Patent Publication Number: US-2023154676-A1

Title: Winding machine and method of manufacturing coil

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a U.S. national stage of application No. PCT/JP2020/039027, filed on Oct. 16, 2020, and with priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) being claimed from Japanese Application No. 2020-062127, filed on Mar. 31, 2020, the entire contents of which are hereby incorporated herein by reference. 
    
    
     1. FIELD OF THE INVENTION 
     The present application relates to a winding machine and a method of manufacturing a coil. 
     2. BACKGROUND 
     For example, there is known a method of manufacturing a coil in which a winding is pressed and wound by moving a wire rod guide holding portion in accordance with a timing at which the winding is wound. 
     In the above-described method of manufacturing the coil, it is necessary to move the wire rod guide holding portion in accordance with the timing at which the winding is wound, and thus the structure of the winding machine for manufacturing the coil tends to be complicated. 
     SUMMARY 
     A winding machine according to an example embodiment of the present disclosure includes a winding core around which a winding is wound, a first winding jig and a second winding jig positioned with the winding core interposed therebetween in an axial direction of a central axis of the winding core, and a first gripper and a second gripper that are located on an outer side of the winding core in a radial direction around the central axis. An outer edge portion of the first winding jig in the radial direction and an outer edge portion of the second winding jig in the radial direction are located on an outer side, in the radial direction, from the winding core. Each of the first gripper and the second gripper includes a pair of rollers to interpose and grip the winding. At least one of the first gripper or the second gripper is rotatable about the central axis. 
     A method of manufacturing a coil according to an example embodiment of the present disclosure includes winding a winding by using the winding machine described above. 
     The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional view schematically illustrating a motor according to an example embodiment of the present disclosure. 
         FIG.  2    is a cross-sectional view illustrating a portion of a stator of the present example embodiment, and is a cross-sectional view taken along line II-II in  FIG.  1   . 
         FIG.  3    is a perspective view illustrating a portion of a coil of the present example embodiment. 
         FIG.  4    is a flowchart illustrating a procedure in a method of manufacturing the coil of the present example embodiment. 
         FIG.  5    is a cross-sectional view illustrating a portion of the procedure in the method of manufacturing the coil of the present example embodiment. 
         FIG.  6    is a perspective view illustrating the winding machine of the present example embodiment. 
         FIG.  7    is a cross-sectional view illustrating the winding machine of the present example embodiment, and is a cross-sectional view taken along line VII-VII in  FIG.  6   . 
         FIG.  8    is a perspective view illustrating a state in the middle of assembly of the winding machine of the present example embodiment. 
         FIG.  9    is a perspective view illustrating a first guide portion and a second guide portion of the present example embodiment. 
         FIG.  10    is a perspective cross-sectional view illustrating a portion of the first gripper of the present example embodiment. 
         FIG.  11    is a perspective cross-sectional view illustrating a portion of the first gripper of the present example embodiment, and is a partially enlarged view of  FIG.  10   . 
         FIG.  12    is a perspective cross-sectional view illustrating a portion of an assembly procedure of the winding machine of the present example embodiment. 
         FIG.  13    is a view illustrating a portion of a winding procedure of a winding using the winding machine of the present example embodiment. 
         FIG.  14    is a view illustrating another portion of the winding procedure of the winding using the winding machine of the present example embodiment. 
         FIG.  15    is a view illustrating still another portion of the winding procedure using the winding machine of the present example embodiment. 
         FIG.  16    is a partial cross-sectional view illustrating a state where a winding is wound around a winding core of the present example embodiment. 
         FIG.  17    is a perspective view illustrating a portion of a second winding body of the present example embodiment. 
         FIG.  18    is a cross-sectional view illustrating another portion of the procedure in the method of manufacturing the coil of the present example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As illustrated in  FIG.  1   , a motor  1  of the present example embodiment is an inner rotor type motor. The central axis of the motor  1  is a motor axis J 1 . The motor axis J 1  is a virtual axis extending in one direction. In each drawing, a direction in which the motor axis J 1  extends is indicated by a Z1 axis. In the following description, the axial direction of the motor axis J 1  is referred to as a “motor axial direction”, the radial direction centered on the motor axis J 1  is referred to as a “motor radial direction”, and the circumferential direction centered on the motor axis J 1  is referred to as a “motor circumferential direction”. 
     The motor  1  includes a housing  2 , a rotor  3 , a stator  10 , a bearing holder  4 , and bearings  5   a  and  5   b . The housing  2  accommodates the rotor  3 , the stator  10 , the bearing holder  4 , and the bearings  5   a  and  5   b . The rotor  3  is rotatable about the motor axis J 1 . The rotor  3  includes a shaft  3   a  and a rotor main body  3   b . 
     The shaft  3   a  extends in the motor axial direction along the motor axis J 1 . The shaft  3   a  has, for example, a columnar shape extending in the motor axial direction with the motor axis J 1  as a center. The shaft  3   a  is rotatably supported about the motor axis J 1  by the bearings  5   a  and  5   b . The rotor main body  3   b  is fixed to an outer peripheral surface of the shaft  3   a . Although not illustrated, the rotor main body  3   b  includes a rotor core fixed to the outer peripheral surface of the shaft  3   a  and a magnet fixed to the rotor core. The bearing holder  4  holds the bearing  5   b . 
     The stator  10  faces the rotor  3  in the motor radial direction with a gap interposed therebetween. In the present example embodiment, the stator  10  is located on the outer side of the rotor  3  in the motor radial direction. As illustrated in  FIG.  2   , the stator  10  includes a stator core  20 , a plurality of coils  30 , and an insulator  40 . The stator core  20  includes an annular core back  21  surrounding the motor axis J 1  and a plurality of teeth  22  extending to an inner side in the motor radial direction from the core back  21 . The core back  21  has, for example, a cylindrical shape centered on the motor axis J 1 . 
     The plurality of teeth  22  are arranged at intervals along the motor circumferential direction. The plurality of teeth  22  are arranged at equal intervals over the entire circumference along the motor circumferential direction, for example. In the present example embodiment, the plurality of teeth  22  are formed integrally with the core back  21 . Each of the teeth  22  has a substantially rectangular parallelepiped shape extending linearly along the motor radial direction. The dimension of the teeth  22  in the motor circumferential direction is substantially constant over the entire motor radial direction. 
     Note that an inner end portion of the tooth  22  in the motor radial direction may be provided with umbrella portions protruding to both sides in the motor circumferential direction. In addition, the tooth  22  may be a member separate from the core back  21 . In this case, the tooth  22  may be fixed to the core back  21 , for example, by press-fitting a protrusion provided at an end portion on the outer side of the teeth  22  in the motor radial direction into a concave portion provided on the inner surface of the core back  21  in the motor radial direction. 
     The plurality of coils  30  are attached to the plurality of teeth  22 , respectively. In the present example embodiment, the coil  30  is attached to the tooth  22  via the insulator  40 . Each tooth  22  passes through the inside of each coil  30  in the motor radial direction. The inner end portion of the teeth  22  in the motor radial direction protrudes to the inner side in the motor radial direction from the coils  30 . 
     The coil  30  is configured by winding a flat wire. Therefore, the space factor of the coil  30  can be improved as compared with the case of using a round wire. In the present specification, the “flat wire” is a wire rod of which a cross-sectional shape is a quadrangular shape or a substantially quadrangular shape. In the present specification, the term “substantially quadrangular shape” includes a rounded quadrangular shape in which the corners of a quadrangular shape are rounded. Although not illustrated, the flat wire configuring the coil  30  in the present example embodiment is an enameled wire having an enamel coating on the surface. 
     The coil  30  includes a pair of axially extending portions  30   b  extending in the motor axial direction on both sides of the tooth  22 , to which the coil  30  is attached, in the motor circumferential direction. The tooth  22  is interposed between the pair of axially extending portions  30   b  in the motor circumferential direction. The axially extending portion  30   b  is configured by bundling a plurality of flat wires configuring the coil  30 . The contour shape of the axially extending portion  30   b  in the cross section orthogonal to the motor axial direction is, for example, a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. 
     The term “fan shape” as used herein involves a shape surrounded by two arcs that are equal in center of curvature to each other and are different in radius from each other, and two line segments extending in radius directions of circles with their centers aligned with the centers of curvature and respectively connecting to opposite ends of the two arcs. In addition, the term “fan shape” as used herein involves a strictly fan shape and a substantially fan shape. The term “substantially fan shape” as used herein involves a shape in which fan-shaped arcs are approximated by a plurality of line segments. In the present example embodiment, the contour shape of the axially extending portion  30   b  in the cross section orthogonal to the motor axial direction is a shape surrounded by the two arcs and two line segments as described above. Although not illustrated, the center of curvature of the contour shape of the axially extending portion  30   b  in the cross section orthogonal to the motor axial direction is located on the inner side of the core back  21  in the motor radial direction and is located at a position different from the motor axis J 1 . 
     The coil  30  includes a first winding body  31  and a second winding body  32 . Each of the first winding body  31  and the second winding body  32  is configured by winding a flat wire. In the present example embodiment, the first winding body  31  configures the inner portion of the coil  30  in the motor radial direction. In the present example embodiment, the second winding body  32  configures the outer portion of the coil  30  in the motor radial direction. That is, the second winding body  32  is located on the outer side of the first winding body  31  in the motor radial direction. 
     The second winding body  32  is connected to the first winding body  31 . More specifically, as illustrated in  FIG.  3   , one end portion  31   c  of the flat wire configuring the first winding body  31  is connected to one end portion  32   c  of the flat wire configuring the second winding body  32 . Accordingly, first winding body  31  and second winding body  32  are connected in series to configure one coil  30 . A method of connecting the one end portion  31   c  and the one end portion  32   c  is not particularly limited. The one end portion  31   c  and the one end portion  32   c  may be fixed by solder, may be fixed by laser welding, or may be fixed by ultrasonic bonding. In addition, the one end portion  31   c  and the one end portion  32   c  may be provided with concave portions that mesh with each other. 
     In the following description, N is a freely-selected integer of 1 or more, and M is a freely-selected integer larger than N. At this time, the first winding body  31  is an N-layer winding body aligned and wound in two rows aligned in the motor radial direction. The second winding body  32  is an M-layer winding body aligned and wound in two rows aligned in the motor radial direction. As illustrated in  FIG.  2   , in the present example embodiment, the first winding body  31  is configured by stacking three layers of windings aligned and wound in two rows aligned in the motor radial direction. That is, in the present example embodiment, N is 3, and the first winding body  31  is a three-layer winding body aligned and wound in two rows aligned in the motor radial direction. Accordingly, the total number of windings of the first winding body  31  is six. 
     In the present example embodiment, the second winding body  32  is configured by stacking four layers of windings aligned and wound in two rows aligned in the motor radial direction. That is, in the present example embodiment, M is 4, and the second winding body  32  is a four-layer winding body aligned and wound in two rows aligned in the motor radial direction. Accordingly, the total number of windings of the second winding body  32  is eight. Therefore, the total number of windings of the coil  30  is fourteen. 
     The first winding body  31  has a pair of first axially extending portions  31   b  extending in the motor axial direction on both sides of the tooth  22 , to which the first winding body  31  is attached, in the motor circumferential direction. The contour shape of the first axially extending portion  31   b  in the cross section orthogonal to the motor axial direction is, for example, a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. More specifically, the contour shape of the first axially extending portion  31   b  in the cross section orthogonal to the motor axial direction is a shape surrounded by two arcs and two line segments, similarly to the axially extending portion  30   b  described above. 
     In the present example embodiment, the cross-sectional shape of the portion configuring the first axially extending portion  31   b  among the flat wires configuring the first winding body  31  is a trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. More specifically, the cross-sectional shape of the portion configuring the first axially extending portion  31   b  among the flat wires configuring the first winding body  31  is a rounded trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. In the following description, a portion configuring the first axially extending portion  31   b  among the flat wires configuring the first winding body  31  is referred to as a first coil wire portion  31   a . 
     Each of the pair of first axially extending portions  31   b  is configured by bundling a plurality of first coil wire portions  31   a . In the present example embodiment, each of the first axially extending portions  31   b  is configured by bundling six first coil wire portions  31   a . More specifically, in the present example embodiment, two rows of the first axially extending portions  31   b  are configured to be arranged in the motor radial direction, each row having three first coil wire portions  31   a  arranged in the motor circumferential direction. The dimension in the motor circumferential direction in the cross section of the first coil wire portion  31   a  configuring the row on the outer side in the motor radial direction among the two rows aligned in the motor radial direction is larger than the dimension in the motor circumferential direction in the cross section of the first coil wire portion  31   a  configuring the row on the inner side in the motor radial direction. The dimension in the motor radial direction in the cross section of the first coil wire portion  31   a  configuring the row on the outer side in the motor radial direction is smaller than the dimension in the motor radial direction in the cross section of the first coil wire portion  31   a  configuring the row on the inner side in the motor radial direction. The cross-sectional areas of the first coil wire portions  31   a  are the same. 
     The second winding body  32  has a pair of second axially extending portions  32   b  extending in the motor axial direction on both sides of the tooth  22 , to which the second winding body  32  is attached, in the motor circumferential direction. The pair of second axially extending portions  32   b  is arranged adjacent to the outer sides of the pair of first axially extending portions  31   b  in the motor radial direction, respectively. The first axially extending portion  31   b  and the second axially extending portion  32   b  adjacent in the motor radial direction configure the axially extending portion  30   b  of the coil  30 . That is, the axially extending portion  30   b  includes the first axially extending portion  31   b  provided on the first winding body  31  and the second axially extending portion  32   b  provided on the second winding body  32 . 
     The contour shape of the second axially extending portion  32   b  in the cross section orthogonal to the motor axial direction is, for example, a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. More specifically, the contour shape of the second axially extending portion  32   b  in the cross section orthogonal to the motor axial direction is a shape surrounded by two arcs and two line segments, similarly to the axially extending portion  30   b  described above. 
     In the present example embodiment, the cross-sectional shape of the portion configuring the second axially extending portion  32   b  among the flat wires configuring the second winding body  32  is a trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. More specifically, the cross-sectional shape of the portion configuring the second axially extending portion  32   b  among the flat wires configuring the second winding body  32  is a rounded trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. In the following description, the portion configuring the second axially extending portion  32   b  among the flat wires configuring the second winding body  32  is referred to as a second coil wire portion  32   a . 
     Each of the pair of second axially extending portions  32   b  is configured by bundling a plurality of second coil wire portions  32   a . In the present example embodiment, each of the second axially extending portions  32   b  is configured by bundling eight second coil wire portions  32   a . More specifically, in the present example embodiment, two rows of the second axially extending portions  32   b  are configured to be arranged in the motor radial direction, each row having four second coil wire portions  32   a  arranged in the motor circumferential direction. The dimension in the motor circumferential direction in the cross section of the second coil wire portion  32   a  configuring the row on the outer side in the motor radial direction among the two rows aligned in the motor radial direction is larger than the dimension in the motor circumferential direction in the cross section of the second coil wire portion  32   a  configuring the row on the inner side in the motor radial direction. The dimension in the motor circumferential direction in the cross section of the second coil wire portion  32   a  is smaller than the dimension in the motor circumferential direction in the cross section of the first coil wire portion  31   a . 
     The dimension in the motor radial direction in the cross section of the second coil wire portion  32   a  configuring the row on the outer side in the motor radial direction is smaller than the dimension in the motor radial direction in the cross section of the second coil wire portion  32   a  configuring the row on the inner side in the motor radial direction. The dimension in the motor radial direction in the cross section of the second coil wire portion  32   a  is larger than the dimension in the motor radial direction in the cross section of the first coil wire portion  31   a . The cross-sectional areas of the second coil wire portions  32   a  are the same. 
     As illustrated in  FIG.  3   , one end portion  31   c  connected to the second winding body  32  is obliquely drawn out from one of the pair of first axially extending portions  31   b  to one side (+ Z1 side) in the motor axial direction. The one end portion  32   c  connected to the first winding body  31  is obliquely drawn out from one of the pair of second axially extending portions  32   b  to one side in the motor axial direction. The first axially extending portion  31   b  from which the one end portion  31   c  is drawn out and the second axially extending portion  32   b  from which the one end portion  32   c  is drawn out are located on opposite sides with the tooth  22  interposed therebetween in the motor circumferential direction. 
     Although not illustrated, the cross-sectional shape of a portion configuring a portion other than the first axially extending portion  31   b  in the flat wire configuring the first winding body  31  is, for example, a rounded square shape. The cross-sectional shape of a portion configuring a portion other than the second axially extending portion  32   b  in the flat wire configuring the second winding body  32  is, for example, a rounded square shape. 
     As illustrated in  FIG.  2   , the insulator  40  is, for example, a sheet-shaped insulating member. The insulators  40  may be an insulating tape or an insulating sheet of paper. In the present example embodiment, the insulator  40  is provided for each of the pair of axially extending portions  30   b . The insulator  40  is wound around each of the pair of axially extending portions  30   b . The insulator  40  provided on the axially extending portion  30   b  surrounds the axially extending portion  30   b  in a cross section orthogonal to the motor axial direction. Although not illustrated, the insulator  40  is provided over substantially the entire axially extending portion  30   b  in the motor axial direction. 
     As illustrated in  FIG.  4   , a method of manufacturing the coil  30  includes a first winding process S 1 , a second winding process S 2 , a compression process S 3 , and a connection process S 4 . As illustrated in  FIG.  5   , the first winding process S 1  is a process of winding a flat wire to form a first winding body  131 . The second winding process S 2  is a process of winding a flat wire to form a second winding body  132 . Either the first winding process S 1  or the second winding process S 2  may be performed first, or may be performed simultaneously. 
     The first winding body  131  is a winding body before becoming the first winding body  31  described above. In the first winding body  131 , each cross-sectional shape of a plurality of first coil wire portions  131   a  configuring a first axially extending portion  131   b  is a rounded square shape. The contour shape of the first axially extending portion  131   b  in the cross section orthogonal to the motor axial direction is, for example, a substantially rectangular shape. The cross-sectional shape of the flat wire configuring the first winding body  131  is the same in any portion. The first winding body  131  is a three-layer winding body aligned and wound in two rows aligned in the motor radial direction. 
     The second winding body  132  is a winding body before becoming the second winding body  32  described above. In the second winding body  132 , each cross-sectional shape of a plurality of second coil wire portions  132   a  configuring a second axially extending portion  132   b  is a rounded square shape. The contour shape of the second axially extending portion  132   b  in the cross section orthogonal to the motor axial direction is, for example, a substantially rectangular shape. The cross-sectional shape of the flat wire configuring the second winding body  132  is the same in any portion. The cross-sectional shape of the flat wire configuring the second winding body  132  is the same as the cross-sectional shape of the flat wire configuring the first winding body  131 . The second winding body  132  is a four-layer winding body aligned and wound in two rows aligned in the motor radial direction. 
     In the present example embodiment, the first winding process S 1  and the second winding process S 2  are performed by using the winding machine  50  illustrated in  FIGS.  6  to  11   . That is, the first winding process S 1  and the second winding process S 2  are processes of winding the winding  33  using the winding machine  50 . In the present example embodiment, the winding  33  is a flat wire. As illustrated in  FIG.  7   , the winding machine  50  of the present example embodiment includes a base member  51 , a first holder  61 , a second holder  62 , a bearing member  63 , a first gripper  70   a , a second gripper  70   b , a winding core  80 , a first winding jig  81 , and a second winding jig  82 . In addition, as illustrated in  FIG.  8   , the winding machine  50  includes elastic portions  65   a  and  65   b . In addition, as illustrated in  FIG.  9   , the winding machine  50  includes a first guide portion  81   d  and a second guide portion  82   d . 
     In  FIGS.  6  to  16   , a direction parallel to the central axis J 2  of the winding core  80  is indicated by a Z2 axis. In the following description, unless otherwise specified, the axial direction of the central axis J 2  is simply referred to as an “axial direction”, the radial direction centered on the central axis J 2  is simply referred to as a “radial direction”, and the circumferential direction around the central axis J 2  is simply referred to as a “circumferential direction”. In addition, a positive side (+ Z side) of the Z2 axis in the axial direction is referred to as an “upper side”, and a negative side (-Z side) of the Z2 axis in the axial direction is referred to as a lower side. In the present example embodiment, the upper side corresponds to “one side in the axial direction”, and the lower side corresponds to “the other side in the axial direction”. 
     A direction parallel to the X axis shown in each drawing among the directions orthogonal to the axial direction is referred to as a “left-right direction X”, and a direction parallel to the Y axis shown in each drawing among the directions orthogonal to the axial direction is referred to as a “front-rear direction Y”. The left-right direction X and the front-rear direction Y are directions orthogonal to each other. A positive side (+X side) in the left-right direction X is referred to as a “right side”, and a negative side (-X side) in the left-right direction X is referred to as a “left side”. A positive side (+Y side) in the front-rear direction Y is referred to as a “front side”, and a negative side (-Y side) in the front-rear direction Y is referred to as a “rear side”. 
     Note that the left-right direction, the front-rear direction, the upper side, the lower side, the right side, the left side, the front side, and the rear side are merely used for describing arrangement and other relationships between each part. The actual arrangement and other relationships may include those other than the relationships indicated by these terms. 
     The positional relationship of each part of the winding machine  50  will be described below with respect to an initial state before the winding  33  is attached to the winding machine  50 , and the winding of the winding  33  is started.  FIGS.  6  and  7    illustrate the winding machine  50  in the initial state. 
     As illustrated in  FIGS.  6  and  7   , the base member  51  expands in a direction orthogonal to the axial direction. As illustrated in  FIG.  7   , the first winding jig  81  is fixed to the central portion of the base member  51  by a bolt  52 . 
     The first winding jig  81  has a columnar shape extending in the axial direction. The first winding jig  81  has, for example, a columnar shape centered on the central axis J 2 . The first winding jig  81  protrudes to the upper side from the central portion of the base member  51 . The first winding jig  81  includes a first winding jig body  81   a  and a first support portion  81   b . 
     The first winding jig body  81   a  has a columnar shape centered on the central axis J 2 . The first winding jig body  81   a  has a first hole  81   c  recessed to the lower side from the upper surface of the first winding jig body  81   a . In the present example embodiment, the first hole  81   c  penetrates the first winding jig body  81   a  in the axial direction. The central axis J 2  passes through the inside of the first hole  81   c . As illustrated in  FIG.  8   , the first hole  81   c  is, for example, a rounded rectangular hole long in the front-rear direction Y. Note that the first hole  81   c  may be a hole having a bottom portion on the lower side. 
     As illustrated in  FIG.  7   , the first support portion  81   b  is located inside the first hole  81   c . The first support portion  81   b  protrudes to the radially inner side from the inner peripheral surface of the first hole  81   c , for example. The first support portion  81   b  is located, for example, in a portion closer to the upper side of the inside of the first hole  81   c . 
     In the present example embodiment, the second winding jig  82  is located on the upper side of the first winding jig  81 . The first winding jig  81  and the second winding jig  82  are arranged with the winding core  80  interposed therebetween in the axial direction. The second winding jig  82  is arranged on the upper side of the first winding jig  81  with a gap therebetween. The interval between the first winding jig  81  and the second winding jig  82  in the axial direction is larger than two times the thickness of the winding  33  and smaller than three times the thickness of the winding  33 . The second winding jig  82  has a columnar shape extending in the axial direction. The second winding jig  82  has, for example, a columnar shape centered on the central axis J 2 . The outer diameter of the second winding jig  82  is, for example, the same as the outer diameter of the first winding jig  81 . The second winding jig  82  includes a second winding jig body  82   a  and a second support portion  82   b . 
     The second winding jig body  82   a  has a columnar shape centered on the central axis J 2 . The second winding jig body  82   a  has a second hole  82   c  recessed to the upper side from the lower surface of the second winding jig body  82   a . In the present example embodiment, the second hole  82   c  penetrates the second winding jig body  82   a  in the axial direction. The central axis J 2  passes through the inside of the second hole  82   c . As illustrated in  FIG.  6   , the second hole  82   c  is, for example, a rounded rectangular hole long in the front-rear direction Y. Note that the second hole  82   c  may be a hole having a bottom portion on the upper side. 
     As illustrated in  FIG.  7   , the second support portion  82   b  is located inside the second hole  82   c . The second support portion  82   b  protrudes to the radially inner side from the inner peripheral surface of the second hole  82   c , for example. The second support portion  82   b  is located, for example, in a portion closer to the lower side of the inside of the second hole  82   c . 
     The winding  33  is wound around the winding core  80 . The winding core  80  has a columnar shape extending in the axial direction with the central axis J 2  as the center. As illustrated in  FIG.  12   , the winding core  80  has, for example, a substantially quadrangular prism shape which is long in the front-rear direction Y and flat in the left-right direction X. As illustrated in  FIG.  7   , the winding core  80  is located between the first winding jig  81  and the second winding jig  82  in the axial direction. The lower portion of the winding core  80  is inserted into the first hole  81   c  from above. The lower portion of the winding core  80  is fitted into the first hole  81   c . The upper portion of the winding core  80  is inserted into the second hole  82   c  from below. The upper portion of the winding core  80  is fitted into the second hole  82   c . 
     The upper portion of the winding core  80  is fixed to the second winding jig  82 , for example, by a hexagon socket set screw  83 . The hexagon socket set screw  83  is fastened to the radially inner side from the outer peripheral surface of the second winding jig  82 . The radially inner end portion of the hexagon socket set screw  83  is pressed against the side surface of the winding core  80  in the left-right direction X. The central portion of the winding core  80  in the axial direction is exposed to a gap in the axial direction between the first winding jig  81  and the second winding jig  82 . 
     The lower end portion of the winding core  80  is in contact with the first support portion  81   b  from above in the first hole  81   c . The upper end portion of the winding core  80  is in contact with the second support portion  82   b  from below in the second hole  82   c . Accordingly, the winding core  80 , the first winding jig  81 , and the second winding jig  82  are positioned in the axial direction. The first winding jig  81  and the second winding jig  82  protrude to the radially outer side from the winding core  80 . That is, the radially outer edge portion of the first winding jig  81  and the radially outer edge of the second winding jig  82  are located on the radially outer side from the winding core  80 . 
     As illustrated in  FIG.  9   , the first guide portion  81   d  is located around the winding core  80 . In the present example embodiment, the first guide portion  81   d  protrudes from the first winding jig  81  toward the second winding jig  82 . More specifically, the first guide portion  81   d  protrudes to the upper side from the peripheral edge portion of the first hole  81   c  of the upper surface of the first winding jig body  81   a . The first guide portion  81   d  and the first winding jig  81  are, for example, a part of the same single member. The first guide portion  81   d  is located, for example, on the rear side (-Y side) of the first hole  81   c . The radially inner surface of the first guide portion  81   d  is in contact with the outer peripheral surface of the winding core  80 . That is, the first guide portion  81   d  is connected to the outer peripheral surface of the winding core  80 . The radially outer surface of the first guide portion  81   d  has, for example, the same shape as the shape of the portion, which is in contact with the first guide portion  81   d , of the outer peripheral surface of the winding core  80  when viewed in the axial direction. The radially outer surface of the first guide portion  81   d  is, for example, a curved surface slightly curved in a direction protruding toward the rear side. 
     The first guide portion  81   d  has a first guide surface  81   e  and a first top surface  81   f . The first guide surface  81   e  is a surface facing to the upper side. The first guide surface  81   e  is an inclined surface located closer to the upper side toward one side in the circumferential direction. In the present example embodiment, one side in the circumferential direction is a side that advances counterclockwise around the central axis J 2  when viewed from above. The first top surface  81   f  is connected to the end portion of the first guide surface  81   e  on one side in the circumferential direction. In the first top surface  81   f , the first top surface  81   f  is, for example, a flat surface that faces to the upper side and is orthogonal to the axial direction. In the present example embodiment, the first guide surface  81   e  and the first top surface  81   f  configure the upper surface of the first guide portion  81   d . 
     The second guide portion  82   d  is located around the winding core  80 . In the present example embodiment, the second guide portion  82   d  protrudes from the second winding jig  82  toward the first winding jig  81 . More specifically, the second guide portion  82   d  protrudes to the lower side from the peripheral edge portion of the second hole  82   c  of the lower surface of the second winding jig body  82   a . The second guide portion  82   d  and the second winding jig  82  are, for example, a part of the same single member. The second guide portion  82   d  is located, for example, on the rear side (-Y side) of the second hole  82   c . The radially inner surface of the second guide portion  82   d  is in contact with the outer peripheral surface of the winding core  80 . That is, the second guide portion  82   d  is connected to the outer peripheral surface of the winding core  80 . The radially outer surface of the second guide portion  82   d  has, for example, the same shape as the shape of the portion, which is in contact with the second guide portion  82   d , of the outer peripheral surface of the winding core  80  when viewed in the axial direction. The radially outer surface of the second guide portion  82   d  is, for example, a curved surface slightly curved in a direction protruding toward the rear side. 
     The second guide portion  82   d  has a second guide surface  82   e  and a second top surface  82   f . The second guide surface  82   e  is a surface facing to the lower side. The second guide surface  82   e  is an inclined surface located closer to the upper side toward one side in the circumferential direction. The shape of the second guide surface  82   e  is similar to the shape of the first guide surface  81   e . The first guide surface  81   e  and the second guide surface  82   e  are arranged to face each other with a gap interposed therebetween in the axial direction. 
     The second top surface  82   f  is connected to the end portion of the second guide surface  82   e  on the other side in the circumferential direction. In the present example embodiment, the other side in the circumferential direction is a side that advances clockwise around the central axis J 2  when viewed from above. The second top surface  82   f  is, for example, a flat surface that faces to the lower side and is orthogonal to the axial direction. The first top surface  81   f  and the second top surface  82   f  are arranged apart from each other in the circumferential direction. A part of the first top surface  81   f  overlaps, for example, an end portion of the second guide surface  82   e  on one side in the circumferential direction when viewed in the axial direction. A part of the second top surface  82   f  overlaps, for example, an end portion of the first guide surface  81   e  on the other side in the circumferential direction when viewed in the axial direction. The first guide portion  81   d  and the second guide portion  82   d  are arranged in attitudes opposite to each other in the axial direction, but have shapes similar to each other, for example. 
     As illustrated in  FIGS.  7  and  8   , the first holder  61  is a member that holds the first gripper  70   a . The first holder  61  is located on the upper side of the base member  51 . The first holder  61  is supported from below by the base member  51 . As illustrated in  FIG.  8   , the first holder  61  has an annular shape surrounding the first winding jig  81 . The outer peripheral surface of the first holder  61  has, for example, an annular shape centered on the central axis J 2 . The first holder  61  includes a first annular portion  61   c , a first bearing portion  61   b , a plurality of first connection portions  61   d , and a pair of protruding wall portions  61   j . 
     The first annular portion  61   c  has an annular shape surrounding the central axis J 2 . The first annular portion  61   c  has, for example, an annular shape centered on the central axis J 2 . The first annular portion  61   c  has a first guide hole  61   i  that penetrates the left (-X side) end portion of the first annular portion  61   c  in the left-right direction X. The first guide hole  61   i  opens to the upper side. 
     The first bearing portion  61   b  is located to be separated on the radially inner side of the first annular portion  61   c . The first bearing portion  61   b  has, for example, a substantially rectangular shape long in the front-rear direction Y when viewed in the axial direction. The first bearing portion  61   b  has a first bearing hole  61   e  axially penetrating the first bearing portion  61   b . The first bearing hole  61   e  is a substantially circular hole centered on the central axis J 2 . The first bearing hole  61   e  opens to the left side (-X side), for example. The first winding jig  81  is fitted to the radially inner side of the first bearing hole  61   e . The first winding jig  81  rotatably supports the first holder  61  about the central axis J 2  via the inner peripheral surface of the first bearing hole  61   e . In the present example embodiment, the first holder  61  is bidirectionally rotatable about the central axis J 2 . 
     The first bearing portion  61   b  has a pair of guide grooves  61   f  and  61   g . The guide grooves  61   f  and  61   g  are recessed to the lower side from the upper surface of the first bearing portion  61   b  and extend in the front-rear direction Y. The guide groove  61   f  and the guide groove  61   g  are arranged with the central axis J 2  interposed therebetween in the front-rear direction Y. The guide groove  61   f  is located on the front side (+Y side) of the first bearing hole  61   e . The rear (-Y side) end portion of the guide groove  61   f  opens to the inside of the first bearing hole  61   e . The guide groove  61   g  is located on the rear side of the first bearing hole  61   e . The end portion of the guide groove  61   g  on the front side opens to the radially inner side of the first bearing hole  61   e . 
     The first bearing portion  61   b  has a pair of accommodation grooves  61   h . The accommodation groove  61   h  is recessed to the lower side from the upper surface of the first bearing portion  61   b  and extends in the left-right direction X. The left (-X side) end portion of the accommodation groove  61   h  opens to the left side surface of the first bearing portion  61   b . The pair of accommodation grooves  61   h  is arranged with the first bearing hole  61   e  interposed therebetween in the front-rear direction Y. The pair of accommodation grooves  61   h  is located on the radially outer side from the pair of guide grooves  61   f  and  61   g . Each of the elastic portions  65   a  and  65   b  is accommodated in each of the pair of accommodation grooves  61   h . The elastic portions  65   a  and  65   b  are, for example, coil springs extending in the left-right direction X. The width of the pair of accommodation grooves  61   h  in the front-rear direction Y is narrowed at the upper opening portion. Accordingly, the elastic portions  65   a  and  65   b  are suppressed from coming out to the upper side from the accommodation groove  61   h . 
     The plurality of first connection portions  61   d  are located between the first bearing portion  61   b  and the first annular portion  61   c  in the radial direction. The plurality of first connection portions  61   d  connect the first bearing portion  61   b  and the first annular portion  61   c . The plurality of first connection portions  61   d  extend from the radially outer surface of the first bearing portion  61   b  to the radially inner surface of the first annular portion  61   c . The plurality of first connection portions  61   d  is arranged at intervals in the circumferential direction. 
     The pair of protruding wall portions  61   j  protrudes to the upper side from different first connection portions  61   d . The pair of protruding wall portions  61   j  is arranged apart from each other on the left side (-X side) of the first bearing portion  61   b . Each of the pair of protruding wall portions  61   j  is arranged apart from the left side of each of the pair of accommodation grooves  61   h . The pair of protruding wall portions  61   j  is arranged with a pair of rollers  72  and  73  described later interposed therebetween in the front-rear direction Y. 
     The first holder  61  includes a pair of pressing members  64  arranged with a pair of protruding wall portions  61   j  interposed in the front-rear direction Y. The pair of pressing members  64  is fixed to the upper surfaces of the first connection portions  61   d  different from each other. The pressing member  64  is fixed to the first connection portion  61   d  by, for example, a bolt. 
     The second holder  62  is a member which holds the second gripper  70   b . As illustrated in  FIG.  7   , the second holder  62  is located on the upper side of the first holder  61 . The second holder  62  is supported from below by the first holder  61 . As illustrated in  FIG.  6   , the second holder  62  has an annular shape surrounding the second winding jig  82 . The upper end portion of the second winding jig  82  protrudes to the upper side from the upper surface of the second holder  62 , for example. The outer peripheral surface of the second holder  62  has, for example, an annular shape centered on the central axis J 2 . The outer diameter of the second holder  62  is, for example, the same as the outer diameter of the first holder  61 . The second holder  62  includes a second annular portion  62   c , a second bearing portion  62   b , and a plurality of second connection portions  62   d . 
     The second annular portion  62   c  has an annular shape surrounding the central axis J 2 . The second annular portion  62   c  has, for example, an annular shape centered on the central axis J 2 . The second annular portion  62   c  overlaps the first annular portion  61   c  when viewed in the axial direction. The second annular portion  62   c  has a second guide hole  62   i  penetrating the right (+X side) end portion of the second annular portion  62   c  in the left-right direction X. The second guide hole  62   i  opens to the lower side. 
     The second bearing portion  62   b  is located on the radially inner side of the second annular portion  62   c . The second bearing portion  62   b  has, for example, a substantially rectangular shape long in the front-rear direction Y when viewed in the axial direction. The second bearing portion  62   b  has a fitting hole  62   e  axially penetrating the second bearing portion  62   b . The fitting hole  62   e  is, for example, a rectangular hole long in the front-rear direction Y. Although not illustrated, the second bearing portion  62   b  has a pair of accommodation grooves on the lower surface. An elastic portion (not illustrated) is accommodated in each of the accommodation grooves of the second bearing portion  62   b . 
     The plurality of second connection portions  62   d  are located between the second bearing portion  62   b  and the second annular portion  62   c  in the radial direction. The plurality of second connection portions  62   d  connect the second bearing portion  62   b  and the second annular portion  62   c . The plurality of second connection portions  62   d  extend from the radially outer surface of the second bearing portion  62   b  to the radially inner surface of the second annular portion  62   c . The plurality of second connection portions  62   d  is arranged at intervals in the circumferential direction. 
     The bearing member  63  is a substantially rectangular parallelepiped member long in the front-rear direction Y. The bearing member  63  is fitted into the fitting hole  62   e . The bearing member  63  is attached to the second holder  62  to be relatively non-rotatable about the central axis J 2 . The upper end portion of the bearing member  63  protrudes to the upper side from the upper surface of the second holder  62 . 
     The bearing member  63  has a second bearing hole  63   a  axially penetrating the bearing member  63 . The second bearing hole  63   a  is a substantially circular hole centered on the central axis J 2 . The second bearing hole  63   a  opens to the right side (+X side), for example. The second winding jig  82  is fitted to the radially inner side of the second bearing hole  63   a . The second winding jig  82  supports the bearing member  63  and the second holder  62  via the inner peripheral surface of the second bearing hole  63   a  to be rotatable about the central axis J 2 . In the present example embodiment, the second holder  62  is bidirectionally rotatable about the central axis J 2 . Accordingly, the first holder  61  and the second holder  62  are rotatable about the central axis J 2  in directions opposite to each other. 
     As illustrated in  FIG.  7   , the first gripper  70   a  and the second gripper  70   b  are located on the outer side of the winding core  80  in the radial direction. In the initial state illustrated in  FIGS.  6  and  7   , the first gripper  70   a  and the second gripper  70   b  are arranged with the central axis J 2  interposed therebetween in the left-right direction X when viewed in the axial direction. The first gripper  70   a  is located on the radial outer side of the first winding jig  81 . The second gripper  70   b  is located on the radial outer side of the second winding jig  82 . In the initial state, the first gripper  70   a  is located on the left side (-X side) of the first winding jig  81 . In the initial state, the second gripper  70   b  is located on the right side (+X side) of the second winding jig  82 . 
     The first gripper  70   a  is held on the upper side of the first holder  61 . The second gripper  70   b  is held on the lower side of the second holder  62 . The first gripper  70   a  and the second gripper  70   b  are arranged to be displaced in the axial direction. The first gripper  70   a  is located on the lower side from the second gripper  70   b . 
     The first gripper  70   a  and the second gripper  70   b  have structures similar to each other. The first gripper  70   a  and the second gripper  70   b  are arranged to be inverted in the axial direction. In the following description, only the first gripper  70   a  may be described as a representative of the first gripper  70   a  and the second gripper  70   b . 
     As illustrated in  FIG.  8   , the first gripper  70   a  includes a base material  71 , a pair of rollers  72  and  73 , and a pair of clamping members  74  and  75 . The base material  71  is located on the radial outer side of the first winding jig  81 . The base material  71  includes a radially extending portion  71   a , a pair of first arms  71   b  and  71   c , and a pair of second arms  71   d  and  71   e . The radially extending portion  71   a  extends in the radial direction. A direction in which the radially extending portion  71   a  extends in the initial state is, for example, the left-right direction X. The radially extending portion  71   a  has, for example, a quadrangular prism shape. 
     The pair of first arms  71   b  and  71   c  extends from the radially inner end portion of the radially extending portion  71   a  to both respective sides in the front-rear direction Y orthogonal to both the direction in which the radially extending portion  71   a  extends and the axial direction. The first arm  71   b  extends, for example, from the radially inner end portion of the radially extending portion  71   a  to the front side (+Y side). The first arm  71   c  extends, for example, from the radially inner end portion of the radially extending portion  71   a  to the rear side (-Y side). Each of the pair of first arms  71   b  and  71   c  passes between each of the pair of protruding wall portions  61   j  and the first bearing portion  61   b  in the left-right direction X. The pair of first arms  71   b  and  71   c  is supported from below by the first connection portion  61   d . 
     The pair of second arms  71   d  and  71   e  respectively extends from the distal ends of the pair of first arms  71   b  and  71   c  in the left-right direction X in which the radially extending portion  71   a  extends. The second arm  71   d  extends to the left side (-X side) from the front (+Y side) end portion of the first arm  71   b . The second arm  71   e  extends to the left side from the rear (-Y side) end portion of the first arm  71   c . The pair of second arms  71   d  and  71   e  is arranged with the pair of protruding wall portions  61   j  interposed therebetween in the front-rear direction Y. Each of the pair of second arms  71   d  and  71   e  is located between the protruding wall portion  61   j  and the pressing member  64  in the front-rear direction Y. A part of the pair of second arms  71   d  and  71   e  is covered with the pressing member  64  from above. Therefore, even when the first gripper  70   a  tries to move to the upper side, the pair of second arms  71   d  and  71   e  is caught by the pressing member  64 . Accordingly, the first gripper  70   a  is suppressed from being detached to the upper side from the first holder  61 . 
     The pair of rollers  72  and  73  is arranged with the radially extending portion  71   a  interposed therebetween in the front-rear direction Y. The roller  72  is located, for example, on the front side (+Y side) of the radially extending portion  71   a . The roller  73  is located, for example, on the rear side (-Y side) of the radially extending portion  71   a . The roller  72  is rotatable about a rotation axis R 2 . The roller  73  is rotatable about a rotation axis R 3 . In the present example embodiment, the rotation axis R 2  and the rotation axis R 3  are parallel to the central axis J 2 . That is, in the present example embodiment, the axial direction of the rotation axes R 2  and R 3  is the axial direction of the central axis J 2 . 
     As illustrated in  FIG.  10   , the roller  72  includes a cylindrical portion  72   a , a first roller portion  72   b , and a second roller portion  72   c . The cylindrical portion  72   a  has a cylindrical shape opening on both sides in the axial direction around the rotation axis R 2 . The outer peripheral surface of the cylindrical portion  72   a  has a cylindrical shape. The inner peripheral surface of the cylindrical portion  72   a  has a hexagonal cylindrical shape. The first roller portion  72   b  expands to the radially outer side about the rotation axis R 2  from the upper end portion of the cylindrical portion  72   a . The first roller portion  72   b  has an annular shape centered on the rotation axis R 2 . The first roller portion  72   b  has, for example, a plate shape having the plate surface facing the axial direction. 
     As illustrated in  FIG.  11   , the outer peripheral surface of the first roller portion  72   b  is a contact portion  72   f  that can come into contact with the winding  33  in the radial direction around the rotation axis R 2  of the roller  72 . That is, the roller  72  has the contact portion  72   f . A pair of collar portions  72   d  and  72   e  is provided on the outer peripheral surface of the first roller portion  72   b . That is, the roller  72  has the pair of collar portions  72   d  and  72   e . The pair of collar portions  72   d  and  72   e  protrudes to the outer side from the contact portion  72   f  in the radial direction around the rotation axis R 2  of the roller  72 . The pair of collar portions  72   d  and  72   e  has an annular shape centered on the rotation axis R 2 . The pair of collar portions  72   d  and  72   e  is arranged to face each other with a space interposed therebetween in the axial direction of the rotation axis R 2 . The collar portion  72   d  is located, for example, at the upper end portion of the contact portion  72   f . The collar portion  72   e  is located, for example, at the lower end portion of the contact portion  72   f . The pair of collar portions  72   d  and  72   e  axially interpose the front (+Y side) edge portion of the winding  33 . 
     As illustrated in  FIG.  10   , the second roller portion  72   c  expands to the outer side in the radial direction about the rotation axis R 2  from the lower end portion of the cylindrical portion  72   a . The second roller portion  72   c  has an annular shape centered on the rotation axis R 2 . The second roller portion  72   c  has, for example, a plate shape having the plate surface facing the axial direction. 
     The outer diameter of the second roller portion  72   c  is larger than the outer diameter of the first roller portion  72   b , for example. The radially extending portion  71   a  and the protruding portion  74   c  to be described later are located between the first roller portion  72   b  and the second roller portion  72   c  in the axial direction. The first roller portion  72   b  and the second roller portion  72   c  interpose the front (+Y side) portion of the radially extending portion  71   a  in the axial direction. 
     In the present example embodiment, the shape of the roller  73  is similar to the shape of the roller  72 . Similarly to the roller  72 , the roller  73  includes a cylindrical portion  73   a , a first roller portion  73   b , and a second roller portion  73   c . The radially extending portion  71   a  and the protruding portion  75   c  to be described later are located between the first roller portion  73   b  and the second roller portion  73   c  in the axial direction. The first roller portion  73   b  and the second roller portion  73   c  interpose the rear (-Y side) portion of the radially extending portion  71   a  in the axial direction. As illustrated in  FIG.  11   , similarly to the roller  72 , the roller  73  has a contact portion  73   f  and a pair of collar portions  73   d  and  73   e . That is, each of the pair of rollers  72  and  73  has the contact portion and the pair of collar portions. The pair of collar portions  73   d  and  73   e  axially interpose the rear edge portion of the winding  33 . 
     The first roller portion  72   b  and the first roller portion  73   b  can grip the winding  33  with the winding interposed therebetween in the front-rear direction Y. Accordingly, the pair of rollers  72  and  73  can grip the winding  33  with the winding interposed therebetween. In a state where the winding  33  is gripped by the pair of rollers  72  and  73 , each of the contact portion  72   f  and the contact portion  73   f  is in contact with the winding  33  in the radial direction around the rotation axes R 2  and R 3  to interpose the winding  33 . As illustrated in  FIG.  10   , the second roller portion  72   c  and the second roller portion  73   c  are in contact with each other in the radial direction around the rotation axes R 2  and R 3 . 
     As illustrated in  FIG.  8   , the pair of clamping members  74  and  75  is arranged with the radially extending portion  71   a  and the pair of rollers  72  and  73  interposed in the front-rear direction Y. The clamping member  74  is located on the front side (+Y side) of the radially extending portion  71   a  and the roller  72 . The clamping member  75  is located on the rear side (-Y side) of the radially extending portion  71   a  and the roller  73 . 
     The clamping member  74  includes a straight portion  74   a , a curved portion  74   b , and a protruding portion  74   c . The straight portion  74   a  extends in the left-right direction X in which the radially extending portion  71   a  extends. The straight portion  74   a  is located on the front side (+Y side) of the radially extending portion  71   a . The straight portion  74   a  has a portion axially interposing the front side portion of the radially extending portion  71   a . The curved portion  74   b  is connected to the radially inner end portion of the straight portion  74   a . The curved portion  74   b  is located on the front side of the roller  72 . The curved portion  74   b  extends in the circumferential direction around the rotation axis R 2 . The curved portion  74   b  is curved in a direction to protrude to the front side when viewed in the axial direction. 
     The protruding portion  74   c  protrudes from the curved portion  74   b  toward the radially extending portion  71   a . The protruding portion  74   c  protrudes to the rear side (-Y side) from the curved portion  74   b , for example. The protruding portion  74   c  is located between the first roller portion  72   b  and the second roller portion  72   c  in the axial direction. The protruding portion  74   c  has a bearing concave portion  74   e  recessed in a direction away from the radially extending portion  71   a . The bearing concave portion  74   e  is recessed to the front side (+Y side) from the rear end portion of the protruding portion  74   c . As illustrated in  FIG.  10   , the cylindrical portion  72   a  is located inside the bearing concave portion  74   e . The inner surface of the bearing concave portion  74   e  supports the cylindrical portion  72   a  to be rotatable about the rotation axis R 2 . The inner surface of the bearing concave portion  74   e  is pressed against the outer peripheral surface of the cylindrical portion  72   a  from the front side. The cylindrical portion  72   a  is interposed in the front-rear direction Y by the protruding portion  74   c  and the radially extending portion  71   a . 
     The shape of the clamping member  75  is arranged substantially symmetrically in the front-rear direction Y with respect to the shape of the clamping member  74 . The clamping member  75  includes a straight portion  75   a , a curved portion  75   b , and a protruding portion  75   c . The straight portion  75   a  extends in the left-right direction X in which the radially extending portion  71   a  extends. The straight portion  75   a  is located on the rear side (-Y side) of the radially extending portion  71   a . The straight portion  75   a  has a portion axially interposing the rear portion of the radially extending portion  71   a . The curved portion  75   b  is connected to the radially inner end portion of the straight portion  75   a . The curved portion  75   b  is located on the rear side of the roller  73 . The curved portion  75   b  extends in the circumferential direction around the rotation axis R 3 . The curved portion  75   b  is curved in a direction to be convex to the rear side when viewed in the axial direction. 
     The protruding portion  75   c  protrudes from the curved portion  75   b  toward the radially extending portion  71   a . The protruding portion  75   c  protrudes to the front side (+Y side) from the curved portion  75   b , for example. The protruding portion  74   c  is located between the first roller portion  73   b  and the second roller portion  73   c  in the axial direction. The protruding portion  75   c  has a bearing concave portion  75   e  recessed in a direction away from the radially extending portion  71   a . The bearing concave portion  75   e  is recessed to the rear side (-Y side) from the front end portion of the protruding portion  75   c . The cylindrical portion  73   a  is located inside the bearing concave portion  75   e . The inner surface of the bearing concave portion  75   e  supports the cylindrical portion  73   a  to be rotatable about the rotation axis R 3 . The inner surface of the bearing concave portion  75   e  is pressed against the outer peripheral surface of the cylindrical portion  73   a  from the rear side. The cylindrical portion  73   a  is interposed in the front-rear direction Y by the protruding portion  75   c  and the radially extending portion  71   a . 
     The clamping member  75  has a through hole  75   d  penetrating the straight portion  75   a  in the front-rear direction Y. A bolt  79  passes through the through hole  75   d  from the rear side (-Y side). The bolt  79  passes through a through hole  71   h  provided in the radially extending portion  71   a  in the front-rear direction Y and is fastened into a female screw hole  74   d  provided in the straight portion  74   a  of the clamping member  74 . As the bolt  79  is fastened, the clamping members  74  and  75  approach each other in the front-rear direction Y. As the bolt  79  is fastened, the cylindrical portion  72   a  of the roller  72  is pressed against the radially extending portion  71   a  by the inner surface of the bearing concave portion  74   e  in the protruding portion  74   c . As the bolt  79  is fastened, the cylindrical portion  73   a  of the roller  73  is pressed against the radially extending portion  71   a  by the inner surface of the bearing concave portion  75   e  in the protruding portion  75   c . 
     Accordingly, by adjusting the fastening amount of the bolt  79 , the frictional force around the rotation axes R 2  and R 3  generated between the outer peripheral surfaces of the cylindrical portions  72   a  and  73   a  of the rollers  72  and  73  and the inner surfaces of the bearing concave portions  74   e  and  75   e  and the side surface of the radially extending portion  71   a  in the front-rear direction Y can be adjusted. In the following description, the frictional force around the rotation axes R 2  and R 3  generated between the outer peripheral surfaces of the cylindrical portions  72   a  and  73   a  of the rollers  72  and  73  and the inner surfaces of the bearing concave portions  74   e  and  75   e  and the side surface of the radially extending portion  71   a  in the front-rear direction Y is referred to as “the rotational static frictional force of the rollers  72  and  73 ”. 
     By adjusting the fastening amount of the bolt  79 , a force for interposing the winding  33  between the first roller portions  72   b  and  73   b  can also be adjusted. That is, the radial frictional force generated between the first roller portions  72   b  and  73   b  and the winding  33  can be adjusted by adjusting the fastening amount of the bolt  79 . In the following description, the radial frictional force generated between the first roller portions  72   b  and  73   b  and the winding  33  is referred to as “the holding static frictional force of the winding  33 ”. 
     In the present example embodiment, since the second roller portions  72   c  and  73   c  are in contact with each other in the front-rear direction Y, a part of the fastening force due to the fastening of the bolt  79  can be received by the second roller portions  72   c  and  73   c . Accordingly, the load applied to the cylindrical portions  72   a  and  73   a  and the first roller portions  72   b  and  73   b  can be suppressed from becoming excessively large, and the rotational static frictional force of the rollers  72  and  73  and the holding static frictional force of the winding  33  can be suitably adjusted. 
     The first gripper  70   a  is held to be movable in the radial direction with respect to the first holder  61  within a range in which the pair of first arms  71   b  and  71   c  is movable between the first bearing portion  61   b  and the protruding wall portion  61   j . As illustrated in  FIG.  8   , the radially outer portion of the first gripper  70   a  passes through the first guide hole  61   i  in the radial direction. The radially outer portion of the first gripper  70   a  is fitted into the first guide hole  61   i . In the present example embodiment, the radially outer portion of the first gripper  70   a  includes the radially outer portion of the radially extending portion  71   a  and the radially outer portions of the straight portions  74   a  and  75   a . The radially outer end portion of the first gripper  70   a  protrudes to the radially outer side from the first holder  61 . 
     An elastic force FE toward the radially outer side is applied to the first gripper  70   a  by the elastic portions  65   a  and  65   b . That is, the elastic portions  65   a  and  65   b  apply a force to the pair of rollers  72  and  73  in a direction away from the winding core  80 . In the initial state, the elastic portion  65   a  applies, to the first arm  71   b , the elastic force FE toward the left side (-X direction). The elastic portion  65   b  applies, to the first arm  71   c , the elastic force FE toward the left side. 
     The total value of the elastic forces FE applied by the two elastic portions  65   a  and  65   b  is smaller than the holding static frictional force of the winding  33 . In addition, the rotational moment generated in the rollers  72  and  73  by applying the elastic force FE of the two elastic portions  65   a  and  65   b  to the first gripper  70   a  is smaller than the rotational static frictional force of the rollers  72  and  73 . Therefore, even when the elastic portions  65   a  and  65   b  apply the elastic force FE to the rollers  72  and  73 , the rollers  72  and  73  do not rotate about the rotation axes R 2  and R 3 , and slippage does not occur between the rollers  72  and  73  and the winding  33 . Accordingly, the winding  33  can be interposed and pulled by the pair of rollers  72  and  73 , and a tension T can be applied to the winding  33 . The magnitude of the tension T is the sum of the magnitudes of the elastic forces FE applied by the two elastic portions  65   a  and  65   b . 
     As illustrated in  FIG.  6   , the second gripper  70   b  includes a pair of rollers  77  and  78  that can be gripped with the winding  33  interposed therebetween. The pair of rollers  77  and  78  is located to be slightly separated above the pair of rollers  72  and  73  of the first gripper  70   a . Similarly to the first gripper  70   a , the second gripper  70   b  is held to be movable in the radial direction with respect to the second holder  62 . The radially outer portion of the second gripper  70   b  passes through the second guide hole  62   i  in the radial direction. The radially outer portion of the second gripper  70   b  is fitted into the second guide hole  62   i . The radially outer end portion of the second gripper  70   b  protrudes to the radially outer side from the second holder  62 . 
     As described above, the first holder  61  and the second holder  62  are bidirectionally rotatable about the central axis J 2 , and thus the first gripper  70   a  held by the first holder  61  and the second gripper  70   b  held by the second holder  62  are also bidirectionally rotatable about the central axis J 2 . Accordingly, in the present example embodiment, the first gripper  70   a  and the second gripper  70   b  are rotatable about the central axis J 2  in the directions opposite to each other. 
     In the present example embodiment, a worker or the like forms the first winding body  131  and the second winding body  132  by using the winding machine  50  described above. In the following description, an example of a case where the second winding body  132  is formed by the winding machine  50  will be described. Note that, in the present specification, the “worker or the like” includes a worker, an assembling device, and the like that perform each work. Each work may be performed only by the worker, may be performed only by the assembling device, or may be performed by the worker and the assembling device. 
     In a state where the windings  33  are gripped by the first gripper  70   a  and the second gripper  70   b , the worker or the like assembles the first holder  61  holding the first gripper  70   a  and the second holder  62  holding the second gripper  70   b  on the base member  51 . As illustrated in  FIG.  12   , at this time, the second winding jig  82 , the winding core  80 , and the bearing member  63  are not assembled. In addition, at this time, the winding  33  linearly extends from the first gripper  70   a  to the second gripper  70   b  when viewed in the axial direction. In this state, the winding  33  passes over the first hole  81   c  of the first winding jig  81 . 
     Next, the worker or the like assembles the second winding jig  82  in a state where the winding core  80  is fixed. The worker or the like inserts the winding core  80  into the guide groove  61   g  from above, and moves the winding core  80  and the second winding jig  82  to the rear side (-Y side) along the guide groove  61   g . Accordingly, the worker or the like fits the winding core  80  into the first hole  81   c . At this time, the winding core  80  pushes and bends the portion of the winding  33  arranged on the first hole  81   c  toward the rear side. Accordingly, as illustrated in  FIG.  13   , the portion of the winding  33  located between the portion gripped by the first gripper  70   a  and the portion gripped by the second gripper  70   b  is slightly curved toward the rear side. 
     In this state, a portion of the winding  33  which is in contact with the rear (-Y side) end portion of the winding core  80  is located between the first guide portion  81   d  and the second guide portion  82   d  in the axial direction. As illustrated in  FIG.  9   , a portion of the winding  33  which is in contact with the rear end portion of the winding core  80  is arranged obliquely along the first guide surface  81   e  and the second guide surface  82   e . After assembling the winding core  80  and the second winding jig  82 , the worker or the like fits the bearing member  63  into the fitting hole  62   e . Accordingly, the winding machine  50  in the initial state illustrated in  FIGS.  6  and  7    is assembled. 
     The worker or the like rotates the first holder  61  and the second holder  62  about the central axis J 2  in the directions opposite to each other with respect to the winding machine  50  in the initial state to wind the winding  33  around the winding core  80 . The worker or the like rotates the first holder  61  clockwise about the central axis J 2  when viewed from above, and rotates the second holder  62  counterclockwise about the central axis J 2  when viewed from above. Accordingly, as illustrated in  FIGS.  13  to  15   , the first gripper  70   a  and the second gripper  70   b  rotate about the central axis J 2  in the directions opposite to each other, and the winding  33  is wound around the winding core  80 . By repeating the procedure illustrated in  FIGS.  13  to  15   , the second winding body  132  wound around the winding core  80  is formed as illustrated in  FIG.  16   . 
     In  FIG.  16   , in the cross section of a plurality of second coil wire portions  132   a  in the second winding body  132 , the winding order is virtually indicated by a number. Among the plurality of second coil wire portions  132   a  stacked in two layers in the axial direction, the second coil wire portion  132   a  located on the lower side is a portion wound around the winding core  80  by the first gripper  70   a . Among the plurality of second coil wire portions  132   a  stacked in two layers in the axial direction, the second coil wire portion  132   a  located on the upper side is a portion wound around the winding core  80  by the second gripper  70   b . 
     When the winding  33  is wound around the winding core  80 , the winding  33  is pulled to the radially inner side. Therefore, the first gripper  70   a  which grips the winding  33  is also pulled to the radially inner side to be moved. Accordingly, the elastic portions  65   a  and  65   b  are further compressed and deformed, and the elastic force FE applied from the elastic portions  65   a  and  65   b  to the pair of rollers  72  and  73  increases. Further, when the rotational moment applied to the pair of rollers  72  and  73  by the elastic force FE becomes larger than the rotational static frictional force of the rollers  72  and  73 , the pair of rollers  72  and  73  rotates to sequentially feed the winding  33 . Accordingly, the winding  33  can be fed in a state where the tension T is suitably applied to the winding  33 . Note that since the holding static frictional force of the winding  33  is larger than the elastic force FE when the pair of rollers  72  and  73  starts to rotate, it is possible to suppress slippage from occurring between the winding  33  and the pair of rollers  72  and  73 . As for the second gripper  70   b , the winding  33  is fed from the pair of rollers  77  and  78  similarly to the first gripper  70   a . 
     According to the present example embodiment, each of the first gripper  70   a  and the second gripper  70   b  includes a pair of rollers that can be gripped with the winding  33  interposed therebetween. At least one of the first gripper  70   a  and the second gripper  70   b  is rotatable about the central axis J 2 . Therefore, by rotating the rotatable gripper, among the first gripper  70   a  and the second gripper  70   b , about the central axis J 2 , the winding  33  can be wound around the winding core  80 . At this time, since the first winding jig  81  and the second winding jig  82  are arranged with the winding core  80  interposed in the axial direction, the movement of the winding  33  in the axial direction can be suppressed by the first winding jig  81  and the second winding jig  82 . In addition, since the winding  33  can be gripped by the pair of rollers  72  and  73  and the pair of rollers  77  and  78 , the winding  33  can be fed by the rotation of each roller while applying the tension T to the winding  33  as described above. Accordingly, the winding  33  can be wound suitably along the outer peripheral surface of the winding core  80 . As described above, according to the present example embodiment, the winding  33  can be suitably wound around the winding core  80  without providing a member or the like that moves in accordance with the timing at which the winding  33  is wound. Therefore, the coil  30  can be suitably manufactured while the winding machine  50  has a simple structure. 
     According to the present example embodiment, the first gripper  70   a  and the second gripper  70   b  are rotatable about the central axis J 2  in the directions opposite to each other. Therefore, as described above, the first gripper  70   a  and the second gripper  70   b  are simultaneously rotated about the central axis J 2  in the directions opposite to each other, and the winding  33  can be wound around the winding core  80 . Accordingly, when the winding  33  is wound around the winding core  80  one or more turns as illustrated in  FIG.  15   , the portion of the winding  33  fed out from the first gripper  70   a  and wound around the winding core  80  and the portion fed out from the second gripper  70   b  and wound around the winding core  80  overlap each other in the axial direction. Therefore, the portion of the winding  33  wound by one of the first gripper  70   a  and the second gripper  70   b  can be pressed in the axial direction by the portion of the winding  33  wound by the other of the first gripper  70   a  and the second gripper  70   b . 
     Specifically, in the present example embodiment, the portion of the winding  33  wound by the first gripper  70   a  is suppressed from moving to the lower side by the first winding jig  81 , and the portion of the winding  33  wound by the second gripper  70   b  is suppressed from moving to the upper side. In addition, the portion of the winding  33  wound by the second gripper  70   b  is suppressed from moving to the upper side by the second winding jig  82 , and the portion of the winding  33  wound by the first gripper  70   a  is suppressed from moving to the lower side. Accordingly, the windings  33  can be suitably aligned and wound, and the coil  30  can be more suitably manufactured. 
     According to the present example embodiment, the winding machine  50  includes the first holder  61  that holds the first gripper  70   a  and the second holder  62  that holds the second gripper  70   b . The first holder  61  has an annular shape surrounding the first winding jig  81 . The second holder  62  has an annular shape surrounding the second winding jig  82 . The first holder  61  and the second holder  62  are rotatable about the central axis J 2  in the directions opposite to each other. Therefore, by rotating the first holder  61  and the second holder  62  in opposite directions to each other about the central axis J 2 , the first gripper  70   a  and the second gripper  70   b  can be easily revolved about the central axis J 2 . 
     According to the present example embodiment, the winding machine  50  has the first guide portion  81   d  located around the winding core  80 . The first guide portion  81   d  has the first guide surface  81   e  located closer to the upper side toward one side in the circumferential direction around the central axis J 2 . Therefore, as illustrated in  FIG.  9   , when the winding  33  is attached to the winding machine  50 , the portion of the winding  33  that comes into contact with the winding core  80  can be arranged obliquely to be inclined in the axial direction along the first guide surface  81   e . Accordingly, the portion of the winding  33  wound in the first turn by the first gripper  70   a  and the portion of the winding  33  wound in the first turn by the second gripper  70   b  can be arranged to be suitably shifted in the axial direction. Therefore, the portion of the winding  33  wound in the second turn by the first gripper  70   a  and the second gripper  70   b  is easy to be suitably overlapped with the portion of the winding  33  wound in the first turn in the axial direction. 
     Specifically, in the present example embodiment, the portion of the winding  33  wound in the second turn by the first gripper  70   a  is easy to be inserted into the lower side of the portion wound in the first turn by the second gripper  70   b . In addition, the portion wound in the second turn by the second gripper  70   b  is easy to be inserted into the upper side of the portion wound in the first turn by the first gripper  70   a . 
     The end portion of the winding  33  wound in the second turn by the first gripper  70   a  can be supported from the front side (+Y side) by the radially outer surface of the first guide portion  81   d . Therefore, it is possible to suppress the end portion of the winding  33  wound in the second turn by the first gripper  70   a  from entering the lower side of the portion of the winding  33  arranged obliquely along the first guide portion  81   d . Therefore, the portion of the winding  33  wound in the third turn by the first gripper  70   a  can be suitably overlapped on the outer side of the portion of the winding  33  wound in the first turn by the first gripper  70   a . Therefore, the windings  33  can be more suitably aligned and wound. 
     By providing the first guide portion  81   d  as described above, it is possible to suppress the displacement of the winding  33  and to suitably align and wind the winding  33 . Therefore, the winding  33  can be wound at a relatively high speed in a state where a relatively strong tension T is applied to the winding  33 . 
     According to the present example embodiment, the winding machine  50  has the second guide portion  82   d  located around the winding core  80 . The second guide portion  82   d  has the second guide surface  82   e  located closer to the upper side toward one side in the circumferential direction around the central axis J 2 . The first guide surface  81   e  and the second guide surface  82   e  are arranged to face each other with a gap interposed therebetween in the axial direction. Therefore, by the first guide surface  81   e  and the second guide surface  82   e , the portion of the winding  33  in contact with the winding core  80  can be arranged more suitably to be obliquely inclined in the axial direction. Accordingly, the windings  33  can be more suitably aligned and wound. 
     The end portion of the winding  33  wound in the second turn by the second gripper  70   b  can be supported from the front side (+Y side) by the radially outer surface of the second guide portion  82   d . Therefore, it is possible to suppress the end portion of the winding  33  wound in the second turn by the second gripper  70   b  from entering the upper side of the portion of the winding  33  arranged obliquely between the first guide portion  81   d  and the second guide portion  82   d . Therefore, the portion of the winding  33  wound in the third turn by the second gripper  70   b  can be suitably overlapped on the outer side of the portion of the winding  33  wound in the first turn by the second gripper  70   b . Accordingly, the windings  33  can be more suitably aligned and wound. 
     According to the present example embodiment, the first guide portion  81   d  and the second guide portion  82   d  are connected to the outer peripheral surface of the winding core  80 . Therefore, the portion of the winding  33  brought into contact with the winding core  80  is easy to be brought into contact with the first guide portion  81   d  and the second guide portion  82   d . Accordingly, the winding  33  can be suitably guided by the first guide portion  81   d  and the second guide portion  82   d . Therefore, the windings  33  can be more suitably aligned and wound. 
     According to the present example embodiment, the first guide portion  81   d  protrudes from the first winding jig  81  toward the second winding jig  82 , and the second guide portion  82   d  protrudes from the second winding jig  82  toward the first winding jig  81 . Therefore, by changing the axial interval between the first winding jig  81  and the second winding jig  82 , the axial interval between the first guide portion  81   d  and the second guide portion  82   d  can be easily changed. Accordingly, even in a case where the thickness of the winding  33  is changed, by changing the interval between the first guide portion  81   d  and the second guide portion  82   d  according to the thickness of the winding  33 , the winding  33  can be suitably wound around the winding core  80 . 
     According to the present example embodiment, the roller  72  has the collar portions  72   d  and  72   e  protruding from the contact portion  72   f  to the outer side in the radial direction about the rotation axis R 2  of the roller  72 . The roller  73  has the collar portions  73   d  and  73   e  protruding from the contact portion  73   f  to the outer side in the radial direction about the rotation axis R 3  of the roller  73 . Therefore, the windings  33  in contact with the contact portions  72   f  and  73   f  can be pressed in the axial direction by the collar portions  72   d ,  72   e ,  73   d , and  73   e . Accordingly, it is possible to suppress the winding  33  gripped by the first gripper  70   a  from being displaced in the axial direction. In addition, similarly, the collar portion provided on the second gripper  70   b  can suppress the winding  33  gripped by the second gripper  70   b  from being displaced in the axial direction. Therefore, when the winding  33  is wound by the first gripper  70   a  and the second gripper  70   b , when the portion of the winding  33  wound by the first gripper  70   a  and the portion of the winding  33  wound by the second gripper  70   b  intersect to be displaced in the axial direction, the portions of the winding  33  can be suppressed from coming into contact with each other. Therefore, the winding  33  can be more suitably wound. In addition, the inclination of the winding  33  can be suppressed. Accordingly, it is possible to suppress the twisting of the winding  33 . 
     According to the present example embodiment, each the pair of rollers  72  and  73  includes a pair of collar portions arranged to face each other with a space interposed therebetween in the axial direction of the rotation axis R 2 , R 3 . Therefore, the winding  33  can be interposed and pressed in the axial direction by each of the pair of collar portions  72   d  and  72   e  and the pair of collar portions  73   d  and  73   e . Accordingly, the winding  33  can be further suppressed from being displaced in the axial direction with respect to the pair of rollers  72  and  73 . Therefore, when the winding  33  is wound, it is possible to further suppress the contact between the portion of the winding  33  wound by the first gripper  70   a  and the portion of the winding  33  wound by the second gripper  70   b . Therefore, the winding  33  can be more suitably wound. In addition, the inclination of the winding  33  can be further suppressed. Accordingly, it is possible to further suppress the twisting of the winding  33 . 
     According to the present example embodiment, the winding machine  50  includes the elastic portions  65   a  and  65   b  that apply a force to the pair of rollers  72  and  73  in a direction away from the winding core  80 . Therefore, the tension T can be applied to the winding  33  gripped by the pair of rollers  72  and  73  by the force received from the elastic portions  65   a  and  65   b . Accordingly, the tension T can be easily applied to the winding  33 . 
     According to the present example embodiment, the winding  33  wound around the winding core  80  is a flat wire. Therefore, it is easy to align and wind the winding  33  with respect to the winding core  80 . 
     As illustrated in  FIG.  17   , the second winding body  132  formed by using the winding machine  50  is provided with a first concave portion  132   d  generated by providing the first guide portion  81   d . The first concave portion  132   d  is provided in a circumferentially extending portion  132   c  connecting the end portions of the pair of second axially extending portions  132   b  in the motor axial direction to each other. More specifically, the first concave portion  132   d  is provided at the first turn of the circumferentially extending portion  132   c . The first concave portion  132   d  is recessed in the motor radial direction. Although not illustrated, the second winding body  132  is also provided with a second concave portion generated by providing the second guide portion  82   d . The second concave portion is provided in a portion of the circumferentially extending portion  132   c  on the side opposite to the side where the first concave portion  132   d  is provided in the motor radial direction. 
     As illustrated in  FIG.  18   , the compression process S 3  is a process of compressing and deforming the first winding body  131  and the second winding body  132 . As illustrated in  FIG.  4   , in the present example embodiment, the compression process S 3  includes a first compression process S 3   a  and a second compression process S 3   b . The first compression process S 3   a  is a process of compressing and deforming the first winding body  131 . The second compression process S 3   b  is a process of compressing and deforming the second winding body  132 . In the present example embodiment, the first compression process S 3   a  and the second compression process S 3   b  are provided before the connection process S 4 . Either the first compression process S 3   a  or the second compression process S 3   b  may be performed first, or may be performed simultaneously. 
     In the first compression process S 3   a  of the present example embodiment, the contour shape of the first axially extending portion  131   b  in the cross section orthogonal to the motor axial direction is deformed into a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. Accordingly, the cross-sectional shape of the portion configuring the first axially extending portion  131   b  among the flat wires configuring the first winding body  131 , that is, the cross-sectional shape of the first coil wire portion  131   a  is deformed into a trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. By the first compression process S 3   a , the first axially extending portion  131   b  becomes the first axially extending portion  31   b , and the above-described first winding body  31  is formed. 
     In the second compression process S 3   b  of the present example embodiment, the contour shape of the second axially extending portion  132   b  in the cross section orthogonal to the motor axial direction is deformed into a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. Accordingly, the cross-sectional shape of the portion configuring the second axially extending portion  132   b  among the flat wires configuring the second winding body  132 , that is, the cross-sectional shape of the second coil wire portion  132   a  is deformed into a trapezoidal shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. By the second compression process S 3   b , the second axially extending portion  132   b  becomes the second axially extending portion  32   b , and the above-described second winding body  32  is formed. 
     As described above, in the compression process S 3 , the contour shape of the first axially extending portion  131   b  in the cross section orthogonal to the motor axial direction is deformed into a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction, and the contour shape of the second axially extending portion  132   b  in the cross section orthogonal to the motor axis J 1  is deformed into a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. 
     A method of compressing and deforming each winding body in first compression process S 3   a  and second compression process S 3   b  is not particularly limited. In the first compression process S 3   a  and the second compression process S 3   b  of the present example embodiment, each axially extending portion is subjected to press working by a mold surrounding each axially extending portion of each winding body, and each winding body is compressed and deformed. 
     The connection process S 4  is a process of arranging the second winding body  32  on the outer side of the first winding body  31  in the motor radial direction to connect the first winding body  31  and the second winding body  32 . In the connection process S 4  of the present example embodiment, the one end portion  31   c  of the first winding body  31  and the one end portion  32   c  of the second winding body  32  are connected. As described above, a method of connecting the one end portion  31   c  and the one end portion  32   c  is not particularly limited. Through the above processes, the coil  30  is manufactured. 
     According to the present example embodiment, the coil  30  includes the first winding body  31  and the second winding body  32  connected to the first winding body  31 . When N is a freely-selected integer of 1 or more, and M is a freely-selected integer larger than N, the first winding body  31  is an N-layer winding body aligned and wound in two rows aligned in the motor radial direction, and the second winding body  32  is an M-layer winding body aligned and wound in two rows aligned in the motor radial direction. In the case of aligning and winding flat wires in two rows, it is easy to align and wind the flat wires with high accuracy as compared with the case of aligning and winding the flat wires in three or more rows. Therefore, by connecting a plurality of winding bodies each aligned and wound in two rows, it is possible to easily manufacture the coil  30  in which flat wires are accurately aligned in four or more rows. Accordingly, the distortion of the shape of the coil  30  can be suppressed. 
     M is a freely-selected integer larger than N. Therefore, the number of layers of the second winding body  32  located on the outer side of the first winding body  31  in the motor radial direction is larger than the number of layers of the first winding body  31 . Here, in a case where the motor  1  is an inner rotor type motor, an interval between the teeth  22  adjacent to each other in the motor circumferential direction increases toward the outer side in the motor radial direction. Therefore, by making the number of layers of the second winding bodies  32  located on the outer side of the first winding body  31  in the motor radial direction larger than the number of layers of the first winding body  31 , more windings can be arranged between the teeth  22  with high space efficiency. Accordingly, the total number of windings of the coil  30  can be suitably increased. 
     For example, in a case where a multilayer wound coil is simply formed by aligning and winding flat wires, the total number of windings of the coil is the number obtained by multiplying the number of alignments by the number of layers. Therefore, for example, in a case where at least one of the number of alignments and the number of layers is limited, there is a possibility that the total number of windings of the coil that can be adopted is limited. On the other hand, according to the present example embodiment, since the number of layers of the first winding body  31  and the number of layers of the second winding body  32  are different from each other, it is easy to adjust the total number of windings of the coil  30  by adjusting the number of layers of each winding body. Therefore, the degree of freedom of the total number of windings of the coil  30  that can be adopted can be improved. In the present example embodiment, for example, the total number of windings of the coil  30  can be set to any even number of six or more. 
     In addition, according to the present example embodiment, the contour shape of the axially extending portion  30   b  in the cross section orthogonal to the motor axial direction is a fan shape in which the dimension in the motor circumferential direction decreases toward the inner side in the motor radial direction. Therefore, the coils  30  can be suitably filled and arranged between the teeth  22  adjacent to each other in the motor circumferential direction. Accordingly, it is easy to further improve the space factor of the coil  30 . 
     In addition, for example, in a case where the contour shape of the axially extending portion is formed into the fan shape as described above in the conventional multilayer wound coil, the cross-sectional shape of the coil wire portion located on the inner side in the motor radial direction has a smaller dimension in the motor circumferential direction and a larger dimension in the motor radial direction. On the other hand, the cross-sectional shape of the coil wire portion located on the outer side in the motor radial direction has a larger dimension in the motor circumferential direction and a smaller dimension in the motor radial direction. Accordingly, the cross-sectional shape of at least some of the coil wire portions tends to be flat. In this case, the eddy current loss of the coil tends to increase. When a flat wire having a substantially square cross-sectional shape is deformed to have a flat cross-sectional shape, the deformation amount of the flat wire tends to increase. Therefore, when the flat wire is deformed, there is a possibility that the enamel coating provided on the surface is broken. In addition, the deformation of each coil wire portion configuring the axially extending portion tends to be non-uniform. 
     On the other hand, according to the present example embodiment, the number of layers of the second winding body  32  located on the outer side of the first winding body  31  in the motor radial direction is larger than the number of layers of the first winding body  31 . Therefore, the number of layers of the second winding bodies  32  configuring the portion of the axially extending portion  30   b  on the outer side in the motor radial direction can be relatively large, and the number of layers of the first winding bodies  31  configuring the portion of the axially extending portion  30   b  on the inner side in the motor radial direction can be relatively small. Accordingly, even when the contour shape of the axially extending portion  30   b  is deformed into a fan shape, the deformation amount of each coil wire portion configuring the axially extending portion  30   b  can be reduced. Therefore, the cross-sectional shape of each coil wire portion can be suppressed from becoming flat. Therefore, it is possible to suppress an increase in eddy current loss of the coil  30 . In addition, it is possible to suppress breakage of the enamel coating provided on the surface of the flat wire. In addition, it is possible to suppress the deformation of each coil wire portion configuring the axially extending portion  30   b  from becoming non-uniform. 
     For example, in a case where flat wires are simply aligned and wound to form a multilayer wound coil, in a certain number of layers or the like, the contour shape of the axially extending portion may be difficult to be compressed and deformed into a fan shape due to the increase in the deformation amount of the flat wires as described above. Therefore, in a case where the contour shape of the axially extending portion is formed in a fan shape, the number of layers and the like are likely to be limited, and there is a possibility that the total number of windings of the coil that can be adopted is limited. On the other hand, according to the present example embodiment, the contour shape of the axially extending portion can be formed into a fan shape while suppressing the deformation amount of each coil wire portion as described above. Therefore, it is possible to suppress the occurrence of limitation on the total number of windings of the coil  30  that can be adopted, and it is easy to adopt the desired total number of windings of the coil  30  within an even number range of six or more. 
     According to the present example embodiment, the first compression process S 3   a  and the second compression process S 3   b  are provided before the connection process S 4 . Therefore, it is possible to connect the first winding body  31  and the second winding body  32  after the first winding body  131  and the second winding body  132  are respectively deformed to form the first winding body  31  and the second winding body  32 . Accordingly, each winding body can be easily compressed and deformed as compared with a case where the first winding body  131  and the second winding body  132  are collectively compressed and deformed after being bonded. 
     The present disclosure is not limited to the above-described example embodiment, and another configuration may be adopted within the scope of the technical idea of the present disclosure. The type of the winding wound by the winding machine is not particularly limited. The winding may be, for example, a round wire. One of the first gripper and the second gripper may be non-rotatable about the central axis of the winding core. In this case, the winding core may be rotatable about the central axis. In this case, the winding can be wound similarly to the above-described example embodiment by simultaneously rotating the other gripper rotatable about the central axis and the winding core in the same direction about the central axis. The first gripper and the second gripper may be rotatable only in one direction around the central axis. 
     The first guide portion may be provided on the winding core. The first guide portion may not have the first guide surface. The first guide portion may not be provided. The second guide portion may be provided on the winding core. The second guide portion may not have the second guide surface. The second guide portion may not be provided. 
     One of the pair of rollers of the first gripper may not have the collar portion. One of the pair of rollers of the second gripper may not have the collar portion. The collar portion may not be provided. The elastic portion may be any member as long as a force is applied to the pair of rollers in a direction away from the winding core. One elastic portion may be provided for each gripper, or three or more elastic portions may be provided for each gripper. The elastic portion may not be provided. 
     N is not particularly limited as long as it is an integer of 1 or more. M is not particularly limited as long as it is an integer larger than N. L is not particularly limited as long as it is an integer larger than M. For example, N may be 1, M may be 2, and L may be 3. That is, the first winding body may be a single-layer winding body, the second winding body may be a two-layer winding body, and the third winding body may be a three-layer winding body. In addition, M may be greater than N by 2 or more, and L may be greater than M by 2 or more. N, M, and L are preferably, for example, 10 or less. This is because it is easy to wind the flat wire to form each winding body, and it is easy to compress and deform each winding body. In addition, M is preferably, for example, three times or less of N. In this way, when the second winding body is compressed and deformed, the cross-sectional shape of the coil wire portion configuring the second axially extending portion can be suppressed from becoming flatter. The contour shape of the axially extending portion in the cross section orthogonal to the axial direction may not be a fan shape. The cross-sectional shape of the coil wire portion configuring the axially extending portion may not be a trapezoidal shape. 
     The process of compressing and deforming the first winding body and the process of compressing and deforming the second winding body may be provided after the process of connecting the first winding body and the second winding body. The processes of compressing and deforming the first winding body and the second winding body may not be provided. The coil formed by the winding machine of the present disclosure is not particularly limited. The coil formed by the winding machine of the present disclosure may be the first winding body itself or the second winding body itself. 
     The motor to which the coil formed by the winding machine of the present disclosure is applied is not particularly limited. The motor to which the coil formed by the winding machine of the present disclosure is applied may be an outer rotor type motor. The configurations and methods described above in the present specification can be appropriately combined within a range consistent with each other. 
     Features of the above-described preferred example embodiments and the modifications thereof may be combined appropriately as long as no conflict arises. 
     While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.