Stator manufacturing method and stator manufacturing device

Abstract

To suppress an increase in an iron loss of a stator core.SOLUTION: A stator manufacturing method includes: an insertion step of inserting a coil having a rectangular cross-sectional shape into a slot of a stator core in a twisted state where the coil is previously twisted around an axis of the coil; and a rotation step of rotating the inserted coil around the axis so as to cancel the twisted state inside of the slot.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Regarding a stator manufacturing method, Patent Document 1 discloses a technique for inserting a coil conductor wire into a slot of a stator core, the diameter of which, when the cross section is circular, is larger than the slot opening width. The technique of Patent Document 1 involves inserting the coil conductor wire into the slot with its wire width equal to or smaller than the slot opening width, and then pressing the inserted coil conductor wire in the depth direction of the slot to deform the cross section of the coil conductor wire. This results in an increased coil space factor within the slot. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-158212 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technology of Patent Document 1, when compressing the coil conductor wire, a load must be applied to the coil conductor wire in the depth direction to a degree that causes deformation of the cross-sectional shape. When this load is transmitted to the stator core, compressive stress is generated in the stator core, which may increase iron loss in the stator core. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first aspect of the present disclosure, there is provided a method for manufacturing a stator, the method comprising: an insertion step of inserting a coil having a rectangular cross section into a slot of a stator core in a twisted state in advance around an axis of the coil; and a rotation step of rotating the inserted coil within the slot around the axis to untwist the coil. According to this embodiment, it is not necessary to press the coil against the stator core, so that an increase in iron loss of the stator core can be suppressed. (2) In the above embodiment, the slot may have an inlet portion for receiving the coil in the insertion process, and the opening diameter of the inlet portion in the circumferential direction of the stator core may be larger than the outer diameter of the coil in the twisted state in the circumferential direction and smaller than the outer diameter of the coil when the twisted state is released. This embodiment allows the opening diameter of the slot inlet portion to be made smaller. Therefore, it is possible to effectively manufacture a stator that can further increase the output of a motor incorporating the stator. (3) In the above embodiment, the slot may include a placement portion in which the coil is placed when the twisted state is released, the coil including a first coil and a second coil, the first coil being placed within the opening of the placement portion so as to contact the second coil and an inner wall of the placement portion in the circumferential direction of the stator core, and the second coil being placed within the opening of the placement portion so as to contact the first coil and the inner wall in the circumferential direction. According to this embodiment, two coils can be placed within the opening of the placement portion so as to contact each other in the circumferential direction and so as to contact the inner wall of the placement portion in the circumferential direction. Therefore, a stator that can further increase the output of a motor incorporating the stator can be effectively manufactured. (4) In the above embodiment, the inserting step of inserting the second coil into the slot and the rotating step of rotating the second coil may be performed before the twisted state of the first coil is released. This embodiment allows for more efficient manufacturing of the stator. (5) According to a second aspect of the present disclosure, there is provided a stator manufacturing apparatus. The stator manufacturing apparatus includes: a coil having a rectangular cross-section, the coil having a first portion having a portion to be disposed in a slot of a stator core and a second portion connected to the first portion; a first holding unit configured to be able to hold and rotate the first portion of the coil; a second holding unit configured to be able to hold the second portion; a moving mechanism configured to be able to move the first holding unit and the second holding unit; and a controller that controls the first holding unit, the second holding unit, and the moving mechanism. The controller executes the following processes: using the first holding unit and the second holding unit to twist the coil around its axis; using the moving mechanism to insert the coil in the twisted state into the slot; and using the first holding unit and the second holding unit to rotate the inserted coil around the axis to eliminate the twisted state. In addition to the above-described stator manufacturing method and stator manufacturing apparatus, the present disclosure can also be realized in the form of, for example, a stator, a motor, a motor manufacturing method, a control method for a stator manufacturing apparatus, a program, or a non-temporary recording medium on which a program is recorded. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a perspective view showing a schematic configuration of a stator in the first embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing a schematic configuration of a stator manufacturing apparatus. [Figure 3] FIG. 2 is a cross-sectional view showing a schematic configuration of a stator core. [Figure 4] 1 is a flowchart of a manufacturing process. [Figure 5] 10A to 10C are diagrams illustrating a method for manufacturing a stator according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] A. First embodiment: FIG. 1 is a perspective view showing a schematic configuration of a stator 100 according to the first embodiment. FIG. 2 is an explanatory diagram showing a schematic configuration of a stator manufacturing apparatus 200 for manufacturing the stator 100. FIG. 3 is a cross-sectional view showing a schematic configuration of a stator core 110. Note that FIGS. 2 and 3 show the stator 100 being manufactured. An arrow representing the Z-axis is shown in FIGS. 1 to 3. The Z-axis is a coordinate axis parallel to the vertical direction. The arrow representing the Z-axis in FIGS. 1 to 3 and the arrow representing the Z-axis in other figures point in the same direction. To specify a direction, positive and negative signs are used together to indicate the direction, with "+" indicating the positive direction indicated by the arrow and "-" indicating the negative direction opposite to the direction indicated by the arrow. Hereinafter, the +Z direction will also be referred to as "up" and the -Z direction as "down."

[0009] 1, the stator 100 includes a stator core 110 and a stator coil 130. The stator 100 is incorporated into an inner rotor type motor (not shown) for use.

[0010] As shown in FIG. 1 , the stator core 110 has a substantially cylindrical shape. The stator core 110 is formed, for example, by laminating multiple non-oriented electromagnetic steel sheets formed into an annular shape by press working. The stator core 110 has multiple teeth 111 and multiple slots 112. Each tooth 111 is formed on the inner circumferential surface of the stator core 110. Each tooth 111 protrudes radially inward of the stator core 110. The slot 112 is a groove portion formed between two teeth 111 adjacent to each other in the circumferential direction dc of the stator core 110. In this embodiment, the stator core 110 is disposed such that the up-down direction of the stator core 110 is aligned with the Z direction. The up-down direction of the stator core 110 is aligned with the direction in which the bottom surfaces of the stator cores 110 face each other.

[0011] The stator coil 130 is wound in a distributed manner around the stator core 110. The stator coil 130 is made up of a plurality of coils 120 connected to each other. Each coil 120 is configured as a segment coil. As shown in FIGS. 2 and 3, the coil 120 has an overall U-shape and a rectangular cross-sectional shape.

[0012] The coil 120 is formed by bending a rectangular wire into a U-shape. As shown in FIG. 3, the rectangular wire has a conductor 128 having a rectangular cross section and an insulating coating 129 covering the surface of the conductor 128. The conductor 128 is made of various conductors such as copper, aluminum, iron, various copper alloys, and various aluminum alloys. The insulating coating 129 is made of a resin material such as polyimide (PI), fluororesin such as polytetrafluoroethylene enamel (PTFE), or polyphenylene sulfide (PPS). The thickness of the insulating coating 129 is preferably 50 μm or more and 100 μm or less.

[0013] 2, the coil 120 has two first portions 121 and a second portion 122. Specifically, the first portions 121 correspond to the portion of the U-shaped coil 120 that constitutes the open end side. The second portion 122 corresponds to the base end portion of the U-shaped coil 120 that connects the two first portions 121 on the side opposite the open end side. The coils 120 are connected to each other by electrically and physically connecting the first portions 121 to each other by welding or the like, thereby forming the stator coil 130.

[0014] The first portion 121 has a portion p1 that is disposed within the slot 112. The portion p1 is disposed within the slot 112 such that the axis AX of the portion p1 is aligned with the up-down direction of the stator core 110. The axis AX of the portion p1 is also referred to as the "axis AX of the coil 120." A tip end of the first portion 121 is disposed to protrude from the slot 112 on one side in the up-down direction. The second portion 122 is disposed to protrude from the slot 112 on the other side in the up-down direction.

[0015] 3 shows an enlarged view of a portion of the stator core 110, specifically, the vicinity of the slots 112. As shown in FIG. 3, each slot 112 has an inlet portion 113 and a placement portion 116.

[0016] The inlet portion 113 is a portion for receiving the coil 120 into the slot 112 in the insertion process described below. Note that "receiving the coil 120" specifically means receiving the portion p1. The inlet portion 113 constitutes the radially inner end of the slot 112. An opening 114 of the inlet portion 113 opens toward the radially inner side of the stator core 110.

[0017] The placement portion 116 is a portion where the released coil 120r is placed after a rotation process described below. The direction of the placement portion 116 toward the outside in the radial direction, which constitutes a portion of the slot 112 radially outward from the inlet portion 113, is also referred to as the "depth direction." The placement portion 116 has an opening 117 and an inner wall 118 that defines the opening 117.

[0018] In this embodiment, the inlet portion 113 constitutes a portion of the slot 112 that is closer to the arrangement portion 116 in the depth direction and that is narrower in the circumferential direction dc than the arrangement portion 116. Specifically, the opening diameter d3 of the inlet portion 113 is smaller than the opening diameter d4 of the arrangement portion 116. The opening diameter d3 refers to the diameter of the opening 114 in the circumferential direction dc. Specifically, the opening diameter d3 is the diameter of the opening 114 at a portion where the diameter in the circumferential direction dc is smallest. The opening diameter d4 refers to the diameter of the opening 117 in the circumferential direction dc. Specifically, the opening diameter d4 is the diameter of the opening 117 at a portion where the diameter in the circumferential direction dc is smallest. In this embodiment, the opening 117 has a substantially uniform opening diameter d4 in the radial direction.

[0019] The opening diameter d3 is larger than the outer diameter d2 and is equal to or smaller than the outer diameter d1. The outer diameter d2 refers to the maximum diameter in the circumferential direction dc of the coil 120t in the twisted state. The twisted state is a state in which the coil 120, specifically the first portion 121, is twisted around the axis AX. The outer diameter d1 refers to the maximum diameter in the circumferential direction dc of the coil 120r in the released state. The released state is a state in which the twisted state is released. The released state can also be said to be a normal state in which the coil 120 is not twisted. Specifically, the outer diameter d1 corresponds to the longitudinal diameter of the coil 120. The opening diameter d4 of the placement portion 116 is larger than the outer diameter d1. Specifically, as described below, the opening diameter d4 is slightly larger than the outer diameter d1. The "diameter in the circumferential direction dc" of the coil 120 and the slot 112, such as the outer diameters d1 and d2 and the opening diameters d3 and d4, can be approximated to the "diameter in the width direction." The width direction refers to the width direction of the slot 112, which is the direction perpendicular to the radial direction and the up-down direction.

[0020] The outer diameter d2 is determined by the diameter of the coil 120 in the longitudinal direction, the diameter of the coil 120 in the lateral direction, and the angle θ at which the coil 120 is twisted. That is, the angle θ is determined so that the coil 120t can be inserted into the slot 112 from the inlet 113. Furthermore, the angle θ is preferably as small as possible in order to reduce the difference in the degree of twist of the coil 120 between the twisted state and the normal state. For example, the angle θ is preferably less than 90 degrees, more preferably 75 degrees or less, and even more preferably 45 degrees or less.

[0021] The opening diameter d3 is preferably smaller from the viewpoint of increasing the magnetic flux density in the air gap between the stator 100 and the inner rotor. On the other hand, the outer diameter d1 is preferably larger from the viewpoint of increasing the space factor of the stator coil 130 in the slot 112. Furthermore, the opening diameter d4 is preferably larger corresponding to the outer diameter d1.

[0022] 2, the stator manufacturing apparatus 200 includes a first holding mechanism 205, a second holding mechanism 210, and a control unit 250. In this embodiment, the stator manufacturing apparatus 200 includes two first holding mechanisms 205 for the two first portions 121 of the coil 120.

[0023] Each first holding mechanism 205 includes a first holding unit 206, a rotation mechanism 207, and a first moving mechanism 208. The first holding unit 206 is configured to hold the first portion 121 of the coil 120 under the control of the control unit 250. The rotation mechanism 207 is configured to rotate the first holding unit 206 under the control of the control unit 250. The first moving mechanism 208 is configured to move the first holding unit 206 under the control of the control unit 250. That is, the first holding unit 206 is configured to rotate the first portion 121 around the axis AX while holding the first portion 121 under the control of the control unit 250. The first holding unit 206 is configured, for example, as a chuck mechanism or a robot hand for holding the first portion 121. The rotation mechanism 207 is configured, for example, by a motor, and rotates the first holding unit 206 by transmitting a rotational driving force to the first holding unit 206. The first moving mechanism 208 is configured as a moving mechanism that uses, for example, a ball screw mechanism or a link mechanism. A motor, for example, is used as a driving source for the movement by the first moving mechanism 208.

[0024] Second holding mechanism 210 includes second holding unit 211 and second moving mechanism 213. Second holding unit 211 is configured to be able to hold second portion 122 of coil 120 under the control of control unit 250. Second holding unit 211 is configured, for example, as a chuck mechanism or a robot hand for holding second portion 122, similar to first holding unit 206. Second moving mechanism 213 is configured, for example, as a moving mechanism similar to first moving mechanism 208.

[0025] First moving mechanism 208 and second moving mechanism 213 are collectively referred to as moving mechanism 220. That is, moving mechanism 220 is configured to be able to move first holding unit 206 and second holding unit 211 under the control of control unit 250.

[0026] The control unit 250 is configured by a computer including one or more processors 251, a storage unit 252 including ROM and RAM, an input / output interface 253, and an internal bus 254. The processor 251, the storage unit 252, and the input / output interface 253 are connected via the internal bus 254 to enable bidirectional communication. The input / output interface 253 is connected to the first holding mechanism 205 and the second holding mechanism 210. The processor 251 executes a program 255 stored in the storage unit 252 to realize various functions including a function to control the first holding mechanism 205, a function to control the second holding mechanism 210, and a function to execute the manufacturing process described below.

[0027] 4 is a flowchart of a manufacturing process for realizing the manufacturing method of the stator 100 in this embodiment. The manufacturing process is started by the control unit 250, for example, when a predetermined start operation is performed by the user on the stator manufacturing apparatus 200.

[0028] In S105, control unit 250 controls moving mechanism 220 and second holding unit 211 to cause second holding unit 211 to hold second portion 122 of coil 120.

[0029] In S110, the control unit 250 controls the moving mechanism 220 and the first holding unit 206 to hold the first portion 121 of the coil 120 using the first holding unit 206. Next, in S115, the control unit 250 controls the rotation mechanism 207 to twist the coil 120 around the axis AX using the first holding unit 206 and the second holding unit 211. Specifically, the control unit 250 rotates the first holding unit 206 while fixing the second holding unit 211, which holds the second portion 122, to twist the first portion 121 around the axis AX. As a result, the coil 120 is in a twisted state. Note that in S115, it is sufficient that at least the portion p1 is twisted by the angle θ. Note that in FIG. 4, the coil 120n in its normal state before being twisted is shown by a dashed line.

[0030] In S120, the control unit 250 controls the moving mechanism 220 to insert the coil 120t in a twisted state from the entrance portion 113 into the slot 112 in the depth direction dd. Specifically, while the coil 120t in a twisted state is held by the first holding unit 206 and the second holding unit 211, a portion p1 of the coil 120t is inserted into the slot 112 and moved to the placement unit 116. In this way, the coil 120t is inserted into the slot 112 in a pre-twisted state. The step of inserting the coil 120t in a twisted state into the slot 112 as in S120 is also referred to as an insertion step.

[0031] In S120, because the outer diameter d2 is smaller than the opening diameter d3, for example, the coil 120t can be inserted more smoothly into the slot 112 without contacting the inner wall of the inlet portion 113. Furthermore, if the opening diameter d4 of the arrangement portion 116 is slightly larger than the outer diameter d1, as in this embodiment, it is difficult to move the coil 120 in the normal state in the depth direction dd within the arrangement portion 116. On the other hand, in this embodiment, by inserting the coil 120t in a twisted state into the slot 112, the coil 120t can be moved smoothly in the depth direction dd within the arrangement portion 116. As a result, the compressive stress generated in the stator core 110 can be reduced compared to when the coil 120 in the normal state is moved in the depth direction dd within the arrangement portion 116.

[0032] In S125, the control unit 250 controls the first holding mechanism 205 to rotate the coil 120t inserted into the slot 112 around the axis AX so as to eliminate the twisted state. As a result, the coil 120 is released from the twisted state and enters a released state. The process of rotating the coil 120t around the axis AX so as to eliminate the twisted state, as in S125, is also referred to as a rotation process.

[0033] In S125, the coil 120 may come into contact with, for example, the inner wall 118 as it rotates. The coil 120 may also be elastically deformed by contact with the inner wall 118. Specifically, in S125, the cross-sectional shape of the coil 120 may be temporarily deformed to the extent that it can return to its original shape. Even when the coil 120 comes into contact with the inner wall 118 as it rotates, the compressive stress generated in the stator core 110 during the manufacturing process of the stator 100 can be reduced compared to, for example, other forms of plastically deforming the coil. "Other forms of plastically deforming the coil" refers to, for example, a form in which the coil is pressed against the stator core in the depth direction, thereby deforming the coil so that the dimensions of the coil increase in the width direction within the slot.

[0034] In S130, the control unit 250 controls the second holding mechanism 210 to place the released coil 120r in the placement unit 116. As described above, in this embodiment, the opening diameter d4 of the placement unit 116 is slightly larger than the outer diameter d1. Specifically, the opening diameter d4 is a diameter such that the coil 120r placed in the placement unit 116 comes into contact with the inner wall 118 in the circumferential direction dc. That is, in S130 in this embodiment, the coil 120r is placed in the placement unit 116 so that both sides of the coil 120r in the circumferential direction dc come into contact with the inner wall 118. Note that S125 and S130 may be executed simultaneously or as a series of steps, for example.

[0035] In S135, the control unit 250 determines whether processing of all coils 120 is complete. If unprocessed coils 120 remain, the control unit 250 returns to S105 and executes S105 to S130 for the next coil 120x. In this embodiment, the coils 120 are arranged in a row in the circumferential direction dc within the slot 112. If the arrangement of the coils 120 in the depth direction dd is referred to as a "row," then in this embodiment, one coil 120 is arranged per row. Specifically, as shown in FIG. 4, in S130 in this embodiment, the next coil 120x is arranged so as to contact the coil 120 immediately preceding it in the depth direction dd. The coil 120 immediately following the next coil 120x is arranged so as to contact the coil 120x in the depth direction dd in a similar manner. In this manner, multiple coils 120 are filled into the slot 112.

[0036] According to the manufacturing method of the stator 100 in the first embodiment described above, the coil 120 is inserted into the slot 112 in a twisted state, and the inserted coil 120t is rotated in the slot 112 to release the twisted state. This eliminates the need to press the coil 120 against the stator core 110 in the depth direction dd of the slot 112 during the manufacturing process of the stator 100. This makes it possible to suppress the occurrence of compressive stress in the stator core 110 due to the pressing of the coil 120, and to suppress an increase in iron loss in the stator core 110.

[0037] Furthermore, in this embodiment, the coil 120r is arranged in the arrangement portion 116 so that both sides of the coil 120r in the circumferential direction dc are in contact with the inner wall 118. This can further increase the space factor of the stator coil 130 in the slot 112, thereby further improving the output of a motor incorporating the stator 100. Furthermore, when a motor incorporating the stator 100 is in use, vibration of the stator coil 130 caused by a gap between the stator coil 130 and the inner wall 118 can be suppressed. As a result, it is possible to suppress the generation of abnormal noise caused by vibration and the deterioration of the insulating coating 129 caused by contact between the stator coil 130 and the inner wall 118 caused by vibration.

[0038] Conventionally, insulating paper may be disposed between the stator coil 130 and the inner wall 118. The insulating paper is used, for example, to fill the gap between the stator coil 130 and the inner wall 118 while ensuring insulation between the stator core 110 and the stator coil 130. In this embodiment, such insulating paper can be eliminated. Note that in other embodiments, insulating paper may be disposed inside the slots 112.

[0039] In addition, in this embodiment, the opening diameter d3 of the inlet portion 113 of the slot 112 is larger than the outer diameter d2 of the coil 120 in the twisted state and smaller than the outer diameter d1 of the coil 120 in the released state. This allows the opening diameter d3 to be made smaller. As a result, in a motor incorporating the manufactured stator 100, the magnetic flux density in the air gap can be made larger, thereby increasing the motor output. In this way, this embodiment can effectively manufacture a stator 100 that can further improve the motor output.

[0040] B. Second embodiment: FIG. 5 is a diagram illustrating a manufacturing method of the stator 100 according to the second embodiment. In the second embodiment, unlike the first embodiment, the first coil 120A and the second coil 120B are arranged side by side in the circumferential direction dc within the opening 117b of the arrangement portion 116b. That is, in this embodiment, each coil 120 is arranged in two rows in the circumferential direction dc within the slot 112. That is, in this embodiment, two coils 120 are arranged in one row. The first coil 120A and the second coil 120B each correspond to the coil 120. The configurations of the stator 100 and the stator manufacturing apparatus 200 according to this embodiment that are not particularly described are the same as those according to the first embodiment.

[0041] FIG. 5 illustrates the coils 120, including the first coil 120A and the second coil 120B, as well as the third coil 120C and the fourth coil 120D. In FIG. 5, each coil 120 is in a released state. The coils 120 illustrated in FIG. 5 are arranged in the arrangement section 116 in the following order: first coil 120A, second coil 120B, third coil 120C, and fourth coil 120D. The first coil 120A and the second coil 120B are arranged in the first row from the back of the slot 112, and the third coil 120C and the fourth coil 120D are arranged in the second row from the back of the slot 112. The third coil 120C and the fourth coil 120D are arranged side by side in the circumferential direction dc, similar to the first coil 120A and the second coil 120B. The third coil 120C is arranged so as to be in contact with the first coil 120A in the depth direction dd. The fourth coil 120D is disposed so as to be in contact with the second coil 120B in the depth direction dd. The third coil 120C and the fourth coil 120D in the second row can also be regarded as the first coil 120A and the second coil 120B, respectively.

[0042] In this embodiment, the opening diameter d4 of the opening 117b of the arrangement portion 116 is at least twice the outer diameter d1b of the coil 120 in the released state. Specifically, the opening diameter d4 is slightly larger than the diameter d5. The diameter d5 is twice the outer diameter d1b. As a result, the first coil 120A is arranged in the opening 117b of the arrangement portion 116b so as to be in contact with the second coil 120B and the inner wall 118 in the circumferential direction dc. The second coil 120B is arranged in the opening 117b so as to be in contact with the first coil 120A and the inner wall 118 in the circumferential direction dc. The third coil 120C and the fourth coil 120D are arranged in substantially the same manner as the first coil 120A and the second coil 120B.

[0043] Note that, when the opening diameter d4b of the placement portion 116 is slightly larger than the diameter d5, as in the second embodiment, it is difficult to arrange the second coil 120B in the placement portion 116b in a normal state so that it is aligned with the already-arranged first coil 120A. Therefore, in the second embodiment, it is preferable to arrange the second coil 120B in the placement portion 116b by utilizing the rotation of the second coil 120B in the rotation process. Specifically, it is preferable to arrange the second coil 120B in the placement portion 116b by moving the second coil 120B to the vicinity of the first coil 120A and then pushing the second coil 120B into the space adjacent to the first coil 120A in the circumferential direction dc by the rotation in the rotation process. As a result, the compressive stress generated in the stator core 110 can be reduced compared to when the second coil 120B is arranged in the placement portion 116b in a normal state.

[0044] According to the manufacturing method of the stator 100 in the second embodiment described above, two coils 120 can be arranged in the opening 117b of the arrangement portion 116b so that the coils 120 are in contact with each other in the circumferential direction dc and so that the coils 120 are in contact with the inner wall 118 in the circumferential direction dc. This makes it possible to arrange two rows of coils 120 in the slot 112 and further increase the space factor of the stator coil 130 in the slot 112. Therefore, it is possible to effectively manufacture a stator 100 that can further improve the output of a motor into which the stator 100 is incorporated.

[0045] Furthermore, in this embodiment, the second coil 120B is placed in the placement portion 116b before the third coil 120C is placed in the placement portion 116b. This prevents the path of the second coil 120B in the slot 112 from narrowing in the width direction due to the already placed third coil 120C, compared to a configuration in which the third coil 120C is placed in the placement portion 116b before the second coil 120B. Therefore, for example, the second coil 120B can be placed in the placement portion 116b more smoothly.

[0046] C. Other Embodiments: (C1) In the second embodiment, the insertion step of inserting the second coil 120B into the slots 112 and the rotation step of rotating the second coil 120B may be started simultaneously with or after the start of the insertion step of inserting the first coil 120A into the slots 112 and before the twisted state of the first coil 120A is released. This allows the stator 100 to be manufactured more efficiently than in a configuration in which the insertion step and rotation step for the second coil 120B are started after the twisted state of the first coil 120A is released. Furthermore, in this case, for example, the insertion step for the first coil 120A and the insertion step for the second coil 120B may be performed simultaneously, and the rotation step for the first coil 120A and the rotation step for the second coil 120B may be performed simultaneously. This allows the stator 100 to be manufactured even more efficiently. In this case, for example, one first portion 121 of first coil 120A and one first portion 121 of second coil 120B may be held simultaneously by one first holding part 206, and both held first portions 121 may be twisted simultaneously by first holding part 206. In this way, the number of first holding parts 206 can be reduced, and the configuration of stator manufacturing apparatus 200 can be further simplified. Furthermore, second holding part 211 may be configured to be able to hold first coil 120A and second coil 120B simultaneously. In this way, the number of second holding parts 211 can be reduced, and the configuration of stator manufacturing apparatus 200 can be further simplified.

[0047] (C2) In each of the above embodiments, the opening diameter d3 of the inlet portion 113 is smaller than the outer diameter d1 of the untwisted coil 120r. Alternatively, the opening diameter d3 may be equal to or larger than the outer diameter d1. Even in this case, the twisted coil 120t can be smoothly moved within the slot 112, and the untwisted coil 120r can be placed in the placement portion 116. Therefore, it is not necessary to press the coil 120t against the stator core 110 in the depth direction dd of the slot 112, which can prevent compressive stress from occurring in the stator core 110 and prevent an increase in iron loss in the stator core 110.

[0048] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0049] 100... stator, 110... stator core, 111... teeth, 112... slot, 113... inlet portion, 114... opening, 116, 116b... placement portion, 117, 117b... opening, 118... inner wall, 120... coil, 120A... first coil, 120B... second coil, 120C... third coil, 120D... fourth coil, 120n... coil in normal state, 120r... coil in released state, 120t... coil in twisted state, 120x... next coil, 121... first Part, 122...second part, 128...conductor, 129...insulating coating, 130...stator coil, 200...stator manufacturing apparatus, 205...first holding mechanism, 206...first holding unit, 207...rotation mechanism, 208...first moving mechanism, 210...second holding mechanism, 211...second holding unit, 213...second moving mechanism, 220...moving mechanism, 250...control unit, 251...processor, 252...memory unit, 253...input / output interface, 254...internal bus, 255...program

Claims

1. A method for manufacturing a stator, comprising: an insertion step of inserting a coil having a rectangular cross section into a slot of a stator core in a twisted state in which the coil is pre-twisted around an axis of the coil; a rotating step of rotating the inserted coil within the slot about the axis to release the twisted state.

2. A method for manufacturing a stator according to claim 1, the slot includes an entrance for receiving the coil during the insertion step; a manufacturing method in which, in the circumferential direction of the stator core, the opening diameter of the inlet portion is larger than the outer diameter of the coil in the circumferential direction in the twisted state and smaller than the outer diameter of the coil when the twisted state is released.

3. A method for manufacturing a stator according to claim 1 or 2, the slot includes a placement portion in which the coil is placed when the coil is in a released state in which the twisted state is released, The coil includes a first coil and a second coil, the first coil is disposed within the opening of the disposing portion so as to be in contact with the second coil and an inner wall of the disposing portion in the circumferential direction of the stator core; The second coil is arranged within the opening of the arrangement portion so as to be in contact with the first coil and the inner wall in the circumferential direction.

4. A method for manufacturing a stator according to claim 3, A manufacturing method in which the insertion process of inserting the second coil into the slot and the rotation process of rotating the second coil are started simultaneously with or after the start of the insertion process of inserting the first coil into the slot and before the twisted state of the first coil is released.

5. A stator manufacturing apparatus, a first holding part configured to be able to rotate a coil having a rectangular cross section, the coil having a first part having a portion disposed in a slot of a stator core and a second part connected to the first part, while holding the first part; a second holding portion configured to be able to hold the second portion; a movement mechanism configured to be able to move the first holding unit and the second holding unit; a control unit that controls the first holding unit, the second holding unit, and the movement mechanism, The control unit a process of twisting the coil around its axis using the first holding unit and the second holding unit; a process of inserting the coil into the slot in the twisted state using the moving mechanism; and rotating the inserted coil around the axis using the first holding unit and the second holding unit so as to eliminate the twisted state. Stator manufacturing equipment.

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