JP2016123248A - coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize a coil such that when the coil is formed by using a plurality of concentric winding parts, the number of coil side parts arranged radially in one slot can be easily made odd-numbered.SOLUTION: One concentric winding part 10 is represented as a first concentric winding part, the concentric winding part 10 having a second coil side part arranged in a slot where a first coil side part of the first concentric winding part is arranged is represented as a second concentric winding part, and a concentric winding part 10 having a first coil side part arranged in a slot where a second coil side part of the first concentric winding part is arranged is represented as a third concentric winding part. An outer connection part 70 of the first concentric winding part is connected to an outer connection part 70 of one of the second concentric winding part and the third concentric winding part through a first connection member 91, and an inner connection part 71 of the first concentric winding part is connected to an inner connection part 71 of the other of the second concentric winding part and the third concentric winding part through a second connection member 92.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a coil wound around a core in which a plurality of slots extending in the axial direction and the radial direction are distributed in the circumferential direction.

  As such a coil, one described in Japanese Patent Application Laid-Open No. 2012-125043 (Patent Document 1) is known. Patent Document 1 describes a technique for forming a coil by using a plurality of concentric winding portions that are wound a plurality of times between a pair of slots. Specifically, in the configuration described in the first embodiment of Patent Document 1, a concentric winding part formed by winding a flat conductor as shown in FIG. The concentric winding portion has five coil sides on each of one side and the other side in the circumferential direction, and as shown in FIG. 10 of the document, the five coil sides are arranged in the slots. Are arranged in a row with a gap along the radial direction. In each of the five gaps formed in one slot, the five coil side portions of the other concentric winding portions of the same phase are arranged. As a result, a total of 10 coil sides are arranged in one slot in the radial direction.

JP 2012-125043 (paragraph 0040, FIG. 7, FIG. 10)

  By the way, when the coil is a coil for a rotating electrical machine, the torque that can be generated by the rotating electrical machine and the magnitude of the back electromotive force generated in the rotating electrical machine depend on the number of coil sides arranged in one slot. Change. Therefore, in order to obtain desired characteristics of the rotating electrical machine, it may be desirable that the number of coil side portions (number of turns) arranged in the radial direction in one slot be an odd number. However, in the configuration described in Patent Document 1, the number of coil sides arranged in the radial direction in one slot is always an even number, and thus the above requirement cannot be satisfied appropriately.

  Therefore, when a coil is formed using a plurality of concentric winding portions, it is desired to realize a coil in which the number of coil side portions arranged in the radial direction in one slot can be an odd number. .

  In view of the above, the characteristic configuration of the coil wound around the core in which a plurality of axially and radially extending slots are distributed in the circumferential direction is a concentric winding wound a plurality of times between the pair of slots. Each of the concentric winding portions includes a plurality of first coil side portions disposed on one side in the circumferential direction, and the first coil side portion disposed on the other side in the circumferential direction. The first coil side part and the second coil arranged in different slots are provided with a second coil side part less than the number of second coil side parts as coil side parts arranged inside the slot. A plurality of crossing portions for connecting side portions to the core on the outer side in the axial direction, and the first coil side portion and the second coil side portion in the radial direction in one slot. Alternately arranged in the slots The first connection member is connected to the end of the outermost coil side that is the first coil side that is arranged in the outermost layer in the radial direction, on the opposite side of the connection with the crossover. An outer connection portion for the innermost coil side portion, which is the first coil side portion disposed in the radially innermost layer in the slot, and a connection portion with the transition portion An inner connection portion for connecting the second connection member is provided at the opposite end portion, and the one concentric winding portion is defined as a first concentric winding portion, and the first concentric winding portion is configured as the first concentric winding portion. The concentric winding portion in which the second coil side portion is disposed in the slot in which the coil side portion is disposed is defined as a second concentric winding portion, and the second coil side portion of the first concentric winding portion is disposed. The first concentric winding, wherein the concentric winding portion in which the first coil side portion is disposed in the slot is defined as a third concentric winding portion. The outer connection portion is connected to the outer connection portion of one of the second concentric winding portion and the third concentric winding portion via the first connection member, and the first concentric winding portion The inner connection portion is connected to the other inner connection portion of the second concentric winding portion and the third concentric winding portion via the second connection member.

According to said characteristic structure, since the number of the 2nd coil side parts with which one concentric winding part is equipped is one less than the number of the 1st coil side parts with which one concentric winding part is provided, 1 The sum of the number of first coil side parts provided in one concentric winding part and the number of second coil side parts provided in one concentric winding part is always an odd number. Therefore, the number of the coil side parts arranged side by side in the radial direction in the slot in which the first coil side parts and the second coil side parts are alternately arranged in the radial direction can be easily set to an odd number. . That is, a plurality of concentric winding parts are distributed in the circumferential direction so that the second coil side part of the other concentric winding part is arranged in the slot in which the first coil side part of one concentric winding part is arranged. By arranging, the number of coil sides arranged in the radial direction in one slot can be made odd. Therefore, it is possible to easily realize a coil having an odd number of coil side portions arranged in the radial direction in one slot as compared with a case where a coil wound in units of one layer is separately used. .
Moreover, according to said characteristic structure, each of a concentric winding part is used for each of the concentric winding part of the connection object arrange | positioned at the both sides of the circumferential direction using a 1st connection member and a 2nd connection member. It is possible to connect appropriately. And when connecting between concentric winding parts by other members in this way, it becomes easy to reduce the kind of concentric winding parts required in order to form a coil, for example, one kind of concentric windings. It is also possible to form a coil using only the part. As a result, it is possible to improve productivity and reduce manufacturing costs.

It is a perspective view of the stator which concerns on embodiment of this invention. It is a perspective view of the concentric winding set which concerns on embodiment of this invention. It is a perspective view of the two concentric winding sets of the same phase which concerns on embodiment of this invention. It is an axial view of the concentric winding part which concerns on embodiment of this invention. It is a perspective view of the concentric winding part which concerns on embodiment of this invention. It is a partial sectional view of a stator concerning an embodiment of the present invention. It is a partial sectional view of a stator concerning an embodiment of the present invention. FIG. 5 is a partial cross-sectional view of a stator according to another embodiment of the present invention.

  An embodiment of a coil according to the present invention will be described with reference to the drawings. Here, the case where the coil according to the present invention is applied to a coil 3 wound around a stator 1 of a rotating electrical machine as shown in FIG. 1 will be described as an example. That is, in this embodiment, the core 20 around which the coil 3 is wound is the core (stator core) of the stator 1. The “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary.

  In the following description, the “axial direction L”, “circumferential direction C”, and “radial direction R” are defined with reference to the axial center of the core 20 unless otherwise specified. Here, the axis of the core 20 is the axis of the cylindrical inner peripheral surface 21 of the core 20, and the outer peripheral surface 22 of the core 20 (if there is a mounting projection, the cylindrical shape excluding the projection) It is also the axis of the part. “Axial first direction L1” represents a direction toward one side in the axial direction L, and “Axial second direction L2” represents a direction toward the other side in the axial direction L (a direction opposite to the axial first direction L1). Represents. The “circumferential first direction C1” represents a direction toward one side in the circumferential direction C, and the “circumferential second direction C2” represents a direction toward the other side in the circumferential direction C (a direction opposite to the circumferential first direction C1). Represents. Here, as shown in FIG. 1, the clockwise direction when viewed along the axial direction L from the axial first direction L1 side is the circumferential first direction C1.

  In the following, assuming that the coil 3 is wound around the core 20 (the state shown in FIG. 1), the coil 3 will be described using the axial direction L, the circumferential direction C, and the radial direction R. . Further, in this specification, terms relating to dimensions, arrangement direction, arrangement position, and the like (for example, parallel) are used as a concept including a state having a difference due to an error (an error that is acceptable in manufacturing).

1. Overall Configuration of Stator The stator 1 includes a core 20 and a coil 3 wound around the core 20 as shown in FIG. The stator 1 is a stator used in a rotating field type rotating electric machine, and functions as an armature. Inside the radial direction R with respect to the core 20, a rotor (not shown) as a field magnet having a permanent magnet, an electromagnet, or the like is disposed, and the rotor is rotated by a rotating magnetic field generated from the stator 1. In the present embodiment, the stator 1 is a stator of a rotating electrical machine that is driven by three-phase alternating current (an example of multi-phase alternating current), and includes three phase coils: a U-phase coil, a V-phase coil, and a W-phase coil. The coil 3 is wound around the core 20. The core 20 is formed using a magnetic material. For example, a core 20 is formed by laminating a plurality of magnetic plates (for example, electromagnetic steel plates such as silicon steel plates), or a compact material formed by pressing a magnetic material powder is a main component. As a result, the core 20 is formed.

  In the core 20, a plurality of slots 40 extending in the axial direction L and the radial direction R are distributed in the circumferential direction C. Each of the slots 40 has openings on both sides in the axial direction L and on the inner side in the radial direction R. The plurality of slots 40 are arranged at regular intervals along the circumferential direction C. In the present embodiment, the U-phase slot 40, the V-phase slot 40, and the W-phase slot 40 are arranged so as to repeatedly appear in the circumferential direction C. In the present embodiment, the number of slots per phase per pole is “2”, and the core 20 is arranged so that two slots 40 for each phase repeatedly appear along the circumferential direction C. In this embodiment, the number of magnetic poles per phase is “8” (the number of magnetic pole pairs is “4”), and the core 20 has a total of 48 (= 2 × 8 × 3) slots 40. ing. A tooth 23 is formed between two slots 40 adjacent to each other in the circumferential direction C. Each of the teeth 23 is formed to extend inward in the radial direction R from an annular portion (yoke portion) in the core 20. The inner peripheral surface 21 of the core 20 is a cylindrical virtual surface including the inner end surfaces in the radial direction R of the plurality of teeth 23.

2. Coil Configuration The coil 3 is formed by using a linear conductor 4 (see FIGS. 4 and 5) that is a linear conductor. The linear conductor 4 is formed using a conductive material such as copper or aluminum, and an insulating film made of an electrically insulating material such as a resin is formed on the surface of the linear conductor 4. . In the present embodiment, a linear conductor 4 (that is, a flat wire) having a rectangular cross section perpendicular to the extending direction is used. Here, the “rectangular shape” includes a rectangle whose corners are arc-shaped, or a rectangle whose absolute value of the difference between the size of the inner angle and 90 degrees is less than a predetermined angle (for example, 5 degrees or 10 degrees). including.

  The coil 3 includes a plurality of concentric winding portions 10 (in other words, a single coil portion or a lap winding portion) that are wound a plurality of times between a pair of slots 40. The concentric winding part 10 is a cassette coil formed in a spiral shape before being wound around the core 20. In the present embodiment, one concentric winding portion 10 is formed by molding one continuous linear conductor 4. Accordingly, each part of the concentric winding part 10 is formed by different parts in the extending direction of one continuous linear conductor 4. Note that “continuous” for the linear conductor 4 means that the linear conductor 4 is integrally formed in the extending direction without a joint. In the present embodiment, the plurality of concentric winding portions 10 constituting the coil 3 include the types of concentric winding portions 10 as shown in FIGS. 4 and 5. In this example, the coil 3 is formed using one type of concentric winding part 10 as shown in FIG.4 and FIG.5. Here, “type” means that the configurations of the coil side portion 30 and the crossover portion 50 described later are the same. That is, for example, the concentric winding portion 10 connected to the power supply terminal, the neutral point, or the like may have a different configuration from the other concentric winding portion 10, but even in such a case, the coil side If the structure of the part 30 and the crossover part 50 is the same, it will be set as the same kind of concentric winding part 10. FIG. In the present specification, illustration and description of the connection configuration with the power supply terminal, the neutral point, and the like are omitted.

  As shown in FIG. 5, each of the concentric winding portions 10 includes a plurality of first coil side portions 31 arranged on the circumferential first direction C1 side, and a first coil arranged on the circumferential second direction C2 side. The number of second coil side portions 32, which is one less than the side portion 31, is provided as the coil side portion 30 disposed inside the slot 40. As shown in FIG. 7, the coil side portion 30 is disposed so as to extend in the slot 40 in parallel with the axial direction L. In the present embodiment, each of the concentric winding parts 10 includes a plurality of second coil side parts 32. Moreover, in this embodiment, the 1st coil side part 31 and the 2nd coil side part 32 with which one concentric winding part 10 is provided are magnetic pole pitches (in this example, 6 times the arrangement pitch of the slot 40). Only a pair of slots 40 separated from each other are arranged. That is, in this embodiment, the concentric winding part 10 is wound between a pair of slots 40 separated from each other by a magnetic pole pitch (six times the arrangement pitch of the slots 40). And the coil 3 is formed by arrange | positioning the same number (48 in this example) concentric winding part 10 as the slot 40, shifting by the arrangement | positioning pitch of the slot 40 to the one side of the circumferential direction C. FIG.

  In the present embodiment, the concentric winding portion 10 includes an even number of first coil side portions 31 and an odd number of second coil side portions 32 that is one less than the number of first coil side portions 31. . In this example, as shown in FIG. 5, the concentric winding part 10 includes four first coil side parts 31 and three second coil side parts 32. Here, when the half of the total number of coil side portions 30 provided in one concentric winding portion 10 (seven in this example) is the number of turns of the concentric winding portion 10, the winding of the concentric winding portion 10 is used in this example. The number of times is “3.5”. All the first coil side portions 31 included in one concentric winding portion 10 are disposed in the same slot 40. Further, all the second coil side portions 32 provided in one concentric winding portion 10 are different from each other in the same slot 40 (however, different from the slot in which the first coil side portion 31 of the concentric winding portion 10 is disposed). Slot).

  Each of the concentric winding portions 10 includes a plurality of bridges that connect the first coil side portion 31 and the second coil side portion 32 disposed in different slots 40 to the core 20 on the outer side in the axial direction L. Part 50 is provided. Here, the transition part 50 provided on the axial first direction L1 side with respect to the core 20 is defined as a first transition part 51, and the transition part 50 provided on the axial second direction L2 side with respect to the core 20 is defined as the second transition part. 52. At least a part of the coil end portion protruding from the core 20 toward the first axial direction L1 side is formed by the set of the first transition portions 51 of each phase, and from the core 20 by the set of the second transition portions 52 of each phase. At least a part of the coil end portion protruding toward the second axial direction L2 is formed. In the present specification, the conductors (the first connecting member 91 and the second connecting member described later) that connect the coil side portions 30 of the different concentric winding portions 10 to the core 20 on the outer side in the axial direction L are used. 92, etc.) are not included in the crossover section 50.

  As shown in FIG. 7, the first coil side portions 31 and the second coil side portions 32 are alternately arranged in the radial direction R in one slot 40. That is, a plurality of coil side portions 30 are arranged in one slot 40. The plurality of coil sides 30 arranged in one slot 40 are arranged in a line along the radial direction R. Assuming that the arrangement region in the radial direction R of one coil side 30 is one layer, the coil side 30 is divided into a plurality of layers in each slot 40. All the first coil side parts 31 provided in one concentric winding part 10 and all the second coil side parts 32 provided in another one concentric winding part 10 are arranged in one slot 40. . Here, the number of second coil side portions 32 included in one concentric winding portion 10 is one less than the number of first coil side portions 31 included in one concentric winding portion 10. Therefore, as shown in FIG. 7, a total of an odd number of three or more (7 in this example) coil side portions 30 are arranged in one slot 40. In the present embodiment, one concentric winding portion of the pair of concentric winding portions 10 that are spaced apart from each other in the circumferential direction C by six times the arrangement pitch of the slots 40 (that is, the magnetic pole pitch). Ten first coil side portions 31 and the second coil side portion 32 of the other concentric winding portion 10 are disposed in the same slot 40.

  The first coil side portion 31 is disposed in each of the outermost layer that is the outermost layer in the radial direction R in the slot 40 and the innermost layer that is the innermost layer in the radial direction R in the slot 40. . Here, the first coil side portion 31 disposed in the outermost layer in the slot 40 is defined as the outermost layer coil side portion 38, and the first coil side portion 31 disposed in the innermost layer in the slot 40 is defined as the innermost layer coil side portion. 39. One of the first coil side 31 and the second coil side 32 is arranged in each of the outermost layer and the intermediate layer excluding the innermost layer in the slot 40. In the present embodiment, in each slot 40, the first coil side portions 31 and the second coil side portions 32 are alternately arranged in the radial direction R one by one. That is, in the present embodiment, when a plurality of layers in the slot 40 are numbered sequentially from “1” toward the inside in the radial direction R from the outermost layer (first layer), the Mth layer (M 1 is an odd number of 1 or more), the first coil side part 31 is arranged, and the second coil side part 32 is arranged in the Nth layer (N is an even number of 2 or more).

  Specifically, as shown in FIG. 6, the plurality of first coil side portions 31 included in one concentric winding portion 10 is 1 between two first coil side portions 31 adjacent to each other in the radial direction R. They are arranged in a line with a gap along the radial direction R so that a space for the layers is formed. And the 2nd coil side part 32 with which the other concentric winding part 10 of the same phase is provided in each of the said clearance gap is arrange | positioned. As a result, each of the second coil side portions 32 included in one concentric winding portion 10 is disposed so as to be sandwiched from both sides in the radial direction R by the first coil side portions 31 of the other concentric winding portions 10. . In FIG. 6, two concentric winding portions 10 that are arranged so as to be shifted in the circumferential direction C by the arrangement pitch of the slots 40 to facilitate understanding of the arrangement configuration of the concentric winding portion 10 with respect to the core 20. Only the first coil side 31 and the second coil side 32 are shown. Moreover, the two-dot chain line which shows the crossover part 50 in FIG. 6 is for showing the combination of the 1st coil side part 31 and the 2nd coil side part 32 with which the same concentric winding part 10 is equipped, The shape of the part 50 is not shown.

  In the present embodiment, the first coil side portion 31 and the second coil side portion 32 that are respectively arranged in mutually adjacent layers in different slots 40 are connected by the crossover portion 50. That is, in the present embodiment, each of the plurality of coil side portions 30 included in one concentric winding portion 10 is adjacent to another coil side portion 30 (in the direction of current flow) of the linear conductor 4 (current flow direction). That is, it is arranged in a layer adjacent to another coil side portion 30) connected via one crossover portion 50. Specifically, the plurality of coil side portions 30 included in one concentric winding portion 10 are coil side portions (outermost layer coil sides) arranged on the outermost layer coil side portion 38 side in the winding direction of the linear conductor 4. In order from the outermost layer one by one from the outermost layer to the inside in the radial direction R.

  As described above, in the present embodiment, each of the crossover portions 50 connects the first coil side portion 31 and the second coil side portion 32 that are respectively disposed in mutually adjacent layers in different slots 40. As shown in FIGS. 4 and 5, in this embodiment, each of the crossover portions 50 is offset in the radial direction R by the linear conductor 4 constituting the concentric winding portion 10 at the intermediate portion in the circumferential direction C. An offset part is provided. By providing such an offset part 63, the first coil side part 31 and the second coil side part 32 respectively disposed in mutually adjacent layers in different slots 40 without causing the crossover parts 50 to interfere with each other. Each of the crossover parts 50 can be arranged so as to be connected to each other.

  Specifically, as shown in FIGS. 4 and 5, the offset portion 63 extends from the offset portion 63 in the crossover portion 50 along the winding direction of the linear conductor 4 (extending direction of the linear conductor 4). The portion toward the innermost layer coil side portion 39 side is set in the radial direction R with respect to the portion toward the outermost layer coil side portion 38 side along the winding direction of the linear conductor 4 from the offset portion 63 in the crossover portion 50. It is formed so as to be offset inward. In FIG. 4, in order to facilitate understanding of the invention, a portion of the concentric winding portion 10 that is disposed on the second axial direction L2 side with respect to the core 20 is hatched. Specifically, the crossover part 50 includes a first circumferentially extending part 61 and a second circumferentially extending part 62 as circumferentially extending parts extending in the circumferential direction C from the offset part 63. As shown in FIG. 5, the first circumferentially extending portion 61 is a portion from the offset portion 63 toward the innermost coil side portion 39 along the winding direction of the linear conductor 4, and extends in the second circumferential direction. The existing portion 62 is a portion from the offset portion 63 toward the outermost coil side portion 38 along the winding direction of the linear conductor 4. Then, the first circumferential direction extending portion 61 of the transition portion 50 is located inside the radial direction R with respect to the second circumferential direction extending portion 62 of the transition portion 50 by the offset portion 63 provided in the transition portion 50. Is offset. In addition, in the 1st crossover part 51 and the 2nd crossover part 52, the positional relationship of the circumferential direction C between the 1st circumferential direction extension part 61 and the 2nd circumferential direction extension part 62 with which each is provided is reverse. It has become.

  Each of the first circumferentially extending portion 61 and the second circumferentially extending portion 62 is connected to the coil side portion 30 via a bent portion at the end opposite to the connecting portion with the offset portion 63. Yes. This bent portion is a circumferential direction of the extending direction of the first circumferential extending portion 61 and the second circumferential extending portion 62 with respect to the extending direction of the coil side portion 30 (a direction parallel to the axial direction L). It is the circumferential direction bending part for setting it as the direction inclined in C. In the present embodiment, the bending angle with respect to the axial direction L of the circumferential bending portion is set to an acute angle. In addition, the bending angle with respect to the axial direction L of the circumferentially bent portion formed between the coil side portion 30 and the circumferentially extending portion (the first circumferentially extending portion 61 or the second circumferentially extending portion 62). Is a vector extending from the end of the coil side portion 30 on the side of the circumferentially bent portion side to the side away from the core 20 along the axial direction L when viewed along the radial direction R, and the circumference of the circumferentially extending portion. An angle formed by a vector from the end portion on the direction bending portion side toward the end portion on the opposite side of the circumferential extending portion along the extending direction of the circumferential extending portion (an angle that is 180 degrees or less) It is. Therefore, an acute angle with respect to the axial direction L of the circumferentially bent portion means that the inner product of the two vectors is positive. Therefore, each of the first circumferential direction extending portion 61 and the second circumferential direction extending portion 62 is inclined toward the outer side (the side away from the core 20) in the axial direction L as it goes to the offset portion 63 side in the circumferential direction C. Is formed. And in this embodiment, as shown in FIG. 5, the offset part 63 is formed in the site | part (top part) most distant from the core 20 in the crossover part 50 in the axial direction L. As shown in FIG. Further, in the present embodiment, the first circumferential direction extending portion 61 and the second circumferential direction extending portion 62 are set to have the same length in the circumferential direction C. Here, the length of the two members is “same”, in addition to the case where each length is the same, even if there is a difference in each length, the magnitude of the difference is This is used as a concept including a case where the length is shorter than the length of the shorter member. Therefore, in this embodiment, the offset part 63 is formed in the center part of the circumferential direction C in the crossover part 50, or its vicinity. Furthermore, in this embodiment, as shown in FIG. 4, each of the first circumferential direction extending portion 61 and the second circumferential direction extending portion 62 is a circle extending along the circumferential direction C when viewed in the axial direction L. It is formed in an arc shape. In addition, the extension length of the circumferential direction C of the 1st circumferential direction extension part 61 and the extension length of the circumferential direction C of the 2nd circumferential direction extension part 62 mutually differ to such an extent that it does not become said same grade. A configuration is also possible.

  The arrangement positions in the radial direction R of the first circumferential extending portion 61 and the second circumferential extending portion 62 are the positions in the radial direction R of the coil side portions 30 connected via the circumferential bent portion. Is set according to Specifically, the arrangement order in the radial direction R of the first circumferential extension 61 and the second circumferential extension 62 is equal to the arrangement in the radial R of the coil side 30 to which each is connected. Thus, the arrangement position of each radial direction R of the 1st circumferential direction extension part 61 and the 2nd circumferential direction extension part 62 is set. Therefore, as shown in FIGS. 4 and 5, the first circumferential extending portion 61 and the second circumferential extending portion 62 have a diameter of one each for the first transition portion 51 and the second transition portion 52. They are arranged alternately in the direction R (however, at different positions in the circumferential direction C). And the second circumferential direction extension part 62 of another concentric winding part is arrange | positioned in the clearance gap between the two 1st circumferential direction extension parts 61 adjacent to radial direction R, and it adjoins to radial direction R. In the gap between the two second circumferentially extending portions 62, the first circumferentially extending portion 61 of the other concentric winding portion is disposed. Thus, the plurality of concentric winding portions 10 can be arranged on one side in the circumferential direction C while being shifted by the arrangement pitch of the slots 40 without causing the crossover portions 50 to interfere with each other.

  In the present embodiment, the width in the radial direction R of each of the first circumferential direction extending portion 61 and the second circumferential direction extending portion 62 is set equal to the radial direction R width of the coil side portion 30. And in this embodiment, the arrangement position of each radial direction R of the 1st circumferential direction extension part 61 and the 2nd circumferential direction extension part 62 is the coil side part connected via said circumferential direction bending part. 30 and the same position in the radial direction R. Therefore, in the present embodiment, the plurality of first circumferential extending portions 61 are formed so that a space for one layer is formed between the two first circumferential extending portions 61 adjacent in the radial direction R. They are arranged with a gap along the radial direction R. And the offset amount of the radial direction R between the 1st circumferential direction extension part 61 and the 2nd circumferential direction extension part 62 by the offset part 63 is 1 layer (width | variety of radial direction R equivalent to 1 layer). Is set to

  FIG. 2 shows a concentric winding set 5 formed by using a plurality of concentric winding portions 10 having the above-described configuration. The concentric winding set 5 is formed by a plurality of concentric winding portions 10 having the same phase. In the present embodiment, two concentric winding sets 5 are provided for each phase (see FIG. 3), and the six concentric winding sets 5 are arranged so as to be shifted from each other in the circumferential direction C, whereby the coil 3 is formed. (See FIG. 1). As shown in FIG. 2, one concentric winding set is provided by a plurality of concentric winding portions 10 arranged at every magnetic pole pitch (in this example, six times the arrangement pitch of the slots 40) along the circumferential direction C. 5 is formed. That is, in one concentric winding set 5, a pair of concentric winding portions 10 adjacent to each other in the circumferential direction C are the first coil side 31 of one concentric winding portion 10 and the second of the other concentric winding portion 10. The coil side portion 32 is wound around the core 20 so as to be disposed in the same slot 40 (that is, disposed in the same circumferential direction C). In this example, one concentric winding set 5 is formed by eight (an example of an even number) concentric winding portions 10.

  A pair of concentric winding portions 10 adjacent to each other in the circumferential direction C in one concentric winding set 5 are connected to each other by a first connection member 91 or a second connection member 92. 1 to 3, the first connection member 91 and the second connection member 92 are hatched in order to facilitate understanding of the invention. Further, in FIG. 1, only the first connection member 91 and the second connection member 92 shown in FIG. 3 (that is, only the first connection member 91 and the second connection member 92 included in one phase coil) are hatched. Yes. Each of the concentric winding parts 10 has a connection part for connecting the first connection member 91 and the second connection member 92. Specifically, as shown in FIGS. 4 and 5, the first connecting member 91 is provided at the end of the outermost layer coil side 38 that is opposite to the connecting portion with the connecting portion 50 (second connecting portion 52). An outer connecting portion 70 is provided for connecting the two. Further, an inner connection portion 71 for connecting the second connection member 92 is provided at the end of the innermost layer coil side portion 39 opposite to the connection portion with the transition portion 50 (first transition portion 51). In the present embodiment, the outer connection portion 70 is formed so as to continuously extend from the end of the outermost layer coil side portion 38 opposite to the connection portion 50 with the connecting portion 50, and the inner connection portion 71 is the innermost layer. The coil side portion 39 is formed so as to continuously extend from the end portion on the opposite side to the connection portion with the crossover portion 50. That is, in this embodiment, the entire concentric winding part 10 including the outer connection part 70 and the inner connection part 71 is formed by molding one continuous linear conductor 4.

  One concentric winding part 10 is referred to as a “first concentric winding part”, and the second coil side part 32 is arranged in the slot 40 where the first coil side part 31 of the first concentric winding part is arranged. The winding portion 10 is a “second concentric winding portion”, and the concentric winding portion 10 in which the first coil side portion 31 is disposed in the slot 40 in which the second coil side portion 32 of the first concentric winding portion is disposed. When the third concentric winding portion is designated, the outer connecting portion 70 of the first concentric winding portion is connected to one outer connecting portion 70 of the second concentric winding portion and the third concentric winding portion. The inner connection portion 71 of the first concentric winding portion is connected to the other inner connection portion 71 of the second concentric winding portion and the third concentric winding portion via the second connection member 92. The The first concentric winding part is an arbitrary concentric winding part 10 among a plurality of concentric winding parts 10 constituting one concentric winding set 5.

  For example, as shown in FIG. 2, when the concentric winding portion 10 with the reference numeral “11” is used as the first concentric winding portion, the outer connecting portion 70 of the first concentric winding portion is the second concentric winding portion. It is connected to the outer connecting portion 70 of the concentric winding portion (the concentric winding portion 10 to which reference numeral “12” is attached) via the first connecting member 91, and the inner connecting portion of the first concentric winding portion is 71, It is connected via a second connection member 92 to the inner connection portion 71 of a three concentric winding portion (a concentric winding portion denoted by reference numeral “13”). As shown in FIG. 2, when the concentric winding portion 10 with the reference numeral “12” is used as the first concentric winding portion, the outer connecting portion 70 of the first concentric winding portion is the third concentric winding portion. It is connected to the outer connection part 70 of the concentric winding part (the concentric winding part 10 to which reference numeral “11” is attached) via the first connection member 91, and the inner connection part of the first concentric winding part is 71, A second connecting member 92 is connected to the inner connecting portion 71 of the two concentric winding portions (the concentric winding portion 10 denoted by reference numeral “14”).

  As described above, the plurality of concentric winding portions 10 constituting one concentric winding set 5 are connected to the other concentric winding portions 10 adjacent to the circumferential first direction C1 and the first connection member 91. The concentric winding part 10 (hereinafter referred to as “first type concentric winding part”) connected to the other concentric winding part 10 adjacent to the second circumferential direction C2 side and connected via the second connecting member 92. And the other concentric winding part 10 adjacent to the circumferential first direction C1 side and the other concentric winding part 10 connected via the second connection member 92 and adjacent to the circumferential second direction C2 side. The concentric winding part 10 (henceforth "a 2nd type concentric winding part") connected via the 1st connection member 91 is contained. The first type concentric winding parts and the second type concentric winding parts are alternately arranged along the circumferential direction C. As a result, as shown in FIG. 2, the first connection member 91 and the second connection member 92 are arranged in the circumferential direction C with respect to the first connection member 91 and the second connection member 92 provided in one concentric winding set 5. Are arranged alternately. The first connection member 91 connects the pair of concentric winding portions 10 (a pair of outer connection portions 70) to each other on the first axial direction L1 side with respect to the core 20, and the second connection member 92 includes a core 20, a pair of concentric winding portions 10 (a pair of inner connection portions 71) are connected to each other on the second axial direction L2 side.

  In the present embodiment, as shown in FIGS. 4 and 7, the distal end portion of the outer connecting portion 70 is formed to extend outward in the radial direction R. In this example, the distal end portion of the outer connection portion 70 is formed so as to extend in parallel to the radial direction R. A surface facing the first axial direction L <b> 1 side at the distal end portion of the outer connection portion 70 is a bonding surface with the first connection member 91. In accordance with such a shape of the outer connecting portion 70, in the present embodiment, the distal end portion of the first connecting member 91 (joined portion with the outer connecting portion 70) is also in the radial direction R toward the outer side of the radial direction R. It is formed to extend in parallel. Moreover, in this embodiment, as shown in FIG. 2, the main-body part of the 1st connection member 91 sees in the radial direction R, and the transition part 50 (2nd type concentric winding part) of the concentric winding part 10 (2nd type concentric winding part). It arrange | positions so that it may have a part which overlaps with the 1st transit part 51). In addition, the main-body part of the 1st connection member 91 is a part (circumferential extension part) extended in the circumferential direction C between the connection parts with each of a pair of outer side connection part 70 of connection object.

  Moreover, in this embodiment, as shown in FIG.4 and FIG.7, the front-end | tip part of the inner side connection part 71 is formed so that it may extend toward the inner side of radial direction R. As shown in FIG. In this example, the front end portion of the inner connection portion 71 is formed to extend in parallel to the radial direction R. A surface facing the second axial direction L <b> 2 side at the distal end portion of the inner connection portion 71 is a bonding surface with the second connection member 92. In accordance with such a shape of the inner connection portion 71, in the present embodiment, the distal end portion of the second connection member 92 (joint portion with the inner connection portion 71) is also in the radial direction R toward the inner side of the radial direction R. It is formed to extend in parallel. Moreover, in this embodiment, as shown in FIG. 2, the main-body part of the 2nd connection member 92 sees in the radial direction R, and the transition part 50 (the 1st type concentric winding part) of the concentric winding part 10 (first type concentric winding part). It arrange | positions so that it may have a part which overlaps with the 2nd transfer part 52). In addition, the main-body part of the 2nd connection member 92 is a part (circumferential extension part) extended in the circumferential direction C between the connection parts with each of a pair of inner side connection parts 71 of connection object.

  The first connection member 91 and the second connection member 92 are formed using a linear conductor, like the concentric winding part 10. For example, the first connection member 91 and the second connection member 92 can be formed using a linear conductor having the same or equivalent cross-sectional area as the linear conductor 4 constituting the concentric winding portion 10. Further, the joining of the first connecting member 91 and the outer connecting portion 70 and the joining of the second connecting member 92 and the inner connecting portion 71 are, for example, arc welding such as TIG welding, electron beam welding, laser beam welding, resistance, etc. It can be performed by welding, brazing, soldering, or the like.

  In the present embodiment, as shown in FIG. 3, one phase coil is formed by two concentric winding sets 5 (see FIG. 2) that are shifted from each other in the circumferential direction C by the arrangement pitch of the slots 40. The Then, by arranging the three phase coils on the one side in the circumferential direction C while shifting by four times the arrangement pitch of the slots 40, the coil 3 as shown in FIG. 1 is formed. As shown in FIG. 3, in the present embodiment, two concentric winding sets 5 constituting one phase coil have a first connection member 91 having a different shape and a second connection member 92 having a different shape. And are provided. That is, the phase coil shown in FIG. 3 is different from the concentric winding set 5 shown in FIG. 2 in the shape of the first connecting member 91 and the second connecting member 92 in the concentric winding set 5 shown in FIG. Set 5 is provided. Here, the first connection member 91 provided in the concentric winding set 5 shown in FIG. 2 is referred to as a first outer connection member 91a, and the first connection member 91 provided in the other concentric winding set 5 is referred to as a second outer connection member. 91b. Further, the second connecting member 92 provided in the concentric winding set 5 shown in FIG. 2 is referred to as a first inner connecting member 92a, and the second connecting member 92 provided in the other concentric winding set 5 is referred to as a second inner connecting member 92b. And 1 and 3, the hatching applied to the second outer connecting member 91b and the second inner connecting member 92b is applied to the first outer connecting member 91a and the first inner connecting member 92a in order to facilitate understanding of the invention. Is different.

  As shown in FIG. 3, the arrangement | positioning area | region of the circumferential direction C of the 1st outer side connection member 91a has a part which overlaps with the arrangement | positioning area | region of the circumferential direction C of the 2nd outer side connection member 91b. Therefore, each of the first outer connecting member 91a and the second outer connecting member 91b has a shape that avoids mutual interference. In this example, the first outer connecting member 91a is located on the side in the first circumferential direction C1 with respect to the outer intersecting portion 93 where the first outer connecting member 91a and the second outer connecting member 91b intersect in the radial direction R. It overlaps from the first axial direction L1 side (the side opposite to the core 20 in the axial direction L) with respect to the second outer connection member 91b, and the second outer connection on the second circumferential direction C2 side with respect to the outer intersection 93. The member 91b is arrange | positioned so that it may overlap with the 1st outer side connection member 91a from the axial 1st direction L1 side. Further, as can be seen from FIG. 1, each of the first outer connecting member 91a and the second outer connecting member 91b is on the side in the first circumferential direction C1 with respect to the outer intersecting portion 93 in the main body (circumferentially extending portion). The part is offset in the radial direction R (in the radial direction R in this example) with respect to the part on the second circumferential direction C2 side with respect to the outer intersecting part 93 in the main body part. Thereby, interference with the 1st outer side connection member 91a with which the phase coil of another phase is equipped, and the 2nd outer side connection member 91b is avoided.

  As shown in FIG. 3, the arrangement | positioning area | region of the circumferential direction C of the 1st inner side connection member 92a has a part which overlaps with the arrangement | positioning area | region of the circumferential direction C of the 2nd inner side connection member 92b. Therefore, each of the 1st inner side connection member 92a and the 2nd inner side connection member 92b has a shape which avoids mutual interference. In this example, the first inner connecting member 92a is located on the circumferential first direction C1 side with respect to the inner intersecting portion 94 where the first inner connecting member 92a and the second inner connecting member 92b intersect when viewed in the radial direction R. It overlaps from the second axial direction L2 side (the side opposite to the core 20 in the axial direction L) with respect to the second inner connection member 92b, and the second inner connection on the second circumferential direction C2 side with respect to the inner intersection 94. The member 92b is arrange | positioned so that it may overlap with the 1st inner side connection member 92a from the axial 2nd direction L2 side. Further, as can be seen from FIG. 1, each of the first inner connecting member 92a and the second inner connecting member 92b is located on the circumferential first direction C1 side with respect to the inner intersecting portion 94 in the main body portion (circumferentially extending portion). The portion is offset in the radial direction R (in the present example, outside the radial direction R) with respect to the portion on the second circumferential direction C2 side with respect to the inner intersecting portion 94 in the main body portion. Thereby, interference with the 1st inner side connection member 92a with which the phase coil of another phase is equipped, and the 2nd inner side connection member 92b is avoided.

3. Other Embodiments Other embodiments according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, the distal end portion of the outer connection portion 70 is formed so as to extend outward in the radial direction R, and the distal end portion of the inner connection portion 71 faces inward in the radial direction R. The structure formed so as to extend is described as an example. However, the embodiment of the present invention is not limited to this, and the front end portion of the outer connection portion 70 is formed so as to extend toward the outer side in the axial direction L (the side away from the core 20), or the inner connection portion. It can also be set as the structure formed so that the front-end | tip part of 71 may extend toward the outer side of the axial direction L. FIG. Further, as in the example shown in FIG. 8, the distal end portion of the outer connection portion 70 is formed so as to extend outward in the axial direction L, and the distal end portion of the inner connection portion 71 is formed outside the axial direction L. It can also be set as the structure formed so that it may extend toward. In this configuration, the surface facing the outer side in the radial direction R at the distal end portion of the outer connection portion 70 is a bonding surface with the first connection member 91. In addition, a surface facing the inner side in the radial direction R at the distal end portion of the inner connection portion 71 is a bonding surface with the second connection member 92. In the example shown in FIG. 8, each of the distal end portion of the outer connection portion 70 and the distal end portion of the inner connection portion 71 is formed to extend in parallel to the axial direction L.

(2) In the above-described embodiment, the concentric winding part 10 includes the even number of first coil side parts 31 and the odd number of second coil side parts 32 that is one fewer than the number of the first coil side parts 31. The configuration including the above has been described as an example. However, the embodiment of the present invention is not limited to this, and the concentric winding portion 10 has an odd number of three or more odd number of first coil sides 31 and an even number less than the number of first coil sides 31. The second coil side portion 32 may be provided.

(3) In the above embodiment, as shown in FIG. 3, one phase coil is formed by the two concentric winding sets 5 arranged so as to be shifted from each other in the circumferential direction C by the arrangement pitch of the slots 40. The configuration has been described as an example. However, the embodiment of the present invention is not limited to this. For example, a single phase coil may be formed by two concentric winding sets 5 that are shifted from each other in the circumferential direction C by 5 or 7 times the arrangement pitch of the slots 40.

(4) In the above embodiment, the number of slots per pole per phase is “2”, and one phase coil is formed by two concentric winding sets 5 as an example. However, the embodiment of the present invention is not limited to this. For example, the number of slots per pole per phase is “1”, and one phase coil is formed by one concentric winding set 5. It is also possible to adopt a configuration in which the number of slots per phase per pole is “3” and one phase coil is formed by three concentric winding sets 5.

(5) In the above embodiment, the configuration in which the first coil side portions 31 and the second coil side portions 32 are alternately arranged in the radial direction R one by one in the slot 40 has been described as an example. However, the embodiment of the present invention is not limited to this, and the outermost layer that is the outermost layer in the radial direction R in the slot 40 and the innermost layer that is the innermost layer in the radial direction R in the slot 40. The arrangement order in the radial direction R of the coil side portions 30 arranged in the intermediate layer excluding the outermost layer and the innermost layer in the slot 40 is appropriately changed under the restriction that the first coil side portion 31 is arranged in each. It is also possible. For example, a plurality of first coil side portions 31 and second coil side portions 32 may be alternately arranged in the radial direction R in one slot 40.

(6) Regarding other configurations, it should be understood that the embodiments disclosed herein are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Accordingly, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

4). Outline of Embodiment of the Present Invention The embodiment of the present invention described above has at least the following configuration.
A coil (3) wound around a core (20) in which a plurality of slots (40) extending in an axial direction (L) and a radial direction (R) are dispersedly arranged in a circumferential direction (C). A plurality of concentric winding portions (10) wound a plurality of times between the slots (40) are provided, and each of the concentric winding portions (10) is disposed on one side in the circumferential direction (C). The first coil side (31) and the second coil side (32) arranged on the other side in the circumferential direction (C) and one fewer than the first coil side (31). The first coil side part (31) and the second coil side part provided as coil side parts (30) arranged inside the slot (40) and arranged in different slots (40). (32) connected to the core (20) outside the axial direction (L) The first coil side (31) and the second coil side (32) are arranged in the radial direction (R) in one slot (40). The crossing of the outermost coil side portions (38) which are the first coil side portions (31) arranged alternately and arranged in the outermost layer in the radial direction (R) in the slot (40) An outer connection part (70) for connecting the first connection member (91) is provided at the end opposite to the connection part with the part (50), and the radial direction in the slot (40) The end of the innermost coil side (39), which is the first coil side (31) arranged in the innermost layer of (R), on the opposite side of the connection with the transition (50) Are provided with an inner connection portion (71) for connecting the second connection member (92), and the one concentric winding portion ( 0) is the first concentric winding part, and the second coil side part (32) is arranged in the slot (40) in which the first coil side part (31) of the first concentric winding part is arranged. The concentric winding portion (10) is a second concentric winding portion, and the first coil side is placed in the slot (40) where the second coil side portion (32) of the first concentric winding portion is disposed. The concentric winding part (10) in which the part (31) is arranged is a third concentric winding part, and the outer connection part (70) of the first concentric winding part is the second concentric winding part and Connected to one of the outer connecting portions (70) of the third concentric winding portion via the first connecting member (91), the inner connecting portion (71) of the first concentric winding portion is The other inner connection part (71) of the second concentric winding part and the third concentric winding part is connected via the second connection member (92).

According to such a configuration, the number of second coil side portions provided in one concentric winding portion is one less than the number of first coil side portions provided in one concentric winding portion. The sum of the number of first coil side parts provided in one concentric winding part and the number of second coil side parts provided in one concentric winding part is always an odd number. Therefore, the number of the coil side parts arranged side by side in the radial direction in the slot in which the first coil side parts and the second coil side parts are alternately arranged in the radial direction can be easily set to an odd number. . That is, a plurality of concentric winding parts are distributed in the circumferential direction so that the second coil side part of the other concentric winding part is arranged in the slot in which the first coil side part of one concentric winding part is arranged. By arranging, the number of coil sides arranged in the radial direction in one slot can be made odd. Therefore, it is possible to easily realize a coil having an odd number of coil side portions arranged in the radial direction in one slot as compared with a case where a coil wound in units of one layer is separately used. .
Moreover, according to said structure, each of the concentric winding part is used with respect to each of the concentric winding part of the connection object arrange | positioned at the both sides of the circumferential direction using a 1st connection member and a 2nd connection member. Can be connected properly. And when connecting between concentric winding parts by other members in this way, it becomes easy to reduce the kind of concentric winding parts required in order to form a coil, for example, one kind of concentric windings. It is also possible to form a coil using only the part. As a result, it is possible to improve productivity and reduce manufacturing costs.

  In the embodiment of the present invention, one slot (40) includes the first coil side (31) and the second coil side (32) one by one in the radial direction (R). The first coil side portions (31) and the second coil side portions (32), which are alternately arranged and are respectively disposed in mutually adjacent layers in the different slots (40), are connected to the crossover portion ( 50), and each of the crossover portions (50) has a linear conductor (4) constituting the concentric winding portion (10) in the radial direction (R) at an intermediate portion in the circumferential direction (C). The offset portion (63) is offset from the offset portion (63) of the crossover portion (50) along the winding direction of the linear conductor (4). The part toward the inner coil side (39) side , With respect to a portion of the crossing portion (50) from the offset portion (63) toward the outermost coil side portion (38) along the winding direction of the linear conductor (4), the radial direction ( It is preferable that it is formed so as to be offset inside R).

  According to this configuration, a plurality of concentric winding portions adjacent in the circumferential direction can be arranged so as to partially overlap each circumferential arrangement region without causing the crossing portions to interfere with each other. Moreover, according to said structure, since a transition part connects the 1st coil side part and 2nd coil side part which are each arrange | positioned in the mutually adjacent layer in a mutually different slot, a transition part differs from each other. The space occupied by the offset portion can be reduced as compared with the case where the first coil side portion and the second coil side portion, which are respectively arranged in layers separated from each other in the slot by two or more layers, are connected. The coil end portion can be reduced in size. Furthermore, according to said structure, since the 1st coil side part and the 2nd coil side part are alternately arrange | positioned by radial direction one by one in a slot, it is multiple with which one concentric winding part is provided. The first coil sides can be arranged along the radial direction with a gap corresponding to one layer. Moreover, when one concentric winding part is provided with a plurality of second coil side parts, the plurality of second coil side parts are also arranged with a gap corresponding to one layer along the radial direction. Can do. That is, none of the first coil sides are arranged in the layer adjacent to the other first coil sides, and any second coil side is adjacent to the other second coil sides. Therefore, the productivity of the concentric winding portion can be improved.

  The present invention can be used for a coil wound around a core in which a plurality of slots extending in the axial direction and the radial direction are distributed in the circumferential direction.

3: Coil 4: Linear conductor 10: Concentric winding 20: Core 30: Coil side 31: First coil side 32: Second coil side 38: Outermost layer coil side 39: Innermost layer coil side 40: Slot 50: Crossing portion 63: Offset portion 70: Outer connection portion 71: Inner connection portion 91: First connection member 92: Second connection member C: Circumferential direction L: Axial direction R: Radial direction

Claims (2)

A coil wound around a core in which a plurality of slots extending in the axial direction and the radial direction are distributed in the circumferential direction
A plurality of concentric winding portions wound a plurality of times between the pair of slots,
Each of the concentric winding portions has a plurality of first coil side portions arranged on one side in the circumferential direction, and one fewer than the first coil side portions arranged on the other side in the circumferential direction. A plurality of second coil sides as coil sides arranged inside the slot, and the first coil sides and the second coil sides arranged in different slots are different from each other. A plurality of crossing portions connected to the core on the outside in the axial direction;
In one of the slots, the first coil side and the second coil side are alternately arranged in the radial direction,
A first connection is provided at an end of the outermost layer coil side portion, which is the first coil side portion arranged in the outermost layer in the radial direction in the slot, on the side opposite to the connection portion with the crossover portion. An outer connecting portion for connecting a member, and an innermost coil side portion which is the first coil side portion arranged in the radially innermost layer in the slot, An inner connection part for connecting the second connection member is provided at the end opposite to the connection part,
One concentric winding part is defined as a first concentric winding part, and the second coil side part is disposed in the slot in which the first coil side part of the first concentric winding part is disposed. The winding portion is a second concentric winding portion, and the concentric winding portion in which the first coil side portion is disposed in the slot in which the second coil side portion of the first concentric winding portion is disposed is a third. As a concentric winding part,
The outer connection portion of the first concentric winding portion is connected to the outer connection portion of one of the second concentric winding portion and the third concentric winding portion via the first connection member, and The inner connection portion of the one concentric winding portion is a coil connected to the other inner connection portion of the second concentric winding portion and the third concentric winding portion via the second connection member. In each of the slots, the first coil sides and the second coil sides are alternately arranged in the radial direction one by one, and are arranged in mutually adjacent layers in the different slots. The first coil side and the second coil side are connected by the crossover part,
Each of the crossovers includes an offset part that offsets the linear conductor constituting the concentric winding part in the radial direction at an intermediate part in the circumferential direction,
The offset portion is a portion that extends from the offset portion at the transition portion toward the innermost coil side along the winding direction of the linear conductor, from the offset portion at the transition portion to the winding of the linear conductor. The coil according to claim 1, wherein the coil is formed so as to be offset inward in the radial direction with respect to a portion toward the side of the outermost layer coil along the turning direction.

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