Motor and manufacturing method of motor

Abstract

To provide a motor capable of preventing a winding collapse.SOLUTION: A stator 3 constituting a motor together with a rotor includes: an annular stator core having a plurality of teeth 42; an insulator; and a plurality of windings 6. A ratio of the number of poles of the rotor to the number of slots of the stator core is 2:3. Each winding has: a plurality of coil parts 61 wound around the tooth; two lead wire parts 63 that constitute an end part of each winding and extend from each coil part; and a crossover wire part 62 in which mutually different phases are housed in a plurality of crossover grooves 52 of the insulator and which connects the adjacent coil parts. In each coil part in which the lead wire part is drawn from one side in a circumferential direction, the crossover wire part is drawn from the other side in the circumferential direction, and the crossover wire part that is drawn from the other side in the circumferential direction of each coil part extends to the other side in the circumferential direction with respect to each coil part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a motor and a method for manufacturing a motor. [Background technology]

[0002] Patent Document 1 discloses a stator (armature) for a motor (electric motor) that includes a stator core, a winding, and an insulator. The stator core has multiple slots and multiple teeth formed between the slots. The winding is made of a single wire (solid wire) or a multi-filament wire formed by bundling multiple wires in a non-aligned manner. The winding has multiple coil portions wound around each of the multiple teeth, connection portions (crossover portions) that connect the coils, and two lead wire portions that extend from the coil portions at both ends and form the ends of the winding. The crossover portions are housed in crossover grooves that extend circumferentially on the outer periphery of the insulator. A three-phase AC motor has windings for three phases. The crossover wires of the three phases (U, V, and W) are housed in three crossover grooves aligned in the axial direction of the insulator to electrically insulate the windings of different phases from each other. To electrically insulate the windings of different phases from each other, it is necessary to ensure a sufficient creepage distance between the crossover wires housed in different crossover grooves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 133302 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the manner in which the windings are attached to the stator core and insulators, the crossover wires and lead wires constituting the same winding may cross each other. Furthermore, the crossover wires constituting the same winding may cross each other in the crossover grooves. However, if a specific crossover wire crosses a lead wire or another crossover wire in the same winding, the specific crossover wire may overflow the crossover groove or enter a crossover groove containing a crossover wire of another phase, causing the winding to collapse.

[0005] The present disclosure has been made in consideration of such problems, and aims to provide a motor and a method for manufacturing the motor that can prevent the winding from becoming unwound. [Means for solving the problem]

[0006] A motor according to one aspect of the present disclosure includes a rotor, a stator including an annular stator core having a plurality of teeth and a plurality of slots arranged in a circumferential direction, an insulator attached to the stator core, and a plurality of windings wound around the plurality of teeth via the insulator, wherein when the number of poles of the rotor is P, the number of slots of the stator core is S, and n is a natural number equal to or greater than 2, the motor has the following characteristics: P:S=2n:3n or P:S=4n:3n the insulator has a winding holding portion disposed on either one end side in the axial direction of the stator core, the winding holding portion being recessed from the outer periphery, extending in the circumferential direction, and having a plurality of jumper grooves aligned in the axial direction, the plurality of windings each having a plurality of coil portions wound around the teeth by concentrated winding, pull-out wire portions that form ends of the windings and extend from the coil portions, and jumper wire portions of different phases housed in the plurality of jumper grooves and connecting adjacent coil portions, the coil portions from which the pull-out wire portions are pulled out from one side in the circumferential direction have the jumper wire portions pulled out from the other side in the circumferential direction, and the jumper wire portions pulled out from the other side of the coil portions in the circumferential direction extend to the other side in the circumferential direction relative to the coil portions.

[0007] A method for manufacturing the motor, wherein each of the plurality of windings is formed by carrying out the following steps: a first step of forming a first coil portion by concentrating winding from one circumferential side of a first tooth around the first tooth while forming a first pull-out portion; a second step of forming a jumper portion after the first step by pulling out to the other circumferential side of the first tooth and extending to the other circumferential side of the first tooth while being accommodated in the jumper groove; a third step of forming a second coil portion after the second step by concentrating winding from one circumferential side of a second tooth located away from the first tooth on the other circumferential side; and a fourth step of forming a second pull-out portion after the third step by pulling out to the other circumferential side of the second tooth. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to prevent the windings in a motor from becoming unwound. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view schematically illustrating a motor according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view showing an example of a stator having 36 slots in the motor of FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view of an example of the motor of FIG. 1, when viewed from the axial direction, in which the rotor has four poles and the stator has six slots. [Figure 4] 1 is a circuit diagram showing an example of a three-phase AC circuit in a stator according to an embodiment of the present disclosure, in which the number of slots is six. [Figure 5] 1 is a diagram showing an example of a winding connection diagram for a stator having six slots according to an embodiment of the present disclosure, the diagram being divided into U-phase, V-phase, and W-phase. FIG. [Figure 6] FIG. 10 is a diagram showing another example of a winding connection diagram. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to FIGS. In this embodiment, the direction parallel to the axis O of the rotor 2 and stator 3 in Figures 1 to 3 is called the axial direction. The direction radial from the axis O is called the radial direction. The direction going around the axis O is called the circumferential direction. In this embodiment, one side in the axial direction is referred to as the upper side or upward direction, and the other side in the axial direction is referred to as the lower side or downward direction. In the radial direction, the direction approaching the axis O is referred to as the radially inner side, and the direction away from the axis O is referred to as the radially outer side.

[0011] <Motor> As shown in FIGS. 1 and 3, the motor 1 is a three-phase AC motor, and includes a rotor 2 and a stator 3. The rotor 2 includes a rotor shaft 21, a rotor core 22, and a plurality of magnets 23. The rotor shaft 21 is a rod-shaped member centered on an axis O. When viewed in the axial direction, the rotor shaft 21 is formed in a circular shape centered on the axis O and is provided to be rotatable about the axis O. The rotor core 22 is formed in a cylindrical shape centered on the axis O. The rotor core 22 is fixed to the outer circumferential surface of the rotor shaft 21. The rotor core 22 may be formed, for example, of a plurality of steel plates laminated in the axial direction. The magnets 23 are permanent magnets. For example, when the plurality of magnets 23 each form one magnetic pole, the plurality of magnets 23 may be arranged at equal intervals in the circumferential direction of the rotor 2 on the outer circumferential portion of the rotor 2. Alternatively, for example, one magnetic pole may be formed by the plurality of magnets 23. The plurality of magnets 23 forming one magnetic pole may be arranged at equal intervals in the circumferential direction of the rotor 2 on the outer circumferential portion of the rotor 2. The magnet 23 may be embedded inside the rotor core 22 as illustrated in FIGS. 1 and 3, or may be attached to the surface of the rotor core 22, for example.

[0012] <Stator> As shown in FIGS. 1 and 2, the stator 3 includes a stator core 4, an insulator 5, and a plurality of windings 6. <Stator core> The stator core 4 is formed in a cylindrical shape centered on the axis O. The rotor 2 described above is rotatably housed inside the stator core 4. The stator core 4 includes a cylindrical yoke 41, a plurality of teeth 42, and a plurality of slots 43.

[0013] The multiple teeth 42 protrude radially inward from the inner peripheral surface of the yoke 41 and are arranged at intervals in the circumferential direction of the stator core 4. Slots 43 are formed between the teeth 42 adjacent in the circumferential direction. As a result, the multiple teeth 42 and the multiple slots 43 are formed alternately in the circumferential direction of the stator core 4. Specifically, the teeth 42 are formed to have the same shape and size and are arranged at equal intervals in the circumferential direction. Therefore, the slots 43 are arranged at equal intervals in the circumferential direction of the stator core 4. As a result, the teeth 42 and slots 43 are alternately formed at equal intervals in the circumferential direction.

[0014] The stator core 4 is formed by, for example, laminating a plurality of electromagnetic steel sheets in the axial direction, or may be formed by, for example, powder molding.

[0015] <Insulator> The insulator 5 is attached to the stator core 4 so as to cover at least a portion of the surface of the stator core 4, with the aim of electrically insulating the winding 6 (described later) from the stator core 4. In FIGS. 1 and 2, the insulator 5 covers at least the outer peripheral surface of each tooth 42 around which a coil portion 61 of the winding 6 (described later) is wound, and the inner peripheral surface of the yoke 41 on which the teeth 42 are mounted. The insulator 5 is an insulating member. The insulating member is an electrical insulating member made of, for example, a synthetic resin. The insulator 5 may be molded by any molding method, for example, injection molding.

[0016] The insulator 5 has a main body portion that covers the outer peripheral surfaces of the multiple teeth 42 and the inner peripheral surface of the yoke 41, as well as a winding holding portion 51. The winding holding portion 51 may be disposed at either one end in the axial direction of the stator core 4. In the illustrated example, the winding holding portion 51 is disposed at the upper end side of the stator core 4, but it may also be disposed at the lower end side of the stator core 4, for example. The winding holding portion 51 is formed in an annular shape centered on the axis O.

[0017] The winding holding portion 51 has a plurality of transition grooves 52 recessed from its outer periphery and extending circumferentially. The transition grooves 52 are aligned in the axial direction. Each transition groove 52 accommodates a transition wire portion 62 of the winding 6, which will be described later. The transition grooves 52 accommodate the transition wire portions 62 of the windings 6 of different phases. In this embodiment, there are three crossover grooves 52. The three crossover portions 62 house the crossover portions 62 of the windings 6 for three phases (U-phase, V-phase, and W-phase), respectively. In the illustrated example, the crossover groove 52U for the U-phase, the crossover groove 52V for the V-phase, and the crossover groove 52W for the W-phase are aligned in this order axially upward.

[0018] 2 is divided in both the axial and circumferential directions. The insulator 5 includes an upper end insulator 55, a middle insulator 56, and a lower end insulator 57, which are arranged in this order from top to bottom in the axial direction. The upper-end insulator 55 is attached to the upper end of the stator core 4 in the axial direction. The upper-end insulator 55 includes the winding holding portion 51 described above. The middle insulator 56 is attached to the middle portion of the stator core 4 in the axial direction. The lower-end insulator 57 is attached to the lower end of the stator core 4 in the axial direction. The upper-end insulator 55 is connected to the upper end of the middle insulator 56. The lower-end insulator 57 is connected to the lower end of the middle insulator 56.

[0019] <Winding> 1 and 5, the multiple windings 6 are wound around the multiple teeth 42 via the above-mentioned insulators 5. In FIG. 5, the stator 3 is linearly developed so that the circumferential direction of the stator 3 extends in the left-right direction, and only the teeth 42 of the stator 3, the three transition grooves 52 of the insulator 5, and the three windings 6 are schematically shown, with the main body of the insulator 5 and the like being omitted. Also, an example of a wiring diagram for the windings 6 is shown divided into three phases: U phase, V phase, and W phase. As shown in Fig. 5, each of the multiple windings 6 has multiple coil portions 61, at least one crossover portion 62, and two lead-out portions 63. In the same winding 6, the multiple coil portions 61 are wound around each of the teeth 42 using concentrated winding. In Fig. 5, the coil portions 61 are depicted as surrounding the teeth 42 from below, but in reality, they are wound around the teeth 42 using concentrated winding.

[0020] The crossover portion 62 connects adjacent coil portions 61. The number of crossover portions 62 is one less than the number of coil portions 61. The two lead-out portions 63 form the ends of the same winding 6 and extend from the coil portion 61. The winding 6 in this embodiment is a multi-filament wire in which a plurality of strands are bundled together in a non-aligned manner. However, the winding 6 may also be, for example, a single strand.

[0021] In this embodiment, there are three windings 6, and each of the three windings 6 is assigned to one of three phases (U-phase, V-phase, and W-phase). That is, the three windings 6 include a U-phase winding 6U, a V-phase winding 6V, and a W-phase winding 6W. The three phase windings 6U, 6V, and 6W have the same number of coil portions 61. In this embodiment, the number of parallel connections of the windings 6U, 6V, and 6W of each phase is one. However, the number of parallel connections of the windings 6U, 6V, and 6W of each phase may be, for example, two or more.

[0022] As shown in Figure 4, three windings 6 form a three-phase AC circuit. The three-phase AC circuit employs a star connection in which the three phase windings 6 are connected at the neutral point N1. If two or more windings 6 of each phase are connected in parallel, the same number of star connections as shown in Figure 4 should be prepared, and the input points U1, V1, and W1 of the same phase in the multiple star connections should be connected to the same connection terminal. The input points U1, V1, and W1 are the first ends of the windings 6 in the longitudinal direction and are terminals for inputting drive current to the windings 6.

[0023] In the motor 1 of this embodiment, the number of poles of the rotor 2 and the number of slots 43 of the stator core 4 are set so as to satisfy either the following conditional formula (1) or conditional formula (2). (Conditional expression (1)) P:S=2n:3n (Conditional expression (2)) P:S=4n:3n In conditional expressions (1) and (2), P is the number of poles of the rotor 2 (the number of magnetic poles formed by the magnets 23), S is the number of slots 43 of the stator core 4, and n is a natural number equal to or greater than 2. The number of slots S corresponds to the total number of coil portions 61. That is, the total number of coil portions 61 is set to 3n. In a motor 1 that satisfies conditional expressions (1) and (2), the coil portions 61 are all wound around the teeth 42 in the same direction. In FIG. 5, all of the coil portions 61 are wound counterclockwise around the teeth 42. In the motor 1 illustrated in FIG. 3, one magnet 23 forms one magnetic pole, so the number of magnets 23 (number of poles P) is four and the number of slots 43 (number of slots S) is six, satisfying conditional formula (1).

[0024] For example, when the natural number n is 12, the number of slots 43 (number of slots S) is 36. In the stator 3 illustrated in FIG. 2, the number of slots 43 is 36. In the stator 3 illustrated in FIG. 2, the total number of coil portions 61 is 36. Furthermore, for example, when the natural number n is 2, the number of slots 43 (number of slots S) is 6. In the stator 3 illustrated in Fig. 3, the number of slots 43 is 6. In the stator 3 illustrated in Fig. 3 and Fig. 5, the total number of coil portions 61 is 6.

[0025] As shown in FIG. 5, in the stator 3, the coil portions 61 of the U-phase winding 6U (U-phase coil portion 61U), the coil portions 61 of the V-phase winding 6V (V-phase coil portion 61V), and the coil portions 61 of the W-phase winding 6W (W-phase coil portion 61W) are arranged in a circumferentially repeated sequence. Therefore, the coil portions 61 of the winding 6 of the same phase are wound around every third tooth 42. For example, if the number of slots S is six, the two coil portions 61 of the U-phase winding 6U are wound around the first and fourth teeth 42 (42-1, 42-4). The two coil portions 61 of the V-phase winding 6V are wound around the second and fifth teeth 42 (42-2, 42-5). The two coil portions 61 of the W-phase winding 6W are wound around the third and sixth teeth 42 (42-3, 42-6). 5 shows a stator 3 that satisfies conditional formula (1), in which the U-phase coil portion 61U, the V-phase coil portion 61V, and the W-phase coil portion 61W are arranged in sequence in the rightward direction, and therefore the numbers of the teeth 42 are arranged in sequence from the left end to the right. In the stator 3 that satisfies the conditional expression (2), the U-phase coil portion 61U, the W-phase coil portion 61W, and the V-phase coil portion 61V are repeatedly arranged in order in the right direction in FIG.

[0026] In the stator 3 illustrated in Fig. 5, the second ends of the windings 6, which are located opposite to the first ends that form the input points U1, V1, and W1, are output points Un1, Vn1, and Wn1. The three-phase output points Un1, Vn1, and Wn1 form the neutral point N1 of the star connection shown in Fig. 4. Specifically, the three-phase output points Un1, Vn1, and Wn1 are connected to each other by a neutral wire NL1 to form the neutral point N1. The three-phase output points Un1, Vn1, and Wn1 are located at positions drawn from three circumferentially adjacent coil portions 61 (61U-2, 61V-2, and 61W-2). As a result, the three-phase output points Un1, Vn1, and Wn1 are located close to each other, allowing the neutral wire NL1 connecting the three-phase output points Un1, Vn1, and Wn1 to be shortened.

[0027] In the stator 3 illustrated in Fig. 5, each winding 6 has two coil portions 61. Therefore, each winding 6 has only one crossover portion 62. As a result, in a coil portion 61 from which a lead portion 63 is drawn out from one circumferential side, a crossover portion 62 is drawn out from the other circumferential side. The crossover portion 62 drawn out from the other circumferential side of a given coil portion 61 extends from the given coil portion 61 to the other circumferential side in the crossover groove 52.

[0028] For example, in FIG. 5 , a lead wire portion 63 is drawn out from the left side of a first coil portion 61-1 (61U-1, 61V-1, 61W-1) located on the left side of the same winding 6. A crossover portion 62 is drawn out from the right side of the first coil portion 61-1, and extends to the right. Meanwhile, a lead wire portion 63 is drawn out from the right side of a second coil portion 61-2 (61U-2, 61V-2, 61W-2) located on the right side. A crossover portion 62 is drawn out from the left side of the second coil portion 61-2, and extends to the left.

[0029] <Motor manufacturing method> When manufacturing the motor of this embodiment, for example, each of the plurality of windings 6 can be formed by the following procedure. For example, when forming the U-phase winding 6U, a first step is performed in which the first coil portion 61U-1 is formed by concentrated winding from one circumferential side of the first tooth 42-1 around the first tooth 42-1 while forming the first lead-out portion 63. Next, a second step is performed in which the wire is pulled out to the other circumferential side of the first tooth 42-1 and extended to the other circumferential side of the first tooth 42-1 while being accommodated in the jumper groove 52U, forming the jumper portion 62. After that, a third step is performed in which the second coil portion 61U-2 is formed by concentrated winding from one circumferential side of the second tooth 42-4, which is located away from the first tooth 42-1 on the other circumferential side. Finally, a fourth step is performed in which the second lead-out portion 63 is formed by pulling out to the other circumferential side of the second tooth 42-4, forming the U-phase winding 6U. The V-phase winding 6V and the W-phase winding 6W can be formed in the same manner as the method for forming the U-phase winding 6U described above.

[0030] <Effects> As described above, in the stator 3 of this embodiment, the lead wire portions 63 are drawn out from one circumferential side of a given coil portion 61. Furthermore, in a given coil portion 61, the crossover wire portions 62 are drawn out from the other circumferential side and extend to the other circumferential side relative to the coil portion 61. Therefore, the crossover wire portions 62 extending from the coil portion 61 do not extend across the coil portion 61 from one side to the other in the circumferential direction in the crossover groove 52. Furthermore, the draw-out wire portions 63 extending from the coil portion 61 do not extend across the coil portion 61 from one side to the other in the circumferential direction. This prevents the crossover wire portions 62 and the draw-out wire portions 63 that constitute the same winding 6 from crossing each other. In other words, it is possible to prevent the same winding 6 from crossing each other in the crossover groove 52 and in the vicinity of the crossover groove 52.

[0031] The same winding 6 does not cross over in the jumper grooves 52 and in the vicinity of the jumper grooves 52, thereby preventing the winding 6 from collapsing. Even if a multi-strand wire, which is prone to collapsing, is used as the winding 6, the winding 6 can be prevented from collapsing. This ensures a sufficient creepage distance between the jumper wire portions 62 housed in different jumper grooves 52. Furthermore, since the occurrence of defective products in which the creepage distance cannot be ensured can be prevented, a decrease in yield can also be prevented.

[0032] Furthermore, in the stator 3 of this embodiment, the same windings 6 do not cross over each other in the crossing grooves 52 or in the vicinity of the crossing grooves 52, so the overall length of the windings 6 can be kept shorter than in the case where there is such crossing. Furthermore, by shortening the overall length of the winding 6, it is possible to reduce the resistance value of the winding 6. This makes it possible to improve the efficiency of the motor including the stator 3. Furthermore, because the same windings 6 do not cross over each other at or near the transition grooves 52, it is possible to prevent pinholes from being formed in the insulating coating of the windings 6 due to friction between the windings 6 at these crossings, thereby ensuring insulation of the windings 6.

[0033] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to these and can be modified as appropriate within the scope of the technical idea of ​​the invention.

[0034] In the present disclosure, as illustrated in Fig. 6, the same winding 6 may have three or more coil portions 61. In Fig. 6, the coil portions 61 are also depicted as surrounding the teeth 42 from below, but in reality, they are wound around the teeth 42 using concentrated winding. When the same winding 6 has three or more coil portions 61, the multiple coil portions 61 include two end coil portions 61-4 located at both ends of the arrangement direction of the multiple coil portions 61 (the left-right direction in Fig. 6), and a middle coil portion 61-5 located between the two end coil portions 61-4.

[0035] The end coil portion 61-4 has a lead wire portion 63 drawn from one circumferential side thereof and a crossover wire portion 62 drawn from the other circumferential side thereof. The crossover wire portion 62 drawn from the other circumferential side of the end coil portion 61-4 extends toward the other circumferential side of the end coil portion 61-4. For example, in FIG. 6 , the lead wire portion 63 is drawn from the left side of the end coil portion 61-4 located at the left end. The crossover wire portion 62 is drawn from the right side of the end coil portion 61-4 located at the left end, and extends to the right. Meanwhile, the lead wire portion 63 is drawn from the right side of the end coil portion 61-4 located at the right end. The crossover wire portion 62 is drawn from the left side of the end coil portion 61-4 located at the right end, and extends to the left. This makes it possible to prevent the crossover wire portion 62 and the lead wire portion 63 that constitute the same winding 6 from crossing each other in the crossover groove 52 and in the vicinity of the crossover groove 52 .

[0036] The crossover wire portion 62 drawn out from the intermediate coil portion 61-5 to one circumferential side extends to one circumferential side of the intermediate coil portion 61-5. Similarly, the crossover wire portion 62 drawn out from the intermediate coil portion 61-5 to the other circumferential side extends to the other circumferential side of the intermediate coil portion 61-5. For example, the crossover wire portion 62 drawn out to the right side from the intermediate coil portion 61-5 shown in FIG. 6 extends rightward from the intermediate coil portion 61-5. Similarly, the crossover wire portion 62 drawn out to the left side from the intermediate coil portion 61-5 extends leftward from the intermediate coil. This prevents the crossover wire portions 62 constituting the same winding 6 from crossing each other at the crossover groove 52.

[0037] The above-described arrangement of the crossover wire portions 62 and the lead-out wire portions 63 drawn from the end coil portion 61-4 and the intermediate coil portion 61-5 provides the same effect as in the above-described embodiment, i.e., it is possible to prevent the same winding 6 from crossing over in the crossover groove 52 and in the vicinity of the crossover groove 52.

[0038] 6, only the U-phase winding 6U is shown, but the V-phase and W-phase windings 6 are configured in the same manner. The stator illustrated in FIG. 6 has three coil portions 61 in each phase winding 6, for a total of nine windings 6 for the three phases. In other words, the stator illustrated in FIG. 6 is applicable to a motor that satisfies conditional expressions (1) and (2).

[0039] As shown in FIG. 6, when the same winding 6 has three or more coil portions 61, in the method of manufacturing the motor, for example, each of the windings 6 can be formed by the following procedure. 6, for example, a first step is performed in which the first end coil portion 61-4 is formed by concentrating winding from one circumferential side of the first tooth 42 around the first tooth 42 while forming the first lead-out portion 63. Next, a second step is performed in which the first end coil portion 61-4 is formed by drawing it out to the other circumferential side of the first tooth 42 and extending it to the other circumferential side of the first tooth 42 while being accommodated in the jumper groove 52U. Thereafter, a fifth step is performed in which an intermediate coil portion 61-5 is formed by concentrating winding from one circumferential side of a third tooth 42 that is located away from the first tooth 42 on the other circumferential side thereof around the third tooth 42. Furthermore, after the fifth step, a sixth step is performed in which another crossover wire portion 62 is formed by pulling out the wire to the other circumferential side of the third tooth 42 and extending it to the other circumferential side of the third tooth 42 while being accommodated in the crossover groove 52U.

[0040] Then, after the sixth step, a third step is carried out in which second end coil portions 61-4 are formed by concentrated winding from one circumferential side of second teeth 42 that are spaced apart from third teeth 42 on the other circumferential side thereof. Finally, a fourth step is carried out in which second drawn-out wire portions 63 are formed by drawing out the second teeth 42 to the other circumferential side thereof, thereby forming the winding 6U illustrated in FIG. If the same winding 6 has a plurality of intermediate coil portions 61-5, the fifth and sixth steps may be repeated a plurality of times. The V-phase winding 6V and the W-phase winding 6W, each having the intermediate coil portion 61-5, can be formed in the same manner as the method for forming the U-phase winding 6U described above. [Explanation of symbols]

[0041] 1...motor, 2...rotor, 3...stator, 4...stator core, 5...insulator, 6...winding, 42...teeth, 43...slot, 51...winding holding portion, 52...crossover groove, 61...coil portion, 61-4...end coil portion, 61-5...intermediate coil portion, 62...crossover portion, 63...lead-out portion, P...number of poles, S...number of slots

Claims

1. A rotor, a stator including an annular stator core having a plurality of teeth and a plurality of slots arranged in a circumferential direction, an insulator attached to the stator core, and a plurality of windings wound around the plurality of teeth via the insulator, When the number of poles of the rotor is P, the number of slots of the stator core is S, and n is a natural number equal to or greater than 2, P:S=2n:3n or P:S=4n:3n Meet the conditions of The insulator is a winding holding portion disposed on either one end side of the stator core in the axial direction, the winding holding portion has a plurality of connecting grooves recessed from an outer circumferential side, extending in the circumferential direction, and aligned in the axial direction; Each of the plurality of windings comprises: a plurality of coil portions wound around the teeth by concentrated winding; a lead portion that forms an end of the winding and extends from the coil portion; different phases are accommodated in the plurality of crossover grooves, and crossover wire portions connect adjacent coil portions, The coil portion from which the lead wire portion is drawn out from one side in the circumferential direction has the crossover wire portion drawn out from the other side in the circumferential direction, The motor, wherein the crossover wire portion drawn out from the other circumferential side of the coil portion extends to the other circumferential side relative to the coil portion.

2. The same winding has three or more of the coil portions, The plurality of coil sections constituting the same winding include two end coil sections located at both ends in the arrangement direction of the plurality of coil sections, and an intermediate coil section located between the two end coil sections, The end coil portion from which the lead wire portion is drawn out from one side in the circumferential direction has the crossover wire portion drawn out from the other side in the circumferential direction, the crossover wire portion drawn out from the other circumferential side of the end coil portion extends toward the other circumferential side with respect to the end coil portion, the crossover wire portion drawn out from one side of the intermediate coil portion in the circumferential direction extends toward one side of the intermediate coil portion in the circumferential direction, The motor according to claim 1 , wherein the crossover wire portion drawn out from the other circumferential side of the intermediate coil portion extends to the other circumferential side relative to the intermediate coil portion.

3. 3. The motor according to claim 1, wherein the winding is a multi-filament winding in which a plurality of strands are bundled together in a non-aligned manner.

4. A method for manufacturing the motor according to claim 1 or 2, comprising the steps of: Each of the plurality of windings comprises: a first step of forming a first coil portion by concentrating winding the first coil portion around the first tooth from one side in the circumferential direction of the first tooth while forming a first lead wire portion; a second step of forming a crossover wire portion by drawing out the wire to the other side of the first tooth in the circumferential direction and extending the wire to the other side of the first tooth while being accommodated in the crossover groove, after the first step; a third step of forming a second coil portion by concentrating winding a coil from one side of a second tooth in the circumferential direction to the second tooth, the second tooth being spaced apart from the first tooth on the other side in the circumferential direction; A method for manufacturing a motor by carrying out a fourth step after the third step, in which a second lead wire portion is formed by drawing the second tooth to the other side in the circumferential direction.

5. Each of the plurality of windings comprises: a fifth step of forming an intermediate coil portion by concentrating winding around a third tooth, the third tooth being spaced apart from the first tooth on the other side in the circumferential direction, after the second step; a sixth step of drawing out the third tooth to the other side in the circumferential direction and extending the third tooth to the other side in the circumferential direction while being housed in the connecting groove to form a connecting wire portion, after the fifth step; 5. A method for manufacturing a motor as described in claim 4, wherein in the third step, after the sixth step, the second coil portion is formed by concentrating winding from one side of the circumferential direction of the second tooth, which is located away from the third tooth on the other side of the circumferential direction, around the second tooth.

Images