. The convex portions 58 of the upper-end insulators 5 are fitted into the concave portions 64 of the intermediate insulators 6, and the convex portions 57 of the upper-end insulators 5 are fitted into the concave portions 66 of the intermediate insulators 6. The convex portions 78 of the lower-end insulators 7 are fitted into the concave portions 65 of the intermediate insulators 6, and the convex portions 67 of the intermediate insulators 6 are fitted into the concave portions 77 of the lower-end insulators 7. This prevents at least one of the upper-end insulators 5, the intermediate insulators 6, and the lower-end insulators 7 from falling off the stator core 2 before the coils 4 are wound. After the insulators 3 are attached to the stator core 2, the coils 4 are wound around the teeth 22 via the insulators 3. The coil 4 secures the upper end insulator 5, the intermediate insulator 6, and the lower end insulator 7 together.

[0064] [Effects] As described above, according to the embodiment, the upper-end insulator 5 has the convex portion 58, and the intermediate insulator 6 has the concave portion 64 into which the convex portion 58 fits. Furthermore, the upper-end insulator 5 has the convex portion 57, and the intermediate insulator 6 has the concave portion 66 into which the convex portion 57 fits. The lower-end insulator 7 has the convex portion 78, and the intermediate insulator 6 has the concave portion 65 into which the convex portion 78 fits. Furthermore, the lower-end insulator 7 has the concave portion 77, and the intermediate insulator 6 has the convex portion 67 that fits into the concave portion 77. This prevents at least one of the upper-end insulator 5, the intermediate insulator 6, and the lower-end insulator 7 from falling off the stator core 2 before the coil 4 is wound. Therefore, a decrease in productivity of the stator 1 is suppressed.

[0065] [Other Embodiments] In the above-described embodiments, a recess may be provided in the yoke facing portion 50 of the upper insulator 5, and a protrusion may be provided in the yoke facing portion 60 of the intermediate insulator 6. A recess may be provided in the yoke facing portion 70 of the lower insulator 7, and a protrusion may be provided in the yoke facing portion 60 of the intermediate insulator 6.

[0066] In the above-described embodiment, the insulator 3 is manufactured by connecting three insulators (5, 6, 7) that are divided in the axial direction. However, the insulator 3 may be manufactured by connecting at least four insulators that are divided in the axial direction. For example, a plurality of intermediate insulators may be arranged in the axial direction.

[0067] REFERENCE SIGNS LIST 1... stator, 2... stator core, 3... insulator, 4... coil, 5... upper end insulator (first end insulator), 6... intermediate insulator, 7... lower end insulator (second end insulator), 8... connection terminal, 8U... U-phase connection terminal, 8V... V-phase connection terminal, 8W... W-phase connection terminal, 9... jumper wire, 9U... jumper wire, 9V... jumper wire, 9W... jumper wire, 21... yoke, 22... teeth, 23... slot, 50... yoke opposing portion (end yoke opposing portion), 51... tooth opposing portion (end tee 51A...circumferential facing portion, 51B...radial facing portion, 52...teeth facing portion (end tooth facing portion), 52A...circumferential facing portion, 52B...radial facing portion, 53...teeth facing portion (end tooth facing portion), 54...outer coil stopper, 55...inner coil stopper, 56...crossover wire holding groove, 56A...crossover wire holding groove, 56B...crossover wire holding groove, 56C...crossover wire holding groove, 57...convex portion, 57A...outer surface, 57B...support surface, 58...convex portion, 59...insulating paper holding groove (first insulating paper holding groove), 60...yoke facing portion (middle Intermediate yoke facing portion), 61...teeth facing portion (intermediate tooth facing portion), 61A...circumferential facing portion, 61B...radial facing portion, 62...teeth facing portion (intermediate tooth facing portion), 62A...circumferential facing portion, 62B...radial facing portion, 63...rod portion, 64...recess, 65...recess, 66...recess, 66A...inner surface, 66B...support surface, 67...protrusion, 67A...outer surface, 67B...support surface, 69...insulating paper retaining groove, 70...yoke facing portion (end yoke facing portion), 71...teeth facing portion (end tooth facing portion), 71A...circumferential circumferentially facing portion, 71B...radially facing portion, 72...teeth facing portion (end tooth facing portion), 72A...circumferentially facing portion, 72B...radially facing portion, 73...teeth facing portion (end tooth facing portion), 74...outer coil stop portion, 75...inner coil stop portion, 77...recessed portion, 77A...inner surface, 77B...support surface, 78...convex portion, 79...insulating paper retaining groove (first insulating paper retaining groove), 80...insulating paper, 85...insulating paper retaining groove (second insulating paper retaining groove), 86...insulating paper retaining groove, 87...insulating paper retaining groove (second insulating paper retaining groove), 90...crossover wire support groove.

Claims

1. A stator comprising: a stator core having a yoke and a number of teeth protruding from the yoke; an insulator fixed to the stator core; and a coil wound around the teeth via the insulator, wherein the insulator includes end insulators fixed to ends of the stator core in the axial direction, and intermediate insulators positioned closer to the center of the stator core than the end insulators in the axial direction, one of the end insulators and the intermediate insulator having a convex portion, and the other of the end insulator and the intermediate insulator having a concave portion into which the convex portion fits.

2. The stator according to claim 1, wherein the intermediate insulator has an intermediate yoke opposing portion opposing the yoke and an intermediate teeth opposing portion opposing the teeth, and the protrusion or recess is provided on the intermediate yoke opposing portion.

3. The stator according to claim 2, wherein the intermediate insulator has a pair of rod portions protruding in the axial direction from the intermediate yoke facing portion, and the recess is defined between the pair of rod portions.

4. A stator according to claim 3, wherein the end insulator has an end yoke opposing portion that faces the yoke, and the rod portion contacts the end yoke opposing portion.

5. A stator as described in claim 4, wherein the end insulator has a convex portion that fits into the concave portion, the convex portion is provided with a first insulating paper retaining groove that is connected to the concave portion, and insulating paper is inserted into the concave portion and the first insulating paper retaining groove.

6. A stator as described in claim 5, wherein the end insulator has an end yoke facing portion facing the yoke and an end teeth facing portion facing the teeth, and the end teeth facing portion is provided with a second insulating paper retaining groove into which the insulating paper is inserted.

7. The stator according to claim 5, wherein the width of the first insulating paper holding groove is smaller than the width of the recess.

8. A stator as described in claim 1, wherein the end insulator has an end yoke facing portion facing the yoke and an end teeth facing portion facing the teeth, the intermediate insulator has an intermediate yoke facing portion facing the yoke and an intermediate teeth facing portion facing the teeth, one of the end teeth facing portion and the intermediate teeth facing portion has the convex portion, and the other of the end teeth facing portion and the intermediate teeth facing portion has the concave portion.

9. A stator as described in claim 1, further comprising: jumper wires connecting a plurality of said coils; said end insulators having a plurality of jumper wire retaining grooves for retaining each of said plurality of jumper wires; and said plurality of jumper wire retaining grooves being arranged in the axial direction.

10. The stator according to claim 9, wherein the depths of the plurality of crossover wire retaining grooves are different from each other.

11. A stator as described in claim 9, wherein the end insulator has an outer coil stopper portion arranged radially outward from the coil and supporting the coil, and an inner coil stopper portion arranged radially inward from the coil and supporting the coil.

12. A stator as set forth in claim 11, wherein the crossover wire retaining groove is provided on an outer peripheral surface of the outer coil stopper portion, and the end insulator has a crossover wire support groove that is provided radially inward from the crossover wire retaining groove and supports the crossover wire.

13. The stator according to claim 1, wherein each of the end insulators and the intermediate insulator includes a plurality of split insulators split in the circumferential direction.

14. A stator as claimed in claim 13, wherein the end insulators include a first end insulator fixed to one end of the stator core in the axial direction and connected to one end of the intermediate insulator, and a second end insulator fixed to the other end of the stator core in the axial direction and connected to the other end of the intermediate insulator, wherein a dimension of a split insulator of the first end insulator and a dimension of a split insulator of the second end insulator are equal in the circumferential direction, wherein each of the first end insulator and the second end insulator has an end yoke facing portion facing the yoke and an end teeth facing portion facing the teeth, and wherein the coil is wound around the end teeth facing portion of the first end insulator and the end teeth facing portion of the second end insulator with the split insulator of the first end insulator and the split insulator of the second end insulator misaligned in the circumferential direction.

15. A stator as described in claim 1, wherein the end insulators include a first end insulator fixed to one end of the stator core in the axial direction and connected to one end of the intermediate insulator, and a second end insulator fixed to the other end of the stator core in the axial direction and connected to the other end of the intermediate insulator.

Images