Abstract:
Disclosed is a method for producing a stator for a rotary electric machine, which involves preparing a stator core having a plurality of slots. Each of a plurality of coils is provided with a pair of coil ends, a first side, and a second side. The first side and/or the second side is inserted into the retaining groove of a jig, and each coil is set on the jig in a manner such that both coil ends extend further to the outside than the end surfaces of the jig in the axial direction thereof. The jig is disposed inside the stator core in the diameter direction. The space between the first side and the second side of the coil is expanded by applying pressing force to both coil ends from the axial direction of the stator core by means of a pressing member.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a manufacturing method and a manufacturing apparatus for a stator of a rotary electric machine, and more particularly to a manufacturing and a manufacturing apparatus for a stator formed by inserting first sides and second sides of a plurality of coils, which are formed in advance from conductor wires, into different slots. 
       BACKGROUND ART 
       [0002]    When coupling a coil, which is formed in advance as a closed loop, to an annular stator core, which includes a plurality of radially formed slots having openings open to an inner circumference, so as to form a distributed winding, it is necessary to insert two insertion portions (sides) of each coil into two slots, which are spaced apart in the circumferential direction, while widening the insertion portions in accordance with the groove shape of the slots that widen radially. 
         [0003]    In patent document 1, when inserting a coil, which is shaped into a turtle shell form, into slots of a stator core, straight portions of the coil are radially ejected by an ejecting piece to move the straight portions along the slots and insert the straight portion into the slots. Upper and lower end portions of the coil are both formed to be V-shaped. When the straight portions are moved along the slots, the V-shaped portions are deformed to approach the stator core. Patent document 1 describes that the cross-sections of conductor wires forming the coil do not have to be generally circular and may have other shapes, such as a rectangular shape. 
         [0004]    Further, patent document 2 discloses a method for manufacturing a stator in which a first side of each of a plurality of coils, which are formed beforehand, is inserted into a slot of a stator core, and a second side of each of the coils is then inserted into another slot so that the coils are spirally overlapped when viewed from an end surface of the stator core. The method of patent document 2 uses a jig having an outer circumference including a plurality of slit-like holding grooves. The plurality of holding grooves include a plurality of first holding grooves, which are arranged at a pitch that is an integral multiple of the pitch of the slots in the stator core, and a plurality of second holding grooves, which are arranged at the same pitch as the first holding grooves. Further, the first side of each coil is inserted into a first holding groove, and the second side is inserted into a second holding groove, which is adjacent to the first holding groove into which the first side is inserted, and the coils are arranged along a circumference of the jig. The jig is arranged at a radially inner side of the stator core, and the first side of each of the coils is ejected outward in the radial direction by an ejecting means and inserted into the corresponding slot of the stator core. Next, the jig is rotated by a predetermined angle relative to the slots of the stator core and positioned so that the second holding grooves are aligned with the corresponding slots of the stator core. Then, the second side is ejected outward in the radial direction by the ejecting means and inserted into the corresponding slot of the stator core. 
       PRIOR ART DOCUMENTS 
     Patent Documents 
       [0000]    
       
         Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-195011 
         Patent Document 2: Japanese Laid-Open Patent Publication No. 2007-166849 
       
     
       SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
       [0007]    When using a conductor wire that easily deforms such as a round wire, as described in the patent document 1, the straight portions of a coil may be ejected from the inner side of the stator to the outer side and be expanded along the slots. However, when the coil is formed by rectangular wires, the coil differs from a coil formed by round wires and resists deformation. Thus, the coil cannot be easily deformed only when pushing the straight portion, and the coil is required to be pushed into the slit with an extremely large force in a state in which a large friction force acts between the straight portion and a wall surface of the slot. 
         [0008]    Further, the method of the patent document 2 is performed under the assumption that the coil is formed by easily deformed conductor wires such as round wires, and the arrangement of a bundle of the conductor wires forming the straight portions (the first side and the second side), which correspond to the portions inserted to the slots, can be changed in correspondence with the shape of the slots or the holding grooves. Accordingly, this cannot be applied to when the shapes of the first side and the second side cannot change in correspondence with the shape of the slots or the holding grooves, such as when the coils are formed by rectangular wires. 
         [0009]    It is an object of the present invention to provide a manufacturing method and a manufacturing apparatus for a stator of an electric rotating machine that can prevent deformation and damage of a stator core even when a coil requiring a large force for deformation is inserted into a slot of the stator core while being deformed. 
         [0010]    To achieve the above object, one aspect of the present invention is a manufacturing method of a stator for an electric rotating machine including the step of preparing an annular stator core including a plurality of slots arranged along a circumferential direction. Each of the slots includes an opening that opens in an inner circumference of the stator core, and a slot pitch between adjacent ones of the slots increases toward outside in a radial direction of the stator core. The manufacturing method includes the step of preparing the plurality of coils. Each of the coils is formed in advance from a conductor wire and includes two coil ends, a first side, and a second side. The first side and the second side are shaped to a form that fits within the slots of the stator core. The manufacturing method includes the step of preparing a jig that can be arranged at a radially inner side of the stator core. The jig includes a plurality of holding grooves, which are respectively opposed to the openings in a state arranged at the radially inner side of the stator core, and two end surfaces, which are located on two axial ends of the jig. The manufacturing method includes the step of setting each of the coils to the jig so that at least one of the first side and the second side is inserted in the holding groove of the jig and the two coil ends protrude outward in an axial direction of the jig from the two end surfaces. The manufacturing method includes the step of arranging the jig at the radially inner side of the stator core. The manufacturing method includes the step of inserting the first side and the second side into the slots of the stator core by applying a force with an ejecting portion to the coil that ejects at least one of the first side and the second side inserted in the holding groove out of the holding groove and into a corresponding one of the slots, while applying a pushing force with a pushing portion to the two coil ends from an axial direction of the stator core and increasing the distance between the first side and the second side of the coil. 
         [0011]    Here, “shaped” refers to a state in which even when force is applied to conductive wires that are wound together in a state contacting each other, the shape of the conductive wires is sustained. For example, when bundling and using a plurality of round wires as a conductive wire in a flat state in its entirety, the term refers to the flat shape being maintained by hardening it with resin or winding an insulative sheet of synthetic resin around the outer side of the flat shape. When the conductive wire is a rectangular wire, regardless of whether flatwise or edgewise winding is performed, conductive wires wound in a state contacting each other can be maintained in the contacting state even without performing a process such as that performed on round wires. Thus, when a plurality of layers are stacked, this corresponds to a “shaped” state. Further, the “slot pitch” refers to the distance between center lines of two adjacent ones of the slots. 
         [0012]    In this invention, the coils coupled to the stator core in a state forming distributed windings are set in a state in which the first sides and the second sides of the coils, which are formed in advance from conductive wires, are inserted in the holding grooves of the jig or one of the first sides and second sides are inserted in the holding grooves of the jig and the other one of the first sides and the second sides is inserted in the slots with the coil ends both projecting from the end surfaces at portions of the jig where the holding grooves are formed. In this state, the pushing portion applies pushing force to a coil from the axial direction of the stator core to the two coil ends to increase the distance between the first side and the second side. Further, when the ejecting portion applies force to the coil that ejects the first side and the second side out of the holding groove, the first side and the second side are ejected out of the holding grooves and into the corresponding slots to couple the coil to the stator core. The slot pitch is the smallest at where the openings of the slots are located and the larges at the bottom portions of the slots. Thus, when the first side and second side inserted in the holding grooves of the jig are simply ejected toward the slots of the stator core, the coil is moved toward the bottom portions of the slots in a state in which the distance between the first side and second side of the coil is smaller than the slot pitch. Thus, in a state in which the first side and second side are in contact with the wall surfaces of the slots, reaction force from the wall surfaces of the slots moves the first side and second side while increasing the distance therebetween. This may deform or damage the wall surfaces of the slot. However, in this invention, the pushing portion applies pushing force to the coil that increases the distance between the first side and the second side, and the ejecting pushing moves the coil toward the bottom portions of the slots. Accordingly, when inserting a coil, which requires a large force for deformation such as a coil formed from a rectangular wire, into the slot of the stator core, deformation and damage of the stator core can be prevented. 
         [0013]    Preferably, the first sides and the second sides of the coils are both inserted in the holding grooves of the jig. 
         [0014]    In this invention, unlike a case in which the coil is set in a state in which one of the first side and second side is inserted in a holding groove of the jig and the other one is inserted in a slot, there is no need for any special limitation to the coil shape in order to avoid interference between the coil end and the stator core during the setting. 
         [0015]    A second aspect of the present invention is a manufacturing apparatus of a stator for an electric rotating machine that includes a jig, a supporting portion, a pushing portion, and an ejecting portion. The stator includes an annular stator core and a plurality of cores. The stator core has a plurality of slots arranged along a circumferential direction. The coils are coupled to the stator core. Each of the slots includes an opening that opens in an inner circumference of the stator core. A slot pitch between adjacent ones of the slots increases toward outside in a radial direction of the stator core. Each of the coils is formed in advance by a conductor wire and includes two coil ends and a first side and second side, which are inserted into the slots. The jig can be arranged at a radially inner side of the stator core. The jig includes a plurality of holding grooves, which are respectively opposed to the openings in a state arranged at the radially inner side of the stator core, and two end surfaces, which are located on two axial ends of the jig. The holding grooves have a pitch corresponding to a pitch of the openings. The support portion supports the stator core and the jig, which is arranged at the radially inner side of the stator core, in a concentric state. The pushing portion applies a pushing force to the two coil ends from an axial direction of the stator core in a state in which at least one of the first side and the second side is inserted in the holding groove of the jig, which is arranged at the radially inner side of the stator core, and the two coil ends protrude outward from the two end surfaces in an axial direction of the jig. The ejecting portion applies a force to the coil that ejects the sides inserted in the holding grooves out of the holding grooves and into the corresponding slots. 
         [0016]    The present invention provides a manufacturing method and a manufacturing apparatus for a stator of an electric rotating machine that can prevent deformation and damage of a stator core even when a coil requiring a large force for deformation is inserted into a slot of the stator core while being deformed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1(   a ) is a schematic front view of a manufacturing apparatus for a stator according to one embodiment of the present invention; 
           [0018]      FIG. 1(   b ) is a cross-sectional view taken along line  1 B- 1 B in  FIG. 1(   a ); 
           [0019]      FIG. 2  is a schematic perspective view of a jig; 
           [0020]      FIG. 3(   a ) is a schematic perspective view of a coil; 
           [0021]      FIG. 3(   b ) is a schematic plan view of the coil; 
           [0022]      FIG. 4(   a ) is a schematic plan view showing a state in which the jig to which the coils are inserted is arranged in an inner side of a stator core; 
           [0023]      FIG. 4(   b ) is a schematic view showing a protruding state of a coil end at one side; 
           [0024]      FIG. 5  is a schematic view showing the relationship between an ejecting body and the coils when starting an insertion task; 
           [0025]      FIG. 6(   a ) is a schematic view showing a pushing action of the coil produced by a pushing body; 
           [0026]      FIG. 6(   b ) is a schematic view showing a pushing method in another embodiment; 
           [0027]      FIGS. 7(   a ) and  7 ( b ) are schematic views showing the actions produced during insertion; 
           [0028]      FIG. 8  is a schematic plan view showing a state in which a first side reaches a bottom portion of a slot; 
           [0029]      FIG. 9  is a schematic perspective view of the stator; 
           [0030]      FIG. 10(   a ) is a schematic cross-sectional view showing the arrangement of an ejecting portion in a further embodiment; 
           [0031]      FIG. 10(   b ) is a schematic perspective view of an ejecting portion in the further embodiment; 
           [0032]      FIG. 11  is a schematic view of an ejecting portion in another embodiment; 
           [0033]      FIGS. 12(   a ) and  12 ( b ) are partial schematic views showing the shape of a coil end in a further embodiment; and 
           [0034]      FIG. 12(   c ) is a partial schematic perspective view showing a conductor wire in another embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    One embodiment for manufacturing a stator in which coils are coupled in a lap winding to a stator core in accordance with the present invention will now be described with reference to  FIGS. 1 to 9 . 
         [0036]    As shown in  FIGS. 1(   a ) and  1 ( b ), a manufacturing apparatus for a stator includes a support portion  30 , which supports a stator core  10  and a jig  20 , a pushing portion  50 , which applies pushing force to a coil (shown in  FIG. 3)   40 , and an ejecting portion  60 , which applies a force in a radial direction of the stator core  10  to the coil  40  that is in a state pushed and deformed by the pushing portion  50 . 
         [0037]    The stator core  10  is annular and has an inner circumference including a plurality of teeth  11  arranged in fixed intervals. A center line of each tooth  11  lies along a straight line extending radially from the center of the stator core  10 . A slot  12  is formed between adjacent one of the teeth  11 . In detail, each of the slots  12  has an opening  12   a  that opens in the inner circumference of the stator core  10 . The stator core  10  has a slot pitch that widens from the openings  12   a  toward their bottom portions (i.e., outward in the radial direction of the stator core  10 ). The slot pitch refers to the distance between the center lines of two adjacent ones of the slots  12 . 
         [0038]    As shown in  FIG. 2 , the jig  20  includes a support column  21  and a main body  22 , which is generally cylindrical and fixed to an upper end of the support column  21 . A lower end of the support column  21  includes a disk-shaped fixing portion  23 , which fixes the jig  20  to the support portion  30 . The main body  22  has an outer circumferential surface including a plurality of holding grooves  22   a , which extend in a radial direction of the main body  22 . The pitch of two adjacent ones of the holding grooves  22   a  corresponds to the pitch of the openings  12   a  (i.e., is the same as the pitch of the openings  12   a ). Further, the jig  20  can be arranged inward in the radial direction of the stator core  10  in a state in which the holding grooves  22   a  are respectively opposed to the openings  12   a  of the slots  12  of the stator core  10 . 
         [0039]    The support portion  30  can support the stator core  10  and the jig  20 , which is arranged therein, in a concentric state. In detail, the support portion  30  includes a support frame  31 , which is linearly movable along a rail  15  arranged on a base B, and the support frame  31  can be reciprocated by a drive portion  32 . The drive portion  32  reciprocates the support frame  31  with a ball screw mechanism (not shown) which is driven by a motor M. 
         [0040]    The support frame  31  includes two support plates  31   a , an upper one and a lower one, and four support columns  31   b , which connect the support plates  31   a . A support body  33 , which accommodates and supports the stator core  10  and the jig  20 , is supported to be rotatable relative to the upper support plate  31   a . The support body  33  is generally cylindrical and has a closed end, and a gear body  34   a  is fixed to the outer circumference of the support body  33 . The support body  33  includes a hole through which the fixing portion  23  of the jig  20  can be extended. A rotating shaft  35  is arranged on the lower support plate  31   a  extending in the vertical direction coaxially with the gear body  34   a . A gear body  34   b  having the same diameter and the same number of teeth as the gear body  34   a  is fixed to an upper portion of the rotating shaft  35  to be rotated integrally with the rotating shaft  35 . The fixing portion  23  of the jig  20  is coupled in a removable manner to an upper surface of the gear body  34   b . The support frame  31  includes a rotating shaft  37 . Gears  36   a  and  36   b , which are respectively engaged with the gear bodies  34   a  and  34   b , are fixed to the rotating shaft  37 . A worm wheel  38  is fixed to and rotated integrally with the rotating shaft  37 . Further, the worm wheel  38  is rotated by a worm (not shown), which is driven manually or by a motor, thereby rotating the rotating shaft  37 . The rotation of the rotating shaft  37  rotates the support body  33  and the jig  20  with the gears  36   a  and  36   b  and the gear bodies  34   a  and  34   b . The support body  33  and the jig  20  are separated. However, the gear bodies  34   a  and  34   b  are rotated at the same rotating speed. Thus, support body  33  and the jig  20  are rotated at the same rotating speed. 
         [0041]    As shown in  FIG. 3(   a ), the coil  40  is formed by edgewise winding a rectangular wire, which serves as a conductor wire  40   a , into a turtle shell form elongated in the vertical direction. The coil  40  includes a first side  41   a  and a second side  41   b , which are straight portions extending parallel to each other, and coil ends  42   a  and  42   b , which are continuous with the first side  41   a  and the second side  41   b , and bent into ridges extending in opposite directions. In other words, the two coil ends  42   a  and  42   b  are formed to have bulging shapes. The first side  41   a  and the second side  41   b  are formed to be longer than the axial length of the stator core  10 . In a state in which the first side  41   a  and the second side  41   b  are inserted (accommodated) in the slots  12 , end portions of the first side  41   a  and the second side  41   b  protrude from end surfaces of the stator core  10 . In  FIG. 3(   a ), the coil  40  is shown with a simple turtle shell form but is actually formed in a state in which the coil ends  42   a  and  42   b  are twisted (twisting not shown in the drawings). Accordingly, when considering the first side  41   a , the second side  41   b , and the coil ends  42   a  and  42   b  as one member, the coil  40  is formed so that surfaces on the opposite sides of the first side  41   a  and the second side  41   b  are tapered as shown in  FIG. 3(   b ). Further, the rectangular wire is coated to be insulative. 
         [0042]    As shown in  FIG. 1(   a ), the pushing portion  50  includes two lifting support bodies  52   a  and  52   b , which can be lifted and lowered by a ball screw mechanism  51  arranged on the base B. The lifting support bodies  52   a  and  52   b  are synchronously movable in opposite directions. More specifically, when the lifting support body  52   a  is lifted, the lifting support body  52   b  is lowered, and when the lifting support body  52   a  is lowered, the lifting support body  52   b  is lifted. The ball screw mechanism  51  lowers the lifting support body  52   a  and lifts the lifting support body  52   b  when driven by the forward rotation produced by the motor  53 . Further, the ball screw mechanism  51  lifts the lifting support body  52   a  and lowers the lifting support body  52   b  when driven by the reverse rotation of the motor  53 . 
         [0043]    The lifting support bodies  52   a  and  52   b  support pushing bodies  54   a  and  54   b , respectively. The pushing bodies  54   a  and  54   b  are each formed by a roller  55 , and the roller  55  is supported to be rotatable by a support shaft projecting generally parallel to the lifting support bodies  52   a  and  52   b.    
         [0044]    The pushing body  54   a  moves away from the support body  33  when the lifting support body  52   a  is lifted and moves toward the support body  33  when the lifting support body  52   a  is lowered. The pushing body  54   b  moves away from the support body  33  when the lifting support body  52   b  is lowered and moves toward the support body  33  when the lifting support body  52   b  is lifted. Further, horizontal movement of the support frame  31  relatively moves the pushing bodies  54   a  and  54   b  to a position opposed to the support body  33  and a position not opposed to the support body  33 . 
         [0045]    The pushing bodies  54   a  and  54   b  are arranged at a standby position, at which the pushing bodies  54   a  and  54   b  are separated from and opposed to the coil ends  42   a  and  42   b  of the coil  40  (shown in  FIG. 3 ) arranged between the stator core  10  and the jig  20  that are accommodated in an accommodation portion  33   a , and an actuation position, at which the pushing bodies  54   a  and  54   b  come into contact with the coil ends  42   a  and  42   b  and apply a pushing force acting to compress the coil  40  from the upward and downward directions. In other words, the pushing bodies  54   a  and  54   b  form sections where force is applied to the coil  40 . In the pushing portion  50 , the sections where force is applied to the coil  40  are rotatable about axes extending in an axial direction of the stator. 
         [0046]    The ejecting portion  60  includes ejecting bodies  61   a  and  61   b , which are respectively supported by the lifting support bodies  52   a  and  52   b  of the pushing portion  50 . The ejecting bodies  61   a  and  61   b  are formed by rollers  62 . The rollers  62  are rotatably supported by support shafts projecting vertically from the lifting support bodies  52   a  and  52   b , respectively. The ejecting bodies  61   a  and  61   b  are formed so that that they can apply force to the coil  40  that ejects the first side  41   a  and the second side  41   b  out of the holding grooves  22   a  and into the corresponding slots  12  in a state in which the coil  40  is pushed and deformed by the pushing bodies  54   a  and  54   b  of the pushing portion  50 . In detail, the ejecting bodies  61   a  and  61   b  are coupled to the lifting support bodies  52   a  and  52   b  so that the rollers  62  can contact the coil ends  42   a  and  42   b  of the coil  40  from the central side of the jig  20  when the pushing bodies  54   a  and  54   b  are arranged at the actuation position. 
         [0047]    A method for manufacturing a stator with the manufacturing apparatus described above will now be described. 
         [0048]    First, in a state in which the jig  20  is removed from the support portion  30 , the first sides  41   a  and the second sides  41   b  of the coils  40  are inserted into the holding grooves  22   a  so that the coil ends  42   a  and  42   b  substantially extend along the outer circumference of the main body  22 . As shown in  FIG. 4 , each coil  40  is held by the jig  20  in a state in which the first side  41   a  is located at a portion closer to an opening of the holding groove  22   a , and the second side  41   b  is located at a portion (inner side) closer to a bottom portion of the holding groove  22   a . The coil ends  42   a  and  42   b  of each coil  40  are formed so as not to interfere with the adjacent coil ends  42   a  and  42   b . Further, each coil  40  is set in a state in which the coil ends  42   a  and  42   b  both protrude from the two end portions of the corresponding holding grooves  22   a , that is, a state protruding outward from the two end surfaces of the main body  22 . 
         [0049]    Next, in a state in which the pushing bodies  54   a  and  54   b  and the ejecting bodies  61   a  and  61   b  are arranged at positions that are not opposed to the support body  33 , the jig  20 , to which the coils  40  are coupled in the state described above, is coupled to the support body  33  from the upper side. In detail, the jig  20  is inserted into the accommodation portion  33   a  from the side of the fixing portion  23 , and the fixing portion  23  is fixed to the upper surface of the gear body  34   b  in a state in which the support column  21  protrudes downward from the support body  33 . 
         [0050]    Next, the stator core  10  is lowered in a state coaxial with the jig  20  and inserted into the accommodation portion  33   a.    
         [0051]    Next, the support frame  31  is moved to a position at which the pushing bodies  54   a  and  54   b  and the ejecting bodies  61   a  and  61   b  become opposed to the support body  33 . When the motor  53  is driven to produce forward rotation in this state, the upper lifting support body  52   a  is lowered, and the lower lifting support body  52   b  is lifted. Further, as shown by the double-dashed lines in  FIG. 6(   a ), when the pushing bodies  54   a  and  54   b  respectively come into contact with the bulges in the coil ends  42   a  and  42   b  of the coil  40 , the ejecting body  61   a  comes into contact with the coil end  42   a  of one coil  40  from the central side of the jig  20 , that is, the bottom portion side of the holding groove  22   a , as shown in  FIG. 5 . Further, although not shown in the drawings, the lower ejecting body  61   b  contacts the coil end  42   b  from the central side of the jig  20 , that is, the bottom portion side of the holding groove  22   a . When the lowering of the upper lifting support body  52   a  and the lifting of the lower lifting support body  52   b  further continues, the pushing bodies  54   a  and  54   b  of the pushing portion  50  apply pushing force to the two coil ends  42   a  and  42   b  from the axial direction of the stator core  10 , as shown by the solid lines in  FIG. 6(   a ). This increases the distance between the first side  41   a  and the second side  41   b  in the coil  40 . 
         [0052]    Further, from when the ejecting bodies  61   a  and  61   b  come into contact with the coil ends  42   a  and  42   b , the support frame  31  is moved away from the ball screw mechanism  51  in synchronism with the movement of the lifting support bodies  52   a  and  52   b . Further, the force applied by the ejecting bodies  61   a  and  61   b  to the coil ends  42   a  and  42   b  acts to move the first side  41   a  and the second side  41   b  of the coil  40  in the radial direction of the stator core  10  and the jig  20 . 
         [0053]    A slot pitch of the stator core  10  is the narrowest (smallest) at the openings  12   a  of the slots  12  widest (largest) at the bottom portions of the slots  12 , and the holding grooves  22   a  of the jig  20  extend along lines extended from the slots  12 . Accordingly, when force directed in the radial direction from the axis of the stator core  10  is simply applied to the coil  40  without the distance between the first side  41   a  and the second side  41   b  being changed, the first side  41   a  and the second side  41   b  would be arranged outside the slot  12  as shown by the double-dashed lines in  FIG. 7(   b ). However, the first side  41   a  and the second side  41   b  of the coil  40  are actually guided by the wall surfaces of the slots  12  and the holding grooves  22   a  and moved toward the bottom portions of the slots  12 . Here, the force increasing the distance between the first side  41   a  and the second side  41   b  of the coil  40  is applied to the first side  41   a  and the second side  41   b  from the wall surfaces of the slots  12  and the holding grooves  22   a . This produces a reaction force applied to the wall surfaces of the slots  12  and the holding grooves  22   a  from the first side  41   a  and the second side  41   b . The force required for increasing the distance between the first side  41   a  and the second side  41   b  is large. Accordingly, when the first side  41   a  and the second side  41   b  slide in a state in which a large force is applied between the first side  41   a  and second side  41   b  and the wall surfaces of the slots  12  and holding grooves  22   a , the wall surfaces of the slots  12  and the holding grooves  22   a  may be deformed or damaged, and an insulative coating of the coil  40  may fall off. 
         [0054]    However, in this embodiment, the coil  40  is moved toward the bottom portions of the slot  12  by the ejecting bodies  61   a  and  61   b  as the pushing force of the pushing bodies  54   a  and  54   b  increase the distance between the first side  41   a  and the second side  41   b  of the coil  40 . Thus, as shown in  FIG. 7(   a ), the first side  41   a  and the second side  41   b  are smoothly moved in the direction in which the slots  12  extend. Accordingly, even when deforming and inserting the coil  40 , which is formed by a rectangular wire and requires a large force for deformation, into the slots  12  of the stator core  10 , deformation and damage of the stator core  10  and removal of an insulative coating from the coil  40  are prevented. 
         [0055]    The pushing portion  50  and the ejecting portion  60  do not move the first side  41   a  and the second side  41   b  of the coil  40  to a final insertion (accommodation) position in the slots  12  through a single task. A number of tasks are required for movement to the final insertion position. Further, the tasks of the pushing portion  50  and the ejecting portion  60  are interrupted when the pushing bodies  54   a  and  54   b  are moved in the pushing direction by an amount corresponding to a single task. 
         [0056]    The gear bodies  34   a  and  34   b  are rotated by a predetermined angle in this state, and the stator core  10  and the jig  20  are rotated together with the support body  33 . Further, the next coil  40  subject to the operation of the pushing portion  50  and the ejecting portion  60  moves at it undergoes the pushing operation of the pushing bodies  54   a  and  54   b  and the ejecting operations of the ejecting bodies  61   a  and  61   b . As a result, the first side  41   a  and the second side  41   b  of the next coil  40  are moved by a predetermined amount toward the bottom portions of the slots  12 . The same tasks are repeated afterward throughout the entire circumference so that each coil  40  undergoes a single pushing and ejecting task. 
         [0057]    Next, the motor  53  is driven to produce a predetermined amount of forward rotation. This lowers the upper lifting support body  52   a  and lifts the lower lifting support body  52   b . In synchronism with the movement of the lifting support bodies  52   a  and  52   b , the ejecting bodies  61   a  and  61   b  are moved by a predetermined amount in a direction in which the support frame  31  moves away from the ball screw mechanism  51 . Further, in the same manner as described above, a coil  40  is moved toward the bottom portion of the slot  12  by the ejecting bodies  61   a  and  61   b  as the pushing force of the pushing bodies  54   a  and  54   b  increase the distance between the first side  41   a  and the second side  41   b . Subsequently, the stator core  10  and the jig  20  are rotated together with the support body  33  in the same manner as described above to perform a second pushing and ejecting task on each coil  40 . 
         [0058]    The repetition of this task for a number of times results in a state in which the first sides  41   a  reach the bottom portions of the slot  12 , as shown in  FIG. 8 . Then, the second sides  41   b  are moved by the pushing bodies  54   a  and  54   b  until the second sides  41   b  reach the bottom portions of the slots  12 . 
         [0059]    Then, after moving the pushing bodies  54   a  and  54   b  and the ejecting bodies  61   a  and  61   b  to positions where they do not interfere with the removal of the stator core  10  from the support body  33 , the stator core  10 , in which the coils  40  are inserted at predetermined positions in the slots  12 , is removed from the support body  33 . Subsequently, the ends of the conductor wires  40   a  of the coils  40  are connected. This completes a stator S, as shown in  FIG. 9 . 
         [0060]    The present embodiment has the advantages described below. 
         [0061]    (1) The stator manufacturing method uses the jig  20 , which can be arranged in inside the stator core  10  in a state in which the holding grooves  22   a  are opposed to the openings  12   a  of the slots  12  in the stator core  10 . Further, the coil  40  is formed in advance from the conductor wire  40   a  including at least a portion (the first side  41   a  and the second side  41   b ) that fits within the slots  12  of the stator core  10 . Further, each coil  40  is set with the first side  41   a  and the second side  41   b  inserted in the holding grooves  22   a  of the jig  20 , which is arranged inside the stator core  10 , and the coil ends protruding out of the two end portions of the holding groove  22   a . In this state, the pushing portion  50  applies pushing force to both of the coil ends  42   a  and  42   b  from the axial direction of the stator core  10  to increase the distance between the first side  41   a  and the second side  41   b  of the coil  40 . Further, the ejecting portion  60  applies force to the coil  40  ejecting the first side  41   a  and the second side  41   b  out of the holding grooves  22   a  and inserting the first side  41   a  and the second side  41   b  into the corresponding slots  12 . Accordingly, the application of force to the stator core  10  is suppressed when the coils  40  are deformed. This prevents deformation and damage of the stator core  10  and prevents removal of an insulative coating from the conductor wires  40   a  even when inserting and deforming the coils  40 , which are formed by rectangular wires and required a large force for deformation. 
         [0062]    (2) When the coils  40  are deformed, excessive force is not applied to the jig  20 , specifically, the wall surfaces of the holding grooves  22   a . This decreases the strength required for the jig  20  and increases the design freedom of the motor. This because when the diameter of the motor using the stator S is small or when the number of coils is increased, the thickness between the holding grooves  22   a  of the jig  20  decreases and reduces the strength. This must be taken into consideration when designing the motor. However, when excessive force is not applied to the wall surfaces of the holding groove  22   a , such considerations are not necessary. 
         [0063]    (3) The rectangular wire is used as the conductor wire  40   a  forming the coil  40 . This improves the space factor of the coil  40  in comparison with when the coil  40  uses a conductor wire  40   a  having a circular cross-section or an elliptic cross-section. 
         [0064]    (4) The coil  40  is formed so that the coil ends  42   a  and  42   b  are both shaped to be bulging. As the coil  40 , for example, when using a coil  40  having the bulging shape formed on only the coil end  42   a  and applying pushing force to both of the coil ends  42   a  and  42   b  with the pushing portion  50  from the axial direction of the stator core  10 , the distance between the first side  41   a  and the second side  41   b  of the coil  40  will be increased. However, when a coil  40  has both of its coil ends shaped to be bulging, the distance between the first side and second side can easily be increased while the first side and second side remain parallel. 
         [0065]    (5) The pushing force of the pushing portion  50  and the ejecting force of the ejecting portion  60  are applied in a manner divided into parts. Accordingly, in comparison with when the pushing force and the ejecting force are applied to the entire circumference at the same time, the load applied to the pushing portion  50  and the ejecting portion  60  is decreased. Thus, the apparatus can be reduced in size. 
         [0066]    (6) The coils  40  are inserted in the entire circumference by the pushing force of the pushing portion  50  and the ejecting force of the ejecting portion  60  applied in a manner divided into parts. Further, the insertion of the coils  40  is completed by going around the circumference not once but a number of times. That is, the stator core  10  and the jig  20  are rotated a number of times to complete the insertion of the coils  40 . Accordingly, the coils  40  are moved smoothly in comparison to when moving each coil  40  to the predetermined position with a single pushing and ejecting operation. 
         [0067]    (7) The ejecting portion  60  includes the ejecting bodies  61   a  and  61   b , which are formed by the rollers  62 . In other words, the ejecting portion  60  is formed to be rotatable at portions applying force to the coils  40 . Accordingly, when friction force increase at a portion applying force to the coil  40  that is in contact, the portion is moved and another portion comes into contact with the coil  40 . This suppresses stress caused by friction and suppresses the advancement of wear at a particular portion. 
         [0068]    (8) The pushing portion  50  includes the pushing bodies  54   a  and  54   b  that are formed by the rollers  55  so that portions applying force to the coils  40  are rotatable. Accordingly, when the frictional force increases at the portion applying force to the coil  40  that is in contact, the portion is moved and another position comes into contact with the coil  40 . This suppresses stress caused by friction and suppresses the advancement of wear at a particular portion. 
         [0069]    (9) The drive portion that lifts and lowers the lifting support bodies  52   a  and  52   b  is driven by the motor  53 , and the drive portion that moves the ejecting bodies  61   a  and  61   b  relative to the stator core  10  and the jig  20  is driven by the motor M. Accordingly, this facilitates the synchronization of the operation of the pushing portion  50  that applies pushing force to the two coil ends  42   a  and  42   b  from the axial direction of the stator core  10  to increase the distance between the first side  41   a  and the second side  41   b  with the operation of the ejecting portion  60  that applies force to the coil  40  ejecting the second side  41   b  out of the holding groove  22   a  and into the corresponding slot  12 . 
         [0070]    (10) The coils  40  are set in a state inserted in the holding grooves  22   a  so that the first sides  41   a  are located near the openings of the holding grooves  22   a  and the second sides  41   b  are located near the bottom portions of the holding grooves  22   a . Accordingly, in comparison with when the coils  40  are set in a state inserted in the holding grooves  22   a  of the jig  20  so that the first sides  41   a  and the second sides  41   b  are both located near the openings of the holding grooves  22   a , the freedom increases for the shape of the coil ends  42   a  and  42   b  allowing for the jig  20  to be arranged at the inner side of the stator core  10 . 
         [0071]    The embodiment is not limited to the foregoing description and may be modified, for example, as described below. 
         [0072]    The ejecting portion  60  only needs to apply force that moves the first side  41   a  and the second side  41   b  toward an inner side (bottom side) of the slots  12 . For example, the ejecting portion may apply force to only one of the two coil ends  42   a  and  42   b . In other words, one of the ejecting bodies  61   a  and  61   b  may be omitted. 
         [0073]    The ejecting portion  60  may be formed to apply force to the first side  41   a  and the second side  41   b  instead of the coil ends  42   a  and  42   b . For example, as shown in  FIG. 10(   a ), the main body  22  may include an accommodating portion  24  that accommodates the ejecting portion  60 , and the ejecting portion  60  may be arranged in the accommodating portion  24 . As the ejecting portion  60 , for example, a solenoid  63  may be used, and an ejecting body  64  may be arranged on a distal end of a plunger of the solenoid  63 . The ejecting body  64  only needs to contact at least one of the first side  41   a  and the second side  41   b  of a single coil  40 . In a structure in which the pushing portion  50  simultaneously applies pushing force to a plurality of adjacent coils  40 , the ejecting body  64  is also formed so that it can simultaneously contact and apply ejecting force to a plurality of coils  40 . 
         [0074]    The ejection from the holding grooves  22   a  of the second side  41   b  by the ejecting portion  60  may be performed by a pulling device (not shown) arranged outside the jig  20  to pull a pulling tool  65 , which is set inward in the holding grooves  22   a  from the coil  40 , as shown in  FIG. 10(   b ). As the pulling tool  65 , a cord, a rod, a plate, or the like may be used. The pulling device is arranged near the two end surfaces of the stator core  10  and pulls the pulling tool  65  with a hook that is movable back and forth in the radial direction. Further, a member having a structure similar to that of the pulling tool  65  may be ejected by the ejecting portion  60 , which is arranged inward from the holding grooves  22   a  of the jig  20 . 
         [0075]    The ejecting bodies  61   a  and  61   b  do not necessarily have to be rotatable at locations such as the rollers  62  where force is applied to the coil  40  as long as they can diagonally come into contact with the coil  40  and suppress stress caused by the friction with the coil  40 . For example, the ejecting bodies  61   a  and  61   b  may be formed by plates such as spatulas. Further, the locations applying force to the coil  40  may be formed to be rotatable, and members including a plurality of ridges and valleys such as gear or a Caterpillar may be used. 
         [0076]    When pushing force is applied to the coil  40  by the pushing bodies  54   a  and  54   b , first, as shown in  FIG. 6(   a ), the pushing bodies  54   a  and  54   b  are moved in the axial direction of the jig  20  and the stator core  10  to push the coil ends  42   a  and  42   b . Then, as shown in  FIG. 6(   b ), the jig  20  and the stator core  10  may be rotated to push the coil  40  with the relative movement of the pushing bodies  54   a  and  54   b . Further, when rotated a number of times in the state in  FIG. 6(   b ), the positions of the pushing bodies  54   a  and  54   b  may be further changed in the direction the jig  20  and the stator core  10  are pushed in correspondence with the rotation. 
         [0077]    The pushing bodies  54   a  and  54   b  do not necessarily have to be formed to be rotatable at locations such as the rollers  55  where force is applied to the coil  40  and may be plate members or block bodies. 
         [0078]    When the application of the pushing force by the pushing portion  50  and the application of the ejecting force by the ejecting portion  60  are performed in a partial manner, the ejecting portion  60  may be provided at a plurality of locations on the jig  20 . For example, as shown in  FIG. 11 , the accommodating portion  24 , which accommodates the ejecting portion  60 , may be formed at four positions at equal intervals in the circumferential direction on the main body  22  of the jig  20 , and the ejecting portion  60  may be arranged in each accommodating portion  24 . For example, the solenoid  63  is used as the ejecting portion  60 , and the ejecting body  64  is arranged on the distal end of a plunger of the solenoid  63 . Further, the upper and lower support body  33  may both include four pushing portions  50  arranged at equal intervals in the circumferential direction of the support body  33 . This differs from when the pushing portion  50  is arranged at one location in that rotation of the stator core  10  and the jig  20  by 90 degrees allows for the application of the pushing force and the application of the ejecting force over the entire circumference of the stator core  10 . 
         [0079]    The application of the pushing force by the pushing portion  50  and the application of the ejecting force by the ejecting portion  60  may be performed at the same time on the entire circumference. For example, as the ejecting bodies, a plurality of circular arc-shaped ejecting bodies are arranged inward from the holding grooves  22   a  of the jig  20 . The ejecting bodies are circumferentially arranged in a partially overlapping manner as viewed from above. The ejecting bodies are all moved outward in the radial direction of the jig  20  to apply ejecting force at the same time to the entire circumference. As a drive portion that drives each ejecting body, a structure using a rotating cam or a structure driven by a hydraulic cylinder may be used. This differs from when the application of the pushing force and the application of the ejecting force are sequentially performed on parts of the coils  40  arranged over the entire circumference of the stator core  10  in that there is no need to relatively rotate the pushing portion  50  and the ejecting portion  60  to locations corresponding to the coils  40  where the pushing force and the ejecting force are applied. In other words, the structure that rotates the support body  33  becomes unnecessary. 
         [0080]    When the application of the pushing force by the pushing portion  50  and the application of the ejecting force by the ejecting portion  60  are performed at the same time on the entire circumference, as the ejecting bodies, ejecting rods may be used in each of the holding grooves  22   a  to which the first side  41   a  and the second side  41   b  are respectively inserted to be movable between positions in the holding grooves  22   a  inward from the first side  41   a  or the second side  41   b  and positions at the openings of the holding grooves  22   a . Further, like the pushing jig disclosed in the publication of the patent document 2, a pushing jig in which the same number of pushers as the holding grooves  22   a  are attached radially to the shaft may be used to simultaneously move the ejecting rods toward the openings of the holding grooves  22   a.    
         [0081]    The pushing portion  50  is not limited to a structure in which the lifting support bodies  52   a  and  52   b  are simultaneously lifted and lowered by the ball screw mechanism. For example, a mechanism may be employed in which one of the pushing bodies  54   a  and  54   b  supported by the lifting support bodies  52   a  and  52   b  comes into contact with the coil  40  and the other one moves afterward. 
         [0082]    The coil  40  only needs to be deformable so that the distance between the first side  41   a  and the second side  41   b  increases when the pushing force is applied by the pushing portion  50  to the two coil ends  42   a  and  42   b  from the axial direction of the stator core  10 , and there is no need for the coil ends  42   a  and  42   b  to both be shaped to be bulging. For example, a coil  40  may have only one of the two coil ends  42   a  and  42   b  be shaped to be bulging. However, a structure in which the coil ends  42   a  and  42   b  both have bulging shapes is preferable since the distance between the first side  41   a  and the second side  41   b  is smoothly increased when the pushing force is applied by the pushing portion  50 . 
         [0083]    The bulging shapes of the coil ends  42   a  and  42   b  do not have to be ridge-shaped. For example, the coil ends  42   a  and  42   b  may be formed to be semielliptical as shown in  FIG. 12(   a ) or may be formed to have inclined portions that are continuous with the first side  41   a  and the second side  41   b  at the two sides of a horizontally extending distal end as shown in  FIG. 12(   b ). 
         [0084]    The conductor wire  40   a  forming the coil  40  is not limited to a rectangular wire and may be, for example, as shown in  FIG. 12(   c ), a plurality of aligned conductor wires  40   a  having circular cross-sectional shapes. In other words, the coil  40  may be formed so that aligned round wires are wound into a predetermined shape. In this case, at least the portion fitted within the slot  12  is shaped. Thus, in a state in which a plurality of conductor wires  40   a  are formed in the coil  40 , the conductor wires  40   a  are solidified by a resin or the like or an insulating sheet is wound around the conductor wires  40   a  to maintain the portions of the first side  41   a  and the second side  41   b  in the bundled shape. The conductor wires  40   a  may be aligned in a plurality of rows instead of just one row. 
         [0085]    The structure that lifts and lowers the lifting support bodies  52   a  and  52   b  and the structure that moves the ejecting bodies  61   a  and  61   b  relative to the stator core  10  and the jig  20  are not limited to the structure including the ball screw mechanism that drives the drive portion with the motors  53  and M. For example, the lifting support bodies  52   a  and  52   b  may each be driven by a hydraulic cylinder and the support frame  31  may be driven by a hydraulic cylinder. 
         [0086]    The lifting support bodies  52   a  and  52   b  may each be driven by a linear motor, and a linear motor may be used as the drive portion  32  that drives the support frame  31 . 
         [0087]    To prevent deformation of the coil  40  from the predetermined shape when pushed by the pushing portion  50 , a guide may be arranged at the outer side of the coil  40 , for example, a guide plate or a guide bar. 
         [0088]    As long as the gear ratio between the gear body  34   a  and the gear  36   a  is the same as the gear ratio between the gear body  34   b  and the gear  36   b , the two gear bodies  34   a  and  34   b  do not necessarily have to have the same diameter and the same number of teeth. 
         [0089]    When the first side  41   a  and the second side  41   b  are set in a state inserted in the holding grooves  22   a , the first side  41   a  and the second side  41   b  of each coil  40  may both be set to be located near the openings of the holding grooves  22   a.    
         [0090]    Instead of the state in which the first side  41   a  and the second side  41   b  are inserted to the holding grooves  22   a , the insertion task of the coil  40  into the slots  12  may be started from a state in which one of the first side  41   a  and the second side  41   b  is inserted in a holding groove  22   a  of the jig  20 , and the other one of the first side  41   a  and the second side  41   b  is inserted in a slot  12 . In this case, a special shape is necessary so that the coil end does not interfere with the stator core  10  when arranging the jig  20  at the inner side of the stator core  10 . 
         [0091]    When setting the stator core  10  and the jig  20  in the support body  33  in a state in which the first sides  41   a  of the coils  40  are inserted in the slots  12 , the second sides  41   b  are inserted in the holding groove  22   a  of the jig  20 , and the coil ends  42   a  and  42   b  are both projected out of the two end portions of the stator core  10 , whichever one of the stator core  10  and the jig  20  may be set in advance. 
         [0092]    The stator S does not have to be one that inserts one first side  41   a  and one second side  41   b  in each of the slots  12 , and the stator S may be one that inserts a plurality of (for example, two) first sides  41   a  and a plurality of second sides  41   b  in each of the slots  12 . In this case, after inserting the coils  40  into the stator core  10  in the same manner as described above, the jig  20  is removed from the support body  33 . Subsequently, after setting coils  40  that are to be inserted next between the stator core  10  and the jig  20 , the series of insertion tasks described above are performed to complete the insertion of the coils  40 . 
         [0093]    The number of the slots  12  in the stator core  10  is not limited to thirty-six and may be greater than thirty-six (for example, forty-eight) or less than thirty-six (for example, twenty-four). 
         [0094]    The number of the slots  12  arranged between the first side  41   a  and the second side  41   b  of a coil  40  is not limited to four. For example, the number may be set to three, which is less than four, or may be set to five, which is greater than four. 
         [0095]    The coil  40  is not limited to a cassette type and may be formed, for example, so that a plurality of coils  40  are connected by connection wires. 
         [0096]    The coil  40  is not limited to the lap winding as long as it forms a distributed winding coupled to two slots  12  and can be pressed from two sides by the pushing portion  50 . For example, the coil  40  may form a wave winding and a concentric winding. 
         [0097]    The stator core  10  only needs to be annular with the slots  12  having the openings  12   a  that open in the inner circumference and the slot pitch increasing from the opening  12   a  toward the bottom portion. The stator core  10  may be a segmented type core formed by joining a plurality of core segments. However, when using a segmented type core, the magnetic resistance increases, and the output of the electric rotating machine cannot be increased. It is thus preferable that a segmented type core not be used. 
         [0098]    When applying pushing force with the pushing portion  50  and ejecting force with the ejecting portion  60  to some of the coils while repeating this task over the entire circumference, the stator core  10  and the jig  20  may be rotated by a predetermined amount in a state in which the pushing portion  50  and the ejecting portion  60  do not come into contact with the coil  40 . In other words, whenever rotating the stator core  10  and the jig  20  by a predetermined amount, the lifting support bodies  52   a  and  52   b  are moved to space apart the pushing bodies  54   a  and  54   b  from the coil  40  and space apart the ejecting bodies  61   a  and  61   b  from the coil  40 . Then, the stator core  10  and the jig  20  are rotated by a predetermined amount.