Stator and motor

Abstract

A stator in which a coil is wound around a tooth portion via an insulator member is provided with a configuration that prevents the coil from becoming unwound and allows the number of coil turns to be increased. [Solution] An insulator member (24) has plate-shaped tooth cover portions (242) arranged on the axial end faces of multiple teeth (212). The tooth cover portions have multiple coil winding surfaces (243) arranged in the radial direction, around which coils (22) are wound. The multiple coil winding surfaces include a first coil winding surface (243a) and a second coil winding surface (243c) that is located on the core back portion side of the first coil winding surface in the axial direction and is closer to the teeth in the axial direction than the first coil winding surface. The number of layers of the coil wound on the second coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface.

Description

[Technical Field]

[0001] The present invention relates to a stator and a motor. [Background technology]

[0002] A known configuration of a stator having a stator core includes a resin insulator member disposed on an axial end face of the stator core. A coil is wound around the teeth of the stator core via the insulator member. The insulator member insulates the coil from the axial end face of the stator core (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Utility Model No. 216981641 [Patent Document 2] Chinese Patent Application Publication No. 112242783 Summary of the Invention [Problem to be solved by the invention]

[0004] It is known that the motor torque increases with the number of turns of the coil wound around the teeth of a stator. To increase the number of turns of the coil, for example, it is possible to increase the number of layers of the conductor that constitutes the coil. However, if the conductor is made up of multiple layers, the winding may become unbalanced.

[0005] In contrast, by using an insulator member having a wall portion protruding in the axial direction at its radial tip, such as the insulator member disclosed in Patent Document 2, it is possible to prevent the coil from moving radially relative to the insulator member. Therefore, it is possible to prevent the coil from becoming unwound. However, when using such an insulator member, the wall portion at the radial tip limits the radial range in which the coil can be wound. In other words, when using such an insulator member, the number of turns of the coil is reduced by the radial length of the wall portion.

[0006] Therefore, there has been a demand for an insulator member that can increase the number of turns of the coil while preventing the coil from becoming unwound.

[0007] An object of the present invention is to provide a configuration in a stator in which a coil is wound around teeth via an insulator member, which allows the number of turns of the coil to be increased while preventing the coil from becoming unwound. [Means for solving the problem]

[0008] 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 in the circumferential direction, an insulator member covering an axial end face of the stator core, and coils wound around the plurality of teeth via the insulator member. The insulator member has plate-shaped tooth cover portions respectively disposed on the axial end faces of the plurality of teeth. The tooth cover portions have a plurality of radially arranged coil winding surfaces on which the coils are wound. The plurality of coil winding surfaces include a first coil winding surface and a second coil winding surface located on the core back portion side of the first coil winding surface in the axial direction and closer to the teeth than the first coil winding surface. The number of layers of the coil wound on the second coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface.

[0009] A motor according to an exemplary embodiment of the present invention includes the stator and a rotor having a magnet radially opposed to the stator. [Effects of the Invention]

[0010] According to the present invention, in a stator in which a coil is wound around a tooth portion via an insulator member, a configuration can be provided in which the number of turns of the coil can be increased while preventing the coil from becoming unwound. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a motor according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing a schematic configuration of the stator. [Figure 3] FIG. 3 is a plan view of the stator core. [Figure 4] FIG. 4 is an enlarged perspective view of a portion of the stator. [Figure 5] FIG. 5 is a perspective view showing a schematic configuration of an insulator member. [Figure 6] FIG. 6 is a cross-sectional view of the insulator member and the teeth taken along a radial direction. [Figure 7] FIG. 7 is a diagram illustrating the winding coil portion. [Figure 8] FIG. 8 is a diagram schematically showing a method for forming the wound coil portion. [Figure 9] FIG. 9 is a diagram schematically showing a method for forming the wound coil portion. [Figure 10] FIG. 10 is a diagram schematically showing a method for forming the wound coil portion. [Figure 11] FIG. 11 is a cross-sectional view of an insulator member and a tooth portion according to another embodiment, cut in the radial direction. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, exemplary 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.

[0013] In the following description, the direction parallel to the central axis P of the motor 1 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 1 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 212 are located relative to the core back portion 211 is indicated by B1, and the direction in which the core back portion 211 is located relative to the teeth 212 is indicated by B2.

[0014] 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.

[0015] (Motor configuration) A motor 1 according to an exemplary embodiment of the present invention will be described with reference to Figure 1. Figure 1 is a cross-sectional view showing a schematic configuration of motor 1. Motor 1 according to this embodiment is, for example, an in-wheel motor that is disposed on the rear wheel of an electric motorcycle. However, the motor may also be disposed on the front wheel of an electric motorcycle.

[0016] 1, the motor 1 includes a stator 2 and a rotor 3. The motor 1 further includes a shaft 4, a stator holder 5, and bearings 6.

[0017] The shaft 4 is columnar and extends in an axial direction A about a central axis P. The shaft 4 is attached to the main body of the electric motorcycle so as to be non-rotatable.

[0018] The stator holder 5 is disk-shaped and centered on a central axis P. The stator holder 5 has a through-hole 51 at its center that penetrates in the axial direction A. The shaft 4 is inserted into the through-hole 51 and protrudes from both ends of the through-hole 51 in the axial direction A. For example, the shaft 4 is directly press-fitted into the through-hole 51, or a sleeve part is attached to the through-hole 51 and press-fitted indirectly, thereby fixing the stator holder 5 to the shaft 4.

[0019] The stator 2 is an armature of the motor 1. The stator 2 is cylindrical and extends in the axial direction A. The stator 2 is located radially outward of the stator holder 5. The stator 2 is fixed to the stator holder 5. In other words, the stator 2 is fixed so as not to rotate relative to the shaft 4. Details of the stator 2 will be described later.

[0020] The rotor 3 has a magnet 31, a yoke 32, a rim 33, a first wheel cover 34, and a second wheel cover 35. The magnet 31 of the rotor 3 faces the stator 2 in the radial direction B. In this embodiment, the magnet 31 is positioned radially outward from the stator 2 with a gap therebetween. A plurality of magnets 31 are arranged at equal intervals in the circumferential direction C. Note that the number of magnets does not need to be multiple, and a single annular magnet may be used.

[0021] The yoke 32 has a cylindrical shape that extends in the axial direction A around a central axis P. The magnet 31 is fixed to the inner circumferential surface of the yoke 32.

[0022] The rim 33 is annular and centered on the central axis P. The rim 33 is located radially outward of the yoke 32. The rim 33 is fixed to the yoke 32. A rear wheel tire is attached radially outward of the rim 33.

[0023] The first wheel cover 34 is located on one axial side and radially inward of the yoke 32. The first wheel cover 34 is rotatably attached to the shaft 4 via a bearing 6 such as a ball bearing. The outer periphery of the first wheel cover 34 is fixed to the yoke 32 with screws or the like. Therefore, the first wheel cover 34 rotates around the central axis P together with the yoke 32 and the rim 33.

[0024] The second wheel cover 35 is located on the other axial side and radially inward of the yoke 32. The second wheel cover 35 is rotatably attached to the shaft 4 via a bearing 6 such as a ball bearing. The outer periphery of the second wheel cover 35 is fixed to the yoke 32. Therefore, the second wheel cover 35 rotates around the central axis P together with the yoke 32, the rim 33, and the first wheel cover 34.

[0025] The second wheel cover 35 has a brake drum 35a that protrudes in the axial direction. The brake drum 35a is integral with the second wheel cover. For example, a brake mechanism on the electric motorcycle body is disposed on the inner periphery of the brake drum 35a.

[0026] The rotor 3 rotates about the central axis P due to a circumferential torque generated when a driving current is supplied to the stator 2.

[0027] (Details of the stator) A stator 2 according to this embodiment will be described with reference to Fig. 1 to Fig. 4. Fig. 2 is a perspective view showing a schematic configuration of the stator 2. Fig. 3 is a plan view of the stator core 21. Fig. 4 is an enlarged perspective view showing a part of the stator 2 before the coil 22 is wound thereon. In addition to the stator 2, Fig. 2 also shows a stator holder 5.

[0028] As shown in FIG. 2, the stator 2 includes a stator core 21, a coil 22, an insulator member 24, and an insulating sheet 25.

[0029] 1, the stator core 21 is disposed radially inward of the magnet 31 with a gap therebetween. The stator core 21 is made of a magnetic material. In this embodiment, the stator core 21 is formed by laminating electromagnetic steel sheets.

[0030] As shown in FIG. 3 , the stator core 21 has a core back portion 211 and a plurality of tooth portions 212. The core back portion 211 is cylindrical and extends in the axial direction A. The tooth portions 212 extend from the core back portion 211 in the radial direction B. In this embodiment, the tooth portions 212 extend radially outward from the core back portion 211. That is, the core back portion 211 side of the tooth portions 212 is located radially inward, and the tip side is located radially outward. Note that, hereinafter, the tip side of the tooth portions 212 refers to the side of the tooth portions 212 opposite to the core back portion 211 side.

[0031] The plurality of teeth 212 are aligned in the circumferential direction C. A slot 213 is formed between each of the plurality of teeth 212 that are adjacent to each other in the circumferential direction C. The plurality of slots 213 are aligned in the circumferential direction C.

[0032] 2, the coil 22 is wound around the tooth portion 212. More specifically, the coil 22 is formed by winding a conductive wire 22a coated with an insulator around the tooth portion 212.

[0033] The coil 22 has a plurality of winding coil portions 23 wound around each of the teeth 212. The details of the winding coil portions 23 will be described later.

[0034] When a driving current is supplied to the coil 22, a radial magnetic flux is generated in the teeth 212. This generates a circumferential torque in the rotor 3 having the magnet 31, causing the rotor 3 to rotate about the central axis P.

[0035] The coil 22 is wound around each of the teeth 212 via an insulator member 24 and an insulating sheet 25. The insulator member 24 and the insulating sheet 25 are insulators. In this embodiment, the insulator member 24 and the insulating sheet 25 are made of resin.

[0036] 4, the insulator members 24 are disposed on one axial end face and the other axial end face of the stator core 21. That is, the insulator members 24 cover at least a portion of the end face in the axial direction A of the stator core 21. In this embodiment, the insulator member 24 disposed on the one axial end face of the stator core 21 and the insulator member 24 disposed on the other axial end face have the same configuration. Details of the insulator members 24 will be described later.

[0037] 4, the insulating sheets 25 are disposed inside the slots 213. The insulating sheets 25 are disposed one by one on the inner circumferential surfaces of the plurality of slots 213. The insulating sheets 25 have a shape that fits along the inner circumferential surfaces of the slots 213.

[0038] The insulating sheet 25 has a sheet end portion 25a that protrudes from the slot 213 in the axial direction A. In this embodiment, the length of the sheet end portion 25a in the axial direction A is smaller than the length of the insulator member 24 in the axial direction A. Therefore, the sheet end portion 25a covers at least a portion of the end face of the insulator member 24 in the circumferential direction C.

[0039] 2, the coils 22 are wound around the teeth 212 via insulator members 24 and insulating sheets 25. That is, the insulator members 24 are located between the teeth 212 and the coils 22 in the axial direction A. The insulating sheets 25 are located between the teeth 212 and the coils 22 in the circumferential direction C. The insulator members 24 and the insulating sheets 25 insulate the stator core 21 from the coils 22.

[0040] 4, the insulating sheet 25 has a bent portion between a portion that follows the side surface of the tooth portion 212 and a portion that follows the radially outer end surface of the core back portion 211. Therefore, when a force that spreads outward is applied to the insulating sheet 25, the bent portion may break. That is, when the sheet end portion 25a is pushed outward by the coil 22 wound around the tooth portion 212 and spreads outward, it may break.

[0041] In this embodiment, the insulator member 24 is located in the circumferential direction C relative to the sheet end portion 25a. Therefore, the sheet end portion 25a does not expand outward even when pressed by the coil 22. This prevents the insulating sheet 25 from breaking.

[0042] (Details of insulator components) Next, the insulator member 24 will be described in detail with reference to Fig. 4 to Fig. 6. Fig. 5 is a perspective view showing a schematic configuration of the insulator member 24. Fig. 6 is a cross-sectional view of the insulator member 24 and the stator core 21 cut in the radial direction B.

[0043] 5, the insulator member 24 has a plate shape. The insulator member 24 has an annular core back cover portion 241 and a plurality of tooth cover portions 242.

[0044] The core back cover part 241 is annular and centered on the central axis P. As shown in FIG. 4 , the core back cover part 241 is disposed on the end face of the core back part 211 in the axial direction A. The core back cover part 241 covers at least a portion of the end face of the core back part 211 in the axial direction A. The core back cover part 241 insulates the coil 22 from the core back part 211 of the stator core 21.

[0045] 5, the plurality of tooth cover portions 242 extend in the radial direction B from the core back cover portion 241. The extending direction of the tooth cover portions 242 coincides with the extending direction of the tooth portions 212 relative to the core back portion 211 in the stator core 21. That is, in this embodiment, the tooth cover portions 242 extend radially outward from the core back cover portion 241.

[0046] In this embodiment, the base end 242b side of the tooth cover portion 242, which is on the core back cover portion 241 side, is located radially inward, and the radial tip 242a side opposite the base end 242b side is located radially outward.

[0047] As shown in Fig. 4, the plurality of tooth cover portions 242 are arranged on the end faces of the plurality of tooth portions 212 in the axial direction A. The number of the plurality of tooth cover portions 242 is the same as the number of the plurality of tooth portions 212. Each of the plurality of tooth cover portions 242 covers at least a portion of the end face of each tooth portion 212 in the axial direction A. In this embodiment, the plurality of tooth cover portions 242 have the same configuration.

[0048] As shown in FIG. 5 , the tooth cover portion 242 has a plurality of coil winding surfaces 243. The coil 22 is wound on the plurality of coil winding surfaces 243. In this embodiment, the plurality of coil winding surfaces 243 are aligned in the radial direction B. Among the plurality of coil winding surfaces 243, the positions in the axial direction A of the coil winding surfaces 243 adjacent to each other in the radial direction B are different. Therefore, the tooth cover portion 242 has a step wall surface 244 that forms a step between the coil winding surfaces 243 adjacent to each other in the radial direction B.

[0049] 6, in this embodiment, the multiple coil winding surfaces 243 include a first coil winding surface 243a, an intermediate coil winding surface 243b, and a second coil winding surface 243c. The first coil winding surface 243a, the intermediate coil winding surface 243b, and the second coil winding surface 243c are arranged in this order from the radial tip 242a toward the base end 242b.

[0050] Of the multiple coil winding surfaces 243, the first coil winding surface 243a is located closest to the radial tip 242a of the tooth cover portion 242. Of the multiple coil winding surfaces 243, the second coil winding surface 243c is located closest to the base end 242b of the tooth cover portion 242. The intermediate coil winding surface 243b is located between the first coil winding surface 243a and the second coil winding surface 243c in the radial direction B.

[0051] The position in the axial direction A of the first coil winding surface 243a is Aa. The position in the axial direction A of the intermediate coil winding surface 243b is Ab. The position in the axial direction A of the second coil winding surface 243c is Ac. In this embodiment, the axial position Aa of the first coil winding surface 243a is the farthest from the teeth 212 among the multiple coil winding surfaces 243. The axial position Ac of the second coil winding surface 243c is closer to the teeth 212 than the axial position Aa of the first coil winding surface 243a. The axial position Ab of the intermediate coil winding surface 243b is closer to the teeth 212 than the axial position Aa of the first coil winding surface 243a, and is farther from the teeth 212 than the axial position Ac of the second coil winding surface 243c.

[0052] That is, in this embodiment, the axial position Aa of the first coil winding surface 243a, the axial position Ab of the intermediate coil winding surface 243b, and the axial position Ac of the second coil winding surface 243c are closer to the tooth portion 212 in this order from the radial tip 242a to the base end 242b.

[0053] As described above, the tooth cover portion 242 has a stepped wall surface 244 between the coil winding surfaces 243 adjacent to each other in the radial direction B. In this embodiment, the stepped wall surface 244 includes a first stepped wall surface 244a located between the first coil winding surface 243a and the intermediate coil winding surface 243b, and a second stepped wall surface 244b located between the intermediate coil winding surface 243b and the second coil winding surface 243c.

[0054] The coil 22 is wound around the tooth portion 212 via the insulator member 24. That is, a portion of the coil 22 wound around the tooth portion 212 is wound on the first coil winding surface 243a. Another portion of the coil 22 is wound on the intermediate coil winding surface 243b. Yet another portion of the coil 22 is wound on the second coil winding surface 243c.

[0055] In this embodiment, the axial position Ab of the intermediate coil winding surface 243b and the axial position Ac of the second coil winding surface 243c are closer to the teeth 212 than the axial position Aa of the first coil winding surface 243a. Therefore, it is possible to wind a greater number of layers of coils on the intermediate coil winding surface 243b and the second coil winding surface 243c than the number of layers of the coil 22 wound on the first coil winding surface 243a. In this specification, the number of layers of the coil 22 refers to the number of overlaps in the layer direction of the conducting wire 22a that constitutes the coil 22.

[0056] In this embodiment, the number of layers of the coil 22 wound on the second coil winding surface 243c is greater than the number of layers of the coil 22 wound on the first coil winding surface 243a. The number of layers of the coil 22 wound on the intermediate coil winding surface 243b is greater than the number of layers of the coil 22 wound on the first coil winding surface 243a and less than the number of layers of the coil 22 wound on the second coil winding surface 243c.

[0057] Specifically, one layer of the coil 22 is wound on the first coil winding surface 243a, two layers of the coil 22 are wound on the middle coil winding surface 243b, and three layers of the coil 22 are wound on the second coil winding surface 243c.

[0058] A first stepped wall surface 244a is located on the radial tip 242a side of the intermediate coil winding surface 243b. That is, the first stepped wall surface 244a is located on the radial tip 242a side of the first layer of the coil 22 wound on the intermediate coil winding surface 243b. The first layer of the coil 22 wound on the first coil winding surface 243a is located on the radial tip 242a side of the second layer of the coil 22 wound on the intermediate coil winding surface 243b.

[0059] A second stepped wall surface 244b is located on the radial tip 242a side of the second coil winding surface 243c. That is, the second stepped wall surface 244b is located on the radial tip 242a side of the first layer of the coil 22 wound on the second coil winding surface 243c. The first layer of the coil 22 wound on the intermediate coil winding surface 243b is located on the radial tip 242a side of the second layer of the coil 22 wound on the second coil winding surface 243c. The second layer of the coil 22 wound on the intermediate coil winding surface 243b is located on the radial tip 242a side of the third layer of the coil 22 wound on the second coil winding surface 243c.

[0060] The second stepped wall surface 244b prevents the first layer of the coil 22 on the second coil winding surface 243c from moving toward the radial tip 242a, and therefore the second layer of the coil 22 on the second coil winding surface 243c does not unwind toward the first layer.

[0061] The first stepped wall surface 244a prevents the first layer of the coil 22 on the intermediate coil winding surface 243b from moving toward the radial tip 242a, and therefore the second layer of the coil 22 on the intermediate coil winding surface 243b does not collapse toward the first layer.

[0062] The first layer of the coil 22 on the intermediate coil winding surface 243b prevents the second layer of the coil 22 on the second coil winding surface 243c from moving toward the radial tip 242a. Therefore, the second layer of the coil 22 on the second coil winding surface 243c does not move toward the radial tip 242a.

[0063] The single layer of coil 22 does not become unwound. In this embodiment, the single layer of coil 22 is wound on the first coil winding surface 243a located closest to the radial tip 242a. That is, the coil 22 does not become unwound on the radial tip 242a side.

[0064] The first layer of the coil 22 on the first coil winding surface 243a prevents the second layer of the coil 22 on the intermediate coil winding surface 243b and the third layer of the coil 22 on the second coil winding surface 243c from moving toward the radial tip 242a. Therefore, the second layer of the coil 22 on the intermediate coil winding surface 243b and the third layer of the coil 22 on the second coil winding surface 243c do not move toward the radial tip 242a.

[0065] Therefore, with the above-described configuration, it is possible to wind the coil 22 in multiple layers on the middle coil winding surface 243b and the second coil winding surface 243c without the coil 22 becoming unwound. Therefore, it is possible to realize a configuration that allows the number of turns of the coil 22 to be increased while preventing the coil 22 from becoming unwound.

[0066] Furthermore, in this embodiment, the radial tip 242a of the tooth cover portion 242 does not require a wall or the like protruding in the axial direction A. Therefore, the coil 22 can be wound around the tooth cover portion 242 up to the radial tip 242a. This allows for an increased number of turns of the coil 22. Furthermore, compared to a configuration having the wall or the like, the insulator member 24 can be made more compact in the axial direction. Therefore, a stator 2 that is compact in the axial direction can be realized.

[0067] (Details of the winding coil) Next, the winding coil portion 23 wound around one tooth portion 212 will be described with reference to Fig. 7. Fig. 7 is a diagram illustrating the winding coil portion 23. The winding coil portion 23 wound around one tooth portion 212 is connected to another winding coil portion 23 wound around another tooth portion 212. The winding coil portion 23 is formed by a part of the conductor wire 22a that constitutes the coil 22. The winding coil portion 23 is formed by winding the conductor wire 22a around the tooth portion 212 in a predetermined winding order.

[0068] The wound coil portion 23 has a winding start portion 23a and a winding end portion 23b. The winding start portion 23a is located on the winding start side of the wound coil portion 23 wound around the tooth portion 212. The winding end portion 23b is located on the winding end side of the wound coil portion 23 wound around the tooth portion 212.

[0069] Specifically, the winding start portion 23a is the winding start end of the conductor wire 22a that constitutes the wound coil portion 23, or the portion connected to the winding end portion 23b of another wound coil portion 23. The winding end portion 23b is the winding end of the conductor wire 22a, or the portion connected to the winding start portion 23a of another wound coil portion 23.

[0070] The wound coil portion 23 has, between a winding start portion 23a and a winding end portion 23b, a first layer coil portion 231, a second layer coil portion 232, and a third layer coil portion 233. The first layer coil portion 231, the second layer coil portion 232, and the third layer coil portion 233 are connected in this order.

[0071] The first layer coil portion 231 is formed by the conductive wire 22a wound on the second coil winding surface 243c from the base end 242b toward the second stepped wall surface 244b. That is, the first layer coil portion 231 is wound on the second coil winding surface 243c from the end portion on the core back portion 211 side toward the second stepped wall surface 244b. The base end 242b side of the tooth cover portion 242 of the first layer coil portion 231 is connected to the winding start portion 23a.

[0072] The second layer coil portion 232 is formed by a conductive wire 22a wound on the first layer coil portion 231 and the intermediate coil winding surface 243b from a base end 242b toward the first step wall surface 244a. That is, the second layer coil portion 232 is wound on the first layer coil portion 231 and the intermediate coil winding surface 243b from the end portion on the core back portion 211 side toward the first step wall surface 244a. The base end 242b side of the tooth cover portion 242 of the second layer coil portion 232 is connected to the first layer coil portion 231.

[0073] The third layer coil portion 233 is formed by a conductive wire 22a wound on the second layer coil portion 232 and the first coil winding surface 243a from a base end 242b toward a radial tip 242a. That is, the third layer coil portion 233 is wound on the second layer coil portion 232 and the first coil winding surface 243a from the end portion on the core back portion 211 side toward the tip B1 side of the tooth portion 212. The base end 242b side of the tooth cover portion 242 of the third layer coil portion 233 is connected to the second layer coil portion 232. The radial tip 242a side of the tooth cover portion 242 of the third layer coil portion 233 is connected to the winding end portion 23b.

[0074] (Method of forming the wound coil portion) Next, a method for forming the wound coil portion 23 having the above-described configuration will be described with reference to Fig. 8 to Fig. 10. In Fig. 8 to Fig. 10, the numbers attached to the conductors 22a indicate the order in which the conductors 22a are wound around the teeth 212.

[0075] First, the winding start portion 23a of the conductor 22a constituting the first layer coil portion 231 is placed at the base end 242b of the tooth cover portion 242. Next, as shown in Fig. 8, the conductor 22a is wound onto the second coil winding surface 243c toward the radial tip 242a of the tooth cover portion 242 until it contacts the second stepped wall surface 244b. This forms the first layer coil portion 231, in which the conductor 22a is arranged in the radial direction B, between the base end 242b and the second stepped wall surface 244b. The first layer coil portion 231 is prevented from moving toward the radial tip 242a by the second stepped wall surface 244b.

[0076] Next, as shown in Fig. 9, the conductor 22a is placed on the base end 242b of the tooth cover portion 242. Next, the conductor 22a is wound onto the first layer coil portion 231 and the intermediate coil winding surface 243b toward the radial tip 242a of the tooth cover portion 242 until it contacts the first step wall surface 244a. This forms the second layer coil portion 232, in which the conductor 22a is arranged in the radial direction B, between the base end 242b and the first step wall surface 244a. The second layer coil portion 232 is prevented from moving toward the radial tip 242a by the first step wall surface 244a.

[0077] 10, the conductor 22a is placed on the base end 242b of the tooth cover portion 242. Next, the conductor 22a is wound onto the second layer coil portion 232 and the first coil winding surface 243a toward the radial tip 242a. This forms the third layer coil portion 233 in which the conductor 22a is arranged in the radial direction B between the base end 242b and the radial tip 242a.

[0078] As described above, the conductive wire 22a is wound around the tooth portion 212, thereby forming the wound coil portion 23.

[0079] In the above-described method for forming the wound coil portion 23, the first layer coil portion 231 is prevented from moving toward the radial tip 242a. That is, the first layer coil portion 231 does not come apart. Therefore, the first layer coil portion 231 prevents the second layer coil portion 232 formed on the first layer coil portion 231 from moving toward the first layer coil portion 231.

[0080] The second layer coil portion 232 is prevented from moving toward the radial tip 242a. That is, the second layer coil portion 232 does not come apart. Therefore, the second layer coil portion 232 prevents the third layer coil portion 233 formed on the second layer coil portion 232 from moving toward the second layer coil portion 232.

[0081] That is, in the above-described method for forming the wound coil portion 23, the conductive wire 22a constituting each layer is prevented from moving toward the conductive wire 22a in the lower layer and toward the radial tip 242a, and therefore, the coil 22 can be prevented from becoming unwound when the coil 22 is formed.

[0082] As described above, the exemplary stator 2 according to this embodiment is a stator 2 including: a stator core 21 having a cylindrical core back portion 211 extending in the axial direction A; and a plurality of teeth 212 extending from the core back portion 211 in the radial direction B and aligned in the circumferential direction C; an insulator member 24 covering an end face in the axial direction A of the stator core 21; and coils 22 wound around the plurality of teeth 212 via the insulator member 24. The insulator member 24 has plate-shaped tooth cover portions 242 arranged on the end faces in the axial direction A of the plurality of teeth 212. The tooth cover portions 242 have a plurality of coil winding surfaces 243 aligned in the radial direction B, around which the coils 22 are wound, respectively. The multiple coil winding surfaces 243 include a first coil winding surface 243a and a second coil winding surface 243c that is located closer to the core back portion 211 than the first coil winding surface 243a when viewed in the axial direction A and whose position in the axial direction A is closer to the teeth portion 212 than the first coil winding surface 243a. The number of layers of the coil 22 wound on the second coil winding surface 243c is greater than the number of layers of the coil 22 wound on the first coil winding surface 243a.

[0083] In the stator 2 configured as described above, two or more layers of the coil 22 are wound on the second coil winding surface 243c. The first coil winding surface 243a is located closer to the radial tip 242a of the tooth cover portion 242 than the second coil winding surface 243c in the axial direction A and is farther from the end surface of the tooth portion 212 in the axial direction A than the second coil winding surface 243c. That is, a step wall surface 244 forming a step is located closer to the radial tip 242a of the second coil winding surface 243c. The step wall surface 244 prevents the coil 22 from moving toward the radial tip 242a when the coil 22 is wound on the second coil winding surface 243c. Therefore, the wall can prevent the coil 22 from collapsing in multiple layers wound on the second coil winding surface 243c. This allows for a configuration that allows for an increased number of turns of the coil 22 while preventing collapse of the coil.

[0084] In this embodiment, the first coil winding surface 243a is located closest to the tip of the tooth portion 212 on the tooth cover portion 242 and is farthest from the tooth portion 212 in the axial direction A among the multiple coil winding surfaces 243.

[0085] That is, in the above-described configuration, the position in the axial direction A of the coil winding surface 243 other than the first coil winding surface 243a is closer to the tooth portion 212 than the first coil winding surface 243a. Therefore, a greater number of layers of the coil 22 can be wound on the coil winding surface 243 other than the first coil winding surface 243a than the number of layers of the coil 22 wound on the first coil winding surface 243a. A stepped wall surface 244 that restricts the movement of the coil 22 toward the tip end of the tooth portion 212 is located on the coil winding surface 243 other than the first coil winding surface 243a. This prevents the multiple layers of the coil 22 wound on the coil winding surface 243 other than the first coil winding surface 243a from becoming unwound. Therefore, a configuration can be realized that allows the number of turns of the coil 22 to be increased while preventing unwound coiling.

[0086] In this embodiment, the multiple coil winding surfaces 243 further include an intermediate coil winding surface 243b. The first coil winding surface 243a is located on the tooth cover portion 242 closest to the tip B1 of the tooth portion 212. The intermediate coil winding surface 243b is located between the first coil winding surface 243a and the second coil winding surface 243c in the radial direction B, and is located closer to the tooth portion 212 in the axial direction A than the first coil winding surface 243a and farther from the tooth portion 212 than the second coil winding surface 243c. The tooth cover portion 242 has a first stepped wall surface 244a located between the first coil winding surface 243a and the intermediate coil winding surface 243b, and a second stepped wall surface 244b located between the intermediate coil winding surface 243b and the second coil winding surface 243c. The number of layers of the coil 22 wound on the intermediate coil winding surface 243b is greater than the number of layers of the coil 22 wound on the first coil winding surface 243a and less than the number of layers of the coil 22 wound on the second coil winding surface 243c.

[0087] This makes it possible to realize a configuration in which the number of layers of the coil 22 wound around the tooth portion 212 is the smallest on the tip B1 side of the tooth portion 212 and increases toward the core back portion 211. In this configuration, the coil 22 wound around the tooth portion 212 is prevented from moving toward the tip side of the tooth portion 212. This makes it possible to provide a configuration in which the number of turns of the coil 22 can be increased while preventing the coil 22 from becoming unwound.

[0088] In this embodiment, the positions in the axial direction A of the coil winding surfaces 243 adjacent to each other in the radial direction B are different.

[0089] This makes it possible to prevent the coils 22 wound on the plurality of coil winding surfaces 243 from moving in the radial direction B. Therefore, it is possible to prevent the coils 22 wound on the plurality of coil winding surfaces 243 from becoming unwound.

[0090] In this embodiment, the radial tip of the first coil winding surface 243a extends to the radial tip 242a of the tooth cover portion 242.

[0091] That is, the radial tip 242a of the tooth cover portion 242 does not have a wall surface or the like that protrudes in, for example, the axial direction A. Therefore, the coil 22 can be wound up to the radial tip 242a around the tooth cover portion 242. This allows the number of turns of the coil 22 to be increased.

[0092] In this embodiment, the number of layers of the coil 22 wound on the first coil winding surface 243a is one.

[0093] This makes it possible to prevent the coil 22 wound around the tooth portion 212 at the radial tip 242a side of the tooth cover portion 242 from becoming unwound.

[0094] In this embodiment, the coil 22 has a plurality of wound coil portions 23 wound around each of the plurality of teeth 212. Each of the plurality of wound coil portions 23 includes a first layer coil portion 231, a second layer coil portion 232, and a third layer coil portion 233. The first layer coil portion 231 is wound on the second coil winding surface 243c from its end on the core back portion 211 side toward the second stepped wall surface 244b. The second layer coil portion 232 is wound on the first layer coil portion 231 and the middle coil winding surface 243b from its end on the core back portion 211 side toward the first stepped wall surface 244a. The third layer coil portion 233 is wound on the second layer coil portion 232 and the first coil winding surface 243a from its end on the core back portion 211 side toward the tip B1 of the tooth 212. The first layer coil portion 231 and the second layer coil portion 232 are connected, and the second layer coil portion 232 and the third layer coil portion 233 are connected.

[0095] In this configuration, the wound coil portion 23 is formed by winding the conductor wire 22a around the tooth portion 212 in the following order: First, the conductor wire 22a is wound around the tooth portion 212 from the end portion on the core back portion 211 side toward the tip end until it contacts the second stepped wall surface 244b, thereby forming the first layer coil portion 231. Next, the conductor wire 22a is wound around the tooth portion 212 on the first layer coil portion 231 from the end portion on the core back portion 211 side toward the tip end until it contacts the first stepped wall surface 244a, thereby forming the second layer coil portion 232. Finally, the conductor wire 22a is wound around the tooth portion 212 on the second layer coil portion 232 from the end portion on the core back portion 211 side toward the tip end, thereby forming the third layer coil portion 233.

[0096] This winding method allows the conductor wire 22a to be aligned and prevents the coil 22 from moving toward the tip end. This makes it possible to increase the number of turns of the coil 22 while preventing the coil 22 from becoming unwound. Therefore, it is possible to realize a stator 2 that prevents the coil 22 from becoming unwound and allows the number of turns of the coil 22 to be increased.

[0097] The exemplary motor 1 according to this embodiment also includes a stator 2 and a rotor 3 having a magnet 31 that faces the stator 2 in the radial direction B.

[0098] This makes it possible to provide a motor 1 having a stator 2 that can prevent the winding from becoming unbalanced and allows the number of turns of the coil 22 to be increased.

[0099] (Other embodiments) Although 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 it is possible to appropriately modify the above-described embodiments within the scope of the spirit of the present invention.

[0100] In the above embodiment, the configuration of the motor 1 has been described as an in-wheel motor disposed on the rear wheel of an electric motorcycle. However, the motor does not have to be a motor for an electric motorcycle. The motor may be a general motor having a stator and a rotor.

[0101] In the above embodiment, the motor 1 is a so-called outer rotor type motor in which the magnet 31 of the rotor 3 is arranged radially outward from the stator 2. However, the motor may also be a so-called inner rotor type motor in which the magnet of the rotor is arranged radially inward from the stator.

[0102] When the motor is an inner rotor motor, the base end side of the teeth cover portion of the insulator member is located radially outward, and the radial tip side is located radially inward.

[0103] In each drawing, the end surface of the core back portion 211 of the stator 2 in the radial direction B is circular when viewed in the axial direction A. However, the end surface of the core back portion of the stator in the radial direction B may be polygonal when viewed in the axial direction A.

[0104] In the above embodiment, the rotor 3 has a magnet 31, a yoke 32, and a rim 33. The magnet 31 and the yoke 32 to which the magnet 31 is fixed are separate bodies. However, the rotor does not have to have a yoke. In this case, the rotor may have a ring-shaped magnet, which may also function as a yoke. The magnet may be fixed to the rim or another member.

[0105] In the above embodiment, the tooth cover portions 242 have the same configuration. However, the configuration of some of the tooth cover portions may be different from the configuration of the other tooth cover portions.

[0106] In the embodiment, the multiple coil winding surfaces 243 include a first coil winding surface 243a, an intermediate coil winding surface 243b, and a second coil winding surface 243c. The first coil winding surface 243a, the intermediate coil winding surface 243b, and the second coil winding surface 243c are arranged in this order from the tip end side of the tooth portion 212 toward the core back portion 211.

[0107] However, the multiple coil winding surfaces may not include an intermediate coil winding surface and may include only a first coil winding surface and a second coil winding surface. Alternatively, the multiple coil winding surfaces may not include an intermediate coil winding surface and may include a first coil winding surface, a second coil winding surface, and another coil winding surface. There may be one or more other coil winding surfaces. That is, one or more other coil winding surfaces may be located radially distal from the first coil winding surface, or one or more other coil winding surfaces may be located proximal from the second coil winding surface. Alternatively, the multiple coil winding surfaces may include multiple intermediate coil winding surfaces radially between the first coil winding surface and the second coil winding surface.

[0108] In the embodiment described above, the intermediate coil winding surface 243b is located between the first coil winding surface 243a and the second coil winding surface 243c in the radial direction B. However, the first coil winding surface 243a and the second coil winding surface 243c may be adjacent to each other in the radial direction B. In other words, the second coil winding surface 243c may be adjacent to the first coil winding surface 243a on the side of the core back portion 211 when viewed in the axial direction A.

[0109] This allows a stepped wall surface that restricts the coil from moving toward the radial tip side to be positioned radially toward the tip side of the second coil winding surface, thereby preventing the multiple layers of coil wound on the second coil winding surface from moving toward the radial tip side.

[0110] In the above embodiment, the position of the intermediate coil winding surface 243b in the axial direction A is closer to the teeth 212 than the position of the first coil winding surface 243a in the axial direction A, and farther from the teeth 212 than the position of the second coil winding surface 243c in the axial direction A. However, as shown in FIG. 11 , the tooth cover portion 1242 of the insulator member 124 may have an intermediate coil winding surface 1243b whose position in the axial direction A is closer to the teeth 212 than the positions of the first coil winding surface 1243a and the second coil winding surface 1243c in the axial direction A. Even in this case, the first layer of the coil wound on the intermediate coil winding surface 1243b is prevented from moving toward the radial tip. Therefore, multiple layers of coil can be wound on the intermediate coil winding surface 1243b. This allows the number of turns of the coil 22 to be increased while preventing the coil from collapsing.

[0111] In the above embodiment, the axial position A of the first coil winding surface 243a, the axial position A of the intermediate coil winding surface 243b, and the axial position A of the second coil winding surface 243c are closer to the teeth 212 in this order from the radial tip 242a to the base end 242b. That is, in the above embodiment, the multiple coil winding surfaces are positioned in a descending staircase pattern approaching the teeth 212 from the radial tip 242a to the base end 242b. However, it is sufficient that the axial position of the coil winding surface adjacent to the base end side of the first coil winding surface located closest to the radial tip among the multiple coil winding surfaces is closer to the teeth than the axial position of the first coil winding surface. Also, it is sufficient that the axial position A of the coil winding surfaces other than the first coil winding surface is the same as the axial position A of the first coil winding surface or is closer to the teeth than the axial position A of the first coil winding surface.

[0112] (Configuration example) The present technology can also be configured as follows.

[0113] (1) The 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, an insulator member covering an axial end face of the stator core, and coils wound around the plurality of teeth via the insulator member. The insulator member has plate-shaped tooth cover portions respectively disposed on the axial end faces of the plurality of teeth. The tooth cover portions have a plurality of radially arranged coil winding surfaces on which the coils are wound. The plurality of coil winding surfaces include a first coil winding surface and a second coil winding surface located on the core back portion side of the first coil winding surface as viewed in the axial direction and closer to the teeth in the axial direction than the first coil winding surface. The number of layers of the coil wound on the second coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface.

[0114] (2) In the stator described in (1), the axial positions of the coil winding surfaces adjacent to each other in the radial direction are different.

[0115] (3) In the stator described in (1) or (2), the first coil winding surface is, among the multiple coil winding surfaces, located closest to the tip of the tooth portion in the tooth cover portion and positioned furthest axially from the tooth portion.

[0116] (4) In the stator described in (3), a radial tip of the first coil winding surface extends to a radial tip of the tooth cover portion.

[0117] (5) In the stator described in (3) or (4), the number of layers of the coil wound on the first coil winding surface is one.

[0118] (6) In the stator according to any one of (1) to (5), the second coil winding surface is adjacent to the first coil winding surface on the core back portion side when viewed in the axial direction.

[0119] (7) In the stator described in any one of (1) to (5), the multiple coil winding surfaces further include an intermediate coil winding surface. The first coil winding surface is located on the tooth cover portion closest to the tooth portion. The intermediate coil winding surface is located between the first coil winding surface and the second coil winding surface in the radial direction, and is located closer to the tooth portion than the first coil winding surface and farther from the tooth portion than the second coil winding surface in the axial direction. The tooth cover portion has a first stepped wall surface located between the first coil winding surface and the intermediate coil winding surface, and a second stepped wall surface located between the intermediate coil winding surface and the second coil winding surface. The number of layers of the coil wound on the intermediate coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface and less than the number of layers of the coil wound on the second coil winding surface.

[0120] (8) In the stator described in (7), the coil has a plurality of wound coil portions wound around each of the plurality of teeth. Each of the plurality of wound coil portions has a first layer coil portion wound on the second coil winding surface from the end portion on the core back portion side toward the second step wall surface, a second layer coil portion wound on the first layer coil portion and the intermediate coil winding surface from the end portion on the core back portion side toward the first step wall surface, and a third layer coil portion wound on the second layer coil portion and the first coil winding surface from the end portion on the core back portion side toward the tip end of the tooth. The first layer coil portion and the second layer coil portion are connected, and the second layer coil portion and the third layer coil portion are connected.

[0121] (9) A motor includes the stator according to any one of (1) to (8) and a rotor having a magnet that faces the stator in the radial direction. [Industrial Applicability]

[0122] The present invention can be used in an insulator member of a stator. [Explanation of symbols]

[0123] 1 motor 2 stator 21 Stator core 211 Core back part 212 Teeth 213 Slots 22 coils 22a conductor 23 Winding coil section 23a Beginning of winding 23b End of winding 231 First layer coil section 232 Second layer coil section 233 Third layer coil section 24, 124 Insulator member 241 Core back cover part 242, 1242 Teeth cover part 242a Radial tip 242b proximal end 243 Coil winding surface 243a, 1243a First coil winding surface 243b, 1243b Intermediate coil winding surface 243c, 1243c Second coil winding surface 244 Step Wall 244a First step wall 244b Second step wall 25 Insulation sheet 25a Sheet end 3 rotors 31 Magnet 32 York 33 rims 34 No. 1 Wheel Cover 35 Second wheel cover 35a Brake drum 4 shafts 5 Stator holder 51 Through hole 6 Bearings Aa Axial position of the first coil winding surface Ab Axial position of the intermediate coil winding surface Ac Axial position of the second coil winding surface

Claims

1. a stator core having a cylindrical core back portion extending in an axial direction and a plurality of teeth extending radially from the core back portion and arranged in a circumferential direction; an insulator member covering an axial end face of the stator core; a coil wound around the plurality of teeth via the insulator member; A stator having the insulator member has plate-shaped tooth cover portions disposed on end faces of the plurality of tooth portions in the axial direction, The tooth cover portion has a plurality of coil winding surfaces arranged in a radial direction on which the coils are wound, The plurality of coil winding surfaces include: a first coil winding surface; a second coil winding surface that is located on the core back portion side of the first coil winding surface as viewed in the axial direction and that is closer to the teeth portion in the axial direction than the first coil winding surface; Including, the number of layers of the coil wound on the second coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface; Stator.

2. 2. The stator according to claim 1, The axial positions of the coil winding surfaces adjacent in the radial direction are different. Stator.

3. 2. The stator according to claim 1, The first coil winding surface is located closest to the tip of the tooth portion in the tooth cover portion and is farthest from the tooth portion in the axial direction among the plurality of coil winding surfaces. Stator.

4. 4. The stator according to claim 3, A radial tip of the first coil winding surface extends to a radial tip of the tooth cover portion. Stator.

5. 4. The stator according to claim 3, The number of layers of the coil wound on the first coil winding surface is 1. Stator.

6. 2. The stator according to claim 1, the second coil winding surface is adjacent to the first coil winding surface on the core back portion side when viewed in the axial direction; Stator.

7. 2. The stator according to claim 1, the plurality of coil winding surfaces further include an intermediate coil winding surface; the first coil winding surface is located on the most distal end side of the tooth portion in the tooth cover portion, The intermediate coil winding surface is the coil winding surface is located between the first coil winding surface and the second coil winding surface in the radial direction, and the position in the axial direction is closer to the teeth portion than the first coil winding surface and farther from the teeth portion than the second coil winding surface, The teeth cover portion is a first stepped wall surface located between the first coil winding surface and the intermediate coil winding surface; a second stepped wall surface located between the intermediate coil winding surface and the second coil winding surface; and the number of layers of the coil wound on the intermediate coil winding surface is greater than the number of layers of the coil wound on the first coil winding surface and less than the number of layers of the coil wound on the second coil winding surface; Stator.

8. 8. The stator according to claim 7, the coil has a plurality of winding coil portions wound around the plurality of teeth portions, Each of the plurality of winding coil portions is a first layer coil portion wound on the second coil winding surface from the end portion on the core back portion side toward the second step wall surface; a second layer coil portion wound on the first layer coil portion and the intermediate coil winding surface from the end portion on the core back portion side toward the first step wall surface; a third layer coil portion wound on the second layer coil portion and the first coil winding surface from an end portion on the core back portion side toward a tip end side of the tooth portion; and The first layer coil portion and the second layer coil portion are connected to each other, the second layer coil portion and the third layer coil portion are connected to each other; Stator.

9. A stator according to any one of claims 1 to 8; a rotor having a magnet radially opposed to the stator; A motor having

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