Patent Publication Number: US-2021184528-A1

Title: Armature and method of manufacturing armature

Description:
TECHNICAL FIELD 
     The preferred embodiments described herein relate to an armature and a method of manufacturing an armature. 
     BACKGROUND ART 
     There has hitherto been known an armature that includes an armature core provided with a plurality of slots that extend in the center axis direction. Such an armature is disclosed in Japanese Unexamined Patent Application Publication No. 2015-23771 (JP 2015-23771 A), for example. 
     JP 2015-23771 A discloses a rotary electric machine stator (hereinafter referred to as a “stator”) that includes a stator core provided with a plurality of slots that extend in the axial direction. The stator includes a coil constituted by joining the distal end portion of a first-side conductor segment, which is disposed on one axial side of the stator core, and the distal end portion of a second-side conductor segment, which is disposed on the other axial side of the stator core, to each other. The first-side conductor segment and the second-side conductor segment are each constituted from a conductor wire provided with an insulating coating and having a rectangular cross-sectional shape. In addition, the distal end portion of the first-side conductor segment and the distal end portion of the second-side conductor segment are exposed from the insulating coating. In the stator, the distal end portion of the first-side conductor segment and the distal end portion of the second-side conductor segment are joined to each other by heating the first-side conductor segment and the second-side conductor segment while being pressed against each other from both sides in the axial direction with a conductive bonding material in a paste form disposed between the respective exposed distal end portions thereof. In the stator, in addition, a plurality of first-side conductor segments and second-side conductor segments joined to each other are disposed adjacent to each other in the radial direction in each slot. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     
         
         Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-23771 (JP 2015-23771 A) 
       
    
     SUMMARY 
     Problem to be Solved 
     In the stator described in JP 2015-23771 A, however, the distal end portion of the first-side conductor segment and the distal end portion of the second-side conductor segment (conductor portions) are exposed from the insulating coating. Therefore, the insulation performance between a joint portion between the distal end portion of a first-side conductor segment and the distal end portion of a second-side conductor segment and a conductor segment (a first-side conductor segment or a second-side conductor segment) disposed adjacent to the joint portion may be lowered. 
     The preferred embodiment has been made in view of addressing the foregoing issue, and therefore has an object to provide an armature and a method of manufacturing an armature that enable securing the insulation performance between a joint portion and an adjacent segment conductor in the case where segment conductors are to be joined to each other. 
     Means for Solving the Problem 
     In order to achieve the foregoing object, a first aspect of the preferred embodiment provides an armature including: an armature core provided with a plurality of slots that extend in a center axis direction; and a coil portion in which a plurality of segment conductors are joined to each other at a joint portion, in which: sets of the plurality of segment conductors, which are joined to each other at the joint portion, are disposed in parallel in a radial direction of the armature core; and an insulating portion is provided on a conductor surface of one segment conductor, among the plurality of segment conductors which are disposed in parallel in the radial direction, at a position in the center axis direction corresponding to an adjacent joint portion which is the joint portion of a different segment conductor disposed adjacent to the one segment conductor in the radial direction, the insulating portion having a second insulation resistance which is higher than a first insulation resistance of an insulating coating of the different segment conductor. The term “insulating portion” as used herein is used to mean a wide concept including not only a member that is integral with the insulating coating but also a separate member superposed on the insulating coating. 
     In the armature according to the first aspect of the preferred embodiment, as described above, an insulating portion is provided on a conductor surface of one segment conductor at a position in the center axis direction corresponding to an adjacent joint portion, and the insulating portion has a second insulation resistance which is higher than a first insulation resistance of an insulating coating of a different segment conductor. Consequently, the insulation resistance of the insulating portion of the one segment conductor at a position adjacent to the adjacent joint portion can be made relatively high, and thus the insulation performance between the adjacent joint portion and the segment conductor which is adjacent to the adjacent joint portion can be improved. As a result, the insulation performance between the adjacent joint portion and the adjacent segment conductor can be secured in the case where the segment conductors are to be joined to each other, even in the case where the conductor of the adjacent joint portion is exposed. 
     A second aspect of the preferred embodiment provides a method of manufacturing an armature that includes an armature core provided with a plurality of slots that extend in a center axis direction and a coil portion in which respective distal end portions of a plurality of segment conductors are joined to each other, the method including: a step of providing an insulating portion, which has a second insulation resistance which is higher than a first insulation resistance of an insulating coating on the distal end portions, on a conductor surface of a portion of the segment conductors that is different from the distal end portions; a step of disposing the plurality of segment conductors in the armature core, after the step of providing the insulating portion, such that the plurality of segment conductors are arranged in parallel in a radial direction of the armature core and the insulating portion of one segment conductor, among the plurality of segment conductors which are disposed in parallel in the radial direction, is positioned at a position in the center axis direction corresponding to the distal end portion of a different segment conductor disposed adjacent to the one segment conductor in the radial direction; and a step of joining the respective distal end portions of the plurality of segment conductors, which face each other in the center axis direction, to each other after the step of disposing the plurality of segment conductors. 
     In the method of manufacturing an armature according to the second aspect of the preferred embodiment, the insulating portion is provided on the segment conductors, and the plurality of segment conductors are disposed in the armature core such that the insulating portion of one segment conductor is positioned at a position in the center axis direction corresponding to the distal end portion of a different segment conductor disposed adjacent to the one segment conductor in the radial direction. Consequently, it is possible to provide a method of manufacturing an armature that enables securing the insulation performance between an adjacent joint portion and a segment conductor that is adjacent to the adjacent joint portion in the case where the segment conductors are to be joined to each other. 
     Effects 
     According to the preferred embodiment, as described above, the insulation performance between a joint portion and an adjacent segment conductor can be secured in the case where segment conductors are to be joined to each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view illustrating the configuration of a stator (rotary electric machine) according to an embodiment. 
         FIG. 2  is a perspective view illustrating the configuration of the stator according to the embodiment. 
         FIG. 3  is an exploded perspective view of the stator according to the embodiment. 
         FIG. 4  is a plan view illustrating the configuration of a stator core according to the embodiment. 
         FIG. 5  is a sectional view illustrating the configuration of slot insulating paper according to the embodiment. 
         FIG. 6  is a circuit diagram illustrating the connection configuration of a coil portion according to the embodiment. 
         FIG. 7  is a perspective view illustrating a part of a first coil assembly according to the embodiment. 
         FIG. 8  is a cross-sectional view illustrating the configuration of a segment conductor according to the embodiment, in which  FIG. 8A  illustrates an insulating coating and  FIG. 8  illustrates an insulating portion. 
         FIG. 9  illustrates the configuration of a general conductor according to the embodiment. 
         FIG. 10  illustrates the configuration of a power conductor according to the embodiment. 
         FIG. 11  is an enlarged view of a portion indicated by symbol E 1  in  FIG. 1 . 
         FIG. 12  is a sectional view taken along the line  1000 - 1000  in  FIG. 1 . 
         FIG. 13  is a perspective view illustrating the configuration of a radially outer neutral point conductor according to the embodiment. 
         FIG. 14  is an enlarged view of a portion indicated by symbol E 2  in  FIG. 1 . 
         FIG. 15  is a perspective view illustrating the configuration of a radially inner neutral point conductor according to the embodiment. 
         FIG. 16  is a sectional view illustrating the configuration of a first facing surface and a second facing surface according to the embodiment. 
         FIG. 17  is a sectional view illustrating the position of arrangement of insulating members and joint portions according to the embodiment. 
         FIG. 18  is a schematic view illustrating the areas of a first joint surface and a first inverse inclination surface and the areas of a second joint surface and a second inverse inclination surface according to the embodiment. 
         FIG. 19  is a flowchart illustrating steps of manufacturing the stator according to the embodiment. 
         FIG. 20  illustrates a step of disposing segment conductors in a slot according to the embodiment. 
         FIG. 21  is a sectional view illustrating a step of disposing slot insulating paper in slots according to the embodiment. 
         FIG. 22  is a sectional view, taken along the radial direction, illustrating a step of pressing segment conductors with a pressing jig and a wall portion according to the embodiment. 
         FIG. 23  is a sectional view, as seen in plan, illustrating the step of pressing the segment conductors with the pressing jig and the wall portion according to the embodiment. 
         FIG. 24  illustrates the configuration of a stator according to a first modification of the embodiment. 
         FIG. 25  illustrates the configuration of a stator according to a second modification of the embodiment. 
         FIG. 26  illustrates the configuration of a stator according to a third modification of the embodiment. 
         FIG. 27  illustrates the configuration of a stator according to a fourth modification of the embodiment. 
         FIG. 28  illustrates the configuration of a stator according to a fifth modification of the embodiment. 
     
    
    
     DESCRIPTION 
     An embodiment of the preferred embodiment will be described below with reference to the drawings. 
     [Structure of Stator] 
     The structure of a stator  100  according to the present embodiment will be described with reference to  FIGS. 1 to 16 . The stator  100  has a circular ring shape centered on a center axis C 1 . The stator  100  is an example of the “armature” in the claims. 
     The term “axial direction (center axis direction)” as used herein means the direction (Z direction) along the center axis C 1  (rotational axis of a rotor  101 ) of the stator  100  as illustrated in  FIG. 1 . The term “circumferential direction” means the circumferential direction (A direction) of the stator  100 . The term “radial direction” means the radial direction (R direction) of the stator  100 . The term “radially inner side” means the direction (R 1  direction) toward the center axis C 1  of the stator  100 . The term “radially outer side” means the direction (R 2  direction) toward the outside of the stator  100 . 
     The stator  100  constitutes a part of a rotary electric machine together with the rotor  101 . The rotary electric machine is constituted as a motor, a generator, or a motor/generator, for example. As illustrated in  FIG. 1 , the stator  100  is disposed on the radially outer side of the rotor  101  which is provided with permanent magnets (not illustrated). That is, in the present embodiment, the stator  100  constitutes a part of a rotary electric machine  102  of an inner rotor type. 
     As illustrated in  FIG. 2 , the stator  100  includes a stator core  10 , slot insulating paper  20 , and a coil portion  30 . As illustrated in  FIG. 3 , in addition, the coil portion  30  includes a first coil assembly  30   a  and a second coil assembly  30   b . In addition, the coil portion  30  is composed of a plurality of segment conductors  40 . The stator core  10  is an example of the “armature core” in the claims. In addition, the slot insulating paper  20  is an example of the “slot insulating member” in the claims. 
     (Structure of Stator Core) 
     The stator core  10  has a cylindrical shape centered on the center axis C 1  (see  FIG. 1 ). In addition, the stator core  10  is formed by stacking a plurality of electromagnetic steel sheets (e.g. silicon steel sheets) in the axial direction, for example. As illustrated in  FIG. 4 , the stator core  10  is provided with a back yoke  11  in a circular ring shape as seen in the axial direction and a plurality of slots  12  provided on the radially inner side of the back yoke  11  to extend in the axial direction. The stator core  10  includes a plurality of teeth  13  provided on both sides of the slots  12  in the circumferential direction. 
     The slots  12  are each a portion surrounded by a wall portion  11   a  of the back yoke  11  provided on the radially outer side with respect to a first other end surface  73 , to be discussed later, and respective circumferential side surfaces  13   a  of two teeth  13 . The slots  12  are each provided with an opening portion  12   a  provided on the radially inner side with respect to a second one end surface  84 , to be discussed later, to open on the radially inner side. In addition, the slots  12  open on both sides in the axial direction. The teeth  13  are formed so as to project toward the radially inner side from the back yoke  11 , and each have a projecting portion  13   b  formed at the distal end portion thereof on the radially inner side to constitute the opening portions  12   a  of the slots  12 . 
     The opening portion  12   a  has an opening width W 1  in the circumferential direction. Here, the opening width W 1  corresponds to the distance between the respective distal end portions of the projecting portions of the projecting portions  13   b  of the teeth  13 . Meanwhile, a width W 2  of a portion of the slot  12  in which the coil portion  30  and the slot insulating paper  20  are disposed is larger than the opening width W 1 . That is, the slots  12  are constituted as semi-open slots. Here, the width W 2  corresponds to the distance between the respective circumferential side surfaces  13   a  of the teeth  13  which are disposed on both sides of the slot  12 . In addition, the width W 2  of the slots  12  is generally constant over the radial direction. 
     (Structure of Slot Insulating Paper) 
     As illustrated in  FIG. 5 , the slot insulating paper  20  is disposed between the teeth  13  and the segment conductors  40 . Here, in the present embodiment, the slot insulating paper  20  includes a joint portion cover portion  21 . The joint portion cover portion  21  is configured to cover at least the radially inner side of a joint portion  90 , to be discussed later, of the segment conductor  40  disposed closest to the opening portion  12   a  of the slot  12 , among the plurality of segment conductors  40  which are disposed in parallel in the radial direction. The joint portion is an example of the “distal end portion” in the claims. 
     Particularly, the slot insulating paper  20  is constituted of an insulating member in a sheet shape such as aramid paper and a polymer film, for example, and has a function of securing the insulation between the segment conductors  40  (coil portion  30 ) and the stator core  10 . The slot insulating paper  20  is disposed between the segment conductors  40  and the circumferential side surfaces  13   a  of the teeth  13  and between the segment conductor  40  disposed on the radially outermost side, among the plurality of segment conductors  40 , and the wall portion  11   a . In addition, as illustrated in  FIG. 3 , the slot insulating paper  20  includes collar portions  22  (cuff portions) that project axially outward from the slot  12  on both sides in the axial direction and that are folded back to be formed. 
     The slot insulating paper  20  is disposed so as to integrally cover the periphery of the plurality of segment conductors  40  which are disposed in parallel in the radial direction as seen in the direction of the arrow Z 2 . In other words, the slot insulating paper  20  covers both sides, in the circumferential direction, and both sides, in the radial direction, of slot housed portions  42   a  and  42   b , to be discussed later, of the plurality of segment conductors  40  which are disposed in parallel in the radial direction. Consequently, the slot insulating paper  20  can secure the insulation between the joint portion  90  and the stator core  10 . The slot housed portions  42   a  and  42   b  are an example of the “leg portions” in the claims. 
     (Structure of Coil Portion) 
     As illustrated in  FIGS. 2 and 3 , the coil portion  30  is formed by combining, in the axial direction, and joining the first coil assembly  30   a , which is provided on one axial side (side in the direction of the arrow Z 1 ), and the second coil assembly  30   b , which is provided on the other axial side (side in the direction of the arrow Z 2 ). The first coil assembly  30   a  and the second coil assembly  30   b  are each formed in a circular ring shape about the center axis C 1  (see  FIG. 1 ) as with the stator core  10 . 
     The coil portion  30  is constituted as a wave-wound coil, for example. In addition, the coil portion  30  is constituted as an eight-turn coil, for example. That is, as illustrated in  FIG. 5 , the coil portion  30  is constituted with eight segment conductors  40  disposed in parallel in the radial direction in each slot  12 . The coil portion  30  is supplied with three-phase AC power from a power source portion (not illustrated) so as to generate magnetic flux with a current flowing one way and the other in the axial direction and with a current flowing in the circumferential direction. 
     &lt;Configuration of Connection of Coil Portion&gt; 
     As illustrated in  FIG. 6 , the coil portion  30  is connected through a Y connection of three phases. That is, the coil portion  30  includes a U-phase coil portion  30 U, a V-phase coil portion  30 V, and a W-phase coil portion  30 W. For example, the coil portion  30  is provided with a plurality of neutral points N. Particularly, the coil portion  30  is connected through a four-parallel connection (star connection). That is, the U-phase coil portion  30 U is provided with four neutral point connection end portions NtU and four power line connection end portions PtU. The V-phase coil portion  30 V is provided with four neutral point connection end portions NtV and four power line connection end portions PtV. The W-phase coil portion  30 W is provided with four neutral point connection end portions NtW and four power line connection end portions PtW. In the following description, the neutral point connection end portions and the power line connection end portions will be referred to simply as “neutral point connection end portions Nt” and “power line connection end portions Pt” in the case where U-phase, V-phase, and W-phase are not specifically differentiated from each other. 
     &lt;Structure of Coil Assembly&gt; 
     As illustrated in  FIG. 7 , the first coil assembly  30   a  includes: a plurality of (e.g. three) power line connection segment conductors  50  (hereinafter referred to as “power conductors  50 ”) that serve as the segment conductors  40 ; a plurality of (e.g. two) neutral point connection segment conductors  60  (hereinafter referred to as “neutral point conductors  60 ”) that serve as the segment conductors  40 ; and a plurality of general conductors  41  that are conductors (general segment conductors  40 ) that are different from the power conductors  50  and the neutral point conductors  60 , among the plurality of segment conductors  40 , and that constitute the coil portion  30 . 
     As illustrated in  FIG. 3 , the second coil assembly  30   b  is constituted from a plurality of general conductors  41 . Preferably, the second coil assembly  30   b  is constituted from only the plurality of general conductors  41 , and all the power conductors  50  and the neutral point conductors  60  provided in the stator  100  are provided in the first coil assembly  30   a.    
     (Structure of Segment Conductors) 
     As illustrated in  FIG. 8A , the segment conductor  40  is constituted as a rectangular conductive wire which has a generally rectangular cross-sectional surface. An insulating coating  40   a  which has a thickness t 1  is provided on a conductor surface  40   b  of the segment conductor  40 . The thickness t 1  of the insulating coating  40   a  is set to such a level that enables securing the insulation performance between different phases (insulation between coil end portions  43 ), for example. The insulating coating  40   a  has an insulation resistance r 1 . Particularly, the insulating coating  40   a  is constituted of a coating agent such as polyimide. Meanwhile, a conductor body  40   c  of the segment conductor  40  is constituted of a metal material (conductive material) such as copper or aluminum, for example. While  FIG. 8  illustrates components with size relationship such as thickness thereof exaggerated for illustration, the preferred embodiment is not limited thereto. 
     As illustrated in  FIG. 2 , the segment conductor  40  includes the slot housed portions  42   a  and  42   b  to be disposed in the slots  12  and the coil end portion  43 . 
     The slot housed portions  42   a  and  42   b  mean portions to be disposed in the slots  12  from the axial position of an end surface  10   a  or  10   b  of the stator core  10 . The coil end portion  43  means a portion formed to be continuous with the slot housed portions  42   a  and  42   b  and disposed on the axially outer side with respect to the end surface  10   a  or  10   b  of the stator core  10 . In addition, the coil end portion  43  has an offset portion shaped to be bent in the axial direction and offset in the radial direction at the bent portion. 
     &lt;Structure of General Conductors&gt; 
     As illustrated in  FIG. 9 , the general conductor  41  includes a pair of slot housed portions  42   a  and  42   b  to be disposed in different slots  12  and a coil end portion  43  that connects between the pair of slot housed portions  42   a  and  42   b . Consequently, the general conductor  41  has a generally U-shape or a generally J-shape as seen from the radially inner side. The slot housed portions  42   a  and  42   b  are formed to be straight along the axial direction. The slot housed portions  42   a  and  42   b  of the power conductors  50  and the slot housed portions  42   a  and  42   b  of the neutral point conductors  60  are configured similarly to the slot housed portions  42   a  and  42   b  of the general conductors  41 , and therefore are not described. 
     Here, the coil pitch of the general conductor  41  is six. That is, the pair of slot housed portions  42   a  and  42   b  are disposed at positions six slots  12  away from each other in the circumferential direction. That is, five slots are provided between the slot  12  in which the slot housed portion  42   a  of the general conductor  41  is disposed and the slot  12  in which the slot housed portion  42   b  is disposed. 
     In the present embodiment, in addition, the pair of slot housed portions  42   a  and  42   b  have different axial lengths. Specifically, an axial length L 1  of the slot housed portion  42   a  is longer than an axial length L 2  of the slot housed portion  42   b . The axial length L 1  (L 2 ) of the slot housed portion  42   a  ( 42   b ) means the length from a distal end  75  ( 85 ) to the axial position corresponding to the axial end surface  10   a  ( 10   b ) of the stator core  10 . In addition, the axial lengths L 1  and L 2  are smaller than an axial length L 3  of the stator core  10 . The axial length L 3  of the stator core  10  means the distance (interval) between the axial end surfaces  10   a  and  10   b . For example, the axial length L 1  is longer than half the axial length L 3 , and the axial length L 2  is shorter than half the axial length L 3 . 
     In addition, the plurality of general conductors  41  include first general conductors  41   a  disposed on one axial side (side in the direction of the arrow Z 1 ) with respect to the stator core  10  and included in the first coil assembly  30   a , and second general conductors  41   b  disposed on the other axial side (side in the direction of the arrow Z 2 ) with respect to the stator core  10  and included in the second coil assembly  30   b.    
     &lt;Structure of Power Conductors&gt; 
     In the power conductor  50 , as illustrated in  FIG. 6 , a plurality of (e.g. four) power line connection end portions Pt for the same phase are electrically connected to each other, and the plurality of power line connection end portions Pt which are connected to each other and a power terminal member  51  are electrically connected to each other. The power conductors  50  have a function of introducing power from a power source portion (not illustrated) to the coil portion  30 . 
     Particularly, as illustrated in  FIG. 7 , the power conductor  50  includes a radially outer power conductor  52  to be disposed on the axially outer side of the stator core  10  and a radially inner power conductor  53  to be disposed on the radially inner side. In other words, the power conductor  50  is formed in a bifurcated shape. 
     Here, in the present embodiment, as illustrated in  FIG. 10 , the radially outer power conductor  52  and the power terminal member  51  are electrically connected to each other by a lead wire  54 . In addition, the radially inner power conductor  53  and the power terminal member  51  are electrically connected to each other by a lead wire  54 . The radially outer power conductor  52  and the radially inner power conductor  53  are electrically connected to each other via the power terminal member  51  and the lead wires  54 . In addition, the lead wires  54  are formed from a stranded wire (conductor), for example, with an insulating tube  51   a  disposed at the outer periphery thereof. 
     The radially outer power conductor  52  includes two slot housed portions  42   a , two power line coil end portions  52   a  that constitute two power line connection end portions Pt and that are led out from the slot housed portions  42   a  in the axial direction, and a conductor plate  52   b  joined to the two power line coil end portions  52   a  to be electrically connected thereto. For example, the conductor plate  52   b  is joined to the radially outer side of the two power line coil end portions  52   a , and the lead wire  54  is joined to the radially outer side of the conductor plate  52   b.    
     The two power line coil end portions  52   a  and the conductor plate  52   b  are connected to each other by being welded at welded portions  52   c . In addition, the conductor plate  52   b  and the lead wire  54  are connected to each other by being brazed or welded at a joint portion  52   d . For example, the welding is implemented through any of resistance welding, arc welding, laser welding, and high-energy beam welding. 
     Here, as illustrated in  FIG. 11 , a spacing D 1  in the radial direction between the welded portion  52   c  and the joint portion  52   d  (conductor plate  52   b ) and an end surface  43   a , on the radially outer side, of the coil end portion  43  of the general conductor  41  is equal to or less than twice a width W 11  of the cross-sectional surface (see  FIG. 8 ) of the segment conductor  40  (preferably equal to or less than the width W 11 ). For example, no welding tool space is provided between the welded portion  52   c  and the joint portion  52   d  and the coil end portion  43 . 
     As illustrated in  FIG. 10 , the radially inner power conductor  53  includes two slot housed portions  42   b , two power line coil end portions  53   a  that constitute two power line connection end portions Pt and that are led out from the slot housed portions  42   b  in the axial direction, and a conductor plate  53   b  joined to the two power line coil end portions  53   a  to be electrically connected thereto. For example, the conductor plate  53   b  is joined to the axially outer side (side in the direction of the arrow Z 1 ) of the two power line coil end portions  53   a , and the lead wire  54  is joined to the axially outer side (side in the direction of the arrow Z 1 ) of the conductor plate  53   b.    
     The two power line coil end portions  53   a  and the conductor plate  53   b  are connected to each other by being welded at joint portions  53   c . In addition, the conductor plate  53   b  and the lead wire  54  are connected to each other by being welded at a welded portion  53   d . Here, a spacing D 2  in the axial direction between the joint portion  53   c  and the welded portion  53   d  (conductor plate  53   b ) and an end surface  43   b , on one axial side, of the coil end portion  43  of the general conductor  41  is equal to or less than twice the width W 11  of the cross-sectional surface (see  FIG. 8 ) of the segment conductor  40  (preferably equal to or less than the width W 11 ). 
     The slot pitch of the radially outer power conductor  52  is one for a portion formed from the slot housed portions  42   a  and the conductor plate  52   b , and zero if only the slot housed portions  42   a  are considered as the segment conductors  40 . Meanwhile, the slot pitch of the radially inner power conductor  53  is one for a portion formed from the slot housed portions  42   b  and the conductor plate  53   b , and zero if only the slot housed portions  42   b  are considered as the segment conductors  40 . That is, the slot pitch of the power conductor  50  is different from the slot pitch ( 6 ) of the general conductor  41 . 
     &lt;Structure of Neutral Point Conductors&gt; 
     As illustrated in  FIG. 7 , the neutral point conductors  60  include a radially outer neutral point conductor  61  and a radially inner neutral point conductor  62 . As illustrated in  FIG. 6 , the radially outer neutral point conductor  61  and the radially inner neutral point conductor  62  each include a neutral point N, at which the neutral point connection end portions NtU of the U-phase coil portion  30 U, the neutral point connection end portions NtV of the V-phase coil portion  30 V, and the neutral point connection end portions NtW of the W-phase coil portion  30 W are electrically connected to each other. 
     As illustrated in  FIG. 13 , the radially outer neutral point conductor  61  includes two U-phase/W-phase neutral point segment conductors  61   a  and two V-phase neutral point segment conductors  61   b . The U-phase/W-phase neutral point segment conductors  61   a  each include a slot housed portion  42   a  for U-phase to be connected to the general conductor  41  for U-phase of three-phase AC, a slot housed portion  42   a  for W-phase to be connected to the general conductor  41  for W-phase, and two neutral point coil end portions  61   c  that each connect between the slot housed portion  42   a  for U-phase and the slot housed portion  42   a  for W-phase. The neutral point coil end portions  61   c  are each formed to be continuous with the slot housed portion  42   a  for U-phase, and formed to be continuous with the slot housed portion  42   a  for W-phase. 
     The U-phase/W-phase neutral point segment conductors  61   a  are each formed in a generally U-shape (generally C-shape) as seen from the radially inner side. The V-phase neutral point segment conductors  61   b  are each formed in a generally straight shape as seen from the radially inner side. 
     As illustrated in  FIG. 14 , the neutral point coil end portions  61   c  are formed along the circumferential direction on the radially outer side of the coil end portion  43  of the general conductor  41 . The neutral point coil end portions  61   c  are formed in a generally arcuate shape as seen in the direction of the arrow Z 2 . 
     In addition, the slot pitch of one of the two U-phase/W-phase neutral point segment conductors  61   a  is nine. Meanwhile, the slot pitch of the other of the two U-phase/W-phase neutral point segment conductors  61   a  is seven. That is, the U-phase/W-phase neutral point segment conductors  61   a  have a slot pitch that is different from the slot pitch ( 6 ) of the general conductor  41 . One of the two U-phase/W-phase neutral point segment conductors  61   a  is disposed on the axially outer side (side in the direction of the arrow Z 1 ) of the other. 
     As illustrated in  FIG. 13 , the V-phase neutral point segment conductors  61   b  each include a slot housed portion  42   a  for V-phase to be connected to the general conductor  41  for V-phase and a neutral point coil end portion  61   d . The neutral point coil end portion  61   d  is formed so as to project toward the axially outer side (in the direction of the arrow Z 1 ) from the slot housed portion  42   a . Each of the two neutral point coil end portions  61   d  is joined to the two neutral point coil end portions  61   c  to be electrically joined thereto. 
     Specifically, as illustrated in  FIG. 14 , the two neutral point coil end portions  61   d  are welded at welded portions  61   e  to the radially outer side of the two neutral point coil end portions  61   c  in an arcuate shape. Consequently, in the radially outer neutral point conductor  61 , the neutral point connection end portions NtU of the U-phase coil portion  30 U, the neutral point connection end portions NtV of the V-phase coil portion  30 V, and the neutral point connection end portions NtW of the W-phase coil portion  30 W are electrically connected to each other. A spacing D 3  between the welded portions  61   e  (an end surface of the neutral point coil end portions  61   c  on the radially inner side) and an end surface  43   c , on the radially outer side, of the coil end portion  43  of the general conductor  41  is equal to or less than twice the width W 11 , along the radial direction, of the cross-sectional surface of the segment conductor  40  (preferably equal to or less than the width W 11 ). 
     As illustrated in  FIG. 15 , the radially inner neutral point conductor  62  includes two U-phase/W-phase neutral point segment conductors  62   a  and two V-phase neutral point segment conductors  62   b . The U-phase/W-phase neutral point segment conductors  62   a  each include a slot housed portion  42   b  for U-phase to be connected to the general conductor  41  for U-phase of three-phase AC, a slot housed portion  42   b  for W-phase to be connected to the general conductor  41  for W-phase, and a neutral point coil end portion  62   c  that connects between the slot housed portion  42   b  for U-phase and the slot housed portion  42   b  for W-phase. The neutral point coil end portions  62   c  are each formed to be continuous with the slot housed portion  42   b  for U-phase, and formed to be continuous with the slot housed portion  42   b  for W-phase. 
     The U-phase/W-phase neutral point segment conductors  62   a  are each formed in a generally U-shape (generally C-shape) as seen from the radially inner side. The V-phase neutral point segment conductors  62   b  are each formed in a generally straight shape as seen from the radially inner side. 
     As illustrated in  FIG. 7 , the neutral point coil end portions  62   c  are formed on the radially inner side of the coil end portion  43  of the general conductor  41  to project toward the axially outer side with respect to the coil end portion  43  of the general conductor  41 . The neutral point coil end portions  62   c  are disposed in proximity to the axially outer side of the coil end portion  43  of the general conductor  41 , and formed along the circumferential direction as seen in the axial direction. 
     In addition, the slot pitch of one of the two U-phase/W-phase neutral point segment conductors  62   a  is nine. Meanwhile, the slot pitch of the other of the two U-phase/W-phase neutral point segment conductors  62   a  is seven. That is, the U-phase/W-phase neutral point segment conductors  62   a  have a slot pitch that is different from the slot pitch ( 6 ) of the general conductor  41 . One of the two U-phase/W-phase neutral point segment conductors  62   a  is disposed on the radially outer side of the other. 
     The V-phase neutral point segment conductors  62   b  each include a slot housed portion  42   b  for V-phase to be connected to the general conductor  41  for V-phase and a neutral point coil end portion  62   d . The neutral point coil end portion  62   d  is formed so as to project toward the axially outer side (in the direction of the arrow Z 1 ) from the slot housed portion  42   b . Each of the two neutral point coil end portions  62   d  is joined to the two neutral point coil end portions  62   c  to be electrically joined thereto. 
     Specifically, as illustrated in  FIG. 15 , the two neutral point coil end portions  62   d  are welded at welded portions  62   e  to the axially outer side of the two neutral point coil end portions  62   c  in an arcuate shape. Consequently, in the radially inner neutral point conductor  62 , the neutral point connection end portions NtU of the U-phase coil portion  30 U, the neutral point connection end portions NtV of the V-phase coil portion  30 V, and the neutral point connection end portions NtW of the W-phase coil portion  30 W are electrically connected to each other. As illustrated in  FIG. 12 , a spacing D 4  between the welded portions  62   e  (an end surface of the neutral point coil end portions  62   d  on the axially inner side) and an end surface  43   d , on the axially outer side, of the coil end portion  43  of the general conductor  41  is equal to or less than twice the width W 11 , along the radial direction, of the cross-sectional surface of the segment conductor  40  (preferably equal to or less than the width W 11 ). 
     (Configuration of Joint Portions) 
     Here, in the present embodiment, as illustrated in  FIG. 16 , a first slot housed portion  71  which is the slot housed portion  42   a  or  42   b  of a first segment conductor  70  which is the segment conductor  40  which constitutes the first coil assembly  30   a , among the plurality of segment conductors  40 , and a second slot housed portion  81  which is the slot housed portion  42   a  or  42   b  of a second segment conductor  80  which is the segment conductor  40  which constitutes the second coil assembly  30   b  and which faces the first segment conductor  70  in the axial direction are joined to each other at the joint portion  90  in the slot  12  of the stator core  10 . 
     The first slot housed portion  71  includes a first facing surface  72  that directs to the radially inner side (side in the direction of the arrow R 1 ) and that faces the second slot housed portion  81  and a first other end surface  73  that faces the radially outer side (side in the direction of the arrow R 2 ). Meanwhile, the second slot housed portion  81  includes a second facing surface  82  that directs to the radially outer side and that faces the first facing surface  72  and a second other end surface  83  that directs to the radially outer side and that is continuous with the second facing surface  82 . At least a part of the first facing surface  72  and at least a part of the second facing surface  82  are joined to each other, and the first other end surface  73  is disposed so as to project toward the radially outer side with respect to the second other end surface  83 . 
     In addition, the first slot housed portion  71  includes a first one end surface  74  that is provided on the opposite side, in the radial direction, of the first other end surface  73  and that is continuous with the first facing surface  72 . The second slot housed portion  81  includes a second one end surface  84  that is provided on the opposite side, in the radial direction, of the second other end surface  83  and that directs to the radially inner side. The second one end surface  84  is disposed so as to project toward the radially inner side with respect to the first one end surface  74 . 
     Here, the joint portion  90  is a portion of the coil portion  30  illustrated in  FIG. 16 , includes the first facing surface  72  and the second facing surface  82 , and includes a portion of the first slot housed portion  71  from the distal end  75  to a boundary point  76  between the first facing surface  72  and the first one end surface  74  and a portion of the second slot housed portion  81  from the distal end  85  to a boundary point  86  between the second facing surface  82  and the second other end surface  83 . 
     In the present embodiment, a second stepped portion  111  is formed between the distal end  75  of the first slot housed portion  71  and the boundary point  86  of the second slot housed portion  81 , which is the boundary portion between the first other end surface  73  and the second other end surface  83 . Meanwhile, a first stepped portion  112  is formed between the boundary point  76  of the first slot housed portion  71  and the distal end  85  of the second slot housed portion  81 , which is the boundary portion between the first one end surface  74  and the second one end surface  84 . Specifically, in the second stepped portion  111   a  step is formed to be dented inward of the segment conductor  40  from the first other end surface  73  toward the second other end surface  83 . Meanwhile, in the first stepped portion  112  a step is formed to be dented inward of the segment conductor  40  from the second one end surface  84  toward the first one end surface  74 . 
     In addition, a first deviation width d 1  which is the width of the deviation between a radial position P 1  of the first other end surface  73  and a radial position P 2  of the second other end surface  83  is larger than the thickness t 1  of the insulating coating  40   a  of the segment conductor  40 , for example. The first deviation width d 1  corresponds to the height of the step of the second stepped portion  111 . 
     Particularly, the first deviation width d 1  is set to such a level that the segment conductor  40  is not pressed in the direction of moving the first facing surface  72  and the second facing surface  82  away from each other, or to such a level that a pressing force is reduced when the first slot housed portion  71  or the second slot housed portion  81  is pressed by a pressing jig  200 , to be discussed later, and the wall portion  11   a , even in the case where the first slot housed portion  71  or the second slot housed portion  81  is elastically deformed. 
     For example, as illustrated in  FIG. 17 , a clearance CL 1  is formed in the radial direction between the wall portion  11   a  and the second other end surface  83  of the second slot housed portion  81  disposed on the radially outermost side. Meanwhile, a clearance CL 2  is formed in the radial direction between the pressing jig  200  and the first one end surface  74  of the first slot housed portion  71  disposed on the radially innermost side during manufacture of the stator  100 . 
     In the present embodiment, in addition, as illustrated in  FIG. 16 , the first deviation width d 1  is equal to a second deviation width d 2  which is the width of the deviation between a radial position P 3  of the first one end surface  74  and a radial position P 4  of the second one end surface  84  (height of the step of the first stepped portion  112 ). That is, a width W 21 , in the radial direction, of the first slot housed portion  71  is generally equal to a width W 22 , in the radial direction, of the second slot housed portion  81 . In addition, the first slot housed portion  71  is disposed as displaced toward the radially outer side with respect to the second slot housed portion  81 . 
     As illustrated in  FIG. 17 , a plurality of (e.g. eight) first slot housed portions  71  and second slot housed portions  81  are disposed adjacent to each other in the radial direction in the slot  12 . That is, the plurality of first slot housed portions  71  are disposed in parallel in the radial direction, and the plurality of second slot housed portions  81  are disposed in parallel in the radial direction. 
     In the slot  12 , the first facing surface  72  (joint portion  90 ) of one first slot housed portion  71 , among the plurality of first slot housed portions  71 , is disposed at a different position in the center axis direction from a different first facing surface  72  (joint portion  90 ) that is adjacent in the radial direction. In the slot  12 , in addition, the second facing surface  82  of one second slot housed portion  81 , among the plurality of second slot housed portions  81 , is disposed at a different position in the center axis direction from a different second facing surface  82  that is adjacent in the radial direction. That is, in the present embodiment, an axial position P 11  of the joint portion  90  which is constituted from the first facing surface  72  and the second facing surface  82  is different from an axial position P 12  of the joint portion  90  which is constituted from a different first facing surface  72  and a different second facing surface  82  that are adjacent in the radial direction. 
     In other words, the first slot housed portions  71  and the second slot housed portions  81  are disposed in a staggered manner along the radial direction at the axial positions P 11  and P 12 . The first other end surface  73  is disposed (offset) so as to project toward the radially outer side with respect to the corresponding second other end surface  83  at each of the plurality of joint portions  90 . In addition, the second one end surface  84  is disposed (offset) so as to project toward the radially inner side with respect to the corresponding first one end surface  74  at each of the plurality of joint portions  90 . Consequently, a clearance CL 3  in the radial direction is formed between the first one end surface  74  and the second other end surface  83  in the radial direction. 
     &lt;Configuration of First Facing Surface and Second Facing Surface&gt; 
     Here, in the present embodiment, as illustrated in  FIG. 16 , the first facing surface  72  of the first slot housed portion  71  and the second facing surface  82  of the second slot housed portion  81  are formed so as to be inclined with respect to the axial direction. Specifically, the first facing surface  72  is constituted as an end surface inclined with respect to the axial direction from the distal end  75  of the first slot housed portion  71  in the direction of the arrow E 1 . In addition, the first facing surface  72  is not provided with the insulating coating  40   a . The second facing surface  82  is constituted as an end surface inclined from the distal end  85  of the second slot housed portion  81  in the direction of the arrow E 2 . In addition, the second facing surface  82  is not provided with the insulating coating  40   a . The direction of the arrow E 1  means a direction from the distal end  75  toward the boundary point  76  between the first facing surface  72  and the first one end surface  74 . The direction of the arrow E 2  means a direction from the distal end  85  toward the boundary point  86  between the second facing surface  82  and the second other end surface  83 . 
     The first facing surface  72  and the second facing surface  82  are each formed such that the sectional surface thereof taken along the radial direction has an S-shape. In other words, the first facing surface  72  is formed into a recessed and projected shape to be recessed and projected in the radial direction, and the second facing surface  82  is formed into a recessed and projected shape, corresponding to the recessed and projected shape of the first facing surface  72 , to be recessed and projected in the radial direction. The first facing surface  72  which has an S-shape (recessed and projected shape) and the second facing surface  82  which has an S-shape (recessed and projected shape) are disposed in the slot  12  with the first facing surface  72  and the second facing surface  82  engaged with each other in the radial direction. 
     Here, in the present embodiment, a part of the first facing surface  72  and a part of the second facing surface  82  are joined to each other using a joint material  130 . Particularly, the first facing surface  72  includes a first joint surface  72   a  to be joined to the second facing surface  82  and a first inverse inclination surface  72   b  formed to be continuous with the first joint surface  72   a  and inclined in the direction (direction of the arrow E 12 ) which is opposite to the direction (direction of the arrow E 11 ) in which the first joint surface  72   a  is inclined with respect to the axial direction (axis that is parallel to the center axis C 1 ). In addition, the first joint surface  72   a  and the first inverse inclination surface  72   b  are each formed as a generally flat surface, and the first joint surface  72   a  and the first inverse inclination surface  72   b  form a bent shape. In addition, the second facing surface  82  includes a second joint surface  82   a  to be joined to the first joint surface  72   a  and a second inverse inclination surface  82   b  formed to be continuous with the second joint surface  82   a  and inclined in the direction (direction of the arrow E 22 ) which is opposite to the direction (direction of the arrow E 21 ) in which the second joint surface  82   a  is inclined with respect to the axial direction. 
     The joint material  130  is disposed between the first joint surface  72   a  and the second joint surface  82   a , and joins the first joint surface  72   a  and the second joint surface  82   a  to be electrically connected to each other. Specifically, the joint material  130  contains a conductive material such as silver or copper. Preferably, the joint material  130  is a joint material (silver nano paste) in a paste form in which a solvent contains conductive particles which are metal particles obtained by making silver finer to the nanometer level. In addition, the joint material  130  contains a member (resin member) to be volatilized when heated, and has a function of bringing the first joint surface  72   a  and the second joint surface  82   a  closer to each other with the volume of the joint material  130  decreased when the member to be volatilized is heated. 
     In the present embodiment, an inclination angle θ 2  of the first inverse inclination surface  72   b  and the second inverse inclination surface  82   b  with respect to the axial direction is smaller than an inclination angle θ 1  of the first joint surface  72   a  and the second joint surface  82   a  with respect to the axial direction. Consequently, it is possible to prevent a minimum width W 31 , in the radial direction, of the first slot housed portion  71  on the root side (side in the direction of the arrow Z 1 ) with respect to the first joint surface  72   a  from being small. 
     In addition, as illustrated in  FIG. 18 , an area S 11  of the first joint surface  72   a  is larger than an area S 12  of the first inverse inclination surface  72   b , and an area S 21  of the second joint surface  82   a  is larger than an area S 22  of the second inverse inclination surface  82   b . That is, a length L 11  of the first joint surface  72   a  along the direction of the arrow E 11  is longer than a length L 12  of the first inverse inclination surface  72   b  along the direction of the arrow E 12 , and a length L 21  of the second joint surface  82   a  along the direction of the arrow E 21  is longer than a length L 22  of the second inverse inclination surface  82   b  along the direction of the arrow E 21 . 
     As illustrated in  FIG. 16 , the first facing surface  72  includes a first spaced facing surface  72   c  formed to be continuous with the first inverse inclination surface  72   b  on the opposite side from the first joint surface  72   a  and disposed as spaced from the second facing surface  82 . In addition, the second facing surface  82  includes a second spaced facing surface  82   c  formed to be continuous with the second inverse inclination surface  82   b  on the opposite side from the second joint surface  82   a  and disposed as spaced from the first facing surface  72 . 
     Particularly, the first spaced facing surface  72   c  is inclined in the direction of the arrow E 13  which is opposite to the first inverse inclination surface  72   b  with respect to the axial direction (axis that is parallel to the center axis C 1 ). In addition, the first spaced facing surface  72   c  is smoothly connected to the first inverse inclination surface  72   b  with the connection portion formed in an arcuate shape (round shape). The second spaced facing surface  82   c  is disposed to face the first spaced facing surface  72   c , and a clearance CL 4  is provided between the first spaced facing surface  72   c  and the second spaced facing surface  82   c.    
     In addition, the first facing surface  72  and the second facing surface  82  are each formed such that the sectional surface thereof taken along the radial direction has an asymmetrical shape with respect to a center point C 2  of the first facing surface  72 . Specifically, the first facing surface  72  and the second facing surface  82  are configured such that, in the case where the center point C 2  is defined as the middle point between the distal end  75  and the boundary point  76  and the first facing surface  72  is rotated by 180 degrees about the center point C 2 , the shape of the first facing surface  72  which has been rotated and the shape of the second facing surface  82  do not coincide with each other. Particularly, an asymmetrical shape is achieved since the first facing surface  72  includes the first joint surface  72   a , the first inverse inclination surface  72   b , and the first spaced facing surface  72   c  which are provided in this order from the distal end  75  of the first slot housed portion  71 , while the second facing surface  82  includes the second spaced facing surface  82   c , the second inverse inclination surface  82   b , and the second joint surface  82   a  which are provided in this order from the distal end  85  of the second slot housed portion  81 . 
     In addition, the distal end  75  of the first slot housed portion  71  and the distal end  85  of the second slot housed portion  81  are each formed as a flat surface that is orthogonal to the axial direction. Particularly, the distal ends  75  and  85  are provided between the first facing surface  72  and the first other end surface  73  and between the second facing surface  82  and the second other end surface  83 , respectively, to have a chamfered shape. 
     &lt;Configuration of Insulating Portions&gt; 
     Here, in the present embodiment, the coil portion  30  is provided with insulating portions  120 . As illustrated in  FIG. 17 , an insulating portion  120  is provided on the conductor surface  40   b  (see  FIG. 8B ) of one segment conductor  40 , among the plurality of segment conductors  40  (general conductors  41 , power conductors  50 , and neutral point conductors  60 ) which are disposed in parallel, at an axial position corresponding to the joint portion  90  of a different segment conductor  40  (hereinafter this joint portion  90  will be referred to as an “adjacent joint portion  90 ”) disposed adjacent to the one segment conductor  40  in the radial direction. The insulating portion  120  has a thickness t 2  which is larger than the thickness t 1  of the insulating coating  40   a  of the adjacent joint portion  90  (different segment conductor  40 ). Consequently, an insulation resistance r 2  of the insulating portion  120  is higher than the insulation resistance r 1  of the insulating coating  40   a  alone. In addition, the insulating portions  120  are provided at the positions P 11  and P 12  (see  FIG. 17 ), in the center axis direction, at which the adjacent joint portion  90  is present. The adjacent joint portion  90  is an example of the “adjacent joint portion” in the claims. In addition, the insulation resistance r 1  is an example of the “first insulation resistance” in the claims. In addition, the insulation resistance r 2  is an example of the “second insulation resistance” in the claims. 
     Specifically, as illustrated in  FIG. 8B , the insulating portion  120  includes the insulating coating  40   a  which is provided on the conductor surface  40   b  and which has the thickness t 1 , and an insulating member  121  that covers the insulating coating  40   a  and that has a function of insulating the segment conductor  40  and the adjacent joint portion  90  from each other. A thickness t 3  of the insulating member  121  is smaller than the thickness t 1 . That is, the thickness t 2  is larger than the thickness t 1 , and less than twice the thickness t 1 . 
     Particularly, the insulating member  121  is formed in a sheet shape. For example, the insulating member  121  contains the same material as the material contained in the insulating coating  40   a . Preferably, the insulating member  121  contains an insulation material such as polyimide. The insulating member  121  in a sheet shape is wound around the outer periphery of the insulating coating  40   a  of the segment conductor  40  for at least one round (e.g. more than one round and less than two rounds). For example, the insulating member  121  in a sheet shape is fixed to the insulating coating  40   a  using an adhesive with insulation properties etc. 
     As illustrated in  FIG. 9 , the insulating portion  120  (insulating member  121 ) is provided on the slot housed portion  42   a , of the slot housed portions  42   a  and  42   b , the length of which along the axial direction is the longer. In addition, the insulating member  121  is provided on each of the plurality of slot housed portions  42   a , while the insulating member  121  is not provided on the plurality of slot housed portions  42   b.    
     A length L 31  of the insulating portion  120  (insulating member  121 ) in the axial direction is equal to or more than an insulation creepage distance Dc along the center axis direction from the adjacent joint portion  90 , and less than the length L 3  of the slot  12  in the axial direction. Particularly, the length L 31  of the insulating portion  120  (insulating member  121 ) is set to be at least equal to or more than the insulation creepage distance Dc with respect to the closer one of the distal end  75  of the first slot housed portion  71  and the distal end  85  of the second slot housed portion  81  which are adjacent in the radial direction. That is, as illustrated in  FIG. 17 , the insulation properties are secured by securing the insulation creepage distance Dc between the first facing surface  72  and the second facing surface  82 , which are not provided with the insulating coating  40   a , and the adjacent slot housed portion  42   a.    
     [Method of Manufacturing Stator] 
     Next, a method of manufacturing the stator  100  according to the present embodiment will be described.  FIG. 19  is a flowchart illustrating the method of manufacturing the stator  100 . 
     (Step of Preparing Segment Conductors) 
     First, in step S 1 , a plurality of segment conductors  40  are prepared. Specifically, the power conductors  50  which constitute the power line connection end portions Pt for the individual phases of the coil portion  30  which is connected through a Y connection, the neutral point conductors  60  which constitute the neutral point connection end portions Nt for the individual phases of the coil portion  30 , and the general conductors  41  which constitute the other portions of the coil portion  30  are prepared. 
     For example, as illustrated in  FIG. 8A , an insulating coating  40   a  made of an insulation material such as polyimide is formed (coated) on the conductor surface  40   b  in a rectangular shape which is made of a conductive material such as copper. After that, the conductor (rectangular conductive wire) on which the insulating coating  40   a  is formed is shaped using a shaping jig (not illustrated) to form the general conductors  41  (see  FIG. 9 ), the radially outer power conductors  52  and the radially inner power conductors  53  (see  FIG. 10 ) for forming the power conductors  50 , two U-phase/W-phase neutral point segment conductors  61   a  and two V-phase neutral point segment conductors  61   b  for forming the radially outer neutral point conductor  61  (see  FIG. 13 ), and two U-phase/W-phase neutral point segment conductors  62   a  and two V-phase neutral point segment conductors  62   b  for forming the radially inner neutral point conductor  62  (see  FIG. 15 ). 
     &lt;Formation of General Conductors&gt; 
     Particularly, as illustrated in  FIG. 9 , the general conductors  41  are each formed by forming a pair of slot housed portions  42   a  and  42   b  to be disposed in different slots  12  (e.g. with a slot pitch of six) and having different axial lengths from each other and a coil end portion  43  that connects between the pair of slot housed portions  42   a  and  42   b.    
     &lt;Formation of Power Conductors&gt; 
     In the present embodiment, as illustrated in  FIG. 10 , the power conductors  50  are each formed by electrically connecting the radially outer power conductor  52  and the radially inner power conductor  53  to each other by electrically joining (performing a power conductor joint step) the radially outer power conductor  52  and the radially inner power conductor  53  to the common power terminal member  51  via the lead wires  54 . The power conductors  50  are formed for the respective phases. 
     Particularly, the welded portions  52   c  are formed by welding (joining) two power line coil end portions  52   a , which constitute two power line connection end portions Pt and which are led out in the axial direction from two slot housed portions  42   a , and the conductor plate  52   b  to each other, so that the radially outer power conductor  52  is formed. In addition, the joint portions  53   c  are formed by brazing or welding (joining) two power line coil end portions  53   a , which constitute two power line connection end portions Pt and which are led out in the axial direction from the slot housed portions  42   b , and the conductor plate  53   b  to each other, so that the radially inner power conductor  53  is formed. For example, the welding is implemented through any of resistance welding, arc welding, laser welding, and high-energy beam welding. Consequently, the radially outer power conductor  52  and the radially inner power conductor  53  with a slot pitch of one (in the case where the conductor plates  52   b  and  53   b  are included) or zero (in the case where the conductor plates  52   b  and  53   b  are not included) are formed. 
     In addition, a plurality of lead wires  54  with the insulating tube  51   a  attached to the outer periphery thereof and which are joined to the power terminal member  51  are prepared. The lead wire  54  is welded to the radially outer side of the conductor plate  52   b  of the radially outer power conductor  52  to form the joint portion  52   d . In addition, the lead wire  54  is welded to the axially outer side (side in the direction of the arrow Z 1 ) of the conductor plate  53   b  of the radially inner power conductor  53  to form the welded portion  53   d . Consequently, the power conductors  50  which have a bifurcated shape in which the radially outer power conductor  52  is disposed on the radially outer side and the radially inner power conductor  53  is disposed on the radially inner side are formed. 
     &lt;Formation of Neutral Point Conductors&gt; 
     As illustrated in  FIG. 13 , the U-phase/W-phase neutral point segment conductors  61   a  which each include the neutral point coil end portion  61   c  which connects between the slot housed portion  42   a  for U-phase and the slot housed portion  42   a  for W-phase are shaped. In addition, the U-phase/W-phase neutral point segment conductors  61   a  are shaped such that the slot pitch of one of the two U-phase/W-phase neutral point segment conductors  61   a  is nine while the slot pitch of the other is seven. One of the two U-phase/W-phase neutral point segment conductors  61   a  is disposed on the axially outer side (side in the direction of the arrow Z 1 ) of the other. The V-phase neutral point segment conductors  61   b  which each include the slot housed portion  42   a  for V-phase and the neutral point coil end portion  61   d  are shaped. 
     After that, the welded portions  61   e  are formed by welding (performing a neutral point conductor joint step) the two neutral point coil end portions  61   d  on end surfaces of the two neutral point coil end portions  61   c  on the radially outer side (to each other). Consequently, the radially outer neutral point conductor  61  (neutral point conductor  60 ) in which the neutral point connection end portions NtU of the U-phase coil portion  30 U, the neutral point connection end portions NtV of the V-phase coil portion  30 V, and the neutral point connection end portions NtW of the W-phase coil portion  30 W are electrically connected to each other is formed. 
     As illustrated in  FIG. 15 , the U-phase/W-phase neutral point segment conductors  62   a  which each include the neutral point coil end portion  62   c  which connects between the slot housed portion  42   b  for U-phase and the slot housed portion  42   b  for W-phase are shaped. In addition, the U-phase/W-phase neutral point segment conductors  62   a  are shaped such that the slot pitch of one of the two U-phase/W-phase neutral point segment conductors  62   a  is nine while the slot pitch of the other is seven. The V-phase neutral point segment conductors  62   b  which each include the slot housed portion  42   b  for V-phase and the neutral point coil end portion  62   d  are shaped. 
     After that, the welded portions  62   e  are formed by welding the two neutral point coil end portions  62   d  on end surfaces of the two neutral point coil end portions  62   c  on the axially outer side (to each other). Consequently, the radially inner neutral point conductor  62  (neutral point conductor  60 ) in which the neutral point connection end portions NtU of the U-phase coil portion  30 U, the neutral point connection end portions NtV of the V-phase coil portion  30 V, and the neutral point connection end portions NtW of the W-phase coil portion  30 W are electrically connected to each other is formed. 
     &lt;Formation of Insulating Portion&gt; 
     In the present embodiment, in step S 2  (see  FIG. 19 ), the insulating portion  120  which has the thickness t 2  which is larger than the thickness t 1  of the insulating coating  40   a  of the joint portion  90  is provided on the conductor surface  40   b  of a portion of the segment conductor  40  that is different from a first surface  172  and a second surface  182 . Consequently, the insulation resistance r 2  of the insulating portion  120  is higher than the insulation resistance r 1  of the insulating coating  40   a  alone. 
     As illustrated in  FIG. 9 , the insulating portion  120  is formed by attaching the insulating member  121  to the slot housed portion  42   a , of the pair of slot housed portions  42   a  and  42   b , the length of which along the axial direction is the longer. Specifically, the insulating member  121  is attached to each of the slot housed portions  42   a  of the general conductors  41 , the slot housed portions  42   a  of the radially outer power conductors  52 , and the slot housed portions  42   a  of the radially outer neutral point conductor  61 . 
     Particularly, as illustrated in  FIG. 8B , the insulating member  121  in a sheet shape which has the thickness t 3  which is smaller than the thickness t 1  is wound around the slot housed portion  42   a  for one round or more (e.g. more than one round and less than two rounds) to be fixed. Consequently, in the case where the number of times of winding is one (one round), the insulating portion  120  which has the thickness t 2  (=t 1 +t 3 ) which is larger than the thickness t 1  is formed on the slot housed portion  42   a.    
     (Formation of First Coil Assembly and Second Coil Assembly) 
     In step S 3 , as illustrated in  FIG. 3 , the first coil assembly  30   a  and the second coil assembly  30   b  in a circular ring shape which are composed of a plurality of segment conductors  40  are formed. 
     In the present embodiment, as illustrated in  FIGS. 3 and 20 , the first coil assembly  30   a  and the second coil assembly  30   b  in a circular ring shape which are composed of a plurality of segment conductors  40  are formed such that the insulating portion  120  of one segment conductor  40  is positioned at a position adjacent, in the radial direction, to the joint portion  90  of a different segment conductor  40  disposed adjacent to the one segment conductor  40  in the radial direction. While only some (two) of the plurality of insulating portions  120  are illustrated as hatched for illustration in  FIG. 3 , all the slot housed portions  42   a  are provided with the insulating portions  120  in the present embodiment. 
     Specifically, as illustrated in  FIG. 3 , the first coil assembly  30   a  in a circular ring shape is formed such that the plurality of general conductors  41 , the power conductors  50  for the three phases, and the radially outer neutral point conductor  61  and the radially inner neutral point conductor  62  have an arrangement relationship that is generally similar to that of such conductors at the time when the conductors are disposed in the plurality of slots  12  (with the stator  100  in the completed state). In addition, the second coil assembly  30   b  in a circular ring shape is formed such that the plurality of general conductors  41  have an arrangement relationship that is generally similar to that of such conductors at the time when the conductors are disposed in the plurality of slots  12 . 
     Particularly, as illustrated in  FIG. 20 , the first coil assembly  30   a  and the second coil assembly  30   b  are formed such that a plurality of (e.g. eight) segment conductors  40  are arranged in parallel in the radial direction and sets of the segment conductors  40  are arranged in parallel in the circumferential direction as many as the number of the slots  12 . At this time, in the present embodiment, the first coil assembly  30   a  and the second coil assembly  30   b  are formed such that the insulating portion  120  of one segment conductor  40 , among the plurality of segment conductors  40  which are disposed in parallel, is positioned at an axial position corresponding to the joint portion  90  of a different segment conductor  40  disposed adjacent to the one segment conductor  40  in the radial direction. 
     (Step of Disposing Slot Insulating Paper in Slots) 
     In step S 4  (see  FIG. 19 ), as illustrated in  FIG. 21 , the slot insulating paper  20  is disposed in each of the plurality of slots  12 . The slot insulating paper  20  is disposed with the radially inner side and both sides in the axial direction released or opened. In addition, as illustrated in  FIG. 3 , the slot insulating paper  20  which has been disposed is held in the slots  12  using the collar portions  22  on both sides in the axial direction. 
     (Step of Disposing Segment Conductors in Slots) 
     In step S 5  (see  FIG. 19 ), as illustrated in  FIGS. 20 and 22 , the plurality of segment conductors  40  are disposed in the plurality of slots  12 . That is, the first coil assembly  30   a  and the second coil assembly  30   b  are inserted into the plurality of slots  12 . 
     Particularly, first, as illustrated in  FIG. 3 , the first coil assembly  30   a  is disposed on the side in the direction of the arrow Z 1  with respect to (e.g. directly above) the stator core  10 . In addition, the second coil assembly  30   b  is disposed on the side in the direction of the arrow Z 2  with respect to (e.g. directly below) the stator core  10 . At this time, as illustrated in  FIG. 20 , the joint material  130  is disposed on at least one of the first surface  172  of the first slot housed portion  71  of the first coil assembly  30   a  and the corresponding second surface  182  of the second slot housed portion  81  of the second coil assembly  30   b  which face each other in the axial direction. 
     As illustrated in  FIG. 22 , the slot housed portions  42   a  and  42   b  of the first coil assembly  30   a  and the second coil assembly  30   b  are disposed in the respective slots  12  of the plurality of slots  12  by relatively moving the first coil assembly  30   a  and the second coil assembly  30   b  in the axial direction with respect to the plurality of slots  12 . For example, the slot housed portions  42   a  and  42   b  are disposed in the respective slots  12  of the plurality of slots  12  (slots  12  in which the slot insulating paper  20  is disposed) by translating (linearly moving) the first coil assembly  30   a  in the direction of the arrow Z 2  with respect to the stator core  10  and translating (linearly moving) the second coil assembly  30   b  in the direction of the arrow Z 1  with respect to the stator core  10 . 
     As illustrated in  FIG. 16 , the plurality of segment conductors  40  are disposed in the plurality of slots  12  such that: the first surface  172  to form the first facing surface  72  of the first slot housed portion  71 , which is the slot housed portion  42   a  or  42   b  of the plurality of segment conductors  40  of the first coil assembly  30   a , directs to the radially inner side; the first other end surface  73  of the first slot housed portion  71  directs to the radially outer side; the second surface  182  to form the second facing surface  82  of the second slot housed portion  81 , which is the slot housed portion  42   a  or  42   b  of the plurality of segment conductors  40  of the second coil assembly  30   b , and the second other end surface  83  which is continuous with the second surface  182  direct to the radially outer side; and the first slot housed portion  71  and the second slot housed portion  81  face each other in the axial direction. 
     Particularly, at least a portion of the first facing surface  72  to form the first joint surface  72   a  and a portion of the second facing surface  82  to form the second joint surface  82   a  are proximate to (contact) each other via the joint material  130  because a recessed and projected portion of the first surface  172  as the first facing surface  72 , which is recessed and projected in the radial direction, and a recessed and projected portion of the second surface  182  as the second facing surface  82 , which is recessed and projected in the radial direction, are engaged with each other. 
     At this time, the first other end surface  73  is disposed (offset) so as to project toward the radially outer side with respect to the second other end surface  83 , and the second one end surface  84  is disposed (offset) so as to project toward the radially inner side with respect to the first one end surface  74 . 
     In addition, as illustrated in  FIG. 17 , the plurality of segment conductors  40  are disposed in the slots  12  such that the insulating portion  120  of one segment conductor  40 , among the plurality of segment conductors  40  which are disposed in parallel in the radial direction, is positioned at an axial position corresponding to the first facing surface  72  or the second facing surface  82  (a portion to form the joint portion  90 ) of a different segment conductor  40  disposed adjacent to the one segment conductor  40  in the radial direction with the first coil assembly  30   a  and the second coil assembly  30   b  disposed in the slots  12 . 
     (Step of Joining Slot Housed Portions) 
     In step S 6  (see  FIG. 19 ), the joint portion  90  is formed as at least a part (first joint surface  72   a ) of the first facing surface  72  and at least a part (second joint surface  82   a ) of the second facing surface  82  are joined to each other by a heating device (not illustrated) heating at least the joint material  130  while the pressing jig  200  is pressing the slot housed portions  42   a  and  42   b  (against each other). 
     Here, as illustrated in  FIG. 22 , the pressing jig  200  is provided with movable members  201 , pressing members  202 , and a holding member  203 . The number of the movable members  201  is the same as the number of the slots  12 . The holding member  203  is configured to hold the movable members  201  and the pressing members  202 . In addition, the pressing members  202  are each formed in a wedge shape (tapered shape) to be tapered toward one axial side, for example, and configured to transfer a pressing force to the segment conductors  40  while moving the movable member  201  toward the radially outer side by pressing the movable member  201  toward the radially outer side when the pressing member  202  is moved in the axial direction. 
     As illustrated in  FIG. 23 , the pressing jigs  200  (movable members  201 ) are disposed in the opening portions  12   a  of the slots  12  (on the radially inner side of the slots  12 ). Consequently, the plurality of slot housed portions  42   a  and  42   b  which are arranged in parallel in the radial direction are interposed between the pressing jigs  200  and the wall portions  11   a  of the stator core  10  on both sides in the radial direction. When the pressing jigs  200  apply a pressing force (load) to the plurality of slot housed portions  42   a  and  42   b , which are arranged in parallel in the radial direction, toward the radially outer side, a reaction force directed from the wall portions  11   a  toward the radially inner side is generated, and the plurality of slot housed portions  42   a  and  42   b  which are arranged in parallel in the radial direction are pressed from both sides in the radial direction. 
     Here, in the present embodiment, with the first other end surface  73  disposed (offset) so as to project toward the radially outer side with respect to the second other end surface  83 , the first slot housed portion  71  is pressed toward the radially inner side by the wall portion  11   a  of the stator core  10  as the wall portion  11   a  contacts the first other end surface  73  of the first slot housed portion  71  disposed on the radially outermost side, among the plurality of first slot housed portions  71 . In addition, with the second one end surface  84  disposed (offset) so as to project toward the radially inner side with respect to the first one end surface  74 , the second slot housed portion  81  is pressed toward the radially outer side by the pressing jig  200  as the pressing jig  200  contacts the second one end surface  84  of the second slot housed portion  81  disposed on the radially innermost side, among the plurality of second slot housed portions  81 . 
     Consequently, the first facing surface  72  and the second facing surface  82  are pressed against each other in the direction in which the first facing surface  72  and the second facing surface  82  face each other. With a pressing force and a reaction force transferred between the slot housed portions  42   a  and  42   b  which are disposed in parallel in the radial direction, the first other end surface  73  of the first slot housed portion  71  disposed on the radially outermost side and the first other end surface  73  of the first slot housed portion  71  on the radially innermost side or the first other end surfaces  73  of the first slot housed portions  71  other than the second slot housed portions  81  are pressed toward the radially outer side, and the second one end surfaces  84  of the second slot housed portions  81  are pressed toward the radially inner side. 
     Particularly, the first facing surface  72  and the second facing surface  82  which face each other in the slot  12  are pressed against each other as the insulating member  121  of the first slot housed portion  71  contacts the first other end surface  73  or the second one end surface  84  which is adjacent in the radial direction. 
     The joint material  130  is cured with a part thereof volatilized when the joint material  130 , the first slot housed portion  71 , and the second slot housed portion  81  are heated by a heating device (such as a heater, hot air, etc.) while the first facing surface  72  and the second facing surface  82  are pressed against each other. The joint material  130  is heated to a curing temperature or higher. The first slot housed portion  71  and the second slot housed portion  81  are joined and electrically connected to each other using a conductive material (such as silver) contained in the joint material  130 . All the first joint surfaces  72   a  and the second joint surfaces  82   a  that face each other are joined to each other in all the slots  12 . 
     Consequently, the first slot housed portion  71  of the power conductor  50  and the neutral point conductor  60  and the second slot housed portion  81  which is one of the slot housed portions  42   a  and  42   b  of the general conductor  41  are joined to each other in one slot  12 , and the second slot housed portion  81  which is the other of the slot housed portions  42   a  and  42   b  of the general conductor  41  and the first slot housed portion  71  of the general conductor  41  are joined to each other in a different slot  12 . As a result, the coil portion  30  in a wave-wound shape is formed. 
     As illustrated in  FIG. 17 , the first slot housed portion  71  and the second slot housed portion  81  are electrically joined to each other to form the joint portion  90 . Consequently, the insulating portion  120  is disposed at a position (axial position) adjacent to the joint portion  90  in the radial direction. In addition, the axial position P 11  of the joint portion  90  is different from the axial position P 12  of the joint portion  90  of the segment conductor  40  which is adjacent in the radial direction. In addition, a different joint portion  90  is not provided at a position adjacent to the joint portion  90  in the radial direction. 
     (Step of Covering Joint Portions with Slot Insulating Paper) 
     In step S 7  (see  FIG. 19 ), as illustrated in  FIG. 5 , the joint portion cover portion  21  which covers at least the joint portion  90  is formed by deforming (folding) the slot insulating paper  20  such that the radially inner side of the first slot housed portion  71  and the second slot housed portion  81  disposed on the radially innermost side is covered by the slot insulating paper  20 . After that, the stator  100  is completed as illustrated in  FIG. 2 . As illustrated in  FIG. 1 , the stator  100  and the rotor  101  are combined with each other to manufacture the rotary electric machine  102 . 
     Effects of Structure According to Present Embodiment 
     The following effects can be obtained with the structure according to the embodiment described above. 
     In the embodiment described above, an insulating portion ( 120 ) is provided on a conductor surface ( 40   b ) of one segment conductor ( 40 ), among the plurality of segment conductors ( 40 ) which are disposed in parallel, at a position (P 11 , P 12 ) in the center axis (C 1 ) direction corresponding to an adjacent joint portion ( 90 ) which is the joint portion ( 90 ) of a different segment conductor ( 40 ) disposed adjacent to the one segment conductor ( 40 ) in the radial direction. The insulating portion ( 120 ) has a second insulation resistance (r 2 ) which is higher than a first insulation resistance (r 1 ) of an insulating coating ( 40   a ) of the different segment conductor ( 40 ). Consequently, the insulation resistance (r 2 ) of the insulating portion ( 120 ) of the one segment conductor ( 40 ) at a position adjacent to the adjacent joint portion ( 90 ) can be made relatively high, and thus the insulation performance between the adjacent joint portion ( 90 ) and the segment conductor ( 40 ) which is adjacent to the adjacent joint portion ( 90 ) can be improved. As a result, the insulation performance between the adjacent joint portion ( 90 ) and the adjacent segment conductor ( 40 ) can be secured in the case where the segment conductors ( 40 ) are to be joined to each other, even in the case where the conductor ( 72 ,  82 ) of the adjacent joint portion ( 90 ) is exposed. 
     In the embodiment described above, in addition, the insulating portion ( 120 ) has the second insulation resistance (r 2 ) which is higher than the first insulation resistance (r 1 ) as the insulating portion ( 120 ) has a second thickness (t 2 ) which is larger than a first thickness (t 1 ) which is a thickness of the insulating coating ( 40   a ) of the different segment conductor ( 40 ). With such a configuration, the second insulation resistance (r 2 ) can be easily made higher than the first insulation resistance (r 1 ) by making the second thickness (t 2 ) of the insulating portion ( 120 ) larger than the first thickness (t 1 ) of the insulating coating ( 40   a ). In addition, the size (physical size) of the segment conductors ( 40 ) can be prevented from being large in portions other than the insulating portion ( 120 ) (a portion that requires the second thickness (t 2 )) unlike the case where all the insulating coating ( 40   a ) on the plurality of segment conductors ( 40 ) is configured to have the second thickness (t 2 ) which is relatively large. As a result, an increase in the size of the armature ( 100 ) can be prevented. Consequently, the insulation performance between the adjacent joint portion ( 90 ) and the segment conductor ( 40 ) which is adjacent to the adjacent joint portion ( 90 ) can be secured while preventing an increase in the size of the armature ( 100 ). 
     In the embodiment described above, in addition, the insulating portion ( 120 ) includes the insulating coating ( 40   a ) which has the first thickness (t 1 ) and an insulating member ( 121 ) that covers the insulating coating ( 40   a ) and that has a function of insulating the segment conductor ( 40 ) and the adjacent joint portion ( 90 ) from each other. Here, it is not easy to configure the thickness of the insulating coating ( 40   a ) which is provided on the segment conductors ( 40 ) to be varied partially. With the configuration according to the embodiment described above, in view of the above, the insulating portion ( 120 ) which is constituted from the insulating member ( 121 ) and the insulating coating ( 40   a ) can be easily formed by forming the segment conductors ( 40 ) provided with the insulating coating ( 40   a ) which has the generally uniform first thickness (t 1 ) and thereafter attaching the insulating member ( 121 ) which is formed separately from the insulating coating ( 40   a ) to the segment conductors ( 40 ). Consequently, there is no need to use dedicated conductive wires (segment conductors) that have an insulating coating that has different thicknesses from part to part since the configuration is unlike the case where the insulating portion ( 120 ) is constituted by varying the thickness of a part of the insulating coating ( 40   a ) of the segment conductors ( 40 ). Consequently, general-purpose conductive wires (segment conductors) that have an insulating coating with a uniform thickness can be used, and thus the insulating portion ( 120 ) can be constituted accordingly easily. 
     In the embodiment described above, in addition, a third thickness (t 3 ) which is a thickness of the insulating member ( 121 ) is smaller than the first thickness (t 1 ). Here, in general, the first thickness (t 1 ) of the segment conductors ( 40 ) is set to such a level that enables securing the insulation performance between different phases. That is, the first thickness (t 1 ) is set to such a level that enables securing the insulation performance even in the case where the coil end portions ( 43 ) for different phases which are provided with the insulating coating ( 40   a ) with the first thickness (t 1 ) are disposed in proximity to each other. Meanwhile, it is only necessary that the insulation performance between the segment conductors ( 40 ) for the same phase should be secured in the case where only the segment conductors ( 40 ) for the same phase are disposed in the same slot ( 12 ). In other words, it is possible to secure the insulation performance between the adjacent joint portion ( 90 ) and the segment conductor ( 40 ) which is adjacent to the adjacent joint portion ( 90 ) in the slot ( 12 ) if the thickness of the insulating portion is less than twice the first thickness (t 1 ) of the insulating coating ( 40   a ) of the adjacent segment conductors ( 40 ) and more than the first thickness (t 1 ). In consideration of this respect, the thickness (t 3 ) of the insulating member ( 121 ) can be prevented from being increased more than necessary by configuring the third thickness (t 3 ) which is the thickness of the insulating member ( 121 ) to be less than the first thickness (t 1 ) as in the embodiment described above. As a result, the size of the conductor ( 40   c ) can be secured accordingly since an increase in the thickness (t 3 ) of the insulating member ( 121 ) is prevented. Thus, the insulation performance can be secured while preventing a reduction in the space factor (proportion of the conductor ( 40   c ) of the segment conductor ( 40 )) in the slot ( 12 ). 
     In the embodiment described above, in addition, the insulating member ( 121 ) is formed in a sheet shape; and the insulating member ( 121 ) in the sheet shape is wound around an outer periphery of the insulating coating ( 40   a ) of the segment conductor ( 40 ) for at least one round. With such a configuration, the entire outer periphery of the segment conductor ( 40 ) can be covered by the insulating member ( 121 ). Thus, the insulation creepage distance (Dc) to the surface of the outer periphery of the segment conductor ( 40 ) from the adjacent joint portion ( 90 ) can be secured compared to a case where the insulating member ( 121 ) is provided on only a portion of the segment conductor ( 40 ) that faces the adjacent joint portion ( 90 ). In addition, by winding the insulating member ( 121 ) in a sheet shape around the outer periphery of the insulating coating ( 40   a ) of the segment conductor ( 40 ), the position of attachment of the insulating member ( 121 ) to the segment conductor ( 40 ) can be held by the wound insulating member ( 121 ) itself. Thus, the strength of fixation of the insulating member ( 121 ) to the segment conductor ( 40 ) can be improved. 
     In the embodiment described above, in addition, the segment conductor ( 40 ) includes a pair of leg portions ( 42   a ,  42   b ) disposed (in the slots ( 12 )) at different circumferential positions and having different lengths along the center axis (C 1 ) direction and a coil end portion ( 43 ) that connects between the pair of leg portions ( 42   a ,  42   b ); and the insulating portion ( 120 ) is provided on a leg portion ( 42   a ), of the pair of leg portions ( 42   a ,  42   b ), a length (L 1 ) of which along the center axis (C 1 ) direction is the longer. With such a configuration, the insulating portion ( 120 ) which is provided on the leg portion ( 42   a ) with the longer length (L 1 ) can be positioned at a position in the center axis (C 1 ) direction corresponding to the distal end portion ( 72 ,  82 ,  90 ) of the leg portion ( 42   b ) with the shorter length (L 2 ), by disposing the leg portion ( 42   a ) with the longer length (L 1 ) and the leg portion ( 42   b ) with the shorter length (L 2 ) so as to be adjacent to each other in the radial direction. As a result, the configuration of the segment conductor ( 40 ) can be commonalized, and thus an increase in the number of types of parts of the armature ( 100 ) can be prevented. 
     In the embodiment described above, in addition, the insulating portion ( 120 ) is provided at a position, in the center axis direction, at which the adjacent joint portion ( 90 ) is present. With such a configuration, the insulation performance at the position (P 11 , P 12 ) in the center axis direction at which the adjacent joint portion ( 90 ) which requires improved insulation performance is present can be effectively improved by the insulating portion ( 120 ). 
     In the embodiment described above, in addition, the joint portion ( 90 ) of the one segment conductor ( 40 ) and the joint portion ( 90 ) of the different segment conductor ( 40 ) are not provided adjacent to each other in the radial direction, but provided at different positions (P 11 , P 12 ) in the center axis direction. With such a configuration, the insulation performance between the adjacent segment conductors ( 40 ) can be improved since a plurality of joint portions ( 90 ) are not adjacent to each other in the radial direction. 
     In the embodiment described above, in addition, the joint portions ( 90 ) of the plurality of segment conductors ( 40 ) which are disposed in parallel in the radial direction are disposed alternately in the radial direction at a position (P 11 ) on one side in the center axis direction and a position (P 12 ) on the other side in the center axis direction. With such a configuration, a plurality of segment conductors ( 40 ) can be easily disposed such that a plurality of joint portions ( 90 ) are not adjacent to each other in the radial direction. The insulation performance between the adjacent segment conductors ( 40 ) can be improved since a plurality of joint portions ( 90 ) are not adjacent to each other in the radial direction. 
     In the embodiment described above, in addition, a length (L 31 ) of the insulating portion ( 120 ) in the center axis (C 1 ) direction is equal to or more than an insulation creepage distance (Dc) along the center axis (C 1 ) direction from the adjacent joint portion ( 90 ), and less than a length (L 3 ) of the slots ( 12 ) in the center axis (C 1 ) direction. With such a configuration, the insulation creepage distance (Dc) along the center axis (C 1 ) direction from the adjacent joint portion ( 90 ) can be secured by the insulating portion ( 120 ). Thus, the insulation performance in the slot ( 12 ) can be further improved. In addition, the size of the insulating portion ( 120 ) can be prevented from being increased more than necessary by configuring the length (L 31 ) of the insulating portion ( 120 ) in the center axis (C 1 ) direction to be shorter than the length (L 3 ) of the slot ( 12 ) in the center axis (C 1 ) direction. As a result, the insulation performance in the slot ( 12 ) can be further improved while preventing an increase in the size of the insulating portion ( 120 ). 
     In the embodiment described above, in addition, the armature core ( 10 ) includes a plurality of teeth ( 13 ) formed on both sides, in a circumferential direction, of the slots ( 12 ); the armature further includes a slot insulating member ( 20 ) disposed between the teeth ( 13 ) and the segment conductors ( 40 ); the slots ( 12 ) each have an opening portion ( 12   a ) that opens on one side in the radial direction; and the slot insulating member ( 20 ) includes a joint portion cover portion ( 21 ) that covers one side, in the radial direction, of the joint portion ( 90 ) of a segment conductor ( 40 ) disposed closest to the opening portion ( 12   a ), among the plurality of segment conductors ( 40 ) which are disposed in parallel. Here, a different segment conductor ( 40 ) (insulating portion ( 120 )) is not disposed on one side (the opening portion ( 12   a ) side), in the radial direction, of the segment conductor ( 40 ) disposed closest to the opening portion ( 12   a ). In view of the above, the insulation performance between one side (the opening portion ( 12   a ) side), in the radial direction, of the joint portion ( 90 ) of the segment conductor ( 40 ) disposed closest to the opening portion ( 12   a ) and a different conductor can be secured by the joint portion cover portion ( 21 ), by providing the slot insulating member ( 20 ) with the joint portion cover portion ( 21 ) as in the embodiment described above. As a result, the insulation performance in the slot ( 12 ) can be further improved by the insulating portion ( 120 ) and the slot insulating member ( 20 ). 
     Effects of Method of Manufacturing Armature According to Present Embodiment 
     The following effects can be obtained with the method of manufacturing an armature according to the embodiment described above. 
     In the embodiment described above, the insulating portion ( 120 ) is provided on the segment conductors ( 40 ) (S 2 ), and the plurality of segment conductors ( 40 ) are disposed in the armature core ( 10 ) such that the insulating portion ( 120 ) of one segment conductor ( 40 ) is positioned at a position (P 11 , P 12 ) in the center axis direction corresponding to the distal end portion ( 72 ,  82 ) of a different segment conductor ( 40 ) disposed adjacent to the one segment conductor ( 40 ) in the radial direction. Consequently, it is possible to provide a method of manufacturing an armature ( 100 ) that enables securing the insulation performance between an adjacent joint portion ( 90 ) and a segment conductor ( 40 ) that is adjacent to the adjacent joint portion ( 90 ) in the case where the segment conductors ( 40 ) are to be joined to each other. 
     Here, it is not easy to perform the step (S 2 ) of providing the insulating portion ( 120 ) after the step (S 5 ) of disposing the plurality of segment conductors ( 40 ) in the slots ( 12 ). Specifically, after the step of disposing the plurality of segment conductors ( 40 ) in the slots ( 12 ), both the adjacent joint portion ( 90 ) and the plurality of segment conductors ( 40 ) are disposed in the slot ( 12 ), and therefore the adjacent joint portion ( 90 ) and the segment conductors ( 40 ) are proximate to each other with a slight clearance therebetween. In this case, it is considered to be difficult to provide the insulating portion ( 120 ) on the segment conductors ( 40 ). In the embodiment described above, in contrast, the step of disposing the plurality of segment conductors ( 40 ) in the slots ( 12 ) is performed after the step (S 2 ) of providing the insulating portion ( 120 ). 
     Consequently, the insulating portion ( 120 ) can be provided on the segment conductors ( 40 ) with the plurality of segment conductors ( 40 ) spaced from each other (with a space secured therebetween). As a result, the insulating portion ( 90 ) can be easily provided on the segment conductors ( 40 ) unlike the case where the insulating portion ( 120 ) is provided between the plurality of segment conductors ( 40 ) and the adjacent joint portion ( 90 ) with the plurality of segment conductors ( 40 ) disposed in the slots ( 12 ). 
     In the embodiment described above, in addition, the step (S 2 ) of providing the insulating portion ( 120 ) is a step of providing the insulating portion ( 120 ), which has the second insulation resistance (r 2 ) which is higher than the first insulation resistance (r 1 ) as the insulating portion ( 120 ) has a second thickness (t 2 ) which is larger than a first thickness (t 1 ) which is a thickness of the insulating coating ( 40   a ) of the distal end portions ( 72 ,  82 ,  90 ), on the conductor surface ( 40   b ) of the portion (P 11 , P 12 ) of the segment conductors ( 40 ) which is different from the distal end portions ( 72 ,  82 ,  90 ). With such a configuration, the second insulation resistance (r 2 ) can be easily made higher than the first insulation resistance (r 1 ) by making the second thickness (t 2 ) of the insulating portion ( 120 ) larger than the first thickness (t 1 ) of the insulating coating ( 40   a ). 
     In the embodiment described above, in addition, the segment conductor ( 40 ) includes a pair of leg portions ( 42   a ,  42   b ) disposed (in the slots ( 12 )) at different circumferential positions and having different lengths along the center axis (C 1 ) direction and a coil end portion ( 43 ) that connects between the pair of leg portions ( 42   a ,  42   b ); the step (S 2 ) of providing the insulating portion ( 120 ) is a step of providing the insulating portion ( 120 ) by attaching an insulating member ( 121 ) to a leg portion ( 42   a ), of the pair of leg portions ( 42   a ,  42   b ), a length of which along the center axis (C 1 ) direction is the longer; and the step (S 6 ) of joining the distal end portions ( 72 ,  82 ,  90 ) to each other is a step of joining the distal end portions ( 72 ,  82 ,  90 ) to each other at a position adjacent to the insulating portion ( 120 ) in the radial direction in the slots ( 12 ). With such a configuration, the step (S 2 ) of providing the insulating portion ( 120 ) can be performed when forming the segment conductors ( 40 ). For example, the step (S 2 ) of providing the insulating portion ( 120 ) can be performed continuously with the step (S 1 ) of forming the segment conductors ( 40 ). Consequently, the insulating portion ( 120 ) can be easily formed on the segment conductors ( 40 ) compared to the case where the insulating portion ( 120 ) is provided after the step (S 5 ) of disposing the plurality of segment conductors ( 40 ). In addition, the configuration of the segment conductor ( 40 ) can be commonalized, and thus an increase in the number of types of parts of the armature ( 100 ) can be prevented. 
     In the embodiment described above, in addition, the method further includes a step (S 3 ) of forming an annular coil assembly ( 30   a ,  30   b ) composed of the plurality of segment conductors ( 40 ), after the step (S 2 ) of providing the insulating portion ( 120 ) and before the step (S 5 ) of disposing the plurality of segment conductors ( 40 ), such that the insulating portion ( 120 ) of one segment conductor ( 40 ) is positioned at a position adjacent, in the radial direction, to the distal end portion ( 72 ,  82 ,  90 ) of a different segment conductor ( 40 ) disposed adjacent to the one segment conductor ( 40 ) in the radial direction; and the step (S 5 ) of disposing the plurality of segment conductors ( 40 ) is a step of disposing the plurality of segment conductors ( 40 ) in the plurality of slots ( 12 ) by moving the annular coil assembly ( 30   a ,  30   b ) in the center axis (C 1 ) direction with respect to the plurality of armature cores ( 10 ) so that the annular coil assembly ( 30   a ,  30   b ) is disposed in the plurality of armature cores ( 10 ) such that the plurality of segment conductors ( 40 ) are arranged in parallel in the radial direction of the armature core ( 10 ) and that the insulating portion ( 120 ) of one segment conductor ( 40 ) is positioned at a position (P 11 , P 12 ) in the center axis (C 1 ) direction corresponding to the distal end portion ( 72 ,  82 ,  90 ) of a different segment conductor ( 40 ). With such a configuration, the position (P 11 , P 12 ) of correspondence, in the center axis (C 1 ) direction, between the insulating portion ( 120 ) of one segment conductor ( 40 ) and the distal end portion ( 72 ,  82 ,  90 ) of a different segment conductor ( 40 ) can be fixed in advance before the plurality of segment conductors ( 40 ) are disposed in the armature core ( 10 ). Thus, the insulating portion ( 120 ) can be easily positioned at the position (P 11 , P 12 ) in the center axis (C 1 ) direction corresponding to the distal end portion ( 72 ,  82 ,  90 ) of the different segment conductor ( 40 ) compared to the case where the position of the insulating portion ( 120 ) is adjusted after the plurality of segment conductors ( 40 ) are disposed in the armature core ( 10 ). 
     Modifications 
     The embodiment disclosed herein should be considered as exemplary and non-limiting in all respects. The scope of the preferred embodiment is defined by the scope of the claims, rather than the description of the embodiment described above, and includes all changes (modifications) that fall within the scope of the claims and the meaning and scope of equivalence. 
     First Modification 
     For example, in the embodiment described above, the first facing surface is configured to direct to the radially inner side, and the second facing surface is configured to direct to the radially outer side. However, the preferred embodiment is not limited thereto. For example, as in a stator  300  according to a first modification illustrated in  FIG. 24 , a first facing surface  372  and a second facing surface  382  may each be constituted as a flat surface that is orthogonal to the axial direction. In the first modification, unlike the embodiment described above, the first facing surface  372  and the second facing surface  382  are pressed from the axially outer side of segment conductors  340 , and the first facing surface  372  and the second facing surface  382  are heated and joined to each other while being pressed against each other in the axial direction. Also in the stator  300  according to the first modification, as in the embodiment described above, a plurality of insulating portions  120  (insulating members  121 ) are disposed at axial positions P 21  and P 22  corresponding to the first facing surface  372  and the second facing surface  382  of adjacent segment conductors  340 . 
     Second Modification 
     In the embodiment described above, in addition, the insulating member is wound around the outer periphery of the insulating coating of the segment conductor for at least one round. However, the preferred embodiment is not limited thereto. For example, as in a stator  400  according to a second modification illustrated in  FIG. 25 , an insulating member  441  may be provided for only a part (the radially inner side and both sides in the circumferential direction) of the outer periphery of an insulating coating  440   a  of a segment conductor  440  on the radially outermost side. In this case, slot insulating paper  420  is disposed between the wall portion  11   a  (see  FIG. 5 ) of the stator core and the segment conductor  440 . Therefore, the insulation performance between the segment conductor  440  and the stator core  10  is secured by the slot insulating paper  420 . 
     Third Modification 
     In the embodiment described above, in addition, a segment conductor disposed on one axial side with respect to the stator core and a segment conductor disposed on the other axial side with respect to the stator core are joined to each other at one location in the slot. However, the preferred embodiment is not limited thereto. For example, as in a stator  500  according to a third modification illustrated in  FIG. 26 , a first slot housed portion  571  (first facing surface  572 ) of a first segment conductor  570  and a second slot housed portion  581  (second facing surface  582 ) of a second segment conductor  580  are joined to each other and the second slot housed portion  581  (second facing surface  582 ) of the second segment conductor  580  and a third slot housed portion  591  (third facing surface  592 ) of a third segment conductor  590  are joined to each other (at two locations) in the slot. Also in the stator  500  according to the third modification, as in the embodiment described above, a plurality of insulating portions  520  are disposed at axial positions P 31 , P 32 , P 33 , and P 34  corresponding to the first facing surface  572 , the second facing surface  582 , and the third facing surface  592  of adjacent segment conductors  540 . 
     Fourth and Fifth Modifications 
     In the embodiment described above, in addition, the first slot housed portion and the second slot housed portion are joined to each other in the slot. However, the preferred embodiment is not limited thereto. For example, as in a stator  600  according to a fourth modification illustrated in  FIG. 27 , a first leg portion  671  of a first segment conductor  670  and a second leg portion  681  of a second segment conductor  680  may be joined to each other at a joint portion  690  on the axially outer side with respect to the slot  12 . In this case, an insulating portion  620  is provided at a position adjacent to the joint portion  690  in the radial direction. The joint portion  690  is pressed in the state of being interposed between a first pressing jig  601  and a second pressing jig  602  in the radial direction to be joined. Alternatively, as in a stator  700  according to a fifth modification illustrated in  FIG. 28 , a part of a joint portion  790  may be disposed on the axially outer side of the slot  12 , and the other part of the joint portion  790  may be disposed on the axially inner side of the slot  12  (in the slot  12 ). 
     Other Modifications 
     In the embodiment described above, in addition, the armature according to the preferred embodiment is constituted as a stator. However, the preferred embodiment is not limited thereto. For example, the armature according to the preferred embodiment may be constituted as a rotor that has a rotor core and a coil (segment conductors). 
     In the embodiment described above, in addition, the opening portions are formed on the radially inner side of the stator. However, the preferred embodiment is not limited thereto. For example, the opening portions may be formed on the radially outer side of the stator. 
     In the embodiment described above, in addition, the coil is formed as a wave-wound coil. However, the preferred embodiment is not limited thereto. For example, the coil may be formed as a distributed wound coil or a concentrated wound coil. 
     In the embodiment described above, in addition, the segment conductors are formed to have a rectangular cross-sectional shape. However, the preferred embodiment is not limited thereto. That is, the segment conductors may be formed to have a cross-sectional shape (such as a circular shape and an elliptical shape) other than the rectangular shape. 
     In the embodiment described above, in addition, the slots are constituted as semi-open slots (with the opening width being smaller than the slot width). However, the preferred embodiment is not limited thereto. For example, the slots may be constituted as full-open slots with the opening width being equal to the slot width if the characteristics of the stator (armature) are not affected significantly. For the characteristics of the stator, semi-open slots are more preferable than full-open slots. 
     In the embodiment described above, in addition, the power conductor joint step and the neutral point conductor joint step are performed in the step of forming the segment conductors. However, the preferred embodiment is not limited thereto. For example, the power conductor joint step and the neutral point conductor joint step may be performed after the step of disposing the segment conductors in the slots is performed. In this case, a welding tool space is required in the vicinity of the power conductors and the neutral point conductors with the stator in the completed state. Therefore, from the viewpoint of preventing an increase in the size of the stator, the power conductor joint step and the neutral point conductor joint step are preferably performed before the step of disposing the segment conductors in the slots as in the embodiment described above. 
     In the embodiment described above, in addition, the coil portion is constituted (connected) through a Y connection of four parallel segment conductors (four-parallel connection). However, the preferred embodiment is not limited thereto. For example, the coil portion may be constituted through a Y connection of components other than four parallel segment conductors, or may be constituted through a connection. 
     In the embodiment described above, in addition, a method of pressing the first other end surface or the second one end surface and a method of heating the joint material are described. However, the preferred embodiment is not limited thereto. 
     That is, the first other end surface or the second one end surface may be pressed and the joint material may be heated by a method other than the pressing method and the heating method according to the embodiment described above. 
     In the embodiment described above, in addition, the insulating portion is constituted from an insulating coating and an insulating member that is separate from the insulating coating. However, the preferred embodiment is not limited thereto. For example, the insulating portion may not be provided with an insulating member, and the insulating portion may be constituted from only an insulating coating having the thickness t 2 . 
     In the embodiment described above, in addition, the thickness t 3  of the insulating member is smaller than the thickness t 1  of the insulating coating. However, the preferred embodiment is not limited thereto. For example, the thickness t 3  of the insulating member may be equal to or more than the thickness t 1  of the insulating coating if there is no problem with a reduction in the space factor of the coil in the slot. 
     In the embodiment described above, in addition, the insulating member is formed in a sheet shape. However, the preferred embodiment is not limited thereto. That is, the insulating member is not limited to a sheet shape. For example, the insulating member may be formed in a tube shape, or the insulating member may be constituted from a paint material, a coating agent, etc. 
     In the embodiment described above, in addition, the insulating member is provided on only a slot housed portion, of a pair of slot housed portions, the length of which is the longer. However, the preferred embodiment is not limited thereto. For example, the insulating member may be provided on a slot housed portion, the length of which is the shorter, or the insulating member may be provided on both a pair of slot housed portions, depending on the position of arrangement of an adjacent joint portion. 
     In the embodiment described above, in addition, the joint portion cover portion is formed as a part of the slot insulating paper. However, the preferred embodiment is not limited thereto. For example, the joint portion cover portion may be constituted as a member (insulating member) that is separate from the insulating portion and the slot insulating paper. 
     In the embodiment described above, in addition, the plurality of segment conductors are disposed in the slots after the first coil assembly and the second coil assembly in a circular ring shape are formed. However, the preferred embodiment is not limited thereto. That is, the plurality of segment conductors may be individually disposed in the slots without forming the first coil assembly and the second coil assembly in a circular ring shape. 
     In the embodiment described above, in addition, the insulating portion is configured to have a second insulation resistance which is higher than a first insulation resistance as the insulating portion has a second thickness that is larger than a first thickness which is the thickness of the insulating coating. However, the preferred embodiment is not limited thereto. For example, the insulating portion may be configured to have the insulation resistance r 2  which is higher than the insulation resistance r 1  by using an insulation material with a higher insulation resistance, per unit length (thickness), than the insulation resistance, per unit length (thickness), of the insulation material of the insulating coating. In this case, the insulating portion may be configured to have a thickness t 1  which is generally the same as the thickness t 1  of the insulating coating, for example. That is, an insulation material with a relatively high insulation resistance, per unit length, is used for the insulating portion (portion that is adjacent to the joint portion), and an insulation material with an ordinary insulation resistance, per unit length, is used for the other portions. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
           10  STATOR CORE (ARMATURE CORE) 
           12  SLOT 
           12   a  OPENING PORTION 
           13  TOOTH 
           20 ,  420  SLOT INSULATING PAPER (SLOT INSULATING MEMBER) 
           21  JOINT PORTION COVER PORTION 
           30  COIL PORTION 
           30   a  FIRST COIL ASSEMBLY 
           30   b  SECOND COIL ASSEMBLY 
           40  SEGMENT CONDUCTOR 
           40   a  INSULATING COATING 
           40   b  CONDUCTOR SURFACE 
           42   a ,  42   b  SLOT HOUSED PORTION 
           43  COIL END PORTION 
           90 ,  690 ,  790  JOINT PORTION (ADJACENT JOINT PORTION, DISTAL END PORTION) 
           100 ,  300 ,  400 ,  500 ,  600 ,  700  STATOR (ARMATURE) 
           120 ,  520  INSULATING PORTION 
           121 ,  441  INSULATING MEMBER