Stator, motor, and method for manufacturing stator

Abstract

This stator has: a stator core in which a plurality of slots arranged in a circumferential direction are formed between tooth parts adjacent to each other in the circumferential direction; and a plurality of wound coils that are wound in a distributed manner around the plurality of tooth parts and are accommodated in the plurality of slots. Each of the plurality of wound coils has: a small coil part accommodated in two slots among the plurality of slots; and a large coil part that is continuous with the small coil part and is accommodated in a slot adjacent to one of the two slots in which the small coil part is accommodated on the outer side in the circumferential direction and a slot adjacent to the other of the two slots on the outer side in the circumferential direction. The plurality of slots include a first slot in which the small coil part of one wound coil is accommodated, and a second slot in which the large coil part of the one wound coil and the large coil part of another wound coil are accommodated.

Description

Stator, motor, and method for manufacturing stator

[0001] This application claims priority to Japanese Patent Application No. 2024-147773, filed on August 29, 2024, the contents of which are incorporated herein by reference.

[0002] A known three-phase coil arrangement for a stator is distributed winding, in which the coils of each phase are distributed across several slots. Also known is a coil arrangement in which two phase coils are housed in one slot (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 11-168847

[0004] Generally, in a coil arrangement in which two phase coils are accommodated in one slot, the coil insertion process involves first inserting the first phase coil into the slot, and then inserting the second phase coil into the slot where the first phase coil is accommodated. That is, in this process, the coils are inserted into one slot in two separate steps. Inserting the coils in two separate steps may cause the first phase coil to move into the space in the slot where the second phase coil is intended to be inserted before the second phase coil is inserted. In this case, it becomes difficult to insert the second phase coil into the slot, and therefore it is necessary to reduce the number of turns of the coil inserted into the slot. Therefore, in a stator having a coil arrangement in which two phase coils are accommodated in one slot, it has been difficult to improve the coil space factor in the slot.

[0005] An object of the present invention is to provide a configuration capable of improving the space factor of the coils in a slot in a stator having a coil arrangement in which coils of two phases are housed in one slot.

[0006] A stator according to an exemplary embodiment of the present invention includes a stator core having a cylindrical core back portion extending axially and a plurality of teeth extending radially from the core back portion and arranged circumferentially, with a plurality of slots arranged circumferentially between circumferentially adjacent teeth among the plurality of teeth, and a plurality of winding coils wound in a distributed manner around the plurality of teeth and housed in the plurality of slots. Each of the plurality of winding coils has a small coil portion housed in two of the plurality of slots, and a large coil portion that is continuous with the small coil portion and is housed in a slot adjacent to one of the two slots and circumferentially outward from the other of the two slots. The plurality of slots includes a first slot that houses the small coil portion of one of the plurality of winding coils, and a second slot that houses the large coil portion of the one winding coil and the large coil portions of the other of the plurality of winding coils.

[0007] A motor according to an exemplary embodiment of the present invention includes a stator having the above-described configuration and a rotor disposed radially relative to the stator.

[0008] A method for manufacturing a stator according to an exemplary embodiment of the present invention includes a stator core having a cylindrical core back portion extending in the axial direction and a plurality of teeth extending radially from the core back portion and arranged circumferentially, with a plurality of slots arranged circumferentially between circumferentially adjacent teeth of the plurality of teeth, and a plurality of wound coils wound in a distributed manner around the plurality of teeth and housed in the plurality of slots. Each of the plurality of wound coils has a small coil portion housed in two of the plurality of slots and a large coil portion that is continuous with the small coil portion and is housed in a slot adjacent to one of the two slots and circumferentially outward from the other of the two slots. The plurality of slots includes a first slot housing the small coil portion of one of the plurality of wound coils and a second slot housing the large coil portion of the one wound coil and the large coil portions of the other of the plurality of wound coils. The method for manufacturing the stator includes a coil forming process for forming a plurality of wound coils, each having the small coil portion and the large coil portion, by winding a single conductor, and a coil inserting process for arranging the plurality of wound coils in a circumferential direction of the stator core, inserting the small coil portions into the first slots, and simultaneously inserting two adjacent large coil portions of the wound coils that are adjacent in the circumferential direction into one of the second slots.

[0009] According to a stator according to an exemplary embodiment of the present invention, it is possible to provide a stator that can improve the space factor of the coils in the slots in a coil arrangement in which two phase coils are housed in one slot.

[0010] FIG. 1 is a cross-sectional view showing an example of a schematic configuration of a motor. FIG. 2 is a perspective view showing an example of a schematic configuration of a stator. FIG. 3 is a perspective view showing an example of a schematic configuration of a stator core. FIG. 4 is a diagram schematically showing how coils are wound around a stator core by distributed winding. FIG. 5 is a diagram schematically showing the arrangement of three-phase coils. FIG. 6 is a diagram schematically showing the arrangement of three-phase coils by phase. FIG. 7 is a diagram explaining a coil forming process. FIG. 8 is a diagram showing a state in which multiple wound coils to be inserted into slots are lined up in the circumferential direction in a first insertion process. FIG. 9 is a diagram showing a state in which multiple wound coils have been inserted into slots in the first insertion process. FIG. 10 is a diagram explaining a coil end portion forming process. FIG. 11 is a diagram showing a state in which multiple wound coils to be inserted into slots are lined up in the circumferential direction in a second insertion process. FIG. 12 is a diagram showing a state in which multiple wound coils have been inserted into slots in the second insertion process.

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and their description will not be repeated. Furthermore, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0012] In the following description, the direction parallel to the central axis P of the motor 100 will be referred to as the axial direction, the direction perpendicular to the central axis P as the radial direction, and the direction along the arc centered on the central axis P as the circumferential direction. However, these definitions of directions are not intended to limit the orientation of the motor 100 according to the present invention when in use. In each drawing, the axial direction is indicated by A, the radial direction is indicated by B, and the circumferential direction is indicated by C. Within the radial direction B, the direction in which the teeth 12 are located relative to the core back portion 11 is indicated by B1, and the direction in which the core back portion 11 is located relative to the teeth 12 is indicated by B2.

[0013] Furthermore, in the following description, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing") include not only cases where members are directly fixed to each other, but also cases where members are fixed via other members. In other words, in the following description, the expression "fixing" includes both direct and indirect fixing of members to each other.

[0014] (Motor) FIG. 1 is a cross-sectional view showing an example of the schematic configuration of a motor 100. The motor 100 has a stator 1 and a rotor 2. The stator 1 is cylindrical and extends in an axial direction A about a central axis P. The rotor 2 is cylindrical and extends in an axial direction A about a central axis P, and is located in a radial direction B of the stator 1. The rotor 2 rotates about the central axis P relative to the stator 1. In this embodiment, the rotor 2 is located radially inward of the stator 1. The configuration of the rotor 2 is the same as that of a conventional motor. Therefore, a detailed description of the rotor 2 will be omitted.

[0015] (Stator) Fig. 2 is a perspective view showing an example of a schematic configuration of the stator 1. As shown in Fig. 2, the stator 1 has a stator core 10, an insulating member 20, and a coil 30.

[0016] Fig. 3 is a diagram showing an example of a schematic configuration of stator core 10. As shown in Fig. 3, stator core 10 has a cylindrical shape extending in axial direction A along central axis P. Stator core 10 has, for example, a plurality of disk-shaped electromagnetic steel plates stacked in the thickness direction. Note that stator core 10 may be formed of a cylindrical metal block instead of a plurality of disk-shaped electromagnetic steel plates.

[0017] The stator core 10 has a core back portion 11 and a plurality of teeth 12. The core back portion 11 is cylindrical and extends in the axial direction A. In this embodiment, the plurality of teeth 12 extend radially inward from the inner peripheral surface of the core back portion 11 and are aligned in the circumferential direction. Each of the plurality of teeth 12 has a tooth tip portion 12a at its inner peripheral end.

[0018] Of the multiple teeth 12, slots 13 are formed between adjacent teeth 12 in the circumferential direction. In this embodiment, each of the multiple slots 13 is groove-shaped and extends in the axial direction A on the inner circumferential side of the stator core 10. The slot 13 has an opening 13a that opens radially inward. The inner surface of the slot 13 has a side surface 13b formed by the side surface of the tooth 12 in the circumferential direction C, and a bottom surface 13c formed by the inner circumferential surface of the core back portion 11.

[0019] The end face of the stator core 10 in the axial direction A has a tip side region R1 which is a region on the tooth tip end portion 12a side, and a core back portion side region R2 which is a region on the core back portion 11 side relative to the tip side region R1.

[0020] 2 , in the present embodiment, the coil end portions 40a of some of the multiple winding coils 40 are arranged on the tooth tip portion 12a side when viewed in the axial direction A. The coil end portions 40a of the remaining of the multiple winding coils 40 are arranged on the core back portion 11 side when viewed in the axial direction A. In this specification, the tip side region R1 refers to the region extending in the circumferential direction C where the coil end portions 40a of some of the winding coils 40 are arranged when viewed in the axial direction A. The core back portion side region R2 refers to the region extending in the circumferential direction C where the coil end portions 40a of the remaining winding coils 40 are arranged.

[0021] As shown in Fig. 2, an insulating member 20 and a coil 30 are disposed within the slot 13. The insulating member 20 is a sheet-like member having electrical insulation properties. The insulating member 20 is disposed on the inner surface of the slot 13. The insulating member 20 covers a pair of side surfaces 13b and a bottom surface 13c of the slot 13.

[0022] The coil 30 is wound in a distributed manner around the tooth portion 12. The coil 30 is disposed in the slot 13, more inward than the insulating member 20. In this embodiment, the coil 30 has a plurality of wound coils 40. Each of the plurality of wound coils 40 is formed by a single conductive wire 50 wound multiple times in an annular shape. In this embodiment, the plurality of wound coils 40 includes a plurality of U-phase wound coils 40U, a plurality of V-phase wound coils 40V, and a plurality of W-phase wound coils 40W. The arrangement of the coils for each phase will be described later.

[0023] FIG. 4 is a schematic diagram showing how the wound coil 40 is arranged in the slot 13 by distributed winding. As shown in FIG. 4 , the wound coil 40 has a small coil portion 40S with a relatively small winding diameter and a large coil portion 40L with a relatively large winding diameter. The small coil portion 40S and the large coil portion 40L are continuous. Note that the small coil portion 40S and the large coil portion 40L are continuous means that the small coil portion 40S and the large coil portion 40L are formed from a single conductor 50. In other words, the wound coil 40 is formed by winding one conductor 50 multiple times to form the small coil portion 40S, and then winding the same single conductor 50 multiple times around the outer periphery of the small coil portion 40S. Note that the order of forming the small coil portion 40S and the large coil portion 40L may be reversed. In this embodiment, the number of turns of the conductor 50 of the small coil portion 40S is greater than the number of turns of the conductor 50 of the large coil portion 40L. Specifically, in this embodiment, the number of turns of the conductor 50 of the small coil portion 40S is twice the number of turns of the conductor 50 of the large coil portion 40L.

[0024] The wound coil 40 is inserted into the slots 13 through the openings 13a of the multiple slots 13 and moves radially toward the bottom surface 13c, thereby being accommodated within the slots 13. In Figure 4, the movement direction of the wound coil 40 is indicated by an outline arrow. The small coil portion 40S and the large coil portion 40L are each accommodated in two slots 13.

[0025] Specifically, the small coil portion 40S is housed in two first slots 13S that are spaced apart in the circumferential direction. Three other slots 13 are located between the two first slots 13S in which the small coil portion S is housed.

[0026] The large coil portion 40L is accommodated in a second slot 13L adjacent to, on the circumferential outside, one of the two first slots 13S in which the small coil portion 40S is accommodated, and in a second slot 13L adjacent to, on the circumferential outside, the other of the two first slots 13S. As will be described in detail later, the second slot 13L also accommodates a large coil portion 40L of another winding coil 40 circumferentially adjacent to the winding coil 40.

[0027] In this specification, the first slot 13S refers to a slot 13 that houses one small coil portion 40S. The second slot 13L refers to a slot 13 that houses two large coil portions 40L. In this embodiment, the first slot 13S and the second slot 13L have the same physical shape.

[0028] 2, in the other three slots 13 located between the two first slots 13S in which the small coil portion 40S of one winding coil 40 is accommodated, two other winding coils 40 are arranged in a distributed winding manner. The winding coils 40 arranged in the other three slots 13 will be described later.

[0029] Each wound coil 40 has coil end portions 40a that protrude from the slots 13 to one side and the other in the axial direction A of the stator core 10 and extend in the circumferential direction C on the end surface of the axial direction A of the stator core 10. The coil end portions 40a extend in the circumferential direction C between the two first slots 13S that house the small coil portions 40S and between the two second slots 13L that house the large coil portions 40L. Note that, of the two coil end portions 40a, Fig. 2 shows the coil end portion 40a located at the lower position in the drawing in a simplified manner, but the coil end portion 40a located at the lower position has a similar configuration to the coil end portion 40a located at the upper position.

[0030] As shown in FIG. 2 , the coil end portions 40a of some of the multiple wound coils 40 are located on the outer periphery of the end face in the axial direction A of the stator core 10. The coil end portions 40a of the remaining of the multiple wound coils 40 are located on the inner periphery of the end face in the axial direction A of the stator core 10. That is, the coil end portions 40a of some of the multiple wound coils 40 are located in the core back portion side region R2, and the coil end portions 40a of the remaining wound coils 40 are located in the tip side region R1. The wound coil 40 whose coil end portions 40a are located in the core back portion side region R2 is the core back portion side wound coil of the present invention. The wound coil 40 whose coil end portions 40a are located in the tip side region R1 is the tip side wound coil of the present invention.

[0031] Hereinafter, among the plurality of winding coils 40, the winding coil 40 whose coil end portion 40a is arranged on the outer periphery side of the stator core 10 will also be simply referred to as the outer periphery side winding coil 40. Among the plurality of winding coils 40, the winding coil 40 whose coil end portion 40a is arranged on the inner periphery side of the stator core 10 will also be simply referred to as the inner periphery side winding coil 40.

[0032] FIG. 5 is a diagram schematically illustrating the arrangement of the U-phase winding coil 40U, the V-phase winding coil 40V, and the W-phase winding coil 40W in the slots 13. In FIG. 5, the coil end portion 40a of each winding coil 40 is schematically illustrated by a solid line spanning two slots 13. For ease of explanation, in FIG. 5, the solid line indicating the coil end portion 40a of the outermost winding coil 40 protrudes radially outward from the stator core 10. The solid line indicating the coil end portion 40a of the innermost winding coil 40 protrudes radially inward from the stator core 10. FIG. 6 is a diagram schematically illustrating the arrangement of the winding coils 40 by phase. In FIG. 6, the outermost winding coil 40 is illustrated surrounded by a dashed line.

[0033] 5 and 6 , in this embodiment, the stator core 10 has 36 slots 13. The coil 30 has 12 wound coils 40. The 12 wound coils 40 include four U-phase wound coils 40U, four V-phase wound coils 40V, and four W-phase wound coils 40W. That is, there are three slots per pole per phase.

[0034] The four U-phase winding coils 40U include two outer circumferential winding coils 40 and two inner circumferential winding coils 40. The four V-phase winding coils 40V include two outer circumferential winding coils 40 and two inner circumferential winding coils 40. The four W-phase winding coils 40W include two outer circumferential winding coils 40 and two inner circumferential winding coils 40.

[0035] As shown in Figure 5, the coil end portions 40a of the six outer peripheral wound coils 40 are aligned in the circumferential direction C without interfering with each other in the core back portion side region R2. The coil end portions 40a of the six inner peripheral wound coils 40 are aligned in the circumferential direction C without interfering with each other in the tip side region R1. The core back portion side region R2 and the tip side region R1 are aligned in the radial direction. Therefore, in the above-described coil arrangement, the regions in which the coil end portions 40a of the twelve wound coils 40 are arranged do not overlap when viewed in the axial direction A.

[0036] As shown in Figures 5 and 6, the multiple slots 13 include multiple first slots 13S that accommodate small coil portions 40S of one winding coil 40, and multiple second slots 13L that accommodate large coil portions 40L of two winding coils 40.

[0037] As described above, the small coil portion 40S is made up of a plurality of wound conductor wires 50, and the large coil portion 40L is made up of a plurality of wound conductor wires 50. The number of turns of the conductor wire 50 of the small coil portion 40S is greater than the number of turns of the conductor wire 50 of the large coil portion 40L.

[0038] Therefore, the number of conductors 50 in the first slot 13S accommodating one small coil portion 40S can be made equal to the number of conductors 50 in the second slot 13L accommodating two large coil portions 40L. Therefore, the coil space factor in the first slot 13S accommodating one small coil portion 40S can be made equal to the coil space factor in the second slot 13L accommodating two large coil portions 40L.

[0039] As described above, the small coil portion 40S and the large coil portion 40L are continuous. Furthermore, the coil end portions 40a of the multiple outer peripheral wound coils 40 are aligned in the circumferential direction C without interfering with each other. Therefore, multiple outer peripheral wound coils 40 can be simultaneously inserted into multiple slots 13. In other words, two large coil portions 40L adjacent to each other in the circumferential direction C can be simultaneously inserted into one second slot 13L.

[0040] Furthermore, the radial position of the coil end portion 40a of the outer peripheral winding coil 40 is different from the radial position of the coil end portion 40a of the inner peripheral winding coil 40. The coil end portions 40a of the inner peripheral winding coil 40 are lined up in the circumferential direction C without interfering with each other. Therefore, for a stator core 10 in which a plurality of outer peripheral winding coils 40 are housed in a plurality of slots 13, a plurality of inner peripheral winding coils 40 can be simultaneously inserted into the remaining slots 13.

[0041] Therefore, with the above-described coil arrangement, the coil can be inserted into each slot 13 in one go, without dividing the insertion into multiple times, and therefore the coil space factor for the slot 13 can be improved compared to a coil arrangement that requires the coil to be inserted into one slot 13 in multiple goes.

[0042] As shown in FIG. 5, the other three slots 13 are located between the two first slots 13S in which the two small coil portions 40S of each winding coil 40 are housed.

[0043] If the phase of the wound coils 40 housed in the slots 13 located on both sides of the three slots 13 is U-phase, the three slots 13 house a V-phase wound coil 40V and a W-phase wound coil 40W.

[0044] In detail, the three slots 13 accommodate the small coil portion 40S of the V-phase winding coil 40V, the large coil portion 40L of the V-phase winding coil 40V, the large coil portion 40L of the W-phase winding coil 40W, and the small coil portion 40S of the W-phase winding coil 40W.

[0045] For example, if the slots 13 are numbered in ascending order in one direction of the circumferential direction C, starting from number 1, then on the outer periphery of the stator core 10, the U-phase winding coil 40U, the V-phase winding coil 40V, and the W-phase winding coil 40W are housed in the slots 13 with the following numbers. Note that the following description will be given as an example in which one of the two slots 13 housing the large coil portion 40L of the U-phase winding coil 40U on the outer periphery is designated as slot 1, and the numbering in ascending order is given in the direction in which the other of the two slots 13 is located.

[0046] The large coil portion 40L of the U-phase winding coil 40U is housed in slots 1 and 7. The small coil portion 40S of the U-phase winding coil 40U is housed in slots 2 and 6.

[0047] The large coil portion 40L of the V-phase winding coil 40V, which is adjacent to the U-phase winding coil 40U on one side in the circumferential direction C, is housed in slots 7 and 13. The small coil portion 40S of the U-phase winding coil 40U is housed in slots 8 and 12.

[0048] The large coil portion 40L of the W-phase winding coil 40W, which is adjacent to the V-phase winding coil 40V on one side in the circumferential direction C, is housed in slots 13 and 19. The small coil portion 40S of the W-phase winding coil 40W is housed in slots 14 and 18.

[0049] Furthermore, on the inner circumferential side of the stator core 10, the U-phase winding coil 40U, the V-phase winding coil 40V, and the W-phase winding coil 40W are housed in the slots 13 with the following numbers, respectively.

[0050] The large coil portion 40L of the U-phase winding coil 40U is housed in slots 10 and 16. The small coil portion 40S of the U-phase winding coil 40U is housed in slots 11 and 15.

[0051] The large coil portion 40L of the V-phase winding coil 40V, which is adjacent to the U-phase winding coil 40U on one side in the circumferential direction C, is housed in slots 16 and 22. The small coil portion 40S of the U-phase winding coil 40U is housed in slots 17 and 21.

[0052] The large coil portion 40L of the W-phase winding coil 40W, which is adjacent to the U-phase winding coil 40U on the other side in the circumferential direction C, is housed in slots 4 and 10. The small coil portion 40S of the W-phase winding coil 40W is housed in slots 5 and 9.

[0053] That is, the 9th slot, which is located between the 8th and 12th slots that house the small coil portion 40S of the outer V-phase winding coil 40V, houses the small coil portion 40S of the inner W-phase winding coil 40W. The 10th slot houses the large coil portion 40L of the inner W-phase winding coil 40W and the large coil portion 40L of the inner U-phase winding coil 40U. The 11th slot houses the small coil portion 40S of the inner U-phase winding coil 40U. The same applies to the other winding coils 40.

[0054] That is, the plurality of winding coils 40 include a plurality of U-phase winding coils 40U, a plurality of V-phase winding coils 40V, and a plurality of W-phase winding coils 40W. Between two first slots 13S accommodating the small coil portion 40S of a first phase that is one of the U, V, and W phases, a first slot 13S accommodating the small coil portion 40S of the winding coil 40 of a second phase that is the other phase, a second slot 13L accommodating the large coil portion 40L of the winding coil 40 of the second phase and the large coil portion 40L of the winding coil 40 of a third phase that is the other phase, and a first slot 13S accommodating the small coil portion 40S of the winding coil 40 of the third phase are arranged in this order in the circumferential direction.

[0055] Therefore, with this coil arrangement, a three-phase stator 1 can be realized in which the small coil portion 40S and the large coil portion 40L are continuous, and which has a first slot 13S that accommodates the small coil portion 40S of one winding coil 40, and a second slot 13L that accommodates the large coil portion 40L of one winding coil 40 and the large coil portion 40L of another winding coil 40.

[0056] The stator 1 of this embodiment is a stator having a stator core 10 having a cylindrical core back portion 11 extending in the axial direction and a plurality of teeth 12 extending radially from the core back portion 11 and aligned in the circumferential direction, with a plurality of slots 13 aligned in the circumferential direction between circumferentially adjacent teeth 12 among the plurality of teeth 12, and a plurality of winding coils 40 that are distributedly wound around the plurality of teeth 12 and housed in the plurality of slots 13. Each of the plurality of winding coils 40 has a small coil portion 40S housed in two of the plurality of slots 13, and a large coil portion 40L that is continuous with the small coil portion 40S and is housed in a slot 13 adjacent to one of the two slots 13 in which the small coil portion 40S is housed and a slot 13 adjacent to the other of the two slots 13 and in the circumferentially outer side. The multiple slots 13 include a first slot 13S that accommodates the small coil portion 40S of one of the multiple winding coils 40, and a second slot 13L that accommodates the large coil portion 40L of one of the winding coils 40 and the large coil portion 40L of another of the multiple winding coils 40.

[0057] Generally, in the case of a coil arrangement in which two coils are accommodated in one slot, the coil insertion process involves first inserting a first coil into the slot, and then inserting a second coil into the slot where the first coil is accommodated. That is, in the process, the coils are inserted into one slot in two separate steps. When the coils are inserted in two separate steps, the first coil may move into the space within the slot where the second coil is to be inserted before the second coil is inserted. In this case, it becomes difficult to insert the second coil into the slot, so it is necessary to reduce the number of turns of the coil to be inserted into the slot.

[0058] In the above-described configuration, the small coil portion 40S and the large coil portion 40L of the wound coil 40 are continuous. Therefore, before inserting the wound coil 40 into the slot 13, the coil end portion 40a of the small coil portion 40S and the coil end portion 40a of the large coil portion 40L can be formed so that they do not interfere with each other. Therefore, in one wound coil 40, the small coil portion 40S and the large coil portion 40L can be inserted into the slot 13 at the same time.

[0059] Furthermore, in the above-described configuration, the second slot 13L accommodating the large coil portion 40L of the wound coil 40 and the first slot 13S accommodating the small coil portion 40S are adjacent to each other. That is, the small coil portions 40S of two wound coils 40, each having two large coil portions 40L accommodated in the second slot 13L, are adjacent to each other on one circumferential side of the second slot 13L. Therefore, the coil end portions 40a of the two wound coils 40 can be arranged circumferentially without interfering with each other. This allows the two wound coils 40 to be inserted into the slot 13 simultaneously. Therefore, two large coil portions 40L can be inserted into the second slot 13L simultaneously. Therefore, the above-described coil arrangement eliminates the need to reduce the number of turns of the coil inserted into the slot 13. This improves the coil space factor for the slot 13.

[0060] In this embodiment, each of the multiple wound coils 40 has a coil end portion 40a extending circumferentially on an end surface in the axial direction A of the stator core 10 between two first slots 13S and two second slots 13L in which the wound coil 40 is housed. The end surface of the stator core 10 has a tip side region R1 located on the tip side of the tooth portions 12 as viewed in the axial direction A, and a core back portion side region R2 located on the core back portion 11 side with respect to the tip side region R1 as viewed in the axial direction A. The multiple wound coils 40 include multiple core back portion 11-side wound coils 40 whose coil end portions 40a are arranged in the core back portion side region R2 as viewed in the axial direction A, and multiple wound coils 40 on the tip side of the multiple teeth portions 12 whose coil end portions 40a are arranged in the tip side region R1 as viewed in the axial direction A.

[0061] This allows the winding coils 40 on the core back portion 11 side to be arranged side by side in the circumferential direction on the core back portion 11 side of the stator core 10 without the coil end portions 40a interfering with each other. Also, the winding coils 40 on the tip side of the plurality of teeth portions 12 can be arranged side by side in the circumferential direction on the tip side of the teeth portions 12 without the coil end portions 40a interfering with each other.

[0062] In this configuration, the coil end portion 40a of the wound coil 40 on the core back portion 11 side and the coil end portion 40a of the wound coil 40 on the tip side of the tooth portion 12 are located at different positions in the radial direction B of the stator core 10. Therefore, the wound coil 40 on the core back portion 11 side can be accommodated in the slot 13, and after the coil end portion 40a of the wound coil 40 on the core back portion 11 side is moved toward the core back portion 11, the wound coil 40 on the tip side of the tooth portion 12 can be inserted into the slot 13. This makes it possible to easily insert the wound coil 40 on the tip side of the tooth portion 12 all the way to the bottom of the slot 13. Therefore, the space factor of the coil in the slot 13 can be improved.

[0063] The motor 100 of this embodiment includes the stator 1 having the configuration of this embodiment and the rotor 2 disposed radially relative to the stator 1. This makes it possible to realize the motor 100 having the stator 1 that can improve the space factor of the coils 30 housed in the slots 13 of the stator core 10.

[0064] (Method for manufacturing stator) Next, an example of a method for manufacturing the stator 1 having the above-described configuration will be described. Figures 7 to 12 are diagrams for explaining a method for manufacturing the stator 1. The method for manufacturing the stator 1 includes a coil forming process and a coil inserting process. The coil inserting process includes a first inserting process, a coil end portion shaping process, and a second inserting process. Figure 7 is a diagram for explaining the coil forming process. Figures 8 and 9 are diagrams for explaining the first inserting process. Figure 10 is a diagram for explaining the coil end portion shaping process. Figures 11 and 12 are diagrams for explaining the second inserting process. Note that Figures 9 to 12 show enlarged views of portions of the stator core 10 and the multiple wound coils 40.

[0065] In the coil forming process, the wound coils 40 are formed. Specifically, as shown in Fig. 7, a single conductive wire 50 is wound to form a plurality of wound coils 40, each having a small coil portion 40S and a large coil portion 40L. In this embodiment, the stator 1 has 12 wound coils 40. Therefore, in the coil forming process, 12 wound coils 40 are formed for each stator 1.

[0066] In the first insertion step, multiple outer peripheral winding coils 40 are inserted into predetermined slots 13. Specifically, as shown in FIG. 8 , six winding coils 40, which are half of the twelve winding coils 40, are arranged in a predetermined order in the circumferential direction C and positioned inward in the radial direction B of the stator core 10. Next, the six winding coils 40 are inserted through the openings 13a of the multiple slots 13 and moved radially outward. That is, the small coil portions 40S of the six winding coils 40 are inserted into predetermined first slots 13S, and the large coil portions 40L of the six winding coils 40 are inserted into predetermined second slots 13L.

[0067] 9, the six outer circumferential wound coils 40 are arranged in the predetermined slots 13. The first insertion step may be performed using a coil insertion jig or the like. The coil insertion jig can hold, for example, six wound coils 40 arranged in the circumferential direction, and has the function of simultaneously inserting the six held wound coils 40 into the predetermined slots 13.

[0068] In the coil end portion forming process, the coil end portions 40a of the six outer peripheral wound coils 40 arranged in the predetermined slots 13 in the first insertion process are formed. Specifically, as shown in Fig. 10, the coil end portions 40a of the six outer peripheral wound coils 40 are pushed toward the core back portion 11 of the stator core 10. As a result, the coil end portions 40a of the outer peripheral wound coils 40 move to the core back portion side region R2 of the stator core 10 when viewed in the axial direction A.

[0069] More specifically, when inserted into the predetermined slots 13 in the first insertion step, the coil end portions 40a of the six outer-circumferential wound coils 40 overlap with three slots 13 located between the two first slots 13S in which the small coil portions 40S are accommodated, as viewed in the axial direction A. The three slots 13 accommodate the inner-circumferential wound coils 40.

[0070] In the coil end portion forming process, the coil end portions 40 a of the six outer peripheral wound coils 40 are moved to positions where they do not overlap with the three slots 13 .

[0071] Next, in the second insertion step, the multiple innermost winding coils 40 are inserted into predetermined slots 13. Specifically, the remaining six winding coils 40 are lined up in a predetermined order in the circumferential direction C and arranged inside the stator core 10 in the radial direction B, as shown in FIG. 11 . Next, the six winding coils 40 are inserted through the openings 13a of the multiple slots 13 and moved radially outward. That is, the small coil portions 40S of the six winding coils 40 are inserted into predetermined first slots 13S, and the large coil portions 40L of the six winding coils 40 are inserted into predetermined second slots 13L.

[0072] 12, six inner circumferential side wound coils 40 are arranged in predetermined slots 13. The second insertion step may be performed using a coil insertion jig or the like.

[0073] That is, the manufacturing method of the stator 1 includes a coil forming process in which a plurality of wound coils 40, each having a small coil portion 40S and a large coil portion 40L, are formed by winding one conductor 50, and a coil inserting process in which, with the plurality of wound coils 40 lined up in the circumferential direction of the stator core 10, the small coil portions 40S are inserted into the first slots 13S, and two adjacent large coil portions 40L of circumferentially adjacent wound coils 40 are simultaneously inserted into one second slot 13L.

[0074] In this method, two large coil portions 40L are simultaneously inserted into one second slot 13L. Therefore, it is not necessary to reduce the number of turns of the coil compared to when the wound coil 40 is inserted into the second slot 13L in multiple passes. This makes it possible to improve the space factor of the coil within the slot 13.

[0075] The coil insertion process includes a first insertion process, a coil end portion shaping process, and a second insertion process. In the first insertion process, half of the plurality of wound coils 40 are inserted into some of the plurality of slots 13 while aligned in the circumferential direction C. In the coil end portion shaping process, the coil end portions 40a of half of the wound coils 40 accommodated in some of the slots 13 by the first insertion process, which protrude from the end faces in the axial direction A of the stator core 10, are pushed toward the core back portion 11 of the stator core 10. In the second insertion process, the remaining wound coils 40 are inserted into the remaining slots 13 while aligned in the circumferential direction C.

[0076] As a result, after the coil end portions 40a of the wound coils 40 housed in some of the slots 13 in the first insertion step are moved toward the core back portion 11 of the stator core 10, the remaining wound coils 40 can be inserted into the remaining slots 13. Therefore, the remaining wound coils 40 can be easily inserted all the way to the bottom of the slots 13. This improves the space factor of the coils in the slots 13.

[0077] While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and can be practiced by appropriately modifying the above-described embodiments within the scope of the spirit thereof.

[0078] In the above embodiment, the motor 100 is a so-called inner rotor type motor in which the rotor 2 is located radially inward of the stator 1. However, the motor may be a so-called outer rotor type motor in which the rotor is located radially outward of the stator.

[0079] In the above embodiment, the first slot 13S and the second slot 13L have the same physical shape. However, the physical shapes of the first slot and the second slot may be different.

[0080] In the above embodiment, the stator core 10 has 36 slots 13, and the coil 30 has four wound coils 40 for each phase. However, as long as there are three phases and the number of slots per pole per phase is three, the number of slots does not have to be 36. For example, the stator core may have 54 slots, and the coil may have six coils for each phase. Alternatively, the stator core may have 72 slots, and the coil may have eight coils for each phase.

[0081] In the above embodiment, the number of turns of the conductor 50 of the small coil portion 40S is twice the number of turns of the conductor 50 of the large coil portion 40L. However, the number of turns of the conductor of the small coil portion may be the same as the number of turns of the conductor of the large coil portion. The number of turns of the conductor of the small coil portion does not have to be twice the number of turns of the conductor of the large coil portion. Note that, when the first slot and the second slot have the same physical shape as in the above embodiment, it is preferable that the number of turns of the conductor of the small coil portion be twice the number of turns of the conductor of the large coil portion. This makes it possible to make the coil space factor in the first slot, which houses one small coil portion, equivalent to the coil space factor in the second slot, which houses two large coil portions.

[0082] (Configuration Example) The present technology can also be configured as follows.

[0083] (1) A stator includes a stator core having a cylindrical core back portion extending in the axial direction and a plurality of teeth extending radially from the core back portion and arranged in the circumferential direction, with a plurality of slots arranged in the circumferential direction between circumferentially adjacent teeth among the plurality of teeth, and a plurality of wound coils wound in a distributed manner around the plurality of teeth and housed in the plurality of slots. Each of the plurality of wound coils has a small coil portion housed in two of the plurality of slots, and a large coil portion that is continuous with the small coil portion and is housed in a slot adjacent to one of the two slots and circumferentially outward from the other of the two slots. The plurality of slots includes a first slot that houses the small coil portion of one of the plurality of wound coils, and a second slot that houses the large coil portion of the one wound coil and the large coil portions of the other of the plurality of wound coils.

[0084] (2) In the stator described in (1), each of the plurality of wound coils has a coil end portion extending circumferentially on an axial end surface of the stator core between the two first slots and the two second slots in which the wound coil is housed. The end surface of the stator core has a tip side region located on the tip side of the tooth portion as viewed in the axial direction, and a core back part side region located on the core back part side of the tip side region as viewed in the axial direction. The plurality of wound coils include a plurality of core back part side wound coils whose coil end portions are arranged in the core back part side region as viewed in the axial direction, and a plurality of tip side wound coils whose coil end portions are arranged in the tip side region as viewed in the axial direction.

[0085] (3) In the stator described in (1) or (2), the small coil portion is formed of a conductor wound multiple times, and the large coil portion is formed of a conductor wound multiple times, and the number of turns of the conductor in the small coil portion is greater than the number of turns of the conductor in the large coil portion.

[0086] (4) In the stator described in any one of (1) to (3), the plurality of wound coils include a plurality of U-phase wound coils, a plurality of V-phase wound coils, and a plurality of W-phase wound coils. Between two of the first slots accommodating the small coil portion of a first phase that is one of the U-phase, V-phase, and W-phase, the first slot accommodating the small coil portion of a winding coil of a second phase that is the other of the U-phase, V-phase, and W-phase, the second slot accommodating the large coil portion of the winding coil of the second phase and the large coil portion of a winding coil of a third phase that is the other of the U-phase, V-phase, and W-phase, and the first slot accommodating the small coil portion of the winding coil of the third phase are arranged in this order in the circumferential direction.

[0087] (5) A motor includes the stator according to any one of (1) to (4) and a rotor disposed radially relative to the stator.

[0088] (6) A method for manufacturing a stator includes a stator core having a cylindrical core back portion extending in the axial direction and a plurality of teeth extending radially from the core back portion and arranged circumferentially, with a plurality of slots arranged circumferentially between circumferentially adjacent teeth among the plurality of teeth, and a plurality of wound coils wound in a distributed manner around the plurality of teeth and housed in the plurality of slots. Each of the plurality of wound coils has a small coil portion housed in two of the plurality of slots, and a large coil portion that is continuous with the small coil portion and is housed in a slot adjacent to one of the two slots and circumferentially outward from the other of the two slots. The plurality of slots includes a first slot that houses the small coil portion of one of the plurality of wound coils, and a second slot that houses the large coil portion of the one wound coil and the large coil portions of the other of the plurality of wound coils. The method for manufacturing the stator includes a coil forming process for forming a plurality of wound coils, each having the small coil portion and the large coil portion, by winding a single conductor, and a coil inserting process for arranging the plurality of wound coils in a circumferential direction of the stator core, inserting the small coil portions into the first slots, and simultaneously inserting two adjacent large coil portions of the wound coils that are adjacent in the circumferential direction into one of the second slots.

[0089] (7) In the method for manufacturing a stator described in (6), the coil insertion process includes a first insertion process in which half of the plurality of wound coils are inserted into some of the plurality of slots while being lined up in the circumferential direction; a coil end portion forming process in which coil end portions of the half of the wound coils accommodated in the some of the slots by the first insertion process, which protrude from the axial end face of the stator core, are pressed toward the core back portion of the stator core; and a second insertion process in which the remaining wound coils are inserted into the remaining slots of the plurality of slots while being lined up in the circumferential direction.

[0090] The configuration of the present invention is applicable to a stator having a coil arrangement in which two phase coils are housed in one slot.

[0091] REFERENCE SIGNS LIST 1 stator 2 rotor 10 stator core 11 core back portion 12 teeth portion 12a tooth tip portion 13 slot 13a opening 13b side surface 13c bottom surface 13S first slot 13L second slot 20 insulating member 30 coil 40 wound coil 40a coil end portion 40S small coil portion 40L large coil portion 40U U-phase wound coil 40V V-phase wound coil 40W W-phase wound coil 50 conducting wire 100 motor R1 tip side region R2 core back portion side region

Claims

1. A stator having: a stator core having a cylindrical core back portion extending in the axial direction, and a plurality of teeth portions extending radially from the core back portion and aligned circumferentially, with a plurality of slots aligned circumferentially between circumferentially adjacent teeth portions of the plurality of teeth portions; and a plurality of wound coils that are distributedly wound around the plurality of teeth portions and housed in the plurality of slots, wherein each of the plurality of wound coils has: a small coil portion housed in two of the plurality of slots; and a large coil portion that is continuous with the small coil portion and is housed in a slot adjacent to the circumferential outside of one of the two slots in which the small coil portion is housed, and a slot adjacent to the circumferential outside of the other of the two slots, and the plurality of slots include: a first slot that houses the small coil portion of one of the plurality of wound coils, and a second slot that houses the large coil portion of the one wound coil and the large coil portions of other wound coils of the plurality of wound coils.

2. A stator as claimed in claim 1, wherein the plurality of wound coils each have a coil end portion that extends circumferentially on an axial end face of the stator core between the two first slots and the two second slots in which the wound coil is housed, the end face of the stator core having a tip side region located on the tip side of the teeth when viewed in the axial direction, and a core back part side region located on the core back part side of the tip side region when viewed in the axial direction, and the plurality of wound coils include a plurality of core back part side wound coils whose coil end portions are arranged in the core back part side region when viewed in the axial direction, and a plurality of tip side wound coils whose coil end portions are arranged in the tip side region when viewed in the axial direction.

3. A stator according to claim 1, wherein the small coil section is made up of a conductor wound multiple times, and the large coil section is made up of a conductor wound multiple times, and the number of turns of the conductor in the small coil section is greater than the number of turns of the conductor in the large coil section.

4. A stator according to claim 1, wherein the plurality of wound coils include a plurality of U-phase wound coils, a plurality of V-phase wound coils, and a plurality of W-phase wound coils, and wherein the following are arranged in the circumferential direction in this order between two of the first slots accommodating the small coil portion of a first phase, which is one of the U, V, and W phases: the first slot accommodating the small coil portion of a wound coil of a second phase, which is the other phase; the second slot accommodating the large coil portion of the wound coil of the second phase and the large coil portion of a wound coil of a third phase, which is the other phase.

5. A motor comprising: a stator according to any one of claims 1 to 4; and a rotor disposed radially relative to the stator.

6. A method for manufacturing a stator having a stator core having a cylindrical core back portion extending in the axial direction and a plurality of teeth extending radially from the core back portion and aligned in the circumferential direction, with a plurality of slots aligned in the circumferential direction between circumferentially adjacent teeth of the plurality of teeth, and a plurality of winding coils that are distributedly wound around the plurality of teeth and housed in the plurality of slots, wherein each of the plurality of winding coils has a small coil portion housed in two of the plurality of slots, and a large coil portion that is continuous with the small coil portion and housed in a slot adjacent to the circumferential outside of one of the two slots in which the small coil portion is housed and a slot adjacent to the circumferential outside of the other of the two slots, and the plurality of slots include a first slot that houses the small coil portion of one of the plurality of winding coils, and a second slot that houses the large coil portion of the one winding coil and the large coil portions of the other of the plurality of winding coils, A method for manufacturing a stator, comprising: a coil forming step of forming a plurality of wound coils, each having the small coil portion and the large coil portion, by winding one conducting wire; and a coil inserting step of arranging the plurality of wound coils in a circumferential direction of the stator core, inserting the small coil portions into the first slots, respectively, and simultaneously inserting two adjacent large coil portions of the wound coils that are adjacent in the circumferential direction into one of the second slots.

7. A method for manufacturing a stator as defined in claim 6, wherein the coil insertion step includes: a first insertion step of inserting half of the plurality of wound coils into some of the plurality of slots while they are lined up in the circumferential direction; a coil end portion forming step of pushing coil end portions of the half of the wound coils housed in some of the slots by the first insertion step, the coil end portions protruding from the axial end faces of the stator core, toward the core back portion of the stator core; and a second insertion step of inserting the remaining wound coils into the remaining of the plurality of slots while they are lined up in the circumferential direction.

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