Patent Publication Number: US-2022216760-A1

Title: Armature and manufacturing method thereof

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is the U.S. bypass application of International Application No. PCT/JP2020/35321 filed on Sep. 17, 2020, which designated the U.S. and claims priority to Japanese Patent Application No. 2019-170332, filed Sep. 19, 2019, the contents of both of these are incorporated herein by reference. 
    
    
     BACKGROUND 
     Technical Field 
     The present disclosure relates to an armature and a manufacturing method thereof. 
     Description of the Related Art 
     Conventionally, a rotating electric machine is known. The rotating electric machine is provided with a field magnet including a plurality of magnetic poles having alternating polarities in a circumferential direction and an armature disposed facing the field magnet. 
     SUMMARY 
     The present disclosure provides an armature having an armature winding, an armature core and a first and second insulation sheets. The first insulation sheet is arranged to sequentially pass through a field magnet side of a first phase conductor, a portion between the first phase conductor and a second phase conductor, an armature core side of the second phase conductor and a third phase conductor and a portion between the third phase conductor and the first phase conductor. The second insulation sheet is arranged to sequentially pass through a portion opposite to the first phase conductor with respect to the first insulation sheet, a field magnet side of the second conductor, a portion between the second phase conductor and the third phase conductor, a portion between the third phase conductor and the first insulation sheet and a portion between the third phase conductor and the first insulation sheet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above features and advantages of the present disclosure will be clarified further by the following detailed description with reference to the accompanying drawings. The drawings are: 
         FIG. 1  is a vertical cross-sectional perspective view of a rotating electric machine. 
         FIG. 2  is a vertical cross-sectional view of the rotating electric machine. 
         FIG. 3  is a sectional view taken along a line III-III of  FIG. 2 . 
         FIG. 4  is a cross-sectional view illustrating a part of  FIG. 3  in an enlarged manner. 
         FIG. 5  is an exploded view of the rotating electric machine. 
         FIG. 6  is an exploded view of an inverter unit. 
         FIG. 7  is a torque line diagram illustrating a relation between ampere-turns of a stator winding and torque density. 
         FIG. 8  is a cross-sectional view of a rotor and a stator. 
         FIG. 9  is a view illustrating a part of  FIG. 8  in an enlarged manner. 
         FIG. 10  is a cross-sectional view of the stator. 
         FIG. 11  is a vertical cross-sectional view of the stator. 
         FIG. 12  is a perspective view of the stator winding. 
         FIG. 13  is a perspective view illustrating a configuration of a conductor. 
         FIG. 14  is a schematic diagram illustrating a configuration of wires. 
         FIG. 15A  is a diagram illustrating a form of each conductor in an nth layer. 
         FIG. 15B  is a diagram illustrating a form of each conductor in an nth layer. 
         FIG. 16  is a side view illustrating each conductor of the nth layer and an n+1th layer. 
         FIG. 17  is a diagram illustrating a relation between an electrical angle and a magnetic flux density of a magnet of an embodiment. 
         FIG. 18  is a diagram illustrating a relation between an electrical angle and a magnetic flux density of a magnet of a comparative example. 
         FIG. 19  is an electrical circuit diagram of a control system of the rotating electric machine. 
         FIG. 20  is a functional block diagram illustrating current feedback control processing by a control device. 
         FIG. 21  is a functional block diagram illustrating torque feedback control processing by the control device. 
         FIG. 22  is a cross-sectional view of a rotor and a stator in a second embodiment. 
         FIG. 23  is a view illustrating a part of  FIG. 22  in an enlarged manner. 
         FIG. 24A  is a diagram specifically illustrating a flow of magnetic flux in a magnet unit. 
         FIG. 24B  is a diagram specifically illustrating a flow of magnetic flux in a magnet unit. 
         FIG. 25  is a cross-sectional view of a stator in a first modification. 
         FIG. 26  is a cross-sectional view of the stator in the first modification. 
         FIG. 27  is a cross-sectional view of a stator in a second modification. 
         FIG. 28  is a cross-sectional view of a stator in a third modification. 
         FIG. 29  is a cross-sectional view of a stator in a fourth modification. 
         FIG. 30  is a cross-sectional view of a rotor and a stator in a seventh modification. 
         FIG. 31  is a functional block diagram illustrating a part of the processing of an operation signal generation unit in a eighth modification. 
         FIG. 32  is a flowchart illustrating a procedure of carrier frequency changing processing. 
         FIG. 33A  is a diagram illustrating a connection form of each conductor constituting a conductor group in a ninth modification. 
         FIG. 33B  is a diagram illustrating a connection form of each conductor constituting a conductor group in a ninth modification. 
         FIG. 33C  is a diagram illustrating a connection form of each conductor constituting a conductor group in a ninth modification. 
         FIG. 34  is a diagram illustrating a configuration in which four pairs of conductors are laminated in the ninth modification. 
         FIG. 35  is a cross-sectional view of an inner rotor type rotor and a stator in tenth modification. 
         FIG. 36  is a view illustrating a part of  FIG. 35  in an enlarged manner. 
         FIG. 37  is a vertical cross-sectional view of an inner rotor type rotating electric machine. 
         FIG. 38  is a vertical cross-sectional view illustrating a schematic configuration of the inner rotor type rotating electric machine. 
         FIG. 39  is a diagram illustrating a configuration of a rotating electric machine having an inner rotor structure in a eleventh modification. 
         FIG. 40  is a diagram illustrating a configuration of a rotating electric machine having an inner rotor structure in the eleventh modification. 
         FIG. 41  is a diagram illustrating a configuration of a rotating electric machine having an inner rotor structure in a twelfth modification. 
         FIG. 42  is a cross-sectional view illustrating a configuration of a conductor in a fourteenth modification. 
         FIG. 43  is a diagram illustrating a relation between a reluctance torque, a magnet torque, and DM. 
         FIG. 44  is a diagram illustrating teeth. 
         FIG. 45  is a perspective view illustrating a wheel having an in-wheel motor structure and its peripheral structure. 
         FIG. 46  is a vertical cross-sectional view of the wheel and its peripheral structure. 
         FIG. 47  is an exploded perspective view of the wheel. 
         FIG. 48  is a side view of a rotating electric machine as viewed from the protruding side of a rotating shaft. 
         FIG. 49  is a cross-sectional view taken along a line  49 - 49  of  FIG. 48 . 
         FIG. 50  is a cross-sectional view taken along a line  50 - 50  of  FIG. 49 . 
         FIG. 51  is an exploded cross-sectional view of the rotating electric machine. 
         FIG. 52  is a partial cross-sectional view of the rotor. 
         FIG. 53  is a perspective view of a stator winding and a star core. 
         FIG. 54A  is a front view illustrating the stator winding developed in a plane. 
         FIG. 54B  is a front view illustrating the stator winding developed in a plane. 
         FIG. 55  is a diagram illustrating a skew of the conductor. 
         FIG. 56  is an exploded cross-sectional view of the inverter unit. 
         FIG. 57  is an exploded cross-sectional view of the inverter unit. 
         FIG. 58  is a diagram illustrating a state of arrangement of each electric module in an inverter housing. 
         FIG. 59  is a circuit diagram illustrating an electrical configuration of a power converter. 
         FIG. 60  is a diagram illustrating an example of a cooling structure of a switch module. 
         FIG. 61A  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 61B  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 62A  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 62B  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 62C  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 63A  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 63B  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 64  is a diagram illustrating an example of the cooling structure of the switch module. 
         FIG. 65  is a diagram illustrating an arrangement order of each electric module with respect to a cooling water passage. 
         FIG. 66  is a cross-sectional view taken along a line  66 - 66  of  FIG. 49 . 
         FIG. 67  is a cross-sectional view taken along a line  67 - 67  of  FIG. 49 . 
         FIG. 68  is a perspective view illustrating a busbar module alone. 
         FIG. 69  is a diagram illustrating an electrical connection state between each electric module and the busbar module. 
         FIG. 70  is a diagram illustrating an electrical connection state between each electric module and the busbar module. 
         FIG. 71  is a diagram illustrating an electrical connection state between each electric module and the busbar module. 
         FIG. 72A  is a configuration diagram for explaining a first modification in an in-wheel motor. 
         FIG. 72B  is a configuration diagram for explaining a first modification in an in-wheel motor. 
         FIG. 72C  is a configuration diagram for explaining a first modification in an in-wheel motor. 
         FIG. 72D  is a configuration diagram for explaining a first modification in an in-wheel motor. 
         FIG. 73A  is a configuration diagram for explaining a second modification in the in-wheel motor. 
         FIG. 73B  is a configuration diagram for explaining a second modification in the in-wheel motor. 
         FIG. 73C  is a configuration diagram for explaining a second modification in the in-wheel motor. 
         FIG. 74A  is a configuration diagram for explaining a third modification in the in-wheel motor. 
         FIG. 74B  is a configuration diagram for explaining a third modification in the in-wheel motor. 
         FIG. 75  is a configuration diagram for explaining a fourth modification in the in-wheel motor. 
         FIG. 76  is a process control chart showing a manufacturing process of a stator according a fifteenth modification. 
         FIG. 77A  is a diagram showing a manufacturing mode of a first assembly and a second assembly. 
         FIG. 77B  is a diagram showing a manufacturing mode of a first assembly and a second assembly. 
         FIG. 78A  is a diagram showing a lamination mode of the first assembly, the second assembly and a third insulation sheet. 
         FIG. 78B  is a diagram showing a lamination mode of the first assembly, the second assembly and a third insulation sheet. 
         FIG. 79  is a cross sectional view of a stator. 
         FIG. 80  is a cross sectional view of a stator according to a comparative example. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As a conventional art, for example, Japanese Patent Application Laid-Open Publication No. 2011-24379 discloses a rotating electric machine provided with a field magnet including a plurality of magnetic poles having alternating polarities in a circumferential direction and an armature disposed facing the field magnet. The armature includes a three-phase armature winding and an armature core disposed in an opposite side of the field magnet via the armature winding. 
     The armature winding includes conductors arranged in the circumferential direction at predetermined intervals in the order of the first phase, the second phase and the third phase (e.g. U phase, V phase, W phase). An interphase insulation is required between respective conductors. 
     In this respect, a resin molding in which synthetic resin is filled between respective conductors may be utilized for performing the interphase insulation. In this case, if air bubble is present which may bridge between adjacent phases in the synthetic resin between conductors of adjacently positioned phases in the circumferential direction, a surface discharge possibly occurs between adjacent conductors via the air bubble. 
     In order to suppress such a surface discharge, a method of performing an interphase insulation using an insulation sheet such as insulation papers and the like may be utilized. According to this method, conductors of respective phases are wound around individual insulation sheet. In this case, since insulation sheet for two layers are present between conductors adjacently positioned in the circumferential direction, the insulation sheet occupies large area in the space between adjacent conductors. Hence, the technique of performing the interphase insulation using the insulation sheet still needs to be improved. 
     Hereinafter, a plurality of embodiments will be described with reference to the drawings. In the plurality of embodiments, functionally and/or structurally corresponding parts and/or associated parts may be designated with the same reference sign or reference signs that are different in the hundreds or higher position. For corresponding and/or associated parts, the description of other embodiments can be referred to. 
     The rotating electric machine in this embodiment is used, for example, as a vehicle power source. However, the rotating electric machine can be widely used for industrial use, vehicle use, home appliance use, OA equipment use, game machine use, and the like. Note that, in each of the following embodiments, parts that are the same or equivalent to each other are designated by the same reference signs in the drawings, and the description thereof will be incorporated for the parts having the same reference signs. 
     First Embodiment 
     A rotating electric machine  10  according to the present embodiment is a synchronous multi-phase AC motor and has an outer rotor structure (outer rotating structure). The outline of the rotating electric machine  10  is illustrated in  FIGS. 1 to 5 .  FIG. 1  is a vertical cross-sectional perspective view of the rotating electric machine  10 ,  FIG. 2  is a vertical cross-sectional view of the rotating electric machine  10  in a direction along a rotating shaft  11 ,  FIG. 3  is a cross-sectional view of the rotating electric machine  10  in a direction orthogonal to the rotating shaft  11  (cross-sectional view taken along a line III-III of  FIG. 2 ),  FIG. 4  is a cross-sectional view illustrating a part of  FIG. 3  in an enlarged manner, and  FIG. 5  is an exploded view of the rotating electric machine  10 . Note that, in  FIG. 3 , for convenience of illustration, hatching indicating a cut surface is omitted except for a rotating shaft  11 . In the following description, the direction in which the rotating shaft  11  extends is the axial direction, the direction extending radially from the center of the rotating shaft  11  is the radial direction, and the direction extending circumferentially around the rotating shaft  11  is the circumferential direction. 
     The rotating electric machine  10  includes, substantially, a bearing unit  20 , a housing  30 , a rotor  40 , a stator  50 , and an inverter unit  60 . Each of these members is arranged coaxially with the rotating shaft  11  and is assembled in the axial direction in a predetermined order to form the rotating electric machine  10 . The rotating electric machine  10  of the present embodiment has a configuration having a rotor  40  as a “field magnet” and a stator  50  as an “armature”, and is embodied as a revolving-field type rotating electric machine. 
     The bearing unit  20  includes two bearings  21  and  22  arranged apart from each other in the axial direction, and a holding member  23  that holds the bearings  21  and  22 . The bearings  21  and  22  are, for example, radial ball bearings, each of which has an outer ring  25 , an inner ring  26 , and a plurality of balls  27  arranged between the outer ring  25  and the inner ring  26 . The holding member  23  has a cylindrical shape, and the bearings  21  and  22  are assembled radially thereinside. In addition, the rotating shaft  11  and the rotor  40  are rotatably supported radially inside the bearings  21  and  22 . The bearings  21  and  22  constitute a pair of bearings that rotatably support the rotating shaft  11 . 
     In the respective bearings  21  and  22 , balls  27  are held by retainers (not illustrated), and the pitch between the balls is maintained in that state. The bearings  21  and  22  has sealing members at the upper and lower portions in the axial direction of the retainer, and the inside of the sealing members is filled with nonconductive grease (for example, nonconductive urea grease). Further, the position of the inner ring  26  is mechanically held by a spacer, and a constant pressure preload that rises in the up-down direction from the inside is applied. 
     A housing  30  has a cylindrical peripheral wall  31 . The peripheral wall  31  has a first end and a second end facing each other in the axial direction thereof. The peripheral wall  31  has an end face  32  at the first end and an opening  33  at the second end. The opening  33  is open throughout the second end. A circular hole  34  is formed in the center of the end face  32 , and a bearing unit  20  is fixed by a fixture such as a screw or a rivet in a state of being inserted through the hole  34 . Further, a hollow cylindrical rotor  40  and a hollow cylindrical stator  50  are housed in the housing  30 , that is, in the internal space partitioned by the peripheral wall  31  and the end face  32 . In the present embodiment, the rotating electric machine  10  is an outer rotor type, and in the housing  30 , the stator  50  is arranged radially inside the cylindrical rotor  40 . The rotor  40  is cantilevered and supported by the rotating shaft  11  on the side of the end face  32  in the axial direction. 
     The rotor  40  has a magnet holder  41  formed in a hollow tubular shape and an annular magnet unit  42  provided radially inside the magnet holder  41 . The magnet holder  41  has a substantially cup shape and has a function as a magnet holding member. The magnet holder  41  has a cylindrical section  43  having a cylindrical shape, a fixing section (attachment)  44  having a cylindrical shape and a diameter smaller than that of the cylindrical section  43 , and an intermediate section  45  serving as a part connecting the cylindrical section  43  and the fixing section  44 . The magnet unit  42  is attached to the inner peripheral surface of the cylindrical section  43 . 
     Moreover, the magnet holder  41  is made of a steel plate cold commercial (SPCC) having sufficient mechanical strength, forging steel, carbon fiber reinforced plastic (CFRP), or the like. 
     The rotating shaft  11  is inserted through a through hole  44   a  of the fixing section  44 . The fixing section  44  is fixed to the rotating shaft  11  arranged in the through hole  44   a . That is, the magnet holder  41  is fixed to the rotating shaft  11  by the fixing section  44 . Moreover, the fixing section  44  is preferably fixed to the rotating shaft  1  by spline coupling, key coupling, welding, caulking, or the like using a protrusion and a recess. As a result, the rotor  40  rotates integrally with the rotating shaft  11 . 
     Further, bearings  21  and  22  of the bearing unit  20  are assembled radially inside the fixing section  44 . Since the bearing unit  20  is fixed to the end face  32  of the housing  30  as described above, the rotating shaft  11  and the rotor  40  are rotatably supported by the housing  30 . As a result, the rotor  40  is rotatable in the housing  30 . 
     The rotor  40  is provided with the fixing section  44  only on one of the two ends facing in the axial direction, whereby the rotor  40  is cantilevered and supported by the rotating shaft  11 . Here, the fixing section  44  of the rotor  40  is rotatably supported by the bearings  21  and  22  of the bearing unit  20  at two positions different in the axial direction. In other words, the rotor  40  is rotatably supported by the two bearings  21  and  22  separated in the axial direction at one of the two ends of the magnet holder  41  facing in the axial direction. Therefore, even if the rotor  40  is cantilevered and supported by the rotating shaft  11 , stable rotation of the rotor  40  can be achieved. In this case, the rotor  40  is supported by the bearings  21  and  22  at a position displaced to one side with respect to the axial center position of the rotor  40 . 
     Further, in the bearing unit  20 , the bearing  22  near the center of the rotor  40  (lower side in the figure) and the bearing  21  on the opposite side (upper side in the figure) have different gap dimensions between the outer ring  25  and the inner ring  26 , and the ball  27 , and for example, the bearing  22  near the center of the rotor  40  has a larger gap dimension than that of the bearing  21  on the opposite side. In this case, even if shaking of the rotor  40  or vibration due to imbalance caused by component tolerance acts on the bearing unit  20  on the side closer to the center of the rotor  40 , the influence of the shake or vibration is well absorbed. Specifically, by increasing the allowance dimension (gap dimension) by preloading the bearing  22  near the center of the rotor  40  (lower side of the figure), the vibration generated in the cantilever structure is absorbed by the allowance portion. The preload may be either a fixed position preload or a constant pressure preload. In the case of fixed position preload, both the outer rings  25  of the bearing  21  and the bearing  22  are joined to the holding member  23  by a method such as press fitting or adhesion. Further, both the inner rings  26  of the bearing  21  and the bearing  22  are joined to the rotating shaft  11  by a method such as press fitting or adhesion. Here, the preload can be generated by arranging the outer ring  25  of the bearing  21  at a different position in the axial direction with respect to the inner ring  26  of the bearing  21 . The preload can also be generated by arranging the outer ring  25  of the bearing  22  at a different position in the axial direction with respect to the inner ring  26  of the bearing  22 . 
     Further, in a case where a constant pressure preload is adopted, a preload spring, for example, a waved washer  24  or the like is arranged in the same region sandwiched between the bearing  22  and the bearing  21  in such a manner that preload is generated from the region sandwiched between the bearing  22  and the bearing  21  toward the outer ring  25  of the bearing  22  in the axial direction. Also in this case, both the inner rings  26  of the bearing  21  and the bearing  22  are joined to the rotating shaft  11  by a method such as press fitting or adhesion. The bearing  21  or the outer ring  25  of the bearing  22  is arranged with respect to the holding member  23  via a predetermined clearance. With such a configuration, the spring force of the preload spring acts on the outer ring  25  of the bearing  22  in the direction away from the bearing  21 . Then, when this force is transmitted through the rotating shaft  11 , a force that presses the inner ring  26  of the bearing  21  in the direction of the bearing  22  acts. As a result, the positions of the outer ring  25  and the inner ring  26  in the axial direction of both the bearings  21  and  22  are displaced, and the two bearings can be preloaded in the same manner as the aforementioned fixed position preload. 
     Moreover, when generating the constant pressure preload, it is not always necessary to apply the spring force to the outer ring  25  of the bearing  22  as illustrated in  FIG. 2 . For example, the spring force may be applied to the outer ring  25  of the bearing  21 . Further, the inner ring  26  of either of the bearings  21  and  22  may be arranged with respect to the rotating shaft  11  via a predetermined clearance, and the outer ring  25  of the bearings  21  and  22  may be joined to the holding member  23  by press fitting or adhesion, thereby preloading the two bearings. 
     Furthermore, in a case where a force is applied in such a manner that the inner ring  26  of the bearing  21  is separated from the bearing  22 , it is better to apply a force in such a manner that the inner ring  26  of the bearing  22  is also separated from the bearing  21 . On the contrary, in a case where a force is applied in such a manner that the inner ring  26  of the bearing  21  approaches the bearing  22 , it is better to apply a force in such a manner that the inner ring  26  of the bearing  22  also approaches the bearing  21 . 
     Moreover, in a case where the rotating electric machine  10  is applied to a vehicle for the purpose of a vehicle power source or the like, there is a possibility that vibration having a component in the preload generation direction is applied to a mechanism that generates the preload, and the direction of gravity applied to an object to which the preload is applied may fluctuate. Therefore, in the case where the rotating electric machine  10  is applied to a vehicle, it is desirable to adopt a fixed position preload. 
     Further, the intermediate section  45  has an annular inner shoulder section  49   a  and an annular outer shoulder section  49   b . The outer shoulder section  49   b  is located outside the inner shoulder section  49   a  in the radial direction of the intermediate section  45 . The inner shoulder section  49   a  and the outer shoulder section  49   b  are separated from each other in the axial direction of the intermediate section  45 . As a result, the cylindrical section  43  and the fixing section  44  partially overlap in the radial direction of the intermediate section  45 . That is, the cylindrical section  43  protrudes outward in the axial direction from the base end portion (back side end portion on the lower side in the figure) of the fixing section  44 . In this configuration, the rotor  40  can be supported with respect to the rotating shaft  11  at a position near the center of gravity of the rotor  40 , as compared with a case where the intermediate section  45  is provided in a flat plate shape without a step, and the operational stability of the rotor  40  can be achieved. 
     According to the configuration of the intermediate section  45  described above, in the rotor  40 , a bearing housing recess  46  that houses a part of the bearing unit  20  is formed in an annular shape at a position that surrounds the fixing section  44  in the radial direction and is inward of the intermediate section  45 , and a coil housing recess  47  that houses the coil end  54  of the stator winding  51  of the stator  50  which will be described below is formed at a position that surrounds the bearing housing recess  46  in the radial direction and is outward of the intermediate section  45 . In addition, these respective housing recesses  46  and  47  are arranged so as to be adjacent to each other inside and outside in the radial direction. That is, a part of the bearing unit  20  and the coil end  54  of the stator winding  51  are arranged so as to overlap inside and outside in the radial direction. This makes it possible to shorten the axial length dimension in the rotating electric machine  10 . 
     The intermediate section  45  is provided so as to project radially outward from the rotating shaft  11  side. In addition, the intermediate section  45  is provided with a contact avoiding section that extends in the axial direction and avoids contact of the stator winding  51  of the stator  50  with respect to the coil end  54 . The intermediate section  45  corresponds to a projecting section. 
     By bending the coil end  54  inward or outward in the radial direction, the axial dimension of the coil end  54  can be reduced, and the axial length of the stator  50  can be shortened. The bending direction of the coil end  54  may be in consideration of assembly with the rotor  40 . Assuming that the stator  50  is assembled radially inside the rotor  40 , the coil end  54  may be preferably bent radially inside on the insertion tip side with respect to the rotor  40 . The bending direction of the coil end on the side opposite to the coil end  54  may be arbitrary, but a shape in which the coil end is bent outward with a sufficient space is preferable in manufacturing. 
     Further, the magnet unit  42  as a magnet section is composed of a plurality of permanent magnets that are arranged on the radial inside of the cylindrical section  43  in such a manner that the polarities alternate along the circumferential direction. As a result, the magnet unit  42  has a plurality of magnetic poles in the circumferential direction. However, the details of the magnet unit  42  will be described below. 
     The stator  50  is provided radially inside the rotor  40 . The stator  50  has a stator winding  51  formed by winding in a substantially tubular shape (annular shape) and a stator core  52  as a base member arranged radially inside the stator winding  51 . The stator winding  51  is arranged so as to face the annular magnet unit  42  with a predetermined air gap therebetween. The stator winding  51  is composed of a plurality of phase windings. Each of these phase windings is configured by connecting a plurality of conductors arranged in the circumferential direction to each other at a predetermined pitch. In the present embodiment, a U-phase, V-phase, and W-phase three-phase winding and an X-phase. Y-phase, and Z-phase three-phase winding are used. Two of these three-phase windings are used, and the stator winding  51  is thereby configured as a six-phase winding. 
     The stator core  52  is formed in an annular shape by laminated steel sheets in which electromagnetic steel sheets which are soft magnetic materials are laminated, and is assembled radially inside the stator winding  51 . The electromagnetic steel sheet is, for example, a silicon steel sheet in which approximately several % (for example, 3%) of silicon is added to iron. The stator winding  51  corresponds to an armature winding, and the stator core  52  corresponds to an armature core. 
     The stator winding  51  is a portion that overlaps the stator core  52  in the radial direction, and has a coil side section  53  that is radially outside the stator core  52 , and coil ends  54  and  55  that respectively project to one end side and to the other end side of the stator core  52  in the axial direction. The coil side section  53  faces the stator core  52  and the magnet unit  42  of the rotor  40  in the radial direction, respectively. In a state where the stator  50  is arranged inside the rotor  40 , the coil end  54  on the side of the bearing unit  20  (upper side in the figure) of the coil ends  54  and  55  on both sides in the axial direction is housed in the in the coil housing recess  47  formed by the magnet holder  41  of the rotor  40 . Note that, the details of the stator  50  will be described below. 
     The inverter unit  60  has a unit base  61  fixed to the housing  30  by fasteners such as bolts, and a plurality of electric components  62  assembled to the unit base  61 . The unit base  61  is made of, for example, carbon fiber reinforced plastic (CFRP). The unit base  61  has an end plate  63  fixed to the edge of the opening  33  of the housing  30 , and a casing  64  integrally provided with the end plate  63  and extending in the axial direction. The end plate  63  has a circular opening  65  at the center thereof, and the casing  64  is formed so as to stand up from the peripheral edge portion of the opening  65 . 
     The stator  50  is assembled on the outer peripheral surface of the casing  64 . That is, the outer diameter dimension of the casing  64  is the same as the inner diameter dimension of the stator core  52 , or slightly smaller than the inner diameter dimension of the stator core  52 . By assembling the stator core  52  to the outside of the casing  64 , the stator  50  and the unit base  61  are integrated. Further, since the unit base  61  is fixed to the housing  30 , the stator  50  is integrated with the housing  30  in a state where the stator core  52  is assembled to the casing  64 . 
     Moreover, the stator core  52  is preferably assembled to the unit base  61  by adhesion, shrink fitting, press fitting, or the like. As a result, the displacement of the stator core  52  in the circumferential direction or the axial direction with respect to the unit base  61  side is suppressed. 
     Further, the radial inside of the casing  64  is a housing space for housing the electric component  62 , and the electric component  62  is arranged in the housing space so as to surround the rotating shaft  11 . The casing  64  has a role as a housing space forming section. The electric component  62  includes a semiconductor module  66  constituting an inverter circuit, a control board  67 , and a capacitor module  68 . 
     Moreover, the unit base  61  is provided radially inside the stator  50  and corresponds to a stator holder (armature holder) that holds the stator  50 . The housing  30  and the unit base  61  constitute the motor housing of the rotating electric machine  10 . In this motor housing, the holding member  23  is fixed to the housing  30  on one side in the axial direction with the rotor  40  therebetween, and the housing  30  and the unit base  61  are coupled to each other on the other side. For example, in a motor vehicle or the like which is an electric car, the rotating electric machine  10  is mounted to the motor car or the like by attaching a motor housing to the side of the motor car or the like. 
     Here, the configuration of the inverter unit  60  will be further described with reference to  FIG. 6  which is an exploded view of the inverter unit  60 , in addition to  FIGS. 1 to 5  described above. 
     In the unit base  61 , the casing  64  has a tubular section  71  and an end face  72  provided on one (end on the bearing unit  20  side) of both ends facing each other in the axial direction thereof. Of the both ends of the tubular section  71  in the axial direction, the side opposite to the end face  72  is completely opened through the opening  65  of the end plate  63 . A circular hole  73  is formed in the center of the end face  72 , and the rotating shaft  11  can be inserted into the hole  73 . The hole  73  is provided with a sealing material  171  that seals the space between the hole  73  and the outer peripheral surface of the rotating shaft  11 . The sealing material  171  is preferably, for example, a sliding seal made of a resin material. 
     The tubular section  71  of the casing  64  is a partition section that partitions between the rotor  40  and the stator  50  arranged radially outside and the electric component  62  arranged radially inside. The rotor  40 , the stator  50 , and the electric component  62  are arranged side by side radially inside and outside with the tubular section  71  therebetween. 
     Further, the electric component  62  is an electric component constituting an inverter circuit, and has a power running function of passing a current through each phase winding of the stator winding  51  in a predetermined order to rotate the rotor  40  and a power generation function of inputting a three-phase AC current flowing through the stator winding  51  with the rotation of the rotating shaft  11  and outputting same to the outside as generated power. Moreover, the electric component  62  may have only one of the power running function and the power generation function. The power generation function is, for example, a regenerative function that outputs regenerative power to the outside when the rotating electric machine  10  is used as a power source for a vehicle. 
     As a specific configuration of the electric component  62 , as illustrated in  FIG. 4 , a hollow cylindrical capacitor module  68  is provided around the rotating shaft  11 , and a plurality of semiconductor modules  66  are arranged side by side in the circumferential direction on the outer peripheral surface of the capacitor module  68 . The capacitor module  68  includes a plurality of smoothing capacitors  68   a  connected in parallel to each other. Specifically, the capacitor  68   a  is a laminated film capacitor in which a plurality of film capacitors are laminated, and has a trapezoidal cross section. The capacitor module  68  is configured by arranging twelve capacitors  68   a  side by side in an annular shape. 
     Moreover, in the manufacturing process of the capacitor  68   a , for example, a long film having a predetermined width in which a plurality of films are laminated is used, the film width direction is the trapezoid height direction, and the long film is cut into an isosceles trapezoid shape in such a manner that the upper bottom and the lower bottom of the trapezoid alternate, thereby making a capacitor element. Then, the capacitor  68   a  is manufactured by attaching an electrode or the like to the capacitor element. 
     The semiconductor module  66  has a semiconductor switching element such as a MOSFET or an IGBT, and is formed in a substantially plate shape. In the present embodiment, since the rotating electric machine  10  includes two sets of three-phase windings and an inverter circuit is provided for each of the three-phase windings, a semiconductor module group  66 A formed by arranging a total of 12 semiconductor modules  66  in an annular shape is provided in the electric component  62 . 
     The semiconductor module  66  is arranged in a state of being sandwiched between the tubular section  71  of the casing  64  and the capacitor module  68 . The outer peripheral surface of the semiconductor module group  66 A is in contact with the inner peripheral surface of the tubular section  71 , and the inner peripheral surface of the semiconductor module group  66 A is in contact with the outer peripheral surface of the capacitor module  68 . In this case, the heat generated in the semiconductor module  66  is transferred to the end plate  63  via the casing  64  and released from the end plate  63 . 
     The semiconductor module group  66 A preferably has a spacer  69  between the semiconductor module  66  and the tubular section  71  on the outer peripheral surface side, that is, in the radial direction. In this case, in the capacitor module  68 , the cross-sectional shape of the cross section orthogonal to the axial direction is a regular dodecagon, whereas the cross-sectional shape of the inner peripheral surface of the tubular section  71  is circular. Thus, the inner peripheral surface of the spacer  69  is a flat surface and the outer peripheral surface of the spacer  69  is a curved surface. The spacer  69  may be integrally provided so as to be connected in an annular shape on the radial outside of the semiconductor module group  66 A. The spacer  69  is a good thermal conductor, and is preferably, for example, a metal such as aluminum, a heat radiating gel sheet, or the like. Moreover, it is also possible to make the cross-sectional shape of the inner peripheral surface of the tubular section  71  the same dodecagon as that of the capacitor module  68 . In this case, it is preferable that both the inner peripheral surface and the outer peripheral surface of the spacer  69  are flat surfaces. 
     Further, in the present embodiment, a cooling water passage  74  for flowing cooling water is formed in the tubular section  71  of the casing  64 , and the heat generated in the semiconductor module  66  is also released to the cooling water flowing through the cooling water passage  74 . That is, the casing  64  is provided with a water-cooling mechanism. As illustrated in  FIGS. 3 and 4 , the cooling water passage  74  is formed in an annular shape so as to surround the electric component  62  (the semiconductor module  66  and the capacitor module  68 ). The semiconductor module  66  is arranged along the inner peripheral surface of the tubular section  71 , and the cooling water passage  74  is provided at a position overlapping the semiconductor module  66  inside and outside in the radial direction. 
     Since the stator  50  is arranged on the outside of the tubular section  71  and the electric component  62  is arranged on the inside of the tubular section  71 , the heat of the stator  50  is transferred to the tubular section  71  from the outside, and the heat of the electric component  62  (for example, the heat of the semiconductor module  66 ) is transferred from the inside. In this case, the stator  50  and the semiconductor module  66  can be cooled at the same time, and the heat of the heat-generating member in the rotating electric machine  10  can be efficiently released. 
     Furthermore, at least a part of the semiconductor module  66  constituting a part or the whole of the inverter circuit that operates the rotating electric machine by energizing the stator winding  51  is arranged in a region surrounded by the stator core  52  arranged radially outside the tubular section  71  of the casing  64 . Preferably, the entire one semiconductor module  66  is arranged in a region surrounded by the stator core  52 . Furthermore, preferably, the whole of all the semiconductor modules  66  is arranged in a region surrounded by the stator core  52 . 
     Further, at least a part of the semiconductor module  66  is arranged in a region surrounded by the cooling water passage  74 . Preferably, the whole of all the semiconductor modules  66  is arranged in a region surrounded by a yoke  141 . 
     Further, the electric component  62  includes an insulating sheet  75  provided on one end face of the capacitor module  68  and a wiring module  76  provided on the other end face in the axial direction. In this case, the capacitor module  68  has two end faces facing each other in the axial direction, that is, a first end face and a second end face. The first end face of the capacitor module  68  near the bearing unit  20  faces the end face  72  of the casing  64 , and is superimposed on the end face  72  with the insulating sheet  75  sandwiched therebetween. Further, a wiring module  76  is assembled on the second end face of the capacitor module  68  near the opening  65 . 
     The wiring module  76  has a main body section  76   a  made of a synthetic resin material and having a circular plate shape and a plurality of bus bars  76   b ,  76   c  embedded therein, and the bus bars  76   b ,  76   c  form an electrical connection with the semiconductor module  66  and the capacitor module  68 . Specifically, the semiconductor module  66  has a connecting pin  66   a  extending from its axial end face, and the connecting pin  66   a  is connected to the busbar  76   b  on the radial outside of the main body section  76   a . Further, a busbar  76   c  extends to the side opposite to the capacitor module  68  on the radial outside of the main body section  76   a , and is connected to a wiring member  79  at the tip end portion thereof (see  FIG. 2 ). 
     As described above, according to the configuration in which the insulating sheet  75  is provided on the first end face of the capacitor module  68  facing the axial direction and the wiring module  76  is provided on the second end face of the capacitor module  68 , as a heat dissipation path of the capacitor module  68 , a path from the first end face and the second end face of the capacitor module  68  to the end face  72  and the tubular section  71  is formed. In other words, a path from the first end face to the end face  72  and a path from the second end face to the tubular section  71  are formed. As a result, heat can be dissipated from the end face portion of the capacitor module  68  other than the outer peripheral surface on which the semiconductor module  66  is provided. That is, not only heat dissipation in the radial direction but also heat dissipation in the axial direction is possible. 
     Further, since the capacitor module  68  has a hollow cylindrical shape and the rotating shaft  11  is arranged on the inner peripheral portion thereof with a predetermined gap interposed therebetween, the heat of the capacitor module  68  can be released from the hollow portion as well. In this case, the rotation of the rotating shaft  11  causes an air flow to enhance the cooling effect. 
     A disk-shaped control board  67  is attached to the wiring module  76 . The control board  67  has a printed circuit board (PCB) on which a predetermined wiring pattern is formed, and a control device  77  corresponding to a control unit composed of various ICs and a microcomputer is mounted on the board. The control board  67  is fixed to the wiring module  76  by a fixture such as a screw. The control board  67  has, in the central portion thereof, an insertion hole  67   a  in which the rotation shaft  11  is inserted. 
     Moreover, the wiring module  76  has a first surface and a second surface that face each other in the axial direction, that is, face each other in the thickness direction thereof. The first surface faces the capacitor module  68 . The wiring module  76  is provided with the control board  67  on the second surface thereof. The busbar  76   c  of the wiring module  76  extends from one side of both sides of the control board  67  to the other side. In such a configuration, the control board  67  is preferably provided with a notch to avoid interference with the busbar  76   c . For example, a part of the outer edge portion of the control board  67  having a circular shape is preferably notched. 
     As described above, according to the configuration in which the electric component  62  is housed in the space surrounded by the casing  64 , and the housing  30 , the rotor  40  and the stator  50  are provided in layers on the outside thereof, the electromagnetic noise generated in the inverter circuit is suitably shielded. In other words, in the inverter circuit, switching control is performed in each semiconductor module  66  by utilizing PWM control using a predetermined carrier frequency, and it is conceivable that electromagnetic noise is generated by the switching control. However, the noise can be suitably shielded by the housing  30 , the rotor  40 , the stator  50 , and the like on the radially outside the electric component  62 . 
     Furthermore, at least a part of the semiconductor module  66  is arranged in the region surrounded by the stator core  52  arranged radially outside the tubular section  71  of the casing  64 . Thus, compared to a configuration in which the semiconductor module  66  and the stator winding  51  are arranged without the stator core  52 , even if magnetic flux is generated from the semiconductor module  66 , the stator winding  51  is less likely to be affected. Further, even if the magnetic flux is generated from the stator winding  51 , it is unlikely to affect the semiconductor module  66 . Moreover, it is more effective if the entire semiconductor module  66  is arranged in a region surrounded by the stator core  52  arranged radially outside the tubular section  71  of the casing  64 . Further, in a case where at least a pan of the semiconductor module  66  is surrounded by the cooling water passage  74 , it is possible to obtain the effect that the heat generated from the stator winding  51  and the magnet unit  42  is suppressed from reaching the semiconductor module  66 . 
     In the tubular section  71 , a through hole  78  is formed in the vicinity of the end plate  63 , through which the wiring member  79  (see  FIG. 2 ) that electrically connects the outer stator  50  and the inner electric component  62  is inserted. As illustrated in  FIG. 2 , the wiring member  79  is connected to the end of the stator winding  51  and the busbar  76   c  of the wiring module  76  by crimping, welding, or the like, respectively. The wiring member  79  is, for example, a busbar, and it is desirable that the joint surface thereof be flattened. The through holes  78  are preferably provided at one place or a plurality of places, and in the present embodiment, the through holes  78  are provided at two places. In the configuration in which the through holes  78  are provided at two places, the winding terminals extending from the two sets of three-phase windings can be easily connected by the wiring members  79  respectively, which is suitable for performing multi-phase connection. 
     As described above, as illustrated in  FIG. 4 , the rotor  40  and the stator  50  are provided in the housing  30  in this order from the outside in the radial direction, and an inverter unit  60  is provided radially inside the stator  50 . Here, when the radius of the inner peripheral surface of the housing  30  is d, the rotor  40  and the stator  50  are arranged radially outside the distance of d*0.705 from the center of rotation of the rotor  40 . In this case, when the region of the rotor  40  and the stator  50 , that is radially inside from the inner peripheral surface of the stator  50  that is inside in the radial direction (that is, the inner peripheral surface of the stator core  52 ) is a first region X 1 , and the region between the inner peripheral surface of the stator  50  and the housing  30  is a second region X 2 , the cross-sectional area of the first region X 1  is larger than the cross-sectional area of the second region X 2 . Further, the volume of the first region X 1  is larger than the volume of the second region X 2  when viewed in the radial direction in the range where the magnet unit  42  of the rotor  40  and the stator winding  51  overlap. 
     Moreover, when the rotor  40  and the stator  50  are a magnetic circuit component assembly, in the housing  30 , the first region X 1  radially inside from the inner peripheral surface of the magnetic circuit component assembly has a larger volume than that of the second region X 2  between the inner peripheral surface of the magnetic circuit component assembly and the housing  30  in the radial direction. 
     Next, the configurations of the rotor  40  and the stator  50  will be described in more detail. 
     Generally, as a structure of a stator in a rotating electric machine, a structure is known in which a stator core made of a laminated steel sheet and forming an annular shape is provided with a plurality of slots in the circumferential direction, and a stator winding is wound in the slots. Specifically, the stator core has a plurality of teeth extending in the radial direction from a yoke at predetermined intervals, and slots are formed between the teeth adjacent to each other in the circumferential direction. In addition, for example, a plurality of layers of conductors are housed in the slots in the radial direction, and the stator winding is composed of the conductors. 
     However, in the above-mentioned stator structure, when the stator winding is energized, magnetic saturation occurs in the teeth portion of the stator core as the magnetomotive force of the stator winding increases, which may limit the torque density of the rotating electric machine. That is, in the stator core, it is considered that magnetic saturation occurs when the rotating magnetic flux generated by the energization of the stator winding is concentrated on the teeth. 
     Further, generally, as a configuration of an IPM (Interior Permanent Magnet) rotor in a rotating electric machine, a permanent magnet is arranged on the d-axis in the d-q coordinate system and a rotor core is arranged on the q-axis. In such a case, the stator winding near the d-axis is excited, and thus the exciting magnetic flux flows from the stator to the q-axis of the rotor according to Fleming&#39;s law. It is considered that this causes a wide range of magnetic saturation in the q-axis core portion of the rotor. 
       FIG. 7  is a torque line diagram illustrating a relation between an ampere-turn [AT] indicating the magnetomotive force of a stator winding and a torque density [Nm/L]. The broken line indicates the characteristics of a general IPM rotor type rotating electric machine. As illustrated in  FIG. 7 , in a general rotating electric machine, by increasing the magnetomotive force in the stator, magnetic saturation occurs in two places, the teeth portion between the slots and the q-axis core portion, which limits the increase in torque. As described above, in the general rotating electric machine, the ampere-turn design value is limited by A 1 . 
     Accordingly, in the present embodiment, in order to eliminate the limitation caused by magnetic saturation, the rotating electric machine  10  is provided with the following configuration. In other words, as a first measure, in order to eliminate the magnetic saturation that occurs in the teeth of the stator core in the stator, a slotless structure is adopted in the stator  50 , and in order to eliminate the magnetic saturation that occurs in the q-axis core portion of the IPM rotor, an SPM (Surface Permanent Magnet) rotor is adopted. According to the first measure, it is possible to eliminate the above-mentioned two parts where magnetic saturation occurs, but it is considered that the torque in the low current region is reduced (see the alternate long and short dash line in  FIG. 7 ). Therefore, as a second measure, in order to recover the torque decrease by increasing the magnetic flux of the SPM rotor, in the magnet unit  42  of the rotor  40 , a polar anisotropic structure in which the magnet magnetic path is lengthened to increase the magnetic force is adopted. 
     Further, as a third measure, in the coil side section  53  of the stator winding  51 , a flat conductor structure in which the radial thickness of the stator  50  of the conductor is reduced is adopted to recover the torque decrease. Here, it is conceivable that a larger eddy current is generated in the stator winding  51  facing the magnet unit  42  due to the above-mentioned polar anisotropic structure in which the magnetic force is increased. However, according to the third measure, since the flat conductor structure is thin in the radial direction, it is possible to suppress the generation of eddy current in the radial direction in the stator winding  51 . As described above, according to each of these first to third configurations, as illustrated by the solid line in  FIG. 7 , by adopting a magnet with a high magnetic force, it is expected that the torque characteristics will be significantly improved, and at the same time, the concern about the generation of a large eddy current that may occur due to the magnet with a high magnetic force also can be improved. 
     Furthermore, as a fourth measure, a magnet unit having a magnetic flux density distribution close to a sine wave is adopted by utilizing a polar anisotropic structure. According to this, the sine wave matching rate can be increased by pulse control or the like described below to increase the torque, and since the magnetic flux changes more slowly than the radial magnet, the eddy current loss (copper loss due to eddy current: eddy current loss) can also be further suppressed. 
     Hereinafter, the sine wave matching rate will be described. The sine wave matching rate can be obtained by comparing the measured waveform of the surface magnetic flux density distribution measured by tracing the surface of the magnet with a magnetic flux probe and the sine wave having the same period and peak value. In addition, the ratio of the amplitude of the primary waveform, which is the fundamental wave of the rotating electric machine, to the amplitude of the actually measured waveform, that is, the amplitude of the fundamental wave plus other higher harmonic components, corresponds to the sine wave matching rate. As the sine wave matching rate increases, the waveform of the surface magnetic flux density distribution approaches a sine wave shape. In addition, when a primary sine wave current is supplied from the inverter to a rotating electric machine equipped with a magnet having an improved sine wave matching rate, the waveform of the surface magnetic flux density distribution of the magnet is close to the sine wave shape, and correlatively, can generate a large torque. Moreover, the surface magnetic flux density distribution may be estimated by a method other than an actual measurement, for example, an electromagnetic field analysis using Maxwell&#39;s equations. 
     Further, as a fifth measure, the stator winding  51  has a wire conductor structure in which a plurality of wires are gathered and bundled. According to this, since the wires are connected in parallel, a large current can flow, and the cross-sectional area of each wire is small, the eddy current generated by the conductors that spread in the circumferential direction of the stator  50  in the flat conductor structure can be suppressed more effectively than thinning in the radial direction by the third measure. In addition, by forming a structure in which a plurality of wires are twisted together, for the magnetomotive force from the conductor, it is possible to cancel the eddy current with respect to the magnetic flux generated by the right-handed screw rule in the current energizing direction. 
     In this way, if the fourth and fifth measures are further added, the torque can be increased while adopting the second measure, a magnet with a high magnetic force, while suppressing the eddy current loss caused by the high magnetic force. 
     Hereinafter, the slotless structure of the stator  50  described above, the flat conductor structure of the stator winding  51 , and the polar anisotropic structure of the magnet unit  42  will be individually described. Here, first, the slotless structure of the stator  50  and the flat conductor structure of the stator winding  51  will be described.  FIG. 8  is a cross-sectional view of the rotor  40  and the stator  50 , and  FIG. 9  is a view illustrating a part of the rotor  40  and the stator  50  illustrated in  FIG. 8  in an enlarged manner.  FIG. 10  is a cross-sectional view illustrating a cross section of the stator  50  along a line X-X of  FIG. 11 , and  FIG. 11  is a cross-sectional view illustrating a vertical cross section of the stator  50 . Further,  FIG. 12  is a perspective view of the stator winding St. Note that  FIGS. 8 and 9  illustrate the magnetization direction of the magnet in the magnet unit  42  with arrows. 
     As illustrated in  FIGS. 8 to 11 , the stator core  52  has a cylindrical shape in which a plurality of electromagnetic steel sheets are laminated in the axial direction and has a predetermined thickness in the radial direction, and the stator winding  51  is assembled on the radially outside that is the rotor  40  side. In the stator core  52 , the outer peripheral surface on the rotor  40  side is a conductor installation section (conductor area). The outer peripheral surface of the stator core  52  has a curved surface without unevenness, and a plurality of conductor groups  81  are arranged at predetermined intervals in the circumferential direction on the outer peripheral surface thereof. The stator core  52  functions as a back yoke that is a part of a magnetic circuit for rotating the rotor  40 . In this case, teeth (that is, an iron core) made of a soft magnetic material are not provided between each of the two conductor groups  81  adjacent to each other in the circumferential direction (that is, a slotless structure). In the present embodiment, the resin material of the sealing member  57  is inserted into a void  56  of each of the conductor groups  81 . That is, in the stator  50 , the interconductor member provided between the respective conductor groups  81  in the circumferential direction is configured as the sealing member  57  which is a non-magnetic material. In a state before sealing of the sealing member  57 , on the outer side of the stator core  52  in the radial direction, the conductor groups  81  are respectively arranged at predetermined intervals in the circumferential direction with the void  56 , which is an inter-conductor region, interposed therebetween. As a result, the stator  50  having a slotless structure is constructed. In other words, each conductor group  81  is composed of two conductors (conductor)  82  described below, and only a non-magnetic material occupies a region between the two conductor groups  81  adjacent to each other in the circumferential direction of the stator  50 . The non-magnetic material includes a non-magnetic gas such as air, a non-magnetic liquid, and the like in addition to the sealing member  57 . Moreover, in the following, the sealing member  57  is also referred to as an inter-conductor member (conductor-to-conductor member). 
     Moreover, a configuration in which the teeth are provided between the conductor groups  81  arranged in the circumferential direction is considered to be a configuration in which the teeth have a predetermined thickness in the radial direction and a predetermined width in the circumferential direction, and thus a part of a magnetic circuit, that is, a magnet magnetic path is formed between the conductor groups  81 . In this respect, it can be said that a configuration in which the teeth are not provided between the respective conductor groups  81  is a configuration in which the above-mentioned magnetic circuit is not formed. 
     As illustrated in  FIG. 10 , the stator winding (i.e., armature winding)  51  is formed so as to have a predetermined thickness T 2  (hereinafter, also referred to as a first dimension) and a width W 2  (hereinafter, also referred to as a second dimension). The thickness T 2  is the shortest distance between the outer surface and the inner surface facing each other in the radial direction of the stator winding  51 . The width W 2  is the circumferential length of the stator winding  51  of a part of the stator winding  51  which functions as one of the polyphase of the stator winding  51  (in the example, three phases: three phases of U phase, V phase and W phase or three phases of X phase, Y phase and Z phase). Specifically, in  FIG. 10 , in a case where two conductor groups  81  adjacent to each other in the circumferential direction function as one of the three phases, for example, the U phase, the width W 2  is from one end to the other of the two conductor groups  81  in the circumferential direction. In addition, the thickness T 2  is smaller than the width W 2 . 
     Moreover, the thickness T 2  is preferably smaller than the total width dimension of the two conductor groups  81  existing in the width W 2 . Further, if the cross-sectional shape of the stator winding  51  (more specifically, the conductor wire  82 ) is a perfect circle, an ellipse, or a polygon, in the cross sections of the conductor wire  82  along the radial direction of the stator  50 , the maximum length in the radial direction of the stator  50  may be W 12 , and the maximum length in the circumferential direction of the stator  50  may be W 11 . 
     As illustrated in  FIGS. 10 and 11 , the stator winding  51  is sealed by the sealing member  57  made of a synthetic resin material as a sealing material (molding material). That is, the stator winding  51  is molded together with the stator core  52  by the molding material. The resin can be regarded as a non-magnetic substance or an equivalent of the non-magnetic substance as Bs=0. 
     Looking at the cross section of  FIG. 10 , the sealing member  57  is provided between the respective conductor groups  81 , that is, the void  56  is filled with the synthetic resin material, and with this sealing member  57 , an insulating member is interposed between the respective conductor groups  81 . That is, the sealing member  57  functions as an insulating member in the void  56 . The sealing member  57  is provided on the radial outside of the stator core  52  in a range including all of the conductor groups  81 , that is, in a range in which the radial thickness dimension is larger than the radial thickness dimension of each conductor group  81 . 
     Further, when viewed in the vertical cross section of  FIG. 11 , the sealing member  57  is provided in a range including a turn section  84  of the stator winding  51 . Inside the stator winding  51  in the radial direction, the sealing member  57  is provided within a range including at least a part of the end faces of the stator core  52  facing in the axial direction. In this case, the stator winding  51  is resin-sealed almost entirely except for the ends of the phase winding of each phase, that is, the connection terminals with the inverter circuit. 
     In the configuration in which the sealing member  57  is provided in a range including the end face of the stator core  52 , the laminated steel sheet of the stator core  52  can be pressed inward in the axial direction by the sealing member  57 . As a result, the laminated state of each steel sheet can be maintained with the use of the sealing member  57 . Moreover, in the present embodiment, the inner peripheral surface of the stator core  52  is not resin-sealed, but instead, the entire stator core  52  including the inner peripheral surface of the stator core  52  may be resin-sealed. 
     In a case where the rotating electric machine  10  is used as a vehicle power source, the sealing member  57  is preferably made of a highly heat-resistant fluororesin, epoxy resin, PPS resin, PEEK resin, LCP resin, silicon resin, PAI resin, PI resin, or the like. Further, considering the linear expansion coefficient from the viewpoint of suppressing cracking due to the expansion difference, it is desirable that the material is the same as that of the outer coating of the conductor of the stator winding  51 . In other words, a silicon resin having a linear expansion coefficient that is generally more than double that of other resins is preferably excluded. Moreover, for electric products that do not have an engine that utilizes combustion, such as electric vehicles, PPO resin, phenol resin, and FRP resin that have heat resistance of approximately 180° C. are also candidates. This does not apply in the field where the ambient temperature of the rotating electric machine is considered to be below 100° C. 
     The torque of the rotating electric machine  10  is proportional to the magnitude of the magnetic flux. Here, in a case where the stator core has teeth, the maximum amount of magnetic flux in the stator is limited depending on the saturation magnetic flux density in the teeth, but in a case where the stator core does not have teeth, the maximum amount of magnetic flux in the stator is not limited. Therefore, the configuration is advantageous in increasing the energization current for the stator winding  51  to increase the torque of the rotating electric machine  10 . 
     In the present embodiment, the inductance of the stator  50  is reduced by using a structure (slotless structure) in which the stator  50  has no teeth. Specifically, in the stator of a general rotating electric machine in which a conductor is housed in each slot partitioned by a plurality of teeth, the inductance is, for example, around 1 mH, whereas in the stator  50  of the present embodiment, the inductance is reduced to approximately 5 to 60 pH. In the present embodiment, it is possible to reduce a mechanical time constant Tm by reducing the inductance of the stator  50  while using the rotating electric machine  10  having an outer rotor structure. That is, it is possible to reduce the mechanical time constant Tm while increasing the torque. Moreover, when the inertia is J, the inductance is L, the torque constant is Kt, and the counter electromotive force constant is Ke, the mechanical time constant Tm is calculated by the following formula. 
         Tm =( J*L )/( Kt*Ke ) 
     In this case, it can be confirmed that the mechanical time constant Tm is reduced by reducing the inductance L. 
     Each conductor group  81  on the radially outside the stator core  52  is configured by arranging a plurality of conductor wires  82  having a flat rectangular cross section side by side in the radial direction of the stator core  52 . Each conductor wire  82  is arranged in a direction in such a manner that “radial dimension&lt;circumferential dimension” in the cross section. As a result, the thickness of each conductor group  81  is reduced in the radial direction. Further, the thickness in the radial direction is reduced, and the conductor region extends flatly to the region where the teeth have been conventionally, forming a flat conductor region structure. As a result, the increase in the amount of heat generated of the conductor, which is a concern because the cross-sectional area becomes smaller due to the thinning, is suppressed by flattening in the circumferential direction and increasing the cross-sectional area of the conductor. Moreover, even if a plurality of conductors are arranged in the circumferential direction and connected in parallel, the conductor cross-sectional area of the conductor coating is reduced, but the effect by the same reason can be obtained. Moreover, in the following, each conductor group  81  and each conductor wire  82  will also be referred to as a conductive member. 
     Since there is no slot, in the stator winding  51  in the present embodiment, the conductor region occupied by the stator winding  51  in one circumference in the circumferential direction can be designed to be larger than the conductor non-occupied region which the stator winding  51  does not occupy. Moreover, in a conventional rotating electric machine for vehicles, it is natural that the conductor region/conductor non-occupied region in one circumference in the circumferential direction of the stator winding is one or less. On the other hand, in the present embodiment, each conductor group  81  is provided in such a manner that the conductor region is equal to the conductor non-occupied region or the conductor region is larger than the conductor non-occupied region. Here, as illustrated in  FIG. 10 , when the conductor region in which the conductor wire  82  (that is, a straight section  83  described below) is arranged in the circumferential direction is WA and the region between the adjacent conductor wires  82  is WB, the region WA is larger than the interconductor region WB in the circumferential direction. 
     As a configuration of the conductor group  81  in the stator winding  51 , the radial thickness dimension of the conductor group  81  is smaller than the circumferential width dimension for one phase in one magnetic pole. In other words, a configuration in which the conductor group  81  is composed of two layers of conductor wires  82  in the radial direction and two conductor groups  81  are provided in the circumferential direction for one phase in one magnetic pole fulfills “Tc*2&lt;Wc* 2 ” when the radial thickness dimension of each conductor wire  82  is Tc, and the circumferential width dimension of each conductor wire  82  is Wc. Moreover, as another configuration, a configuration in which the conductor group  81  is composed of two layers of conductor wires  82  and one conductor group  81  is provided in the circumferential direction for one phase in one magnetic pole preferably fulfills a relation “Tc*2&lt;We”. In short, the conductor section (conductor group  81 ) arranged at predetermined intervals in the circumferential direction in the stator winding  51  has a radial thickness dimension that is smaller than the circumferential width dimension for one phase in one magnetic pole. 
     In other words, it is preferable that the radial thickness dimension Tc of each conductor wire  82  is smaller than the circumferential width dimension Wc. Furthermore, a radial thickness dimension (2Tc) in the radial direction of the conductor group  81  composed of two layers of conductors  82 , that is, a radial thickness dimension (2Tc) in the circumferential direction of the conductor group  81  is preferably smaller than the width dimension We. 
     The torque of the rotating electric machine  10  is substantially inversely proportional to the radial thickness of the stator core  52  of the conductor group  81 . In this regard, the thickness of the conductor group  81  is reduced on the radial outside of the stator core  52 , which is advantageous in increasing the torque of the rotating electric machine  10 . The reason is that the magnetic resistance can be lowered by reducing the distance from the magnet unit  42  of the rotor  40  to the stator core  52  (that is, the distance of the iron-free portion). According to this, the interlinkage magnetic flux of the stator core  52  by the permanent magnet can be increased, and the torque can be increased. 
     Further, by reducing the thickness of the conductor group  81 , even if the magnetic flux leaks from the conductor group  81 , it is easily collected by the stator core  52 , and the magnetic flux can be prevented from not being effectively used for improving torque and leaking to the outside. That is, it is possible to suppress a decrease in magnetic force due to magnetic flux leakage, and it is possible to increase the interlinkage magnetic flux of the stator core  52  by the permanent magnet to increase the torque. 
     The conductor wire (conductor)  82  is composed of a coated conductor in which the surface of the conductor (conductor body)  82   a  is coated with an insulating coating  82   b , and insulation is ensured between the conductor wires  82  that overlap each other in the radial direction and between the conductor wires  82  and the stator core  52 , respectively. This insulating coating  82   b  is composed of a coating if a wire  86  described below is a self-fusion coated wire, or an insulating member laminated separately from the coating of the wire  86 . Moreover, each phase winding composed of the conductor wire  82  retains the insulating property by the insulating coating  82   b  except for the exposed portion for connection. The exposed portion is, for example, an input/output terminal portion or a neutral point portion in the case of a star-shaped connection. In the conductor group  81 , the conductor wires  82  adjacent to each other in the radial direction are fixed to each other with the use of resin fixing or a self-fusion coated wire. As a result, dielectric breakdown, vibration, and sound due to the friction of the conductor wires  82  against each other are suppressed. 
     In the present embodiment, the conductor  82   a  is configured as an aggregate of a plurality of wires (wire)  86 . Specifically, as illustrated in  FIG. 13 , the conductor  82   a  is formed in a twisted state by twisting a plurality of wires  86 . Further, as illustrated in  FIG. 14 , the wires  86  are configured as a composite in which thin fibrous conductive materials  87  are bundled. For example, the wire  86  is a composite of CNT (carbon nanotube) fibers, and as the CNT fiber, a fiber containing boron-containing fine fibers in which at least a part of carbon is replaced with boron is used. As the carbon-based fine fiber, a vapor-grown carbon fiber (VGCF) or the like can be used in addition to the CNT fiber, but it is preferable to use the CNT fiber. Moreover, the surface of the wire  86  is covered with a polymer insulating layer such as enamel. Further, it is preferable that the surface of the wire  86  is covered with a so-called enamel coating made of a polyimide film or an amide-imide film. 
     The conductor wire  82  constitutes an n-phase winding in the stator winding  51 . In addition, the respective wires  86  of the conductor wire  82  (that is, the conductor  82   a ) are adjacent to each other in contact with each other. In the conductor wire  82 , the winding conductor has a portion formed by twisting the plurality of wires  86  at one or more places in a phase, and the resistance value among the twisted wires  86  is larger than the resistance value of each wire  86  per se. In other words, if each of the two adjacent wires  86  has a first electrical resistivity in its adjacent direction and each of the wires  86  has a second electrical resistivity in its length direction, then the first electrical resistivity is larger than the second electrical resistivity. Moreover, the conductor wire  82  may be formed of the plurality of wires  86 , and may be an aggregate of wires covering the plurality of wires  86  by an insulating member having an extremely high first electrical resistivity. Further, the conductor  82   a  of the conductor wire  82  is composed of a plurality of twisted wires  86 . 
     Since the conductor  82   a  is configured by twisting the plurality of wires  86 , it is possible to suppress the generation of the eddy current in the respective wires  86  and reduce the eddy current in the conductor  82   a . Further, since each wire  86  is twisted, portions where the magnetic field application directions are opposite to each other are generated in one wire  86 , and the counter electromotive voltage is canceled out. Therefore, the eddy current can also be reduced. In particular, by forming the wire  86  with the fibrous conductive material  87 , it is possible to make the wire thinner and to significantly increase the number of twists, and it is possible to more preferably reduce the eddy current. 
     Moreover, the method for insulating the wires  86  from each other here is not limited to the above-mentioned polymer insulating film, and may be a method for making it difficult for current to flow between the twisted wires  86  by utilizing contact resistance. That is, if the resistance value between the twisted wires  86  is larger than the resistance value of the wire  86  per se, the above effect can be obtained by the potential difference generated due to the difference in the resistance values. For example, by using the manufacturing equipment for creating the wire  86  and the manufacturing equipment for making the stator  50  (armature) of the rotating electric machine  10  as separate non-continuous equipment, the wire  86  can be oxidized due to the movement time, work interval, and the like, and the contact resistance can be increased, which is suitable. 
     As described above, the conductor wires  82  have a flat rectangular cross section and are arranged side by side in the radial direction, and for example, a plurality of wires  86  covered with a self-fusion coated wire having a fusion layer and an insulating layer is assembled in a twisted state, and the fusion layers are fused to maintain the shape of the conductor wires  82 . Moreover, the wires having no fusion layer or the wires with the self-fusion coated wire may be twisted and solidified and molded into a desired shape with a synthetic resin or the like. When the thickness of the insulating coating  82   b  in the conductor wire  82  is set to, for example, 80 μm to 100 μm and is set to be thicker than the film thickness (5 to 40 μm) of a commonly used conductor, even if an insulating paper or the like is not interposed between the conductor wire  82  and the stator core  52 , the insulating property between the two can be ensured. 
     Further, it is desirable that the insulating coating  82   b  has higher insulating performance than that of the insulating layer of the wire  86  and is configured to be able to insulate between phases. For example, when the thickness of the polymer insulating layer of the wire  86  is set to, for example, approximately 5 μm, it is desirable that the thickness of the insulating coating  82   b  of the conductor wire  82  is set to approximately 80 μm to 100 μm, and thus insulation between phases can be preferably performed. 
     Further, the conductor wire  82  may have a configuration in which a plurality of wires  86  are bundled without being twisted. That is, the conductor wire  82  may have any of a configuration in which a plurality of wires  86  are twisted in the total length, a configuration in which a plurality of wires  86  are twisted in a part of the total length, and a configuration in which a plurality of wires  86  are bundled without being twisted anywhere in the total length. In summary, each conductor wire  82  constituting the conductor section is a wire aggregate in which a plurality of wires  86  are bundled and the resistance value between the bundled wires is larger than the resistance value of the wire  86  per se. 
     Each conductor wire  82  is bent and formed so as to be arranged in a predetermined arrangement pattern in the circumferential direction of the stator winding  51 , and as a result, a phase winding for each phase is formed as the stator winding  51 . As illustrated in  FIG. 12 , in the stator winding  51 , the coil side section  53  is formed by the straight section  83  of each conductor wire  82  extending linearly in the axial direction, and the coil ends  54  and  55  are formed by the turn section  84  protruding to both outsides from the coil side section  53  in the axial direction. Each conductor wire  82  is configured as a series of wave winding-shaped conductors by alternately repeating the straight section  83  and the turn section  84 . The straight sections  83  are arranged at positions facing the magnet unit  42  in the radial direction, and in-phase straight sections  83  arranged at positions on the axially outer side of the magnet unit  42  at predetermined intervals are connected to each other by the turn section  84 . Note that the straight section  83  corresponds to a “magnet facing section”. 
     In the present embodiment, the stator winding  51  is wound in an annular shape by distributed winding, in this case, in the coil side section  53 , straight sections  83  are arranged in the circumferential direction at intervals corresponding to one pole pair of the magnet unit  42  for each phase, and in the coil ends  54  and  55 , the respective straight sections  83  for each phase are connected to each other by the turn section  84  formed in a substantially V shape. The directions of the currents of the straight section  83  that are paired corresponding to one-pole pair are opposite to each other. Further, the combination of the pair of straight sections  83  connected by the turn section  84  is different between one coil end  54  and the other coil end  55 , and the connections at the coil ends  54  and  55  are repeated in the circumferential direction, and thus the stator winding  51  is formed in a substantially cylindrical shape. 
     More specifically, the stator winding  51  constitutes a winding for each phase with the use of two pairs of conductor wires  82  for each phase, and one three-phase winding (U-phase, V-phase, W-phase) and the other three-phase winding (X-phase, Y-phase, Z-phase) of the stator winding  51  are provided in two layers inside and outside in the radial direction. In this case, if the number of phases of the stator winding  51  is S ( 6  in the case of the example) and the number of conductor wires  82  per phase is m, then 2*S*m=2Sm conductor wires  82  will be formed for each pole pair. In the present embodiment, since the number of phases S is 6, the number of m is 4, and an 8-pole pair (16 poles) rotating electric machine is used, 6*4*8=192 conductor wires  82  are arranged in the circumferential direction of the stator core  52 . 
     In the stator winding  51  illustrated in  FIG. 12 , in the coil side section  53 , the straight sections  83  are arranged so as to overlap in two layers adjacent in the radial direction, and in the coil ends  54  and  55 , the turn sections  84  extend in directions opposite to each other in the circumferential direction, from each of the straight sections  83  overlapping in the radial direction. That is, in the respective conductor wires  82  adjacent to each other in the radial direction, the directions of the turn sections  84  are opposite to each other except for the ends of the stator winding  51 . 
     Here, the winding structure of the conductor wire  82  in the stator winding  51  will be specifically described. In the present embodiment, a plurality of conductor wires  82  formed by wave winding are provided so as to be stacked in a plurality of layers (for example, two layers) adjacent to each other in the radial direction.  FIGS. 15A and 15B  are diagrams illustrating a form of each conductor wire  82  in an nth layer,  FIG. 15A  illustrates a shape of the conductor wire  82  seen from the side of the stator winding  51 , and  FIG. 15B  illustrates a shape of the conductor wire  82  seen from one side in the axial direction of the stator winding  51 . Moreover, in  FIG. 15A  and  FIG. 15B , the positions where the conductor group  81  is arranged are illustrated as D 1 , D 2 , D 3 , . . . , respectively. Further, for convenience of explanation, only three conductor wires  82  are illustrated, which are referred to as a first conductor  82 _A, a second conductor  82 _B, and a third conductor  82 _C. 
     In each of the conductors  82 _A to  82 _C, the straight sections  83  are all arranged at the nth layer position, that is, at the same position in the radial direction, and the straight sections  83  separated from each other by 6 positions (3*m pairs) in the circumferential direction are connected to each other by the turn section  84 . In other words, in each of the conductors  82 _A to  82 _C, on the same circle centered on the shaft center of the rotor  40 , both ends of the seven straight sections  83  arranged adjacent to each other in the circumferential direction of the stator winding  51  are connected to each other by one turn section  84 . For example, in the first conductor  82 _A, a pair of straight sections  83  are arranged at D 1  and D 7 , respectively, and the pair of straight sections  83  are connected to each other by an inverted V-shaped turn section  84 . Further, the other conductors  82 _B and  82 _C are arranged in the same nth layer with their circumferential positions shifted by one. In this case, since the conductors  82 _A to  82 _C are all arranged in the same layer, it is conceivable that the turn sections  84  might interfere with each other. Therefore, in the present embodiment, an interference avoidance section is formed in the turn section  84  of each of the conductors  82 _A to  82 _C with a part thereof offset in the radial direction. 
     Specifically, the turn section  84  of each of the conductors  82 _A to  82 _C has one tilted portion  84   a  which is a portion extending in the circumferential direction on the same circle (first circle), a top portion  84   b  that shifts from the tilted portion  84   a  radially inward (upper side in  FIG. 15B ) of the same circle and reaches another circle (second circle), an tilted portion  84   c  that extends in the circumferential direction on the second circle, and a return portion  84   d  that returns from the first circle to the second circle. The top portion  84   b , tilted portion  84   c , and return portion  84   d  correspond to the interference avoidance section. Moreover, the tilted portion  84   c  may be configured to shift outward in the radial direction with respect to the tilted portion  84   a.    
     That is, the turn sections  84  of the conductors  82 _A to  82 _C have a tilted portion  84   a  on one side and a tilted portion  84   c  on the other side on both sides of the top portion  84   b  which is a central position in the circumferential direction. The radial positions of the tilted portions  84   a  and  84   c  (the position in the front-rear direction of the plane of  FIG. 15A  and the position in the up-down direction in  FIG. 15B ) are different from each other. For example, the turn section  84  of the first conductor  82 _A extends along the circumferential direction with a D 1  position of the nth layer as the start point position, bends in the radial direction (for example, inward in the radial direction) at the top portion  84   b  which is the central position in the circumferential direction, and then bends again in the circumferential direction, thereby extending along the circumferential direction again, and further bends in the radial direction (for example, outside in the radial direction) again at the return portion  84   d , thereby reaching a D 7  position of the nth layer, which is the end point position. 
     According to the above configuration, in the conductors  82 _A to  82 _C, each tilted portion  84   a  on one side is arranged vertically in the order of the first conductor  82 _A, the second conductor  82 _B, and the third conductor  82 _C from the top, and at the top portion  84   b , the top and bottom of each conductor  82 _A to  82 _C are interchanged, and each tilted portion  84   c  on the other side is arranged vertically in the order of the third conductor  82 _C, the second conductor  82 _B, and the first conductor  82 _A from the top. Therefore, the respective conductors  82 _A to  82 _C can be arranged in the circumferential direction without interfering with each other. 
     Here, in a configuration in which a plurality of conductor wires  82  are stacked in the radial direction to form a conductor group  81 , it is preferable that the turn section  84  connected to the straight section  83  on the radially inside and the turn section  84  connected to the straight section  83  on the radial outside of the respective straight sections  83  of the plurality of layers are arranged so as to be radially separated from each of the straight sections  83 . Further, when the conductor wires  82  of a plurality of layers are bent to the same side in the radial direction near the end of the turn section  84 , that is, the boundary portion with the straight section  83 , it is preferable that the insulating property is not impaired due to the interference between the conductor wires  82  of the adjacent layers. 
     For example, in D 7  to D 9  of  FIG. 15A  and  FIG. 15B , the respective conductor wires  82  overlapping in the radial direction are respectively bent in the radial direction at the return portion  84   d  of the turn section  84 . In this case, as illustrated in  FIG. 16 , it is preferable that the radius of curvature of the bent portion is different between the conductor wire  82  of the nth layer and the conductor wire  82  of the n+1 layer. Specifically, a radius of curvature R 1  of the conductor wire  82  on the radially inside (nth layer) is made smaller than a radius of curvature R 2  of the conductor wire  82  on the radially outside (n+1th layer). 
     Further, it is preferable that the radial shift amount is different between the nth layer conductor wire  82  and the n+1th layer conductor wire  82 . Specifically, a shift amount S 1  of the conductor wire  82  on the radially inside (nth layer) is made larger than a shift amount S 2  of the conductor wire  82  on the radially outside (n+1th layer). 
     With the above configuration, mutual interference of the respective conductor wires  82  can be suitably avoided even when the respective conductor wires  82  overlapping in the radial direction are bent in the same direction. As a result, good insulating properties can be obtained. 
     Next, the structure of the magnet unit  42  in the rotor  40  will be described. In the present embodiment, it is assumed that the magnet unit  42  is made of a permanent magnet, has a residual magnetic flux density Br=1.0 [T], and has an intrinsic coercive force Hcj=400 [kA/m] or more. In short, the permanent magnet used in this embodiment is a sintered magnet obtained by sintering and solidifying a granular magnetic material, and the intrinsic coercive force Hcj on the J-H curve is 400 [kA/m] or more, and the residual magnetic flux density Br is 1.0 [T] or more. When 5000 to 10000 [AT] is applied by interphase excitation, if a permanent magnet with a length of 25 [mm] is used in the magnetic length of one pole pair, that is, the N pole and the S pole, in other words, the path of the magnetic flux flowing between the N pole and the S pole, then Hcj=10000 [A], indicating that demagnetization is not performed. 
     In other words, the magnet unit  42  has a saturation magnetic flux density Js of 1.2 [T] or more, a crystal particle size of 10 [μm] or less, and Js*α of 1.0 [T] or higher when the orientation ratio is α. 
     The magnet unit  42  will be supplemented below. The magnet unit  42  (magnet) is characterized in that 2.15 [T]≥Js≥1.2 [T]. In other words, examples of the magnet used in the magnet unit  42  include NdFe11TiN, Nd2Fe14B, Sm2Fe17N3, and FeNi magnets having L10 type crystals. Moreover, configurations such as SmCo5 which is usually called samarium-cobalt, FePt, Dy2Fe14B, and CoPt cannot be used. Note that, like the same type of compounds such as Dy2Fe14B and Nd2Fe14B, in some cases, even a magnet that generally uses dysprosium which is a heavy rare earth to have a high coercive force of Dy while slightly losing the high Js characteristics of neodymium fulfills 2.15 [T]≥Js≥1.2 [T], the magnet can be employed in this case as well. In such a case, the magnet is referred to as ([Nd1−xDyx]2Fe14B), for example. Furthermore, the magnet can be achieved by two or more types of magnets having different compositions, for example, magnets made of two or more types of materials such as FeNi plus Sm2Fe17N3, and for example, the magnet can also be achieved by a mixed magnet in which a small amount of Js&lt;1 [T], for example, Dy2Fe14B is mixed with a magnet of Nd2Fe14B having sufficient value of Js, i.e. J s =1.6 [T], and the coercive force is increased. 
     Further, for rotating electric machines that operate at temperatures outside the range of human activity, for example, 60° C. or higher, which exceeds the temperature of a desert, for example, in vehicle motor applications where the temperature inside the vehicle is close to 80° C. in summer, it is desirable to contain the components of FeNi and Sm2Fe17N3, which have a particularly small temperature dependence coefficient. This is because the motor characteristics differ greatly depending on the temperature dependence coefficient in the motor operation from a temperature state close to −40° C. in Northern Europe, which is within the range of human activity, to 60° C. or higher, which exceeds the desert temperature mentioned above, or to a heat resistant temperature of coil enamel coating approximately 180-240° C., and thus it becomes difficult to perform optimum control with the same motor driver. If the aforementioned FeNi having 10 type crystals, Sm2Fe17N3, or the like is used, the burden on the motor driver can be suitably reduced due to its characteristic of having a temperature dependence coefficient of less than half that of Nd2Fe14B. 
     Additionally, the magnet unit  42  is characterized in that the size of the particle diameter in the fine powder state before orientation is 10 μm or less and the single magnetic domain particle diameter or more by using the aforementioned magnet blending. In magnets, the coercive force is increased by miniaturizing the powder particles to the order of several hundred nm. Therefore, in recent years, powder as fine as possible has been used. However, if they are made too fine, the BH product of the magnet will drop due to oxidation or the like, and thus a single magnetic domain particle diameter or larger is preferable. It is known that the coercive force increases by the miniaturization when the particle diameter is up to the single magnetic domain particle diameter. Moreover, the size of the particle diameter that has been described here is the size of the particle diameter in the fine powder state at the time of the orientation process in the magnet manufacturing process. 
     Furthermore, each of the first magnet  91  and the second magnet  92  of the magnet unit  42  is a sintered magnet formed by so-called sintering, in which magnetic powder is baked and hardened at a high temperature. In this sintering, when the saturation magnetization Js of the magnet unit  42  is 1.2 T or more, the crystal grain diameter of the first magnet  91  and the second magnet  92  is 10 μm or less, and the orientation ratio is a, sintering is performed in such a manner that Js*a fulfills a condition of 1.0 T (tesla) or more. Further, each of the first magnet  91  and the second magnet  92  is sintered so as to fulfill the following conditions. In addition, the orientation is performed in the orientation process in the manufacturing process, the orientation ratio is different from the definition of the magnetic force direction by the magnetizing process of the isotropic magnet. With the saturation magnetization Js of the magnet unit  42  of the present embodiment is 1.2 T or more, a high orientation ratio is set in such a manner that the orientation ratio α of the first magnet  91  and the second magnet  92  is Jr≥Js*α≥1.0 [T]. Moreover, the orientation ratio α referred to here is that, in a case where in each of the first magnet  91  and the second magnet  92 , for example, there are six axes of easy magnetization, if five of the axes face a direction A 10  in the same direction and the remaining one faces a direction B 10  tilted 90 degrees with respect to the direction A 10 , α=5/6, and if the remaining one faces the direction B 10  tilted 45 degrees with respect to the direction A 10 , the component for the remaining one facing the direction A 10  is cos 45°=0.707, and thus α=(5+0.707)/6. In this example, the first magnet  91  and the second magnet  92  are formed by sintering, but if the above conditions are fulfilled, the first magnet  91  and the second magnet  92  may be molded by another method. For example, a method for forming an MQ3 magnet or the like can be employed. 
     In this embodiment, since a permanent magnet whose axis of easy magnetization is controlled by orientation is used, the magnetic circuit length inside the magnet can be made longer than the magnetic circuit length of a linearly oriented magnet that conventionally produces 1.0 [T] or more. That is, the magnetic circuit length per pole pair can be achieved with a small amount of magnets, and the reversible demagnetization range can be maintained even when exposed to harsh high thermal conditions compared to the conventional design using linearly oriented magnets. Further, the discloser of the present application has found a configuration in which characteristics similar to those of a polar anisotropic magnet can be obtained even with the use of a magnet of the prior art. 
     Note that, the axis of easy magnetization refers to a crystal orientation that is easily magnetized in a magnet. The direction of the axis of easy magnetization in the magnet is a direction in which the orientation ratio indicating the degree to which the directions of the axes of easy magnetization are aligned is 50% or more, or a direction in which the orientation of the magnet is average. 
     As illustrated in  FIGS. 8 and 9 , the magnet unit  42  has an annular shape and is provided inside the magnet holder  41  (specifically, radially inside the cylindrical section  43 ). The magnet unit  42  has a first magnet  91  and a second magnet  92 , which are respectively polar anisotropic magnets and have different polarities from each other. The first magnet  91  and the second magnet  92  are arranged alternately in the circumferential direction. The first magnet  91  is a magnet that forms an N pole in a portion close to the stator winding  51 , and the second magnet  92  is a magnet that forms an S pole in a portion close to the stator winding  51 . The first magnet  91  and the second magnet  92  are permanent magnets made of rare earth magnets such as neodymium magnets. 
     In each of the magnets  91  and  92 , as illustrated in  FIG. 9 , in the known d-q coordinate system, the magnetization direction extends in an are shape between the d-axis (direct-axis) which is the center of the magnetic pole and the q-axis (quadrature-axis) which is the magnetic pole boundary between the N pole and the S pole (in other words, the magnetic flux density is 0 tesla). In each of the magnets  91  and  92 , the magnetization direction is the radial direction of the annular magnet unit  42  on the d-axis side, and the magnetization direction of the annular magnet unit  42  is the circumferential direction on the q-axis side. Hereinafter, it will be described in more detail. As illustrated in  FIG. 9 , each of the magnets  91  and  92  has a first portion  250  and two second portions  260  located on both sides of the first portion  250  in the circumferential direction of the magnet unit  42 . In other words, the first portion  250  is closer to the d-axis than the second portion  260  is, and the second portion  260  is closer to the q-axis than the first portion  250  is. In addition, the magnet unit  42  is configured in such a manner that the direction of an axis of easy magnetization  300  of the first portion  250  is more parallel to the d-axis than the direction of an axis of easy magnetization  310  of the second portion  260 . In other words, the magnet unit  42  is configured in such a manner that an angle θ 11  formed by the axis of easy magnetization  300  of the first portion  250  and the d-axis is smaller than an angle θ 12  formed by the axis of easy magnetization  310  of the second portion  260  and the q-axis. 
     More specifically, the angle θ 11  is an angle formed by the d-axis and the axis of easy magnetization  300  when the direction from the stator  50  (armature) to the magnet unit  42  is positive on the d-axis. The angle θ 12  is an angle formed by the q-axis and the axis of easy magnetization  310  when the direction from the stator  50  (armature) to the magnet unit  42  is positive on the q-axis. Both the angle θ 11  and the angle θ 12  are 90° or less in this embodiment. Each of the axes of easy magnetization  300  and  310  referred to here is defined by the following. If one axis of easy magnetization faces a direction A 11  and the other axis of easy magnetization faces a direction B 11  in each of the magnets  91  and  92 , the absolute value (|cos θ|) of the cosine of the angle θ formed by the direction A 11  and the direction B 11  is the axis of easy magnetization  300  or the axis of easy magnetization  310 . 
     That is, each of the magnets  91  and  92  has a different direction of the axis of easy magnetization on the d-axis side (the portion near the d-axis) and the q-axis side (the portion near the q-axis), and on the d-axis side, the direction of the axis of easy magnetization is close to the direction parallel to the d-axis, and on the q-axis side, the direction of the easy magnetization axis is close to the direction orthogonal to the q-axis. In addition, an arc-shaped magnet magnetic path is formed in accordance with the direction of the axis of easy magnetization. Moreover, in each of the magnets  91  and  92 , the axis of easy magnetization may be oriented parallel to the d-axis on the d-axis side, and the axis of easy magnetization may be oriented orthogonal to the q-axis on the q-axis side 
     Further, in the magnets  91  and  92 , of the peripheral surfaces of the magnets  91  and  92 , the outer surface on the stator side on the stator  50  side (lower side in  FIG. 9 ) and the end face on the q-axis side in the circumferential direction are magnetic flux acting surfaces which are inflow and outflow surfaces of magnetic flux, and a magnet magnetic path is formed so as to connect these magnetic flux acting surfaces (the outer surface on the stator side and the end face on the q-axis side). 
     In the magnet unit  42 , magnetic flux flows in an arc shape between adjacent N and S poles due to the magnets  91  and  92 , and thus the magnet magnetic path is longer than that of, for example, a radial anisotropic magnet. Therefore, as illustrated in  FIG. 17 , the magnetic flux density distribution is close to a sine wave. As a result, unlike the magnetic flux density distribution of the radial anisotropic magnet illustrated as a comparative example in  FIG. 18 , the magnetic flux can be concentrated on the center side of the magnetic poles, and the torque of the rotating electric machine  10  can be increased. Further, it can be confirmed that the magnet unit  42  of the present embodiment has a difference in the magnetic flux density distribution as compared with a conventional Halbach array magnet. Moreover, in  FIGS. 17 and 18 , the horizontal axis represents an electrical angle and the vertical axis represents a magnetic flux density. Further, in  FIGS. 17 and 18 , 90° on the horizontal axis indicates the d-axis (that is, the center of the magnetic pole), and 0° and 180° on the horizontal axis indicate the q-axis. 
     That is, according to the magnets  91  and  92  having the above configuration, the magnet magnetic flux on the d-axis is strengthened and the change in magnetic flux near the q-axis is suppressed. As a result, magnets  91  and  92  in which the change in surface magnetic flux from the q-axis to the d-axis at each magnetic pole is gentle can be preferably achieved. 
     The sine wave matching rate of the magnetic flux density distribution should be, for example, a value of 40% or more. By doing so, it is possible to reliably improve the amount of magnetic flux in the central portion of the waveform as compared with the case of using a radially oriented magnet or a parallel oriented magnet having a sine wave matching rate of approximately 30%. Further, if the sine wave matching rate is 60% or more, the amount of magnetic flux in the central portion of the waveform can be reliably improved as compared with the magnetic flux concentrated array such as the Halbach array. 
     In the radial anisotropic magnet illustrated in  FIG. 18 , the magnetic flux density changes steeply in the vicinity of the q-axis. The steeper the change in magnetic flux density, the greater the eddy current generated in the stator winding  51 . Further, the change in magnetic flux on the stator winding  51  side is also steep. On the other hand, in the present embodiment, the magnetic flux density distribution is a magnetic flux waveform close to a sine wave. Therefore, the change in the magnetic flux density in the vicinity of the q-axis is smaller than the change in the magnetic flux density of the radial anisotropic magnet. As a result, the generation of eddy current can be suppressed. 
     In the magnet unit  42 , a magnetic flux is generated in the vicinity of the d-axis (that is, the center of the magnetic pole) of each of the magnets  91  and  92  in a direction orthogonal to a magnetic flux acting surface  280  on the stator  50  side, and the farther away from the magnetic flux acting surface  280  on the stator  50  side, the magnetic flux forms an arc shape farther away from the d-axis. Further, the magnetic flux more orthogonal to the magnetic flux acting surface becomes stronger. In this respect, in the rotating electric machine  10  of the present embodiment, since each conductor group  81  is thinned in the radial direction as described above, the radial center position of the conductor group  81  approaches the magnetic flux acting surface of the magnet unit  42 , and the stator  50  can receive a strong magnet magnetic flux from the rotor  40 . 
     Further, the stator  50  is provided with a cylindrical stator core  52  on the radial inside of the stator winding  51 , that is, on the side opposite to the rotor  40  with the stator winding  51  therebetween. Therefore, the magnetic flux extending from the magnetic flux acting surface of each of the magnets  91  and  92  is attracted to the stator core  52  and orbits while using the stator core  52  as a part of the magnetic path. In this case, the direction and path of the magnet magnetic flux can be optimized. 
     The procedure for assembling the bearing unit  20 , the housing  30 , the rotor  40 , the stator  50 , and the inverter unit  60  illustrated in  FIG. 5  will be described below as a method for manufacturing the rotating electric machine  10 . Moreover, as illustrated in  FIG. 6 , the inverter unit  60  has a unit base  61  and an electric component  62 , and each work process including the assembling process of the unit base  61  and the electric component  62  will be described. In the following description, the assembly including the stator  50  and the inverter unit  60  is referred to as a first unit, and the assembly including the bearing unit  20 , the housing  30  and the rotor  40  is referred to as a second unit. 
     This manufacturing process has
         a first process for mounting the electric component  62  radially inside the unit base  61 ,   a second process for mounting the unit base  61  radially inside the stator  50  to manufacture the first unit,   a third process for inserting the fixing section  44  of the rotor  40  into the bearing unit  20  assembled to the housing  30  to manufacture the second unit,   a fourth process for mounting the first unit radially inside the second unit, and   a fifth process for fastening and fixing the housing  30  and the unit base  61 .       

     The execution order of each of these processes is the first process, second process, third process, fourth process, and fifth process. 
     According to the above manufacturing method, the bearing unit  20 , housing  30 , rotor  40 , stator  50 , and inverter unit  60  are assembled as a plurality of assemblies (subassemblies), and then the assemblies are assembled to each other. Therefore, ease of handling and completion of inspection for each unit can be achieved, and a rational assembly line can be constructed. Consequently, it is possible to easily cope with multi-product production. 
     In the first process, a good thermal conductor having good thermal conductivity is attached to at least one of the radial inside of the unit base  61  and the radial outside of the electric component  62  by coating, adhesion, or the like, and in that state, the electric component  62  is preferably attached to the unit base  61 . This makes it possible to effectively transmit the heat generated by the semiconductor module  66  to the unit base  61 . 
     In the third process, the rotor  40  is preferably inserted while maintaining the coaxiality between the housing  30  and the rotor  40 . Specifically, for example, using a jig for determining the position of the outer peripheral surface of the rotor  40  (outer peripheral surface of the magnet holder  41 ) or the inner peripheral surface of the rotor  40  (inner peripheral surface of the magnet unit  42 ) with reference to the inner peripheral surface of the housing  30 , the housing  30  and the rotor  40  are assembled while sliding either the housing  30  or the rotor  40  along the jig. As a result, heavy parts can be assembled without applying an unbalanced load to the bearing unit  20 , and the reliability of the bearing unit  20  is improved. 
     In the fourth process, it is preferable to assemble the first unit and the second unit while maintaining the coaxiality between both units. Specifically, for example, using a jig for determining the position of the inner peripheral surface of the unit base  61  with reference to the inner peripheral surface of the fixing section  44  of the rotor  40 , each of the first unit and the second unit is assembled while sliding either one of them along the jig. As a result, it is possible to assemble the rotor  40  and the stator  50  while preventing mutual interference with each other between the minimum gaps, and therefore it is possible to eliminate defective products caused by assembly, such as damage to the stator winding  51  and chipping of permanent magnets. 
     The order of each of the above processes may also be the second process, third process, fourth process, fifth process, and first process. In this case, the delicate electric component  62  is assembled last, and the stress on the electric component  62  in the assembling process can be minimized. 
     Next, the configuration of the control system that controls the rotating electric machine  10  will be described.  FIG. 19  is an electrical circuit diagram of the control system of the rotating electric machine  10 , and  FIG. 20  is a functional block diagram illustrating control processing by a control device  110 . 
     In  FIG. 19 , two sets of three-phase windings  51   a  and  51   b  are illustrated as the stator winding  51 . The three-phase winding  51   a  includes a U-phase winding, a V-phase winding, and a W-phase winding, and the three-phase winding  51   b  includes an X-phase winding, a Y-phase winding, and a Z-phase winding. A first inverter  101  and a second inverter  102 , which correspond to power converters, are provided for each of the three-phase windings  51   a  and  51   b , respectively. The inverters  101  and  102  are composed of a full bridge circuit having the same number of upper and lower arms as the number of phases of the phase windings, and the energization current is adjusted in each phase winding of the stator winding  51  by turning on/off a switch (semiconductor switching element) provided on each arm. 
     A DC power supply  103  and a smoothing capacitor  104  are connected in parallel to each of the inverters  101  and  102 . The DC power supply  103  is composed of, for example, an assembled battery in which a plurality of single batteries are connected in series. Moreover, each switch of the inverters  101  and  102  corresponds to the semiconductor module  66  illustrated in  FIG. 1  and the like, and the capacitor  104  corresponds to the capacitor module  68  illustrated in  FIG. 1  and the like. 
     The control device  110  includes a microcomputer composed of a CPU and various memories, and performs energization control by turning on/off each switch in the inverters  101  and  102  on the basis of various detected information in the rotating electric machine  10  and requests for power running and power generation. The control device  110  corresponds to the control device  77  illustrated in  FIG. 6 . The detected information of the rotating electric machine  10  includes, for example, a rotation angle (electrical angle information) of the rotor  40  detected by an angle detector such as a resolver, a power supply voltage (inverter input voltage) detected by a voltage sensor, and an energization current of each phase detected by a current sensor. The control device  110  generates and outputs an operation signal for operating each switch of the inverters  101  and  102 . Moreover, the request for power generation is, for example, a request for regenerative driving when the rotating electric machine  10  is used as a power source for a vehicle. 
     The first inverter  101  includes a series connection body of an upper arm switch Sp and a lower arm switch Sn in three phases composed of the U phase, V phase, and W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive electrode terminal of the DC power supply  103 , and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative electrode terminal (ground) of the DC power supply  103 . One ends of the U-phase winding, V-phase winding, and W-phase winding are connected to the intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase, respectively. These respective phase windings are connected in a star-shape (Y-connected), and the other ends of the respective phase windings are connected to each other at a neutral point. 
     The second inverter  102  has the same configuration as that of the first inverter  101 , and includes a series connection body of the upper arm switch Sp and the lower arm switch Sn in three phases composed of the U phase, V phase, and W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive electrode terminal of the DC power supply  103 , and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative electrode terminal (ground) of the DC power supply  103 . One ends of the X-phase winding, Y-phase winding, and Z-phase winding are connected to the intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase, respectively. These respective phase windings are connected in a star-shape (Y-connected), and the other ends of the respective phase windings are connected to each other at a neutral point. 
       FIG. 20  illustrates current feedback control processing for controlling each phase current of the U, V, and W phases, and current feedback control processing for controlling each phase current of the X, Y, and Z phases. Here, first, the control processing on the U, V, and W phase side will be described. 
     In  FIG. 20 , a current command value setting unit  111  uses a torque-dq map and sets a d-axis current command value and a q-axis current command value on the basis of the power running torque command value or the power generation torque command value for the rotating electric machine  10  and an electric angular velocity ω obtained by time-differentiating an electrical angle  9 . Moreover, the current command value setting unit  111  is commonly provided on the U, V, and W phase side and the X, Y, and Z phase side. Note that the power generation torque command value is, for example, a regenerative torque command value when the rotating electric machine  10  is used as a power source for a vehicle. 
     A dq conversion unit  112  converts, the current detected values (three phase currents) by the current sensors provided for each phase, into a d-axis current and a q-axis current which are components of an orthogonal two-dimensional rotation coordinate system with the field magnet direction (direction of an axis of a magnetic field or field direction) as the d-axis. 
     A d-axis current feedback control unit  113  calculates a d-axis command voltage as an operation amount for feedback-controlling the d-axis current to the d-axis current command value. Further, a q-axis current feedback control unit  114  calculates a q-axis command voltage as an operation amount for feedback-controlling the q-axis current to the q-axis current command value. In each of these feedback control units  113  and  114 , the command voltage is calculated with the use of the PI feedback method on the basis of the deviation with respect to the current command values of the d-axis current and the q-axis current. 
     A three-phase conversion unit  115  converts the d-axis and q-axis command voltages into U-phase, V-phase, and W-phase command voltages. Moreover, each of the above units  111  to  115  is a feedback control unit that performs feedback control of the fundamental wave current according to the dq conversion theory, and the U-phase, V-phase, and W-phase command voltages are feedback control values. 
     In addition, an operation signal generation unit  116  uses a well-known triangular wave carrier comparison method to generate an operation signal of the first inverter  101  on the basis of the command voltages of the three phases. Specifically, the operation signal generation unit  116  generates a switch operation signal (duty signal) of the upper and lower arms in each phase by PWM control based on the magnitude comparison between the signal obtained by standardizing the command voltage of the three phases with the power supply voltage and the carrier signal such as a triangular wave signal. 
     Further, the X, Y, and Z phase side also has the same configuration, and a dq conversion unit  122  converts the current detected values (three phase currents) by the current sensor provided for each phase into the d-axis current and q-axis current, which are components of an orthogonal two-dimensional rotation coordinate system with the field direction as the d-axis. 
     A d-axis current feedback control unit  123  calculates a d-axis command voltage, and a q-axis current feedback control unit  124  calculates a q-axis command voltage. A three-phase conversion unit  125  converts the d-axis and q-axis command voltages into X-phase, Y-phase, and Z-phase command voltages. In addition, an operation signal generation unit  126  generates an operation signal of the second inverter  102  on the basis of the command voltages of the three phases. Specifically, the operation signal generation unit  126  generates a switch operation signal (duty signal) of the upper and lower arms in each phase by PWM control based on the magnitude comparison between the signal obtained by standardizing the command voltage of the three phases with the power supply voltage and the carrier signal such as a triangular wave signal. 
     A driver  117  turns on/off the switches Sp and Sn of each of the three phases in the inverters  101  and  102  on the basis of the switch operation signals generated by the operation signal generation units  116  and  126 . 
     Subsequently, the torque feedback control processing will be described. This process is mainly used for the purpose of increasing the output of the rotating electric machine  10  and reducing the loss under operating conditions in which the output voltage of each of the inverters  101  and  102  becomes large, such as in a high rotation region and a high output region. The control device  110  selects and executes either the torque feedback control processing or the current feedback control processing on the basis of the operating conditions of the rotating electric machine  10 . 
       FIG. 21  illustrates torque feedback control processing corresponding to the U, V, and W phases and torque feedback control processing corresponding to the X, Y, and Z phases. Moreover, in  FIG. 21 , the same configurations as those in  FIG. 20  are designated by the same reference signs and the description thereof will be omitted. Here, first, the control processing on the U, V, and W phase side will be described. 
     A voltage amplitude calculation unit  127  calculates a voltage amplitude command which is a command value of the magnitude of the voltage vector, on the basis of the power running torque command value or the power generation torque command value for the rotating electric machine  10  and the electric angular velocity (o obtained by time-differentiating the electrical angle θ. 
     A torque estimation unit  128   a  calculates a torque estimated value corresponding to the U, V, and W phases on the basis of the d-axis current and the q-axis current converted by the dq conversion unit  112 . Moreover, the torque estimation unit  128   a  may calculate the voltage amplitude command on the basis of the map information in which the d-axis current, the q-axis current, and the voltage amplitude command are associated. 
     A torque feedback control unit  129   a  calculates a voltage phase command which is a command value of the phase of the voltage vector, as an operation amount for feedback-controlling the torque estimated value to the power running torque command value or the power generation torque command value. The torque feedback control unit  129   a  calculates the voltage phase command with the use of the PI feedback method on the basis of the deviation of the torque estimated value with respect to the power running torque command value or the power generation torque command value. 
     The operation signal generation unit  130   a  generates an operation signal of the first inverter  101  on the basis of the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit  130   a  calculates command voltages of three phases on the basis of the voltage amplitude command, the voltage phase command, and the electrical angle θ, and generates the switch operation signal of the upper and lower arms in each phase by PWM control based on the magnitude comparison between the signal obtained by standardizing the calculated command voltages of three phases with the power supply voltage and the carrier signal such as a triangular wave signal. 
     By the way, the operation signal generation unit  130   a  may generate the switch operation signal on the basis of the pulse pattern information which is map information in which the voltage amplitude command, the voltage phase command, the electrical angle θ, and the switch operation signal are associated, the voltage amplitude command, the voltage phase command, and the electrical angle θ. 
     Further, the X, Y, and Z phase side also has the same configuration, and the torque estimation unit  128   b  calculates a torque estimated value corresponding to the X, Y, and Z phases on the basis of the d-axis current and the q-axis current converted by the dq conversion unit  122 . 
     The torque feedback control unit  129   b  calculates a voltage phase command as an operation amount for feedback-controlling the torque estimated value to the power running torque command value or the power generation torque command value. The torque feedback control unit  129   b  calculates the voltage phase command with the use of the PI feedback method on the basis of the deviation of the torque estimated value with respect to the power running torque command value or the power generation torque command value. 
     The operation signal generation unit  130   b  generates an operation signal of the first inverter  102  on the basis of the voltage amplitude command, the voltage phase command, and the electrical angle θ. Specifically, the operation signal generation unit  130   b  calculates command voltages of three phases on the basis of the voltage amplitude command, the voltage phase command, and the electrical angle θ, and generates the switch operation signal of the upper and lower arms in each phase by PWM control based on the magnitude comparison between the signal obtained by standardizing the calculated command voltages of three phases with the power supply voltage and the carrier signal such as a triangular wave signal. The driver  117  turns on/off the switches Sp and Sn of each of the three phases in the inverters  101  and  102  on the basis of the switch operation signals generated by the operation signal generation units  130   a  and  130   b.    
     Incidentally, the operation signal generation unit  130   b  may generate switch operation signals on the basis of the pulse pattern information which is map information in which the voltage amplitude command, the voltage phase command, the electrical angle θ, and the switch operation signal are associated, the voltage amplitude command, the voltage phase command, and the electrical angle θ. 
     By the way, in the rotating electric machine  10 , there is a concern that electrolytic corrosion of the bearings  21  and  22  may occur due to the generation of a shaft current. For example, there is a concern that, when the energization of the stator winding  51  is switched by switching, magnetic flux distortion occurs due to a slight deviation in switching timing (switching imbalance), which causes electrolytic corrosion in the bearings  21  and  22  that support the rotating shaft  11 . The distortion of the magnetic flux occurs in accordance with the inductance of the stator  50 , and the electromotive voltage in the axial direction generated by the distortion of the magnetic flux causes dielectric breakdown in the bearings  21  and  22 , and electrolytic corrosion proceeds. 
     In this regard, in the present embodiment, the following three countermeasures are taken as countermeasures against electrolytic corrosion. A first electrolytic corrosion countermeasure is an electrolytic corrosion suppression countermeasure by reducing the inductance due to the coreless stator  50  and by smoothing the magnet magnetic flux of the magnet unit  42 . A second electrolytic corrosion countermeasure is an electrolytic corrosion suppression countermeasure by adopting a cantilever structure with the bearings  21  and  22  for the rotating shaft. A third electrolytic corrosion countermeasure is an electrolytic corrosion suppression countermeasure by molding the annular stator winding  51  together with the stator core  52  with a molding material. The details of each of these countermeasures will be described below individually. 
     First, in the first electrolytic corrosion countermeasure, in the stator  50 , the spaces between each conductor group  81  in the circumferential direction are made teethless, and a sealing member  57  made of a non-magnetic material instead of the teeth (iron core) is provided between each conductor group  81  (see  FIG. 10 ). This makes it possible to reduce the inductance of the stator  50 . By reducing the inductance of the stator  50 , even if the switching timing shift occurs when the stator winding  51  is energized, the occurrence of magnetic flux distortion due to the switching timing shift can be suppressed, and thus it is possible to suppress the electrolytic corrosion of the bearings  21  and  22 . Moreover, it is preferable that the inductance of the d-axis is equal to or less than the inductance of the q-axis. 
     Further, the magnets  91  and  92  are oriented in such a manner that the direction of the axis of easy magnetization is more parallel to the d-axis on the d-axis side as compared with the q-axis side (see  FIG. 9 ). As a result, the magnet magnetic flux on the d-axis is strengthened, and the change in surface magnetic flux (increase/decrease in magnetic flux) from the q-axis to the d-axis becomes gentle at each magnetic pole. Therefore, the sudden voltage change caused by the switching imbalance is suppressed, and thus a configuration that can contribute to the suppression of electrolytic corrosion is implemented. 
     In the second electrolytic corrosion countermeasure, in the rotating electric machine  10 , the respective bearings  21  and  22  are arranged unevenly on either side in the axial direction with respect to the axial center of the rotor  40  (see  FIG. 2 ). As a result, the influence of electrolytic corrosion can be reduced as compared with a configuration in which a plurality of bearings are provided on both sides of the rotor in the axial direction. That is, in a configuration in which the rotor is supported from both sides by a plurality of bearings, a closed circuit that passes through the rotor, the stator, and each bearing (that is, each bearing on both sides in the axial direction with the rotor therebetween) is formed as a high frequency magnetic flux is generated, and there is a concern about electrolytic corrosion of the bearing due to the shaft current. On the other hand, in the configuration in which the rotor  40  is cantilevered and supported by a plurality of bearings  21  and  22 , the closed circuit is not formed and the electrolytic corrosion of the bearings is suppressed. 
     Further, the rotating electric machine  10  has the following configuration in connection with the configuration for arranging the bearings  21  and  22  on one side. In the magnet holder  41 , the contact avoiding section that extends in the axial direction and avoids contact with the stator  50  is provided at the intermediate section  45  that projects in the radial direction of the rotor  40  (see  FIG. 2 ). In this case, when a closed circuit of the shaft current is formed via the magnet holder  41 , the closed circuit length can be lengthened to increase the circuit resistance. As a result, the electrolytic corrosion of the bearings  21  and  22  can be suppressed. 
     The holding member  23  of the bearing unit  20  is fixed to the housing  30  on one side in the axial direction with the rotor  40  therebetween, and the housing  30  and the unit base  61  (stator holder) are coupled to each other on the other side (see  FIG. 2 ). According to this configuration, it is possible to preferably implement a configuration in which the respective bearings  21  and  22  are unevenly arranged on one side of the rotating shaft  11  in the axial direction. In addition, in this configuration, since the unit base  61  is connected to the rotating shaft  11  via the housing  30 , the unit base  61  can be arranged at a position electrically separated from the rotating shaft  11 . Moreover, if an insulating member such as resin is interposed between the unit base  61  and the housing  30 , the unit base  61  and the rotating shaft  11  are electrically further separated from each other. As a result, the electrolytic corrosion of the bearings  21  and  22  can be appropriately suppressed. 
     In the rotating electric machine  10  of the present embodiment, the shaft voltage acting on the bearings  21  and  22  is reduced by arranging the respective bearings  21  and  22  on one side, and the like. Further, the potential difference between the rotor  40  and the stator  50  is reduced. Therefore, it is possible to reduce the potential difference acting on the bearings  21  and  22  without using conductive grease in the bearings  21  and  22 . Since the conductive grease generally contains fine particles such as carbon, it is considered that noise is generated. In this regard, in the present embodiment, non-conductive grease is used in the bearings  21  and  22 . Therefore, it is possible to suppress the inconvenience of noise in the bearings  21  and  22 . For example, in the application to an electric vehicle such as an electric vehicle, it is considered that a countermeasure against the noise of the rotating electric machine  10  is required, and it is possible to preferably implement the countermeasure against the noise. 
     In the third electrolytic corrosion countermeasure, the stator winding  51  is molded together with the stator core  52  with a molding material to suppress the displacement of the stator winding  51  in the stator  50  (see  FIG. 11 ). In particular, since the rotating electric machine  10  of the present embodiment does not have an interconductor member (teeth) between each conductor group  81  in the circumferential direction of the stator winding  51 , there is a concern that the stator winding  51  may be displaced, but by molding the stator winding  51  together with the stator core  52 , the displacement of the conductor position of the stator winding  51  is suppressed. Consequently, it is possible to suppress the distortion of the magnetic flux due to the displacement of the stator winding  51  and the occurrence of electrolytic corrosion of the bearings  21  and  22  due to the distortion. 
     Moreover, since the unit base  61  as a housing member that fixes the stator core  52  is made of carbon fiber reinforced plastic (CFRP), the electric discharge to the unit base  61  is suppressed as compared with the case where it is made of, for example, aluminum. Thus, a suitable countermeasure against electrolytic corrosion is possible. 
     In addition to that, as a countermeasure against electrolytic corrosion of the bearings  21  and  22 , it is also possible to use a configuration in which at least one of the outer ring  25  and the inner ring  26  is made of a ceramic material, or in which an insulating sleeve is provided on the outside of the outer ring  25 . 
     Hereinafter, other embodiments will be described with a focus on differences from the first embodiment. 
     Second Embodiment 
     In the present embodiment, the polar anisotropic structure of the magnet unit  42  in the rotor  40  is changed, which will be described in detail below. 
     As illustrated in  FIGS. 22 and 23 , the magnet unit  42  is composed with the use of a magnet array called a Halbach array. That is, the magnet unit  42  has a first magnet  131  in which the magnetization direction (direction of the magnetization vector) is the radial direction and a second magnet  132  in which the magnetization direction (direction of the magnetization vector) is the circumferential direction. The first magnets  131  are arranged at predetermined intervals in the circumferential direction, and the second magnets  132  are arranged at a position between the adjacent first magnets  131  in the circumferential direction. The first magnet  131  and the second magnet  132  are permanent magnets made of rare earth magnets such as neodymium magnets. 
     The first magnets  131  are arranged so as to be apart from each other in the circumferential direction in such a manner that the poles on the side facing the stator  50  (inside in the radial direction) are alternately N poles and S poles. Further, the second magnets  132  are arranged next to each first magnet  131  in such a manner that the polarities alternate in the circumferential direction. The cylindrical section  43  provided so as to surround each of the magnets  131  and  132  is preferably a soft magnetic substance core made of a soft magnetic material, and functions as a back core. Moreover, the magnet unit  42  of the second embodiment also has the same relation of the axis of easy magnetization with respect to the d-axis and the q-axis in the d-q coordinate system as in the first embodiment. 
     Further, a magnetic substance  133  made of a soft magnetic substance is arranged on radially outside the first magnet  131 , that is, on the side of the cylindrical section  43  of the magnet holder  41 . For example, the magnetic substance  133  is preferably made of an electromagnetic steel sheet, soft iron, or a dust core material. In this case, the circumferential length of the magnetic substance  133  is the same as the circumferential length of the first magnet  131  (particularly, the circumferential length of the outer peripheral portion of the first magnet  131 ). Further, in a state where the first magnet  131  and the magnetic substance  133  are integrated, the radial thickness of the integrated object is the same as the radial thickness of the second magnet  132 . In other words, the radial thickness of the first magnet  131  is thinner than that of the second magnet  132  by the amount of the magnetic substance  133 . Each of the magnets  131  and  132  and the magnetic substance  133  are fixed to each other by, for example, an adhesive. In the magnet unit  42 , the radial outside of the first magnet  131  is the opposite side to the stator  50 , and the magnetic substance  133  is provided on the side opposite to the stator  50  (opposite-to-stator side) in both sides of the first magnet  131  in the radial direction. 
     A key  134  is formed on the outer peripheral portion of the magnetic substance  133  as a protrusion that protrudes outward in the radial direction, that is, toward the side of the cylindrical section  43  of the magnet holder  41 . Further, a key groove  135  is formed on the inner peripheral surface of the cylindrical section  43  as a recess for housing the key  134  of the magnetic substance  133 . The protruding shape of the key  134  and the groove shape of the key groove  135  are the same, and the same number of key grooves  135  as the key  134  are formed corresponding to the key  134  formed on each magnetic substance  133 . By engaging the key  134  and the key groove  135 , the displacement of the first magnet  131  and the second magnet  132  and the magnet holder  41  in the circumferential direction (rotation direction) is suppressed. Moreover, it is optional whether the key  134  and the key groove  135  (protrusion and recess) are provided in either of the cylindrical section  43  or the magnetic substance  133  of the magnet holder  41 , and contrary to the above, it is also possible to provide the key groove  135  on the outer peripheral portion of the magnetic substance  133  and to provide the key  134  on the inner peripheral portion of the cylindrical section  43  of the magnet holder  41 . 
     Here, in the magnet unit  42 , the magnetic flux density in the first magnet  131  can be increased by alternately arranging the first magnet  131  and the second magnet  132 . Therefore, in the magnet unit  42 , the magnetic flux can be concentrated on one side, and the magnetic flux can be strengthened on the side closer to the stator  50 . 
     Further, by arranging the magnetic substance  133  radially outside the first magnet  131 , that is, on the opposite-to-stator side, it is possible to suppress partial magnetic saturation on the radial outside of the first magnet  131 , and thus demagnetization of the first magnet  131  caused by the magnetic saturation can be suppressed. As a result, it is accordingly possible to increase the magnetic force of the magnet unit  42 . The magnet unit  42  of the present embodiment has, so to speak, a configuration in which a portion of the first magnet  131  in which demagnetization is likely to occur is replaced with the magnetic substance  133 . 
       FIGS. 24A and 24B  are diagrams specifically illustrating the flow of magnetic flux in the magnet unit  42 ,  FIG. 24A  illustrates a case where a conventional configuration is used in which the magnet unit  42  does not have the magnetic substance  133 , and  FIG. 24B  illustrates a case where the configuration of the present embodiment having the magnetic substance  133  in the magnet unit  42  is used. Moreover, in  FIGS. 24A and 24B , the cylindrical section  43  of the magnet holder  41  and the magnet unit  42  are illustrated in a linearly developed manner, with the lower side of the figure being the stator side and the upper side being the opposite-to-stator side. 
     In the configuration of  FIG. 24A , the magnetic flux acting surface of the first magnet  131  and the side surface of the second magnet  132  are in contact with the inner peripheral surface of the cylindrical section  43 , respectively. Further, the magnetic flux acting surface of the second magnet  132  is in contact with the side surface of the first magnet  131 . In this case, in the cylindrical section  43 , the combined magnetic flux of a magnetic flux F 1  that enters the contact surface with the first magnet  131  through the outer path of the second magnet  132  and the magnetic flux that is substantially parallel to the cylindrical section  43  and attracts a magnetic flux F 2  of the second magnet  132  is generated. Therefore, there is a concern that magnetic saturation may partially occur in the vicinity of the contact surface between the first magnet  131  and the second magnet  132  in the cylindrical section  43 . 
     On the other hand, in the configuration of  FIG. 24B , the magnetic substance  133  is formed between the magnetic flux acting surface of the first magnet  131  and the inner peripheral surface of the cylindrical section  43  on the side opposite to the stator  50  of the first magnet  131 , and therefore the magnetic substance  133  allows the passage of magnetic flux. Consequently, magnetic saturation in the cylindrical section  43  can be suppressed, and the proof stress against demagnetization is improved. 
     Further, in the configuration of  FIG. 24B , unlike  FIG. 24A , the flux F 2  that promotes magnetic saturation can be cancelled As a result, the permeance of the entire magnetic circuit can be effectively improved. With such a configuration, the magnetic circuit characteristics can be maintained even under severe high heat conditions. 
     Further, the magnet magnetic path passing through the inside of the magnet becomes longer than that of a radial magnet in a conventional SPM rotor. Therefore, the magnet permeance can rise, the magnetic force can be enhanced, and the torque can be increased. Furthermore, the magnetic flux is concentrated in the center of the d-axis, and thus the sine wave matching rate can be increased. In particular, if the current waveform is made into a sine wave or a trapezoidal wave by PWM control, or if a switching IC energized at 120 degrees is used, the torque can be increased more effectively. 
     Moreover, in a case where the stator core  52  is made of an electromagnetic steel sheet, the radial thickness of the stator core  52  is preferably ½ or more than ½ of the radial thickness of the magnet unit  42 . For example, the radial thickness of the stator core  52  is preferably ½ or more of the radial thickness of the first magnet  131  provided at the center of the magnetic pole in the magnet unit  42 . Further, the radial thickness of the stator core  52  is preferably smaller than the radial thickness of the magnet unit  42 . In this case, the magnet magnetic flux is approximately 1 [T], and the saturation magnetic flux density of the stator core  52  is 2 [T]. Therefore, by setting the radial thickness of the stator core  52  to ½ or more of the radial thickness of the magnet unit  42 , it is possible to prevent magnetic flux leakage to the inner peripheral side of the stator core  52 . 
     In a magnet having a Halbach structure or a polar anisotropic structure, since the magnetic path has a pseudo arc shape, the magnetic flux can be increased in proportion to the thickness of the magnet that handles the magnetic flux in the circumferential direction. In such a configuration, it is considered that the magnetic flux flowing through the stator core  52  does not exceed the magnetic flux in the circumferential direction. That is, in a case where an iron-based metal having a saturation magnetic flux density of 2 [T] is used with respect to a magnetic flux of the magnet 1 [T], if the thickness of the stator core  52  is set to half or more of the magnet thickness, it is possible to provide a rotating electric machine that is not magnetically saturated and is suitably small and lightweight. Here, since the diamagnetic field from the stator  50  acts on the magnet magnetic flux, the magnet magnetic flux is generally 0.9 [T] or less. Therefore, if the stator core has half the thickness of the magnet, its magnetic permeability can be kept suitably high. 
     Hereinafter, a modification in which a part of the above-described configuration is modified will be described. 
     First Modification 
     In the above embodiment, the outer peripheral surface of the stator core  52  has a curved surface without unevenness, and a plurality of conductor groups  81  are arranged side by side at predetermined intervals on the outer peripheral surface, but this may be changed. For example, as illustrated in  FIG. 25 , the stator core  52  has an annular yoke  141  provided on the side opposite to the rotor  40  (lower side in the figure) on both sides of the stator winding  51  in the radial direction and protruding sections  142  extending from the yoke  141  so as to protrude between the straight sections  83  adjacent to each other in the circumferential direction. The protruding sections  142  are provided at predetermined intervals on the radially outside the yoke  141 , that is, on the rotor  40  side. The respective conductor groups  81  of the stator winding  51  are engaged with the protruding sections  142  in the circumferential direction, and are arranged side by side in the circumferential direction while using the protruding section  142  as a positioning section of the conductor group  81 . Moreover, the protruding section  142  corresponds to the “interconductor member”. 
     In the protruding section  142 , the radial thickness dimension from the yoke  141 , in other words, as illustrated in  FIG. 25 , in the radial direction of the yoke  141 , a distance W from the inner side surface  320  adjacent to the yoke  141  of the straight section  83  to the apex of the protruding section  142  is smaller than ½ of the radial thickness dimension of the straight section  83  radially adjacent to the yoke  141  among the plurality of straight sections  38  inside and outside the radial direction (H 1  in the figure). In other words, the non-magnetic member (sealing member  57 ) should occupy a range of three-quarters of a dimension (thickness) T 1  of the conductor group  81  (conducting member) in the radial direction of the stator winding  51  (stator core  52 ) (twice the thickness of the conductor wire  82 , in other words, the shortest distance between the surface  320  in contact with the stator core  52  of the conductor group  81  and a surface  330  facing the rotor  40  of the conductor group  81 ). Due to the thickness limitation of the protruding section  142 , the protruding section  142  does not function as teeth between the conductor groups  81  (that is, the straight section  83 ) adjacent to each other in the circumferential direction, and the magnetic path is not formed by the teeth. Not all of the protruding sections  142  may not be provided between the conductor groups  81  arranged in the circumferential direction, but should be provided between at least one set of the conductor groups  81  adjacent to each other in the circumferential direction. For example, the protruding sections  142  are preferably provided at equal intervals for each predetermined number of the conductor groups  81  in the circumferential direction. The shape of the protruding section  142  may be any shape such as a rectangular shape or an are shape. 
     Further, the straight section  83  may be provided as a single layer on the outer peripheral surface of the stator core  52 . Consequently, in a broad sense, the radial thickness dimension of the protruding section  142  from the yoke  141  may be smaller than ½ of the radial thickness dimension of the straight section  83 . 
     Moreover, assuming a virtual circle centered on the shaft center of the rotating shaft  11  and passing through the radial center position of the straight section  83  radially adjacent to the yoke  141 , the protruding section  142  preferably has a shape that protrudes from the yoke  141  within the range of the virtual circle, in other words, a shape that does not protrude radially outward of the virtual circle (that is, on the rotor  40  side). 
     According to the above configuration, the protruding section  142  has a limited radial thickness dimension and does not function as the teeth between the straight sections  83  adjacent to each other in the circumferential direction. Therefore, it is possible to bring the respective adjacent straight sections  83  closer to each other as compared with the case where the teeth are provided between the respective straight sections  83 . As a result, the cross-sectional area of the conductor  82   a  can be increased, and the heat generated by the energization of the stator winding  51  can be reduced. In such a configuration, the absence of teeth makes it possible to eliminate magnetic saturation and increase the energization current to the stator winding  51 . In this case, it is possible to preferably cope with the increase in the amount of heat generated as the energization current increases. Further, in the stator winding  51 , since the turn section  84  is shifted in the radial direction and has an interference avoidance section for avoiding interference with other turn sections  84 , the different turn sections  84  can be separated from each other in the radial direction. As a result, heat dissipation can be improved even in the turn section  84 . As described above, it is possible to optimize the heat dissipation performance of the stator  50 . 
     Further, if the yoke  141  of the stator core  52  and the magnet unit  42  of the rotor  40  (that is, the magnets  91  and  92 ) are separated by a predetermined distance or more, the radial thickness dimension of the protruding section  142  is not limited to H 1  in  FIG. 25  Specifically, if the yoke  141  and the magnet unit  42  are separated by 2 mm or more, the radial thickness dimension of the protruding section  142  may be H 1  or more in  FIG. 25 . For example, in a case where the radial thickness dimension of the straight section  83  exceeds 2 mm and the conductor group  81  is composed of two layers of conductor wires  82  inside and outside the radial direction, the protruding section  142  may be provided in the straight section  83  not adjacent to the yoke  141 , that is, in the range from the yoke  141  to the half position of the second conductor wire  82 . In this case, if the radial thickness dimension of the protruding section  142  is up to “H 1 ×3/2”, the effect can be obtained not a little by increasing the conductor cross-sectional area in the conductor group  81 . 
     Further, the stator core  52  may have the configuration illustrated in  FIG. 26 . Moreover, although the sealing member  57  is omitted in  FIG. 26 , the sealing member  57  may be provided. In  FIG. 26 , for convenience, the magnet unit  42  and the stator core  52  are illustrated in a linearly developed manner. 
     In the configuration of  FIG. 26 , the stator  50  has the protruding section  142  as an interconductor member between the conductor wires  82  (that is, the straight section  83 ) adjacent to each other in the circumferential direction. When the stator winding  51  is energized, the stator  50  magnetically functions together with one of the magnetic poles (N pole or S pole) of the magnet unit  42 , and has a part  350  extending in the circumferential direction of the stator  50 . When the circumferential length of the stator  50  of this part  350  is Wn, the total width of the protruding sections  142  existing in this length range Wn (that is, the total dimension of the stator  50  in the circumferential direction) is Wt, the saturation magnetic flux density of the protruding section  142  is Bs, the width dimension for one pole of the magnet unit  42  in the circumferential direction is Wm, and the residual magnetic flux density of the magnet unit  42  is Br, the protruding section  142  is made of a magnetic material of a formula (1). 
         Wt*Bs≤Wm*Br   (1)
 
     Moreover, the range Wn is set so as to include a plurality of conductor groups  81  adjacent to each other in the circumferential direction and include a plurality of conductor groups  81  having overlapping excitation times. In doing so, it is preferable to set the center of the void  56  of the conductor group  81  as a reference (boundary) when setting the range Wn. For example, in the case of the configuration illustrated in  FIG. 26 , the conductor groups  81  up to the fourth in order from the one with the shortest distance from the center of the magnetic pole of the N pole in the circumferential direction correspond to the aforementioned plurality of conductor groups  81 . In addition, the range Wn is set so as to include the four conductor groups  81 . In doing so, the ends (starting point and ending point) of the range Wn are set as the center of the void  56 . 
     In  FIG. 26 , since halves of the protruding sections  142  are included at both ends of the range Wn, the range Wn includes a total of four protruding sections  142 . Consequently, when the width of the protruding section  142  (that is, the dimension of the protruding section  142  in the circumferential direction of the stator  50 , in other words, the interval between the adjacent conductor groups  81 ) is A, the total width of the protruding sections  142  included in the range Wn is Wt=½A+A+A+A+½A=4A. 
     Specifically, in the present embodiment, the three-phase winding of the stator winding  51  is a distributed winding, and in the stator winding  51 , the number of protruding sections  142  with respect to one pole of the magnet unit  42 , that is, the number of voids  56  between the respective conductor groups  81  is a “number of phases*Q”. Here, Q is the number of the one-phase conductor wires  82  that are in contact with the stator core  52 . Moreover, in a case where the conductor wires  82  are the conductor group  81  stacked in the radial direction of the rotor  40 , it can also be considered to be the number of the conductor wires  82  on the inner peripheral side of the one-phase conductor group  81 . In this case, when the three-phase winding of the stator winding  51  is energized in a predetermined order for each phase, the protruding sections  142  for two phases are excited in one pole. Consequently, the total circumferential width dimension Wt of the protruding section  142  excited by the energization of the stator winding  51  in the range for one pole of the magnet unit  42  is “the number of excited phases*Q*A=2*2*A” when the circumferential width dimension of the protruding section  142  (that is, the void  56 ) is A. 
     In addition, after the total width dimension Wt is defined in this way, in the stator core  52 , the protruding section  142  is configured as a magnetic material fulfilling the relation (1) above. Moreover, the total width dimension Wt is also the circumferential dimension of the portion where the relative magnetic permeability can be larger than 1 in one pole. Further, in consideration of a margin, the total width dimension Wt may be set as the circumferential width dimension of the protruding section  142  in one magnetic pole. Specifically, since the number of protruding sections  142  with respect to one pole of the magnet unit  42  is “number of phases*Q”, the circumferential width dimension (total width dimension Wt) of the protruding sections  142  in one magnetic pole may be set to “the number of phases*Q*A=3*2*A=6A”. 
     Moreover, the distributed winding referred to here is a one-pole pair period (N-pole and S-pole) of the magnetic pole, and has a one-pole pair of the stator winding  51 . The one-pole pair of the stator winding  51  referred to here is composed of two straight sections  83  and a turn section  84  in which currents flow in opposite directions and which are electrically connected at the turn section  84 . If the above conditions are met, even a Short Pitch Winding is regarded as an equivalent of a distributed winding of a Full Pitch Winding. 
     Next, an example in the case of concentrated winding is indicated. The concentrated winding referred to here is that the width of the one-pole pair of magnetic poles and the width of the one-pole pair of the stator winding  51  are different. Example of concentrated winding include a concentrated winding that has relation such as three conductor groups  81  for one magnetic pole pair, three conductor groups  81  for two magnetic pole pairs, nine conductor groups  81  for four magnetic pole pairs, and nine conductor groups  81  for five magnetic pole pairs. 
     Here, in a case where the stator winding  51  is a concentrated winding, when the three-phase windings of the stator winding  51  are energized in a predetermined order, the stator windings  51  for two phases are excited. As a result, the protruding sections  142  for two phases are excited. Consequently, the circumferential width dimension Wt of the protruding section  142  excited by the energization of the stator winding  51  in the range for one pole of the magnet unit  42  is “A*2”. In addition, after the total width dimension Wt is defined in this way, the protruding section  142  is configured as a magnetic material fulfilling the relation (1) above. Moreover, in the case of the concentrated winding indicated above, the total circumferential width of the protruding sections  142  of the stator  50  in the region surrounded by the conductor groups  81  of the same phase is defined as A. Further, Wm in the concentrated winding corresponds to “the entire circumference of the surface facing the air gap of the magnet unit  42 ” *“the number of phases”/“the number of dispersions of the conductor group  81 ”. 
     Incidentally, for magnets with a BH product of 20 [MGOe (kJ/m{circumflex over ( )}3)] or more, such as neodymium magnets, samarium-cobalt magnets, and ferrite magnets, Bd=over 1.0 [T], and for iron, Br=over 2.0 [T]. Therefore, as the high output motor, in the stator core  52 , the protruding section  142  may be a magnetic material fulfilling the relation of Wt&lt;½ *Wm. 
     Further, in a case where the conductor wire  82  includes an outer layer coating  182  as described below, the conductor wire  82  may be arranged in the circumferential direction of the stator core  52  in such a manner that the outer layer coatings  182  of the conductor wires  82  come into contact with each other. In this case, Wt can be regarded as 0 or the thickness of the outer layer coating  182  of both conductor wires  82  in contact with each other. 
     In the configurations of  FIGS. 25 and 26 , an interconductor member (protruding section  142 ) that is disproportionately small with respect to the magnet magnetic flux on the rotor  40  side is provided. Moreover, the rotor  40  is a flat surface magnet type rotor having a low inductance and does not have saliency in terms of magnetic resistance. In such a configuration, the inductance of the stator  50  can be reduced, the generation of magnetic flux distortion due to the deviation of the switching timing of the stator winding  51  is suppressed, and thus the electrolytic corrosion of the bearings  21  and  22  is suppressed. 
     Second Modification 
     The following configuration can also be adopted as the stator  50  using the interconductor member fulfilling the relation of the above formula (1). In  FIG. 27 , a tooth-shaped section  143  is provided as an interconductor member on the outer peripheral surface side of the stator core  52  (upper surface side in the figure). The tooth-shaped section  143  is provided at predetermined intervals in the circumferential direction so as to protrude from the yoke  141 , and have the same thickness dimension as that of the conductor group  81  in the radial direction. The side surface of the tooth-shaped section  143  is in contact with each conductor wire  82  of the conductor group  81 . However, there may be a gap between the tooth-shaped section  143  and each conductor wire  82 . 
     The tooth-shaped section  143  is provided with a limitation on the width dimension in the circumferential direction, and is provided with polar teeth (stator teeth) that are disproportionately thin with respect to the amount of magnets. With such a configuration, the tooth-shaped section  143  is surely saturated by the magnetic flux of the magnet at 1.8 T or more, and the inductance can be lowered by lowering the permeance. 
     Here, in the magnet unit  42 , when the surface area per pole of the magnetic flux acting surface on the stator side is Sm and the residual magnetic flux density of the magnet unit  42  is Br, the magnetic flux on the magnet unit side is, for example, “Sm*Br”. Further, when the surface area on the rotor side in each tooth-shaped section  143  is St, the number per phase of the conductor wire  82  is m, and the tooth-shaped sections  143  for two phases are excited in one pole by energization of the stator winding  51 , the magnetic flux on the stator side is, for example, “St*m*2*Bs”. In this case, the inductance is reduced by limiting the dimension of the tooth-shaped section  143  in such a manner that a relation (2) is established. 
         St*m* 2* Bs&lt;Sm*Br   (2)
 
     Moreover, in a case where the magnet unit  42  and the tooth-shaped section  143  have the same axial dimension, when the circumferential width dimension for one pole of the magnet unit  42  is Wm, and the circumferential width dimension of the tooth-shaped section  143  is Wst, then the above formula (2) is replaced as in a formula (3). 
         Wst*m* 2* Bs&lt;Wm*Br   (3)
 
     More specifically, assuming that, for example, Bs=2T, Br=1T, and m=2, the above formula (3) has a relation of “Wst&lt;Wm/8”. In this case, the inductance is reduced by making the width dimension Wst of the tooth-shaped section  143  smaller than ⅛ of the width dimension Wm for one pole of the magnet unit  42 . Moreover, if the number m is 1, the width dimension Wst of the tooth-shaped section  143  is preferably made to be smaller than ¼ of the width dimension Wm for one pole of the magnet unit  42 . 
     Moreover, in the above formula (3), “Wst*m*2” corresponds to the circumferential width dimension of the tooth-shaped section  143  excited by energization of the stator winding  51  in the range for one pole of the magnet unit  42 . 
     In the configuration of  FIG. 27 , similarly to the configurations of  FIGS. 25 and 26  described above, the interconductor member (tooth-shaped section  143 ) which is disproportionately small with respect to the magnet magnetic flux on the rotor  40  side is provided. In such a configuration, the inductance of the stator  50  can be reduced, the generation of magnetic flux distortion due to the deviation of the switching timing of the stator winding  51  is suppressed, and thus the electrolytic corrosion of the bearings  21  and  22  is suppressed. 
     Third Modification 
     In the above embodiment, the sealing member  57  covering the stator winding  51  is provided radially outside the stator core  52  in the range including all the conductor groups  81 , that is, in the range in which the radial thickness dimension is larger than the radial thickness dimension of each conductor group  81 , but this may be changed. For example, as illustrated in  FIG. 28 , the sealing member  57  is provided in such a manner that a part of the conductor wire  82  protrudes. More specifically, the sealing member  57  is provided in a state where a part of the conductor wire  82  which is the outermost in the radial direction in the conductor group  81  is exposed on the radial outside, that is, on the stator  50  side. In this case, the radial thickness dimension of the sealing member  57  may be the same as or smaller than the radial thickness dimension of each conductor group  81 . 
     Fourth Modification 
     As illustrated in  FIG. 29 , in the stator  50 , each conductor group  81  may not be sealed by the sealing member  57 . That is, the sealing member  57  that covers the stator winding  51  is not used. In this case, no interconductor member is provided between the conductor groups  81  arranged in the circumferential direction, and an airspace is formed. In short, the interconductor member is not provided between the conductor groups  81  arranged in the circumferential direction. Moreover, air may be regarded as a non-magnetic substance or an equivalent of a non-magnetic substance as Bs=0, and air may be arranged in this airspace. 
     Fifth Modification 
     In a case where the interconductor member in the stator  50  is made of a non-magnetic material, it is possible to use a material other than resin as the non-magnetic material. For example, a metal-based non-magnetic material may be used, such as using SUS304 which is an austenitic stainless steel. 
     Sixth Modification 
     The stator  50  may be configured not to include the stator core  52 . In this case, the stator  50  is composed of the stator winding  51  illustrated in  FIG. 12 . Moreover, in the stator  50  that does not include the stator core  52 , the stator winding  51  may be sealed with a sealing material. Alternatively, the stator  50  may be configured to include an annular winding holding section made of a non-magnetic material such as synthetic resin as an alternative to the stator core  52  made of a soft magnetic material. 
     Seventh Modification 
     In the above first embodiment, the plurality of magnets  91  and  92  arranged in the circumferential direction are used as the magnet unit  42  of the rotor  40 , but this may be changed, and an annular magnet which is an annular permanent magnet may be used as the magnet unit  42 . Specifically, as illustrated in  FIG. 30 , an annular magnet  95  is fixed radially inside the cylindrical section  43  of the magnet holder  41 . The annular magnet  95  is provided with a plurality of magnetic poles having alternating polarities in the circumferential direction, and the magnet is integrally formed on both the d-axis and the q-axis. The annular magnet  95  is formed with an arc shaped magnet magnetic path such that the direction of orientation is the radial direction on the d-axis of each magnetic pole and the direction of orientation is the circumferential direction on the q-axis between the respective magnetic poles. 
     Moreover, in the annular magnet  95 , the orientation should be made in such a manner that an arc-shaped magnet magnetic path is formed, in which the axis of easy magnetization is parallel to the d-axis or close to parallel to the d-axis in the portion near the d-axis, and the axis of easy magnetization is orthogonal to the q-axis or close to parallel to the q-axis in the portion near the q-axis. 
     Eighth Modification 
     In this modification, a part of the control method of the control device  110  is changed. In this modification, the difference from the configuration described in the first embodiment will be mainly described. 
     First, with reference to  FIG. 31 , the processing in the operation signal generation units  116  and  126  illustrated in  FIG. 20  and the operation signal generation units  130   a  and  130   b  illustrated in  FIG. 21  will be described. Moreover, the processing in each operation signal generation unit  116 ,  126 ,  130   a , and  130   b  is basically the same. Therefore, in the following, the processing of the operation signal generation unit  116  will be described as an example. 
     The operation signal generation unit  116  includes a carrier generation unit  116   a  and U, V, W phase comparators  116   b U,  116   b V, and  116   b W. In the present embodiment, the carrier generation unit  116   a  generates and outputs a triangular wave signal as a carrier signal SigC. 
     The carrier signal SigC generated by the carrier generation unit  116   a  and the U, V, W phase command voltages calculated by the three-phase conversion unit  115  are input to the U, V, W phase comparators  116   b U,  116   b V, and  116   b W. The U, V, W phase command voltages are, for example, sinusoidal waveforms, and the phases are shifted by 120° depending on the electrical angle. 
     The U, V, W phase comparators  116   b U,  116   b V, and  116   b W generate the operation signals of the respective switches Sp and Sn of the upper arm and the lower arm of the U, V, W phases in the first inverter  101 , by PWM (pulse width modulation) control based on the magnitude comparison between the U, V, W phase command voltages and the carrier signal SigC. Specifically, the operation signal generation unit  116  generates the operation signals of the respective switches Sp and Sn of the U, V, W phases by PWM control based on the magnitude comparison between the signal obtained by standardizing the U, V. W command voltages with the power supply voltage and the carrier signal. The driver  117  turns on/off each of the switches Sp and Sn of the U, V, W phases in the inverter  101  on the basis of the operation signals generated by the operation signal generation unit  116 . 
     The control device  110  performs processing that changes the carrier frequency fc of the carrier signal SignC, that is, the switching frequency of each of the switches Sp and Sn. The carrier frequency fc is set high in the low torque region or high rotation region of the rotating electric machine  10  and low in the high torque region of the rotating electric machine  10 . This setting is made in order to suppress a decrease in controllability of the current flowing through each phase winding. 
     That is, as the stator  50  becomes coreless, the inductance of the stator  50  can be reduced. Here, when the inductance becomes low, the electrical time constant of the rotating electric machine  10  becomes small. As a result, there is a concern that the ripple of the current flowing through each phase winding increases, the controllability of the current flowing through the winding decreases, and the current control diverges. The effect of this decrease in controllability can be more pronounced when the current flowing through the winding (for example, the effective value of the current) is included in the low current region than in the high current region. In order to deal with this problem, in this modification, the control device  110  changes the carrier frequency fc. 
     The processing that changes the carrier frequency fc will be described with reference to  FIG. 32 . This processing is repeatedly executed by the control device  110 , for example, at a predetermined control cycle as the processing of the operation signal generation unit  116 . 
     In step S 10 , it is determined whether the current flowing through a winding  51   a  of each phase is in the low current region. This processing is processing for determining that the current torque of the rotating electric machine  10  is in the low torque region. Examples of the method for determining whether the current is included in the low current region include the following first and second methods. 
     &lt;First Method&gt; 
     The torque estimated value of the rotating electric machine  10  is calculated on the basis of the d-axis current and the q-axis current converted by the dq conversion unit  112 . Then, when it is determined that the calculated torque estimated value is less than the torque threshold value, it is determined that the current flowing through the winding  51   a  is included in the low current region, and when it is determined that the torque estimated value is equal to or more than the torque threshold value, it is determined that the current flowing through the winding  51   a  is included in the high current region. Here, the torque threshold value should be set to, for example, ½ of the starting torque (also referred to as restraint torque) of the rotating electric machine  10 . 
     &lt;Second Method&gt; 
     When it is determined that the rotation angle of the rotor  40  detected by the angle detector is equal to or greater than a speed threshold value, it is determined that the current flowing through the winding  51   a  is included in the low current region, that is, in the high rotation region. Here, the speed threshold value should be set to, for example, the rotation speed when the maximum torque of the rotating electric machine  10  becomes the torque threshold value. 
     If a negative determination is made in step S 10 , it is determined to be a high current region, and the processing proceeds to step S 11 . In step S 11 , the carrier frequency fc is set to a first frequency fL. 
     If an affirmative determination is made in step S 10 , the processing proceeds to step S 12 , and the carrier frequency fc is set to a second frequency fH which is higher than the first frequency fL. 
     According to this modification described above, the carrier frequency fc is set higher when the current flowing through each phase winding is included in the low current region than when it is included in the high current region. Therefore, in the low current region, the switching frequencies of the switches Sp and Sn can be increased, and the increase in current ripple can be suppressed. As a result, it is possible to suppress a decrease in current controllability. 
     On the other hand, when the current flowing through each phase winding is included in the high current region, the carrier frequency fc is set lower than when it is included in the low current region. In the high current region, the amplitude of the current flowing through the winding is larger than in the low current region, and therefore the increase in current ripple due to the low inductance has a small effect on the current controllability. Therefore, in the high current region, the carrier frequency fc can be set lower than in the low current region, and the switching loss of the respective inverters  101  and  102  can be reduced. 
     In this modification, the following embodiments can be implemented.
         In a case where the carrier frequency fc is set to the first frequency fL, when an affirmative determination is made in step S 10  of  FIG. 32 , the carrier frequency fc may be gradually changed from the first frequency fL to the second frequency fH.       

     Further, in a case where the carrier frequency fc is set to the second frequency fH, when a negative determination is made in step S 10 , the carrier frequency fc may be gradually changed from the second frequency fH to the first frequency fL.
         A switch operation signal may be generated by space vector modulation (SVM) control instead of PWM control. Even in this case, the above-mentioned change in switching frequency can be applied.       

     Ninth Modification 
     In each of the above embodiments, two pairs of conductors of each phase constituting the conductor group  81  are connected in parallel as illustrated in  FIG. 33A .  FIG. 33A  is a diagram illustrating the electrical connection of first and second conductors  88   a  and  88   b , which are two pairs of conductors. Here, as an alternative to the configuration illustrated in  FIG. 33A , as illustrated in  FIG. 33B , the first and second conductors  88   a  and  88   b  may be connected in series. 
     Further, three or more pairs of multilayer conductors may be laminated and arranged in the radial direction.  FIG. 34  illustrates a configuration in which first to fourth conductors  88   a  to  88   d , which are four pairs of conductors, are laminated and arranged. The first to fourth conductors  88   a  to  88   d  are arranged in the radial direction in the order of the first, second, third, and fourth conductors  88   a ,  88   b ,  88   c , and  88   d  from the side closer to the stator core  52 . 
     Here, as illustrated in  FIG. 33C , the third and fourth conductors  88   c  and  88   d  are connected in parallel, the first conductor  88   a  may be connected to one end of the parallel connection body, and the second conductor  88   b  may be connected to the other end. When connected in parallel, the current density of the conductors connected in parallel can be reduced, and heat generation during energization can be suppressed. Therefore, in the configuration in which the tubular stator winding is assembled to the housing (unit base  61 ) in which the cooling water passage  74  is formed, the first and second conductors  88   a  and  88   b  that are not connected in parallel are arranged on the stator core  52  side that abuts on the unit base  61 , and the third and fourth conductors  88   c  and  88   d  that are connected in parallel are arranged on the opposite-to-stator core side. As a result, the cooling performance of each of the conductors  88   a  to  88   d  in the multilayer conductor structure can be equalized. 
     Moreover, the radial thickness dimension of the conductor group  81  composed of the first to fourth conductors  88   a  to  88   d  should be smaller than the circumferential width dimension for one phase in one magnetic pole. 
     Tenth Modification 
     The rotating electric machine  10  may have an inner rotor structure (adduction structure). 
     In this case, for example, in the housing  30 , it is preferable that the stator  50  is provided on the radially outside and the rotor  40  is provided on the radially inside. Further, it is preferable that the inverter unit  60  is provided on one side or both sides of both ends of the stator  50  and the rotor  40  in the axial direction.  FIG. 35  is a cross-sectional view of the rotor  40  and the stator  50 , and  FIG. 36  is a view illustrating a part of the rotor  40  and the stator  50  illustrated in  FIG. 35  in an enlarged manner. 
     The configurations of  FIGS. 35 and 36 , which are premised on an inner rotor structure, have the same configurations as those of  FIGS. 8 and 9  except that the rotor  40  and stator  50  are reversed in and out of the radial direction. Briefly, the stator  50  has a stator winding  51  having a flat conductor structure and a stator core  52  having no teeth. The stator winding  51  is assembled radially inside the stator core  52 . The stator core  52  has one of the following configurations, as in the case of the outer rotor structure. 
     A In the stator  50 , an interconductor member is provided between each conductor section in the circumferential direction, and as the interconductor member, a magnetic material having a relation of Wt*Bs≤Wm*Br is used when the circumferential width dimension of the interconductor member at one magnetic pole is Wt, the saturation magnetic flux density of the interconductor member is Bs, the circumferential width dimension of the magnet unit at one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit is Br. 
     B In the stator  50 , an interconductor member is provided between each conductor section in the circumferential direction, and a non-magnetic material is used as the interconductor member. 
     C The stator  50  has a configuration in which no interconductor member is provided between each conductor section in the circumferential direction. 
     Further, the same applies to the magnets  91  and  92  of the magnet unit  42 . That is, the magnet unit  42  is composed with the use of the magnets  91  and  92  in which, the orientation was made in such a manner that, on the side of the d-axis, which is the center of the magnetic pole, the direction of the axis of easy magnetization is parallel to the d-axis as compared with the side of the q-axis, which is the magnetic pole boundary. Details such as the magnetization directions of the magnets  91  and  92  are as described above. It is also possible to use the annular magnet  95  (see  FIG. 30 ) in the magnet unit  42 . 
       FIG. 37  is a vertical cross-sectional view of the rotating electric machine  10  in the case of an inner rotor type, which is a figure corresponding to  FIG. 2  described above. Differences from the configuration of  FIG. 2  will be briefly described. In  FIG. 37 , an annular stator  50  is fixed to the inside of the housing  30 , and a rotor  40  is rotatably provided inside the stator  50  with a predetermined air gap therebetween. Similarly to  FIG. 2 , the respective bearings  21  and  22  are arranged unevenly on either side in the axial direction with respect to the axial center of the rotor  40 , whereby the rotor  40  is cantilevered and supported. Further, the inverter unit  60  is provided inside the magnet holder  41  of the rotor  40 . 
       FIG. 38  illustrates another configuration of the rotating electric machine  10  having an inner rotor structure. In  FIG. 38 , the rotating shaft  11  is rotatably supported by the bearings  21  and  22  in the housing  30 , and the rotor  40  is fixed to the rotating shaft  11 . Similarly to the configuration illustrated in  FIG. 2  or the like, the respective bearings  21  and  22  are arranged unevenly on either side in the axial direction with respect to the axial center of the rotor  40 . The rotor  40  has the magnet holder  41  and the magnet unit  42 . 
     The rotating electric machine  10  of  FIG. 38  is different from the rotating electric machine  10  of  FIG. 37  in that the inverter unit  60  is not provided radially inside the rotor  40 . The magnet holder  41  is connected to the rotating shaft  11  at a position radially inside the magnet unit  42 . Further, the stator  50  has the stator winding  51  and the stator core  52 , and is attached to the housing  30 . 
     Eleventh Modification 
     Another configuration as a rotating electric machine having an inner rotor structure will be described below.  FIG. 39  is an exploded perspective view of a rotating electric machine  200 , and  FIG. 40  is a side sectional view of the rotating electric machine  200 . Here, the up-down direction is illustrated with reference to the states of  FIGS. 39 and 40 . 
     As illustrated in  FIGS. 39 and 40 , the rotating electric machine  200  includes a stator  203  having an annular stator core  201  and a multi-phase stator winding  202 , and a rotor  204  rotatably arranged inside the stator core  201 . The stator  203  corresponds to an armature and the rotor  204  corresponds to a field magnet. The stator core  201  is composed by laminating a large number of silicon steel plates, and a stator winding  202  is attached to the stator core  201 . Although not illustrated, the rotor  204  has a rotor core and a plurality of permanent magnets as a magnet unit. The rotor core is provided with a plurality of magnet insertion holes at equal intervals in the circumferential direction. Each of the magnet insertion holes is equipped with a permanent magnet magnetized in such a manner that the magnetization direction changes alternately for each adjacent magnetic pole. Moreover, the permanent magnet of the magnet unit may have a Halbach array as described with reference to  FIG. 23  or a similar configuration. Alternatively, it is preferable that the permanent magnet of the magnet unit has polar anisotropy characteristics such as that described with reference to  FIG. 9  and  FIG. 30 , in which the orientation direction (magnetization direction) extends in an arc shape between the d-axis which is the center of the magnetic pole and the q-axis which is the magnetic pole boundary. 
     Here, the stator  203  preferably has any of the following configurations. 
     A In the stator  203 , an interconductor member is provided between each conductor section in the circumferential direction, and as the interconductor member, a magnetic material having a relation of Wt*Bs≤Wm*Br is used when the width dimension of the interconductor member in the circumferential direction at one magnetic pole is Wt, the saturation magnetic flux density of the interconductor member is Bs, the width dimension in the circumferential direction of the magnet unit at one magnetic pole is Win, and the residual magnetic flux density of the magnet unit is Br. 
     B In the stator  203 , an interconductor member is provided between each conductor section in the circumferential direction, and a non-magnetic material is used as the interconductor member. 
     C The stator  203  has a configuration in which no interconductor member is provided between each conductor section in the circumferential direction. 
     Further, in the rotor  204 , the magnet unit is composed with the use of a plurality of magnets in which, the orientation was made in such a manner that, on the side of the d-axis, which is the center of the magnetic pole, the direction of the axis of easy magnetization is parallel to the d-axis as compared with the side of the q-axis, which is the magnetic pole boundary. 
     An annular inverter case  211  is provided on one end side of the rotating electric machine  200  in the axial direction. The inverter case  211  is arranged in such a manner that the lower surface of the case is in contact with the upper surface of the stator core  201 . Inside the inverter case  211 , a plurality of power modules  212  constituting the inverter circuit, a smoothing capacitor  213  that suppresses voltage/current pulsation (ripple) generated by the switching operation of the semiconductor switching element, a control board  214  having a control unit, a current sensor  215  that detects a phase current, and a resolver stator  216  that is a rotation speed sensor of the rotor  204  are provided. The power module  212  has an IGBT and a diode which are semiconductor switching elements. 
     On the periphery of the inverter case  211 , a power connector  217  connected to the DC circuit of the battery mounted on a vehicle, and a signal connector  218  used for transferring various signals between the rotating electric machine  200  side and the vehicle side control device are provided. The inverter case  211  is covered with a top cover  219 . The direct current power from a vehicle-mounted battery is input via the power connector  217 , converted into alternate current by switching of the power module  212 , and sent to the stator winding  202  of each phase. 
     On both sides of the stator core  201  in the axial direction, on the side opposite to the inverter case  211 , a bearing unit  221  that rotatably holds the rotating shaft of the rotor  204  and an annular rear case  222  that houses the bearing unit  221  are provided. The bearing unit  221  has, for example, a pair of bearings and is arranged unevenly on either side in the axial direction with respect to the axial center of the rotor  204 . However, a plurality of bearings in the bearing unit  221  may be provided in a dispersed manner on both sides of the stator core  201  in the axial direction, and the rotating shafts may be supported from both sides by those respective bearings. The rotating electric machine  200  can be mounted on the vehicle side by bolting and fixing the rear case  222  to a mounting section such as a gear case or a transmission of the vehicle. 
     A cooling flow path  211   a  for flowing a refrigerant is formed in the inverter case  211 . The cooling flow path  211   a  is formed by closing a space recessed in an annular shape from the lower surface of the inverter case  211  with the upper surface of the stator core  201 . The cooling flow path  211   a  is formed so as to surround the coil end of the stator winding  202 . A module case  212   a  of the power module  212  is inserted in the cooling flow path  211   a . Also in the rear case  222 , a cooling flow path  222   a  is formed so as to surround the coil end of the stator winding  202 . The cooling flow path  222   a  is formed by closing a space recessed in an annular shape from the upper surface of the rear case  222  with the lower surface of the stator core  201 . 
     Twelfth Modification 
     So far, the configuration embodied in the revolving-field type rotating electric machine has been described, but it is also possible to change this and embody it in the rotating armature type rotating electric machine.  FIG. 41  illustrates the configuration of a rotating armature type rotating electric machine  230 . 
     In the rotating electric machine  230  of  FIG. 41 , bearings  232  are fixed to housings  231   a  and  231   b , respectively, and a rotating shaft  233  is rotatably supported by the bearings  232 . The bearing  232  is, for example, an oil-impregnated bearing made by impregnating a porous metal with oil. A rotor  234  as an armature is fixed to the rotating shaft  233 . The rotor  234  has a rotor core  235  and a multi-phase rotor winding  236  fixed to the outer peripheral portion of the rotor core  235 . In the rotor  234 , the rotor core  235  has a slotless structure, and the rotor winding  236  has a flat conductor structure. That is, the rotor winding  236  has a flat structure in which the region for each phase is longer in the circumferential direction than in the radial direction. 
     Further, a stator  237  as a field magnet is provided radially outside the rotor  234 . The stator  237  has a stator core  238  fixed to the housing  231   a  and a magnet unit  239  fixed to the inner peripheral side of the stator core  238 . The magnet unit  239  has a configuration including a plurality of magnetic poles having alternating polarities in the circumferential direction, and is configured similarly to the magnet unit  42  or the like described above, in which, the orientation was made in such a manner that the direction of the axis of easy magnetization is parallel to the d-axis on the d-axis side which is the center of the magnetic pole as compared with the q-axis side which is the magnetic pole boundary. The magnet unit  239  has an oriented sintered neodymium magnet, the intrinsic coercive force thereof is 400 [kA/m] or more, and the residual magnetic flux density is 1.0 [T] or more. 
     The rotating electric machine  230  of this modification is a 2-pole 3-coil brushed coreless motor, the rotor winding  236  is divided into three, and the magnet unit  239  has two poles. The number of poles and the number of coils of the brushed motor varies depending on the application, such as 2:3, 4:10, 4:21. 
     A commutator  241  is fixed to the rotating shaft  233 , and a plurality of brushes  242  are arranged on the radially outside thereof. The commutator  241  is electrically connected to the rotor winding  236  via a conductor  243  embedded in the rotating shaft  233 . A direct current flows in and out of the rotor winding  236  through these commutator  241 , brush  242 , and conductor  243 . The commutator  241  is appropriately divided in the circumferential direction in accordance with the number of phases of the rotor winding  236 . The brush  242  may be directly connected to a DC power source such as a storage battery via an electrical wiring, or may be connected to a DC power source via a terminal block or the like. 
     The rotating shaft  233  is provided with a resin washer  244  as a sealing material between the bearing  232  and the commutator  241 . The resin washer  244  suppresses the oil seeping out from the bearing  232 , which is an oil-impregnated bearing, from flowing out to the commutator  241  side. 
     Thirteenth Modification 
     In the stator winding  51  of the rotating electric machine  10 , each conductor wire  82  may have a plurality of insulating coatings inside and outside. For example, it is preferable to bundle a plurality of conductors (wires) with an insulating coating into one and cover the conductors with an outer layer coating to form the conductor wire  82 . In this case, the insulating coating of the wire constitutes the inner insulating coating, and the outer layer coating constitutes the outer insulating coating. Further, in particular, it is preferable that the insulating capability of the outer insulating coating among the plurality of insulating coatings on the conductor wire  82  is higher than the insulating capability of the inner insulating coating. Specifically, the thickness of the outer insulating coating is made thicker than the thickness of the inner insulating coating. For example, the thickness of the outer insulating coating is 100 μm, and the thickness of the inner insulating coating is 40 μm. Alternatively, a material having a lower dielectric constant than that of the inner insulating coating may be used as the outer insulating coating. At least one of these should be applied. Moreover, it is preferable that the wire is configured as an aggregate of a plurality of conductive materials. 
     By strengthening the insulation of the outermost layer of the conductor wire  82  as described above, it becomes suitable for use in a high voltage vehicle system. Further, the rotating electric machine  10  can be properly driven even in highlands where the atmospheric pressure is low. 
     Fourteenth Modification 
     In the conductor wire  82  having a plurality of insulating coatings inside and outside, at least one of the linear expansivity (linear expansion coefficient) and the adhesive strength may be different between the outer insulating coating and the inner insulating coating. The configuration of the conductor wire  82  in this modification is illustrated in  FIG. 42 . 
     In  FIG. 42 , the conductor wire  82  includes a plurality of (four in the figure) wires  181 , an outer layer coating  182  made of, for example, a resin (outer insulating coating), that surrounds the plurality of wires  181 , and an intermediate layer  183  (intermediate insulating coating) filled around each wire  181  in the outer layer coating  182 . The wire  181  has a conductive part  181   a  made of a copper material and a conductor coating  181   b  (inner insulating coating) made of an insulating material. When viewed as a stator winding, the outer layer coating  182  insulates the phases. Moreover, it is preferable that the wire  181  is configured as an aggregate of a plurality of conductive materials. 
     The intermediate layer  183  has a linear expansion coefficient higher than that of the conductor coating  181   b  of the wire  181  and a linear expansion coefficient lower than that of the outer layer coating  182 . That is, in the conductor wire  82 , the linear expansion coefficient is higher toward the outside. Generally, the outer layer coating  182  has a linear expansion coefficient higher than that of the conductor coating  181   b , but by providing the intermediate layer  183  having an intermediate linear expansion coefficient between them, the intermediate layer  183  functions as a cushioning material, and simultaneous cracking on the outer layer side and the inner layer side can be prevented. 
     Further, in the conductor wire  82 , the conductive part  181   a  and the conductor coating  181   b  are adhered to each other in the wire  181 , and the conductor coating  181   b  and the intermediate layer  183  and the intermediate layer  183  and the outer layer coating  182  are adhered to each other, respectively, and the adhesive strength becomes weaker toward the outside of the conductor wire  82  in each of these adhered portions. That is, the adhesive strength of the conductive part  181   a  and the conductor coating  181   b  is weaker than the adhesive strength of the conductor coating  181   b  and the intermediate layer  183  and the adhesive strength of the intermediate layer  183  and the outer layer coating  182 . Further, comparing the adhesive strength of the conductor coating  181   b  and the intermediate layer  183  with the adhesive strength of the intermediate layer  183  and the outer layer coating  182 , it is preferable that the latter (outer side) is weaker or equivalent. Moreover, the magnitude of the adhesive strength between the coatings can be grasped from, for example, the tensile strength required when peeling off the two layers of coatings. By setting the adhesive strength of the conductor wire  82  as described above, it is possible to suppress cracking (co-cracking) on both the inner layer side and the outer layer side even if an internal/external temperature difference occurs due to heat generation or cooling. 
     Here, the heat generation and temperature change of the rotating electric machine mainly occur as copper loss produced from the conductive part  181   a  of the wire  181  and iron loss generated from the inside of the iron core, and these two types of losses are transmitted from the conductive part  181   a  in the conductor wire  82  or the outside of the conductor wire  82 , and the intermediate layer  183  does not have a heat source. In this case, the intermediate layer  183  has an adhesive force that can serve as a cushion for both of them, and thus simultaneous cracking can be prevented. Consequently, suitable use is possible even when used in fields with high withstand pressure or large temperature changes such as vehicle applications. 
     This is supplemented below. The wire  181  may be, for example, an enamel wire, and in such a case, it has a resin coating layer (conductor coating  181   b ) such as PA, PI, and PAI. Further, it is desirable that the outer layer coating  182  outside the wire  181  is made of the same PA, PI, PAI, or the like, and has a large thickness. As a result, damage to the coating due to a difference in linear expansion coefficient is suppressed. Moreover, as the outer layer coating  182 , it is desirable to also use one with a dielectric constant smaller than PI and PAI, such as PPS, PEEK, fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, and LCP, in addition to one made by thickening the aforementioned materials such as PA, PI, and PAI. With these resins, even if they are thinner than the PI and PAI coatings equivalent to the conductor coating  181   b  or the thickness equivalent to the conductor coating  181   b , their insulating capability can be enhanced, and it is thereby possible to increase the occupancy ratio of the conductive part. In general, the resin has better insulation than the insulating coating of an enamel wire in terms of dielectric constant. As a matter of course, there are cases where the dielectric constant is deteriorated depending on the molding state and the mixture. Among them, PPS and PEEK are suitable as the outer layer coating of the second layer because their linear expansion coefficient is generally larger than that of the enamel coating but smaller than that of other resins. 
     Further, it is desirable that the adhesive strength between the two types of coatings (intermediate insulating coating and outer insulating coating) on the outside of the wire  181  and the enamel coating on the wire  181  is weaker than the adhesive strength between the copper wire and the enamel coating on the wire  181 . As a result, the phenomenon that the enamel coating and the aforementioned two types of coatings are destroyed at once is suppressed. 
     In a case where a water-cooled structure, a liquid-cooled structure, or an air-cooled structure is added to the stator, it is considered that thermal stress or impact stress is basically applied to the outer layer coating  182  first. However, even when the insulating layer of the wire  181  and the resin of the two types of coatings are different, thermal stress and impact stress can be reduced by providing a portion where the coatings are not adhered. That is, the aforementioned insulated structure is formed by providing a wire (enamel wire) and an space and arranging fluorine, polycarbonate, silicon, epoxy, polyethylene naphthalate, and LCP. In this case, it is desirable to adhere the outer layer coating and the inner layer coating with the use of an adhesive material made of epoxy or the like having a low dielectric constant and having a low linear expansion coefficient. By doing so, it is possible to suppress not only the mechanical strength but also the destruction of the coating due to friction caused by the vibration of the conductive part or the destruction of the outer layer coating due to a difference in the linear expansion coefficient. 
     As the outermost layer fixing which is generally the final process around the stator winding, which is responsible for mechanical strength, fixing, and the like for the conductor wire  82  having the above configuration, resins such as epoxy, PPS, PEEK, and LCP, which have good moldability and have properties such as dielectric constant and linear expansion coefficient similar to those of an enamel coating, are preferable. 
     Generally, resin potting with urethane or silicon is usually performed, but the linear expansion coefficient of the aforementioned resin is almost double that of other resins, and thermal stress capable of shearing the resin is generated. Therefore, it is not suitable for applications of 60V or higher where strict insulation regulations are used internationally. In this regard, according to the final insulation process for easily making by injection molding or the like using epoxy, PPS, PEEK, LCP or the like, each of the above requirements can be achieved. 
     Modifications other than the above are listed below.
         A distance DM between the surface of the magnet unit  42  on the armature side in the radial direction and the axial center of the rotor in the radial direction may be 50 mm or more. Specifically, a distance DM between, for example, the surface radially inside the magnet unit  42  (specifically, the first and second magnets  91  and  92 ) illustrated in  FIG. 4  and the axial center of the rotor  40  in the radial direction may be 50 mm or more.       

     As a rotating electric machine having a slotless structure, a small-scale one whose output is used for a model of several tens of watts to several hundreds of watts is known. In addition, the discloser of the present application does not grasp a case where the slotless structure is adopted in a large industrial rotating electric machine which generally exceeds 10 kW. The discloser of the present application examined the reason. 
     In recent years, mainstream rotating electric machines are roughly classified into the following four types. These rotating electric machines are a brushed motor, a basket type induction motor, a permanent magnet type synchronous motor, and a reluctance motor. 
     An exciting current is supplied to the brushed motor via the brush. Therefore, in the case of a brushed motor of a large machine, the brush becomes large and the maintenance becomes complicated. As a result, with the remarkable development of semiconductor technology, it has been replaced by brushless motors such as induction motors. Meanwhile, in the world of small motors, coreless motors are also supplied to the world because of their low inertia and economic advantages. 
     In the basket type induction motor, the principle is that torque is generated by receiving the magnetic field generated by the stator winding on the primary side by the iron core of the rotor on the secondary side and intensively passing an induced current through the basket type conductor to form a reaction magnetic field. Therefore, from the viewpoint of small size and high efficiency of equipment, it is not always a good idea to eliminate the iron core on both the stator side and the rotor side. 
     The reluctance motor is a motor that literally utilizes the reluctance change of the iron core, and it is not desirable to eliminate the iron core in principle. 
     In recent years. IPMs (that is, embedded magnet type rotors) have become the mainstream of permanent magnet type synchronous motors, and in large machines in particular, IPMs are often used unless there are special circumstances. 
     The IPM has a characteristic of having both magnet torque and reluctance torque, and is operated while the ratio of these torques is adjusted in a timely manner by inverter control. Therefore, the IPM is a small motor with excellent controllability. 
     According to the analysis of the discloser of the present application, the torque on the rotor surface that generates magnet torque and reluctance torque is drawn with the horizontal axis of the distance DM in the radial direction between the surface of the magnet unit on the armature side in the radial direction and the axial center of the rotor, that is, the radius of the stator core of a general inner rotor, as illustrated in  FIG. 43 . 
     The potential of the magnet torque is determined by the magnetic field strength generated by the permanent magnet as indicated in the following equation (eq1), whereas the potential of the reluctance torque is determined by the inductance, especially, the magnitude of the q-axis inductance as indicated in the following equation (eq2). 
       Magnet torque= k·ψ·Iq   (eq1)
 
       Reluctance torque= k ·( Lq−Ld )· Iq·Id   (eq2)
 
     Here, the magnetic field strength of the permanent magnet and the magnitude of the inductance of the winding were compared by the DM. The magnetic field strength generated by the permanent magnet, that is, the amount of magnetic flux ψ, is proportional to the total area of the permanent magnet on the surface facing the stator. If a cylindrical rotor is used, it will be the surface area of the cylinder. Strictly speaking, since there are N pole and S pole, it is proportional to the occupied area of half of the cylindrical surface. The surface area of a cylinder is proportional to the radius of the cylinder and the length of the cylinder. That is, if the cylinder length is constant, it is proportional to the radius of the cylinder. 
     On the other hand, an inductance Lq of the winding depends on the shape of the iron core but has low sensitivity, and is rather proportional to the square of the number of turns of the stator winding, and therefore the number of turns is highly dependent. Moreover, when μ is the magnetic permeability of the magnetic circuit, N is the number of turns, S is the cross-sectional area of the magnetic circuit, and δ is the effective length of the magnetic circuit, the inductanceL=μ·N{circumflex over ( )}*S/δ. Since the number of turns of the winding depends on the size of the winding space, in the case of a cylindrical motor, it depends on the winding space of the stator, that is, the slot area. As illustrated in  FIG. 44 , since the slot shape is substantially quadrangular, the slot area is proportional to the product a*b of a length dimension a in the circumferential direction and a length dimension b in the radial direction. 
     The circumferential length dimension of the slot is proportional to the diameter of the cylinder because it increases as the diameter of the cylinder increases. The radial length dimension of the slot is exactly proportional to the diameter of the cylinder. That is, the slot area is proportional to the square of the diameter of the cylinder. Further, as can be seen from the above equation (eq2), since the reluctance torque is proportional to the square of the stator current, the performance of the rotating electric machine is determined by how large the current can flow, and that performance depends on the slot area of the stator. From the above, if the length of the cylinder is constant, the reluctance torque is proportional to the square of the diameter of the cylinder. Based on this,  FIG. 43  is a diagram plotting the relation between the magnet torque and the reluctance torque and DM. 
     As illustrated in  FIG. 43 , the magnet torque increases linearly with respect to the DM, and the reluctance torque increases quadratically with respect to the DM. It can be seen that the magnet torque is dominant when the DM is relatively small, and the reluctance torque is dominant as the stator core radius increases. The discloser of the present application has concluded that the intersection of the magnet torque and the reluctance torque in  FIG. 43  is approximately in the vicinity of the stator core radius=50 mm under a predetermined condition. That is, it is difficult to eliminate the iron core in a 10 kW class motor whose stator core radius sufficiently exceeds 50 mm because it is the current mainstream to utilize reluctance torque, and it is presumed that this is one of the reasons why the slotless structure is not adopted in the field of large machines. 
     In the case of a rotating electric machine in which an iron core is used as a stator, magnetic saturation of the iron core is always an issue. In particular, in a radial gap type rotating electric machine, the vertical cross-sectional shape of the rotating shaft is a fan shape per magnetic pole, the magnetic path width becomes narrower toward the inner peripheral side of the equipment, and the inner circumference side dimension of the teeth portion forming the slot determines the performance limit of the rotating electric machine. No matter how high-performance permanent magnets are used, if magnetic saturation occurs in this portion, the performance of the permanent magnets cannot be fully brought out. In order not to generate magnetic saturation in this portion, the inner circumference must be designed to be large, resulting in an increase in the size of the equipment. 
     For example, in a distributed winding rotating electric machine, in the case of a three-phase winding, the magnetic flux is shared by three to six teeth per magnetic pole, but the magnetic flux tends to concentrate on the teeth in the front in the circumferential direction, and thus the magnetic flux does not flow evenly to the three to six teeth. In this case, while the magnetic flux flows intensively through some (for example, one or two) teeth, the teeth that are magnetically saturated with the rotation of the rotor also move in the circumferential direction. This also causes slot ripple. 
     From the above, in a rotating electric machine having a slotless structure in which the DM is 50 mm or more, it is desired to abolish the teeth in order to eliminate magnetic saturation. However, when the teeth are removed, the magnetic resistance of the magnetic circuit in the rotor and the stator increases, and the torque of the rotating electric machine decreases. The reason for the increase in magnetic resistance is, for example, that the air gap between the rotor and the stator becomes large. Therefore, in the above-mentioned rotating electric machine having a slotless structure in which the DM is 50 mm or more, there is room for improvement in increasing the torque. Consequently, there is a great merit of applying the above-mentioned configuration capable of increasing the torque to the above-mentioned rotating electric machine having a slotless structure in which the DM is 50 mm or more. 
     Moreover, with regard to not only the rotating electric machine having an outer rotor structure but also the rotating electric machine having an inner rotor structure may have a distance DM of 50 mm or more in the radial direction between the surface of the magnet unit on the armature side in the radial direction and the axial center of the rotor.
         In the stator winding  51  of the rotating electric machine  10 , the straight section  83  of the conductor wire  82  may be provided in a single layer in the radial direction. Further, when the straight section  83  is arranged in a plurality of layers inside and outside the radial direction, the number of layers may be arbitrary, and may be provided in three layers, four layers, five layers, six layers, and the like.   For example, in the configuration of  FIG. 2 , the rotating shaft  11  is provided so as to protrude to both one end side and the other end side of the rotating electric machine  10  in the axial direction, but this may be changed, and the rotating shaft  11  may be configured to protrude only to one end side. In this case, the rotating shaft  11  may be provided so as to extend outward in the axial direction, with a portion that is cantilevered and supported by the bearing unit  20  as an end. In this configuration, since the rotating shaft  11  does not protrude inside the inverter unit  60 , the internal space of the inverter unit  60 , specifically the internal space of the tubular section  71 , can be used more widely.   In the rotating electric machine  10  having the above configuration, in the bearings  21  and  22 , non-conductive grease is used, but this may be changed, and conductive grease may be used in the bearings  21  and  22 . For example, conductive grease containing metal particles, carbon particles, or the like is used.   As a configuration for rotatably supporting the rotating shaft  11 , bearings may be provided at two locations on one end side and the other end side in the axial direction of the rotor  40 . In this case, in the configuration of  FIG. 1 , it is preferable that bearings are provided at two locations on one end side and the other end side with the inverter unit  60  therebetween.   In the rotating electric machine  10  having the above configuration, in the rotor  40 , the intermediate section  45  of the magnet holder  41  has the inner shoulder section  49   a  and the annular outer shoulder section  49   b . However, these shoulder sections  49   a  and  49   b  may be eliminated to have a flat surface.   In the rotating electric machine  10  having the above configuration, the conductor  82   a  is configured as an aggregate of a plurality of wires  86  in the conductor wire  82  of the stator winding  51 , but this may be changed, and a square conductor having a rectangular cross section may be used as the conductor wire  82 . Further, as the conductor wire  82 , a round conductor having a circular cross section or an elliptical cross section may be used.   in the rotating electric machine  10  having the above configuration, the inverter unit  60  is provided radially inside the stator  50 , but instead of this, the inverter unit  60  may not be provided radially inside the stator  50 . In this case, it is possible to set an internal region inside the stator  50  in the radial direction as a space. Further, it is possible to arrange parts different from the inverter unit  60  in the internal region.   The rotating electric machine  10  having the above configuration may not include the housing  30 . In this case, for example, the rotor  40 , the stator  50 , and the like may be held in a part of the wheel or other vehicle parts.       

     (Embodiment as an In-Wheel Motor for a Vehicle) 
     Next, an embodiment in which the rotating electric machine is provided integrally with the wheels of a vehicle as an in-wheel motor will be described.  FIG. 45  is a perspective view illustrating a wheel  400  having an in-wheel motor structure and its peripheral structure,  FIG. 46  is a vertical cross-sectional view of the wheel  400  and its peripheral structure, and  FIG. 47  is an exploded perspective view of the wheel  400 . Each of these figures is a perspective view of the wheel  400  as viewed from the inside of the vehicle. Moreover, in the vehicle, the in-wheel motor structure of the present embodiment can be applied in various forms. For example, in a vehicle having two wheels in front of and behind the vehicle, it is possible to apply the in-wheel motor structure of the present embodiment to the two wheels on the front side of the vehicle, the two wheels on the rear side of the vehicle, or the four wheels on the front and rear of the vehicle. However, it can also be applied to a vehicle in which at least one of the front and rear of the vehicle has one wheel. Moreover, the in-wheel motor is an application example as a vehicle drive unit. 
     As illustrated in  FIGS. 45 to 47 , the wheel  400  includes, for example, a tire  401  which is a well-known pneumatic tire, a wheel  402  fixed to the inner peripheral side of the tire  401 , and a rotating electric machine  500  fixed to the inner peripheral side of the wheel  402 . The rotating electric machine  500  has a fixing section which is a section including a stator and a rotation section which is a section including a rotor. The fixing section is fixed to the vehicle body side, and the rotation section is fixed to the wheel  402 . The rotation of the rotation section causes the tire  401  and the wheel  402  to rotate. Moreover, the detailed configuration of the rotating electric machine  500  including the fixing section and the rotation section will be described below. 
     Further, as peripheral devices, a suspension device that holds the wheel  400  with respect to a vehicle body (not illustrated), a steering device that changes the direction of the wheels  400 , and a braking device that brakes the wheel  400  are attached to the wheel  400 . 
     The suspension device is an independent suspension type suspension, and any type such as a trailing arm type, a strut type, a wishbone type, and a multi-link type can be applied. In the present embodiment, as the suspension device, a lower arm  411  is provided so as to extend toward the center side of the vehicle body, and a suspension arm  412  and a spring  413  are provided so as to extend in the up-down direction. The suspension arm  412  may be configured as, for example, a shock absorber. However, detailed illustration is omitted. The lower arm  411  and the suspension arm  412  are respectively connected to the vehicle body side and to a disk-shaped base plate  405  fixed to the fixing section of the rotating electric machine  500 . As illustrated in  FIG. 46 , the lower arm  411  and the suspension arm  412  are supported on the rotating electric machine S 0  side (base plate  405  side) by support shafts  414  and  415  in a coaxial state with each other. 
     Further, as the steering device, for example, a rack &amp; pinion type structure, a ball &amp; nut type structure, a hydraulic power steering system, and an electric power steering system can be applied. In the present embodiment, a rack device  421  and a tie rod  422  are provided as steering devices, and the rack device  421  is connected to the base plate  405  on the rotating electric machine  500  side via the tie rod  422 . In this case, when the rack device  421  operates with the rotation of a steering shaft (not illustrated), the tie rod  422  moves in the right-left direction of the vehicle. As a result, the wheel  400  rotates about the support shafts  414  and  415  of the lower arm  411  and the suspension arm  412 , and the wheel direction is changed. 
     As the braking device, it is preferable to apply a disc brake or a drum brake. In the present embodiment, as the braking device, a disc rotor  431  fixed to a rotating shaft  501  of the rotating electric machine  500  and a brake caliper  432  fixed to the base plate  405  on the rotating electric machine  500  side are provided. In the brake caliper  432 , brake pads are operated by oil pressure or the like, and when the brake pads are pressed against the disc rotor  431 , a braking force due to friction is generated and the rotation of the wheel  400  is stopped. 
     Further, the wheel  400  is attached with a housing duct  440  that houses an electric wiring H 1  extending from the rotating electric machine  500  and a cooling pipe H 2 . The housing duct  440  extends from the end of the rotating electric machine  500  on the fixing section side along the end face of the rotating electric machine  500  and is provided so as to avoid the suspension arm  412 , and is fixed to the suspension arm  412  in that state. As a result, the connection portion of the housing duct  440  in the suspension arm  412  has a fixed positional relation with the base plate  405 . Therefore, it is possible to suppress the stress caused by the vibration of the vehicle in the electric wiring H 1  and the cooling pipe H 2 . Moreover, the electrical wiring H 1  is connected to an in-vehicle power supply unit and an in-vehicle ECU (not illustrated), and the cooling pipe H 2  is connected to a radiator (not illustrated). 
     Next, the configuration of the rotating electric machine  500  used as an in-wheel motor will be described in detail. In the present embodiment, an example in which the rotating electric machine  500  is applied to an in-wheel motor is indicated. The rotating electric machine  500  has excellent operating efficiency and output as compared with the motor of a vehicle drive unit having a speed reducer as in the prior art. That is, if the rotating electric machine  500  is adopted in an application in which a practical price can be achieved by reducing the cost as compared with the prior art, it may be used as a motor for applications other than the vehicle drive unit. Even in such a case, it exhibits excellent performance as when applied to an in-wheel motor. Moreover, the operating efficiency refers to an index used during a test in a driving mode that derives the fuel efficiency of a vehicle. 
     The outline of the rotating electric machine  500  is illustrated in  FIGS. 48 to 51 .  FIG. 48  is a side view of the rotating electric machine  500  as viewed from the protruding side (inside the vehicle) of the rotating shaft  501 ,  FIG. 49  is a vertical cross-sectional view of the rotating electric machine  500  (cross-sectional view taken along a line  49 - 49  of  FIG. 48 ),  FIG. 50  is a cross-sectional view of the rotating electric machine  500  (a cross-sectional view taken along a line  50 - 50  of  FIG. 49 ), and  FIG. 51  is an exploded cross-sectional view of the components of the rotating electric machine  500 . In the following description, in  FIG. 51 , the direction in which the rotating shaft  501  extends outward of the vehicle body is the axial direction, the direction extending radially from the rotating shaft  501  is the radial direction, and in  FIG. 48 , both of the two directions extending in a circumferential shape from any point other than the center of rotation of the rotating portion on the center line drawn to form a cross section  49  passing through the center of the rotating shaft  501 , in other words, the center of rotation of the rotating portion are defined as the circumferential directions. In other words, the circumferential direction may be either a clockwise direction starting from an arbitrary point on the cross section  49  or a counterclockwise direction. Further, in the vehicle-mounted state, the right side is the outside of the vehicle and the left side is the inside of the vehicle in  FIG. 49 . In other words, in the vehicle-mounted state, a rotor  510  which will be described below is arranged outward of the vehicle body with respect to a rotor cover  670 . 
     The rotating electric machine  500  according to the present embodiment is an outer rotor type surface magnet type rotating electric machine. The rotating electric machine  500  includes, roughly, a rotor  510 , a stator  520 , an inverter unit  530 , a bearing  560 , and the rotor cover  670 . Each of these members is arranged coaxially with the rotating shaft  501  integrally provided on the rotor  510  and is assembled in the axial direction in a predetermined order to form the rotating electric machine  500 . 
     In the rotating electric machine  500 , the rotor  510  and the stator  520  each have a cylindrical shape, and are arranged so as to face each other with an air gap therebetween. As the rotor  510  rotates integrally with the rotating shaft  501 , the rotor  510  rotates on the radial outside of the stator  520 . The rotor  510  corresponds to a “field magnet” and the stator  520  corresponds to an “armature”. 
     The rotor  510  has a substantially cylindrical rotor carrier  511  and an annular magnet unit  512  fixed to the rotor carrier  511 . The rotating shaft  501  is fixed to the rotor carrier  511 . 
     The rotor carrier  511  has a cylindrical section  513 . A magnet unit  512  is attached to the inner peripheral surface of the cylindrical section  513 . That is, the magnet unit  512  is provided in a state of being surrounded by the cylindrical section  513  of the rotor carrier  511  from the outside in the radial direction. Further, the cylindrical section  513  has a first end and a second end facing each other in the axial direction thereof. The first end is located in the direction outside the vehicle body, and the second end is located in the direction in which the base plate  405  is present. In the rotor carrier  511 , an end plate  514  is continuously provided at the first end of the cylindrical section  513 . That is, the cylindrical section  513  and the end plate  514  have an integral structure. The second end of the cylindrical section  513  is open. The rotor carrier  511  is formed of, for example, a steel plate cold commercial having sufficient mechanical strength (SPCC or SPHC thicker than SPCC), forging steel, carbon fiber reinforced plastic (CFRP), or the like. 
     The axial length of the rotating shaft  501  is longer than the axial dimension of the rotor carrier  511 . In other words, the rotating shaft  501  protrudes toward the open end side (inward direction of the vehicle) of the rotor carrier  511 , and the above-mentioned brake device or the like is attached to the protruding side end. 
     A through hole  514   a  is formed in the central portion of the end plate  514  of the rotor carrier  511 . The rotating shaft  501  is fixed to the rotor carrier  511  in a state of being inserted into the through hole  514   a  of the end plate  514 . The rotating shaft  501  has a flange  502  extending in a direction intersecting with (orthogonal to) the axial direction at a portion where the rotor carrier  511  is fixed, and in a state where the flange and the surface of the end plate  514  outside the vehicle are surface-joined, the rotating shaft  501  is fixed to the rotor carrier  511 . Moreover, in the wheel  400 , the wheel  402  is fixed with the use of a fastener such as a bolt erected from the flange  502  of the rotating shaft  501  toward the outside of the vehicle. 
     Further, the magnet unit  512  is composed of a plurality of permanent magnets arranged in such a manner that the polarities alternate along the circumferential direction of the rotor  510 . As a result, the magnet unit  512  has a plurality of magnetic poles in the circumferential direction. The permanent magnet is fixed to the rotor carrier  511  by, for example, adhesion. The magnet unit  512  has the configuration described as the magnet unit  42  with reference to  FIGS. 8 and 9  of the first embodiment, and as a permanent magnet, has an intrinsic coercive force of 400 [kA/m] or more and is composed with a sintered neodymium magnet having a residual magnetic flux Br of 1.0 [T] or more. 
     Similarly to the magnet unit  42  in  FIG. 9  or the like, the magnet unit  512  has a first magnet  91  and a second magnet  92 , which are respectively polar anisotropic magnets and have different polarities from each other. As described with reference to  FIGS. 8 and 9 , each of the magnets  91  and  92  has a different direction of the axis of easy magnetization on the d-axis side (the portion located near the d-axis) and the q-axis side (the portion located near the q-axis), and on the d-axis side, the direction of the axis of easy magnetization is close to the direction parallel to the d-axis, and on the q-axis side, the direction of the easy magnetization axis is close to the direction orthogonal to the q-axis. In addition, an arc-shaped magnet magnetic path is formed by the orientation according to the direction of the axis of easy magnetization. Moreover, in each of the magnets  91  and  92 , the axis of easy magnetization may be oriented parallel to the d-axis on the d-axis side, and the axis of easy magnetization may be oriented orthogonal to the q-axis on the q-axis side. In short, the magnet unit  512  is configured, in which the orientation was made in such a manner that the direction of the axis of easy magnetization is parallel to the d-axis on the d-axis side which is the center of the magnetic pole as compared with the q-axis side which is the magnetic pole boundary. 
     According to the magnets  91  and  92 , the magnet magnetic flux on the d-axis is strengthened and the change in magnetic flux near the q-axis is suppressed. As a result, the magnets  91  and  92  in which the change in surface magnetic flux from the q-axis to the d-axis at each magnetic pole is gentle can be preferably achieved. As the magnet unit  512 , the configurations of the magnet unit  42  illustrated in  FIGS. 22 and 23  and the configuration of the magnet unit  42  illustrated in  FIG. 30  can also be used. 
     Moreover, the magnet unit  512  may have a rotor core (back yoke) formed by laminating a plurality of electromagnetic steel sheets in the axial direction on the side of the cylindrical section  513  of the rotor carrier  511 , that is, on the outer peripheral surface side. That is, it is also possible to provide a rotor core on the radial inside of the cylindrical section  513  of the rotor carrier  511  and to provide the permanent magnets (magnets  91  and  92 ) on the radial inside of the rotor core. 
     As illustrated in  FIG. 47 , the cylindrical section  513  of the rotor carrier  511  is formed with a recess  513   a  in a direction extending in the axial direction at predetermined intervals in the circumferential direction. The recess  513   a  is formed by, for example, press working, and as illustrated in  FIG. 52 , a protrusion  513   b  is formed on the inner peripheral surface side of the cylindrical section  513  at a position on the back side of the recess  513   a . On the other hand, on the outer peripheral surface side of the magnet unit  512 , a recess  512   a  is formed in accordance with the protrusion  513   b  of the cylindrical section  513 , and the protrusion  513   b  of the cylindrical section  513  enters the recess  512   a , whereby the displacement in the circumferential direction of the magnet unit  512  is suppressed. That is, the protrusion  513   b  on the rotor carrier  511  side functions as the rotation stop section of the magnet unit  512 . Moreover, the method for forming the protrusion  513   b  may be any method other than press working. 
     In  FIG. 52 , the direction of the magnet magnetic path in the magnet unit  512  is indicated by an arrow. The magnet magnetic path extends in an arc shape so as to straddle the q-axis which is the magnetic pole boundary, and is in a direction parallel to or close to parallel to the d-axis on the d-axis which is the center of the magnetic pole. The magnet unit  512  is formed with a recess  512   b  at positions corresponding to the q-axis on the inner peripheral surface side thereof. In this case, in the magnet unit  512 , the magnet magnetic path length differs between the side closer to the stator  520  (lower side in the figure) and the side farther from the stator  520  (upper side in the figure), the magnet magnetic path length is shorter on the side closer to the stator  520 , and the recess  512   b  is formed at a position where the magnet magnetic path length is the shortest. That is, in consideration of the fact that it is difficult for the magnet unit  512  to generate a sufficient magnet magnetic flux in a place where the magnet magnetic path length is short, the magnet is omitted in a place where the magnet magnetic flux is weak. 
     Here, an effective magnetic flux density Bd of the magnet becomes higher as the length of the magnetic circuit passing through the inside of the magnet becomes longer. Further, a permeance coefficient Pc and the effective magnetic flux density Bd of the magnet are in a relation that the higher one is, the higher the other is. According to the configuration of  FIG. 52 , the amount of magnets can be reduced while suppressing a decrease in the permeance coefficient Pc which is an index of the height of the effective magnetic flux density Bd of the magnet. Moreover, in a B-H coordinates, the intersection of the permeance straight line and the demagnetization curve according to the shape of the magnet is the operating point, and the magnetic flux density at the operating point is the effective magnetic flux density Bd of the magnet. The rotating electric machine  500  of the present embodiment has a configuration in which the amount of iron in the stator  520  is reduced, and in such a configuration, a method for setting a magnetic circuit straddling the q-axis is extremely effective. 
     Further, the recess  512   b  of the magnet unit  512  can be used as an air passage extending in the axial direction. Therefore, it is also possible to improve the air cooling performance. 
     Next, the configuration of the stator  520  will be described. The stator  520  has a stator winding  521  and a stator core  522 .  FIG. 53  is a perspective view illustrating the stator winding  521  and the stator core  522  in an exploded manner. 
     The stator winding  521  is composed of a plurality of phase windings formed by winding in a substantially tubular shape (annular shape), and the stator core  522  as a base member is assembled radially inside the stator winding  521 . In the present embodiment, a U-phase, V-phase, and W-phase windings are used, and the stator winding  521  is thereby configured as a three-phase winding. Each phase winding is composed of two inner and outer layers of conductors  523  in the radial direction. Similarly to the stator  50  described above, the stator  520  is characterized by having a slotless structure and a flat conductor structure of the stator winding  521 , and has the same configuration as or a configuration similar to that of the stator  50  illustrated in  FIGS. 8 to 16 . 
     The configuration of the stator core  522  will be described. Similarly to the stator core  52  described above, the stator core  522  has a cylindrical shape in which a plurality of electromagnetic steel sheets are laminated in the axial direction and has a predetermined thickness in the radial direction, and the stator winding  521  is assembled on the radially outside that is the rotor  510  side in the stator core  522 . The outer peripheral surface of the stator core  522  has a curved shape without unevenness, and in a state where the stator winding  521  is assembled, the conductor  523  constituting the stator winding  521  are arranged side by side in the circumferential direction on the outer peripheral surface of the stator core  522 . The stator core  522  functions as a back core. 
     The stator  520  may use any of the following A to C. 
     A In the stator  520 , an interconductor member is provided between each conductor  523  in the circumferential direction, and as the interconductor member, a magnetic material having a relation of Wt*Bs≤Wm*Br is used when the width dimension of the interconductor member in the circumferential direction at one magnetic pole is Wt, the saturation magnetic flux density of the interconductor member is Bs, the width dimension in the circumferential direction of the magnet unit  512  at one magnetic pole is Wm, and the residual magnetic flux density of the magnet unit  512  is Br. 
     B In the stator  520 , an interconductor member is provided between each conductor  523  in the circumferential direction, and a non-magnetic material is used as the interconductor member. 
     C The stator  520  has a configuration in which no interconductor member is provided between each conductor  523  in the circumferential direction. 
     According to such configuration of the stator  520 , the inductance can be reduced as compared with a rotating electric machine having a general teeth structure in which teeth (iron core) for establishing a magnetic path is provided between respective conductor sections as a stator winding. Specifically, the inductance can be reduced to 1/10 or less. In this case, since the impedance decreases as the inductance decreases, the output power with respect to the input power of the rotating electric machine  500  can be increased, which thus can contribute to the increase in torque. Further, it is possible to provide a rotating electric machine with a higher output than a rotating electric machine using an embedded magnet type rotor that outputs torque utilizing the voltage of the impedance component (in other words, utilizing reluctance torque). 
     In the present embodiment, the stator winding  521  is integrally molded together with the stator core  522  by a molding material (insulating member) made of resin or the like, and the molding material is interposed between the respective conductors  523  arranged in the circumferential direction. According to such a configuration, the stator  520  of the present embodiment corresponds to the configuration of B among the above A to C. Further, the respective conductors  523  adjacent to each other in the circumferential direction are arranged in such a manner that the end faces in the circumferential direction are in contact with each other or are arranged close to each other at a minute interval, and the configuration of the above C may be adopted in view of this configuration. Moreover, in a case where the configuration A is adopted, it is preferable that a protrusion is provided on the outer peripheral surface of the stator core  522 , in accordance with the direction of the conductor  523  in the axial direction, that is, in accordance with the skew angle of the stator winding  521  having a skew structure, for example. 
     Next, the configuration of the stator winding  521  will be described with reference to  FIG. 54 .  FIG. 54  is a front view illustrating the stator winding  521  developed in a plane,  FIG. 54A  illustrates each conductor  523  located in the outer layer in the radial direction, and  FIG. 54B  illustrates each conductor  523  located in the inner layer in the radial direction. 
     The stator winding  521  is formed being wound in an annular shape by distributed winding. In the stator winding  521 , the conductor material is wound around the inner and outer two layers in the radial direction, and the respective conductors  523  on the inner layer side and the outer layer side are skewed in different directions (See  FIGS. 54A and 54B ). The respective conductors  523  are insulated from each other. It is preferable that the conductor  523  is configured as an aggregate of a plurality of wires  86  (see  FIG. 13 ). Further, for example, two conductors  523  having the same phase and the same energizing direction are provided side by side in the circumferential direction. In the stator winding  521 , one conductor section having the same phase is composed of each conductor  523  having two layers in the radial direction and two conductors in the circumferential direction (that is, a total of four conductors), and the conductor section is provided one per magnetic pole. 
     It is desirable that the radial thickness dimension of the conductor section be smaller than the circumferential width dimension for one phase in one magnetic pole, whereby the stator winding  521  has a flat conductor structure. Specifically, for example, in the stator winding  521 , one conductor section having the same phase is preferably composed of each conductor  523  having two layers in the radial direction and four conductors in the circumferential direction (that is, a total of eight conductors). Alternatively, in the conductor cross section of the stator winding  521  illustrated in  FIG. 50 , the circumferential width dimension is preferably larger than the radial thickness dimension. As the stator winding  521 , the stator winding  51  illustrated in  FIG. 12  can also be used. However, in this case, it is necessary to secure a space in the rotor carrier  511  for housing the coil end of the stator winding. 
     In the stator winding  521 , the conductors  523  are arranged side by side in the circumferential direction, being tilted at a predetermined angle on a coil side  525  that overlaps the stator core  522  inside and outside the radial direction, and coil ends  526  on both sides, which are axially outer than the stator core  522 , are inverted (folded back) inward in the axial direction to form a continuous connection.  FIG. 54A  illustrates a range of the coil side  525  and a range of the coil end  526 , respectively. The inner layer side conductor  523  and the outer layer side conductor  523  are connected to each other at the coil end  526 , and as a result, each time the conductor  523  is inverted in the axial direction at the coil end  526  (each time it is folded back), the conductor  523  is switched alternately between the inner layer side and the outer layer side. In short, the stator winding  521  has a configuration in which the inner and outer layers are switched in accordance with the reversal of the direction of the current in the respective conductors  523  that are continuous in the circumferential direction. 
     Further, in the stator winding  521 , two types of skews are applied in which the skew angles are different between the end regions that are both ends in the axial direction and the central region sandwiched between the end regions. That is, as illustrated in  FIG. 55 , in the conductor  523 , a skew angle θs 1  in the central region and a skew angle θs 2  in the end region are different, and the skew angle θs 1  is smaller than the skew angle θs 2 . In the axial direction, the end region is defined to include the coil side  525 . The skew angle θs 1  and the skew angle θs 2  are tilt angles at which each conductor  523  is tilted with respect to the axial direction. The skew angle θs 1  in the central region may be set in an angle range appropriate for reducing the harmonic component of the magnetic flux generated by the energization of the stator winding  521 . 
     The skew angle of each conductor  523  in the stator winding  521  is made different between the central region and the end region, and the skew angle θs 1  in the central region is made smaller than the skew angle θs 2  in the end region, whereby the winding coefficient of the stator winding  521  can be increased while reducing the coil end  526 . In other words, the length of the coil end  526 , that is, the conductor length of the portion protruding in the axial direction from the stator core  522 , can be shortened while ensuring a desired winding coefficient. As a result, it is possible to improve the torque while downsizing the rotating electric machine  500 . 
     Here, an appropriate range as the skew angle θs 1  in the central region will be described. When X conductors  523  are arranged in one magnetic pole in the stator winding  521 , it is conceivable that the Xth order harmonic component is generated by energization of the stator winding  521 . When the number of phases is S and the logarithm is m, X=2*S*m. The discloser of the present application focused on the fact that the Xth order harmonic component is a component that constitutes a composite wave of the X−1th order harmonic component and the X+1th order harmonic component, and therefore at least one of the X−1th order harmonic component or the X+1th order harmonic component is reduced, whereby the Xth order harmonic component can be reduced. Based on this focus, the discloser of the present application found that the skew angle θs 1  is set within the angle range of “360°/(X+1) to 360°/(X−1)” in terms of the electrical angle, whereby the Xth harmonic component can be reduced. 
     For example, when S=3 and m=2, the skew angle θs 1  is set within the angle range of “360°/13 to 360°/11” in order to reduce the harmonic component of the X=12th order. That is, the skew angle θs 1  is preferably set at an angle within the range of 27.7° to 32.7°. 
     By setting the skew angle θs 1  in the central region as described above, the magnet magnetic fluxes alternated at N and S poles can be positively interlinked in the central region, and the winding coefficient of the stator winding  521  can be increased. 
     The skew angle θs 2  in the end region is larger than the skew angle θs 1  in the central region described above. In this case, the angle range of the skew angle θs 2  is “θs 1 &lt;θs 2 &lt;90°”. 
     Further, in the stator winding  521 , the inner layer side conductor  523  and the outer layer side conductor  523  are preferably connected by welding or adhesion between the ends of the respective conductors  523 , or are preferably connected by bending. In the stator winding  521 , the end of each phase winding is electrically connected to a power converter (inverter) via a bus bar or the like on one side (that is, one end side in the axial direction) of each coil end  526  on both sides in the axial direction. Therefore, here, the configuration in which the respective conductors are connected to each other at the coil end  526  will be described while distinguishing between the coil end  526  on the bus bar connection side and the coil end  526  on the opposite side. 
     The first configuration is such that each conductor  523  is connected at the coil end  526  on the bus bar connection side by welding, and each conductor  523  is connected at the coil end  526  on the opposite side by means other than welding. As the means other than welding, for example, a connection by bending a conductor material is conceivable. At the coil end  526  on the bus bar connection side, it is assumed that the bus bar is connected to the end of each phase winding by welding. Therefore, by connecting each conductor  523  at the same coil end  526  by welding, each welded portion can be handled in a series of processes, and work efficiency can be improved. 
     The second configuration is such that each conductor  523  is connected at the coil end  526  on the bus bar connection side by means other than welding, and each conductor  523  is connected at the coil end  526  on the opposite side by welding. In this case, if each conductor  523  is connected at the coil end  526  on the bus bar connection side by welding, the separation distance between the bus bar and the coil end  526  needs to be sufficient to avoid contact between the welded portion and the bus bar. However, with this configuration, the separation distance between the bus bar and the coil end  526  can be reduced. As a result, the regulation regarding the length of the stator winding  521  in the axial direction or the bus bar can be relaxed. 
     As the third configuration, each conductor  523  is connected at the coil ends  526  on both sides in the axial direction by welding. In this case, all of the conductor materials prepared before welding may have a short wire length, and the work efficiency can be improved by reducing the bending process. 
     As the fourth configuration, each conductor  523  is connected at the coil ends  526  on both sides in the axial direction by means other than welding. In this case, the portion of the stator winding  521  to be welded can be reduced as much as possible, and the concern that insulation peeling may occur in the welding process can be reduced. 
     Further, in the process of manufacturing the annular stator winding  521 , it is preferable to manufacture the strip-shaped windings arranged in a plane shape, and then to form the strip-shaped windings in an annular shape. In this case, it is preferable to weld the conductors at the coil end  526  in a state where the winding is a flat strip. When forming a flat strip-shaped winding in an annular shape, it is preferable to use a cylindrical jig having the same diameter as that of the stator core  522  and wind the strip-shaped winding around the cylindrical jig to form the strip-shaped winding in an annular shape. Alternatively, the strip-shaped winding may be wound directly around the stator core  522 . 
     Moreover, the configuration of the stator winding  521  can also be changed as follows. 
     For example, in the stator winding  521  illustrated in  FIGS. 54A and 54B , the skew angles of the central region and the end region may be the same. 
     Further, in the stator windings  521  illustrated in  FIGS. 54A and 54B , the ends of the in-phase conductors  523  adjacent to each other in the circumferential direction may be connected by a crossover section extending in a direction orthogonal to the axial direction. 
     The number of layers of the stator winding  521  may be 2*n layers (n is a natural number), and the stator winding  521  may have 4 layers, 6 layers, or the like in addition to the 2 layers. 
     Next, the inverter unit  530 , which is a power conversion unit, will be described. Here, the configuration of the inverter unit  530  will be described with reference to  FIGS. 56 and 57 , which are exploded cross-sectional views of the inverter unit  530 . Moreover, in  FIG. 57 , each member illustrated in  FIG. 56  is illustrated as two subassemblies. 
     The inverter unit  530  includes an inverter housing  531 , a plurality of electric modules  532  assembled to the inverter housing  531 , and a bus bar module  533  that electrically connects each of the electric modules  532 . 
     The inverter housing  531  has a cylindrical outer wall member  541 , an inner wall member  542  having a cylindrical outer peripheral diameter smaller than that of the outer wall member  541  and arranged radially inside the outer wall member  541 , and a boss forming member  543  fixed to one end side in the axial direction of the inner wall member  542 . Each of these members  541  to  543  is preferably made of a conductive material, for example, made of carbon fiber reinforced plastic (CFRP). The inverter housing  531  is configured by combining the outer wall member  541  and the inner wall member  542  inside and outside the radial direction, and assembling the boss forming member  543  on one end side in the axial direction of the inner wall member  542 . The assembled state is the state illustrated in  FIG. 57 . 
     The stator core  522  is fixed to the radial outside of the outer wall member  541  of the inverter housing  531 . As a result, the stator  520  and the inverter unit  530  are integrated. 
     As illustrated in  FIG. 56 , the outer wall member  541  is formed with a plurality of recesses  541   a ,  541   b , and  541   c  on the inner peripheral surface thereof, and the inner wall member  542  is formed with a plurality of recesses  542   a ,  542   b , and  542   c  on the outer peripheral surface thereof, in addition, by the outer wall member  541  and the inner wall member  542  being assembled to each other, three hollow portions  544   a .  544   b , and  544   c  are formed between them (see  FIG. 57 ). Of these, the central hollow portion  544   b  is used as a cooling water passage  545  through which cooling water as a refrigerant flows. Further, a sealing material  546  is housed in the hollow portions  544   a  and  544   c  on both sides of the hollow portion  544   b  (cooling water passage  545 ). The hollow portion  544   b  (cooling water passage  545 ) is sealed by the sealing material  546 . The cooling water passage  545  will be described in detail below. 
     Further, the boss forming member  543  is provided with a disc ring-shaped end plate  547  and a boss section  548  protruding from the end plate  547  toward the inside of the housing. The boss section  548  is provided in a hollow tubular shape. For example, as illustrated in  FIG. 51 , the boss forming member  543  is fixed to the second end, of the first end of the inner wall member  542  in the axial direction and the second end on the protruding side (that is, inside the vehicle) of the rotating shaft  501  facing the first end. Moreover, in the wheels  400  illustrated in  FIGS. 45 to 47 , the base plate  405  is fixed to the inverter housing  531  (more specifically, the end plate  547  of the boss forming member  543 ). 
     The inverter housing  531  has a configuration having a double peripheral wall in the radial direction about the shaft center, and the outer peripheral wall of the double peripheral wall is formed by the outer wall member  541  and the inner wall member  542 , and the inner peripheral wall is formed by the boss section  548 . Moreover, in the following description, the outer peripheral wall formed by the outer wall member  541  and the inner wall member  542  is also referred to as an “outer peripheral wall WA 1 ”, and the inner peripheral wall formed by the boss section  548  is also referred to as an “inner peripheral wall WA 2 ”. 
     An annular space is formed in the inverter housing  531  between the outer peripheral wall WA 1  and the inner peripheral wall WA 2 , and a plurality of electric modules  532  are arranged side by side in the circumferential direction in the annular space. The electric module  532  is fixed to the inner peripheral surface of the inner wall member  542  by adhesion, screw tightening, or the like. In the present embodiment, the inverter housing  531  corresponds to a “housing member” and the electric module  532  corresponds to an “electric component”. 
     A bearing  560  is housed inside the inner peripheral wall WA 2  (boss section  548 ), and the rotating shaft  501  is rotatably supported by the bearing  560 . The bearing  560  is a hub bearing that rotatably supports the wheel  400  at the center of the wheel. The bearing  560  is provided at a position overlapping with the rotor  510 , the stator  520 , and the inverter unit  530  in the axial direction. In the rotating electric machine  500  of the present embodiment, the magnet unit  512  can be made thinner in accordance with the orientation of the rotor  510 , and a slotless structure or a flat conductor structure is adopted in the stator  520 . Thus, it is possible to expand the hollow space radially inside the magnetic circuit section by reducing the radial thickness dimension of the magnetic circuit section. This makes it possible to arrange the magnetic circuit section, the inverter unit  530 , and the bearing  560  in a state of being stacked in the radial direction. The boss section  548  is a bearing holding section that holds the bearing  560  thereinside. 
     The bearing  560  is, for example, a radial ball bearing, and has a tubular inner ring  561 , an outer ring  562  having a diameter larger than that of the inner ring  561  and arranged radially outside the inner ring S 61 , and a plurality of balls  563  arranged between the inner ring  561  and the outer ring  562 . The bearing  560  is fixed to the inverter housing  531  by assembling the outer ring  562  to the boss forming member  543 , and the inner ring  561  is fixed to the rotating shaft  501 . The inner ring  561 , outer ring  562 , and ball  563  are all made of a metallic material such as carbon steel. 
     Further, the inner ring  561  of the bearing  560  has a tubular section  561   a  that houses the rotating shaft  501  and a flange  561   b  that extends in a direction intersecting with (orthogonal to) the axis direction from one end in the axial direction of the tubular section  561   a . The flange  561   b  is a portion that comes into contact with the end plate  514  of the rotor carrier  511  from the inside, and in a state where the bearing  560  is assembled to the rotating shaft  501 , the rotor carrier  511  is held in a state of being sandwiched between the flange  502  of the rotating shaft  501  and the flange  561   b  of the inner ring  561 . In this case, the flange  502  of the rotating shaft  501  and the flange  561   b  of the inner ring  561  have the same angle of intersection with respect to the axial direction (both are right angles in the present embodiment), and the rotor carrier  511  is held in a state of being sandwiched between these respective flanges  502  and  561   b.    
     According to the configuration in which the rotor carrier  511  is supported from the inside by the inner ring  561  of the bearing  560 , the angle of the rotor carrier  511  with respect to the rotating shaft  501  can be maintained at an appropriate angle, and thus the parallelism of the magnet unit  512  with respect to the rotating shaft  501  can be kept good. As a result, even if the rotor carrier  511  is expanded in the radial direction, the resistance to vibration and the like can be enhanced. 
     Next, the electric module  532  housed in the inverter housing  531  will be described. 
     The plurality of electric modules  532  are obtained by dividing electric components such as semiconductor switching elements and smoothing capacitors constituting a power converter into a plurality of individual modules. The electric module  532  includes a switch module  532 A having a semiconductor switching element that is a power element and a capacitor module  532 B having a smoothing capacitor. 
     As illustrated in  FIGS. 49 and 50 , a plurality of spacers  549  having a flat surface for attaching the electric module  532  are fixed to the inner peripheral surface of the inner wall member  542 , and the electric module  532  is attached to the spacer  549 . That is, the inner peripheral surface of the inner wall member  542  is a curved surface, whereas the mounting surface of the electric module  532  is a flat surface, and thus the spacer  549  forms a flat surface on the inner peripheral surface side of the inner wall member  542 , and the electric module  532  is fixed to the flat surface. 
     Note that the configuration in which the spacer  549  is interposed between the inner wall member  542  and the electric module  532  is not essential, and it is also possible to attach the electric module  532  directly to the inner wall member  542  by flattening the inner peripheral surface of the inner wall member  542  or by making the mounting surface of the electric module  532  curved. Further, it is also possible to fix the electric module  532  to the inverter housing  531  in a state of non-contact with the inner peripheral surface of the inner wall member  542 . For example, the electric module  532  is fixed to the end plate  547  of the boss forming member  543 . It is also possible to fix the switch module  532 A to the inner peripheral surface of the inner wall member  542  in a contact state, and to fix the capacitor module  532 B to the inner peripheral surface of the inner wall member  542  in a non-contact state. 
     Moreover, in a case where the spacer  549  is provided on the inner peripheral surface of the inner wall member  542 , the outer peripheral wall WA 1  and the spacer  549  correspond to the “tubular section”. Further, in a case where the spacer  549  is not used, the outer peripheral wall WA 1  corresponds to the “tubular section”. 
     As described above, the outer peripheral wall WA 1  of the inverter housing  531  is formed with the cooling water passage  545  through which cooling water as a refrigerant flows, and each electric module  532  is cooled by the cooling water flowing through the cooling water passage  545 . Moreover, it is also possible to use cooling oil as the refrigerant as an alternative to the cooling water. The cooling water passage  545  is provided in an annular shape along the outer peripheral wall WA 1 , and the cooling water flowing in the cooling water passage  545  flows from the upstream side to the downstream side while passing through each electric module  532 . In the present embodiment, the cooling water passage  545  is provided in an annular shape so as to overlap each electric module  532  inside and outside the radial direction and to surround these respective electric modules  532 . 
     The inner wall member  542  is provided with an inlet passage  571  for flowing the cooling water into the cooling water passage  545  and an outlet passage  572  for discharging the cooling water from the cooling water passage  545 . As described above, the plurality of electric modules  532  are fixed to the inner peripheral surface of the inner wall member  542 , and in such a configuration, the interval between the electric modules adjacent to each other in the circumferential direction is expanded in only one place, and a part of the inner wall member  542  is protruded inward in the radial direction to form a protruding section  573  in the expanded portion. In addition, the protruding section  573  is provided with the inlet passage  571  and the outlet passage  572  in a side-by-side manner along the radial direction. 
       FIG. 58  illustrates a state of arrangement of each electric module  532  in the inverter housing  531 . Note that  FIG. 58  is the same vertical cross-sectional view as  FIG. 50 . 
     As illustrated in  FIG. 58 , the respective electric modules  532  are arranged side by side in the circumferential direction with the interval between the electric modules in the circumferential direction as a first interval INT 1  or a second interval INT 2 . The second interval INT 2  is a wider interval than the first interval INT 1 . The respective intervals INT 1  and INT 2  are, for example, the distance between the center positions of two electric modules  532  adjacent to each other in the circumferential direction. In this case, the interval between the electric modules adjacent to each other in the circumferential direction without sandwiching the protruding section  573  is the first interval INT 1 , and the interval between the electric modules adjacent to each other in the circumferential direction sandwiching the protruding section  573  is the second interval INT 2 . That is, the interval between the electric modules adjacent to each other in the circumferential direction is partially widened, and the protruding section  573  is provided at, for example, the central portion of the widened interval (second interval INT 2 ). 
     The respective intervals INT 1  and INT 2  may be, for example, the distance of an are between the center positions of two electric modules  532  adjacent to each other in the circumferential direction, on the same circle centered on the rotating shaft  501 . Alternatively, the interval between the electric modules in the circumferential direction may be defined by angular distances θi 1  and θi 2  centered on the rotating shaft  501  (θi 1 &lt;θi 2 ). 
     Moreover, in the configuration illustrated in  FIG. 58 , the respective electric modules  532  arranged at the first interval INT 1  are arranged in a state of being separated from each other in the circumferential direction (non-contact state), but instead of this configuration, the respective electric modules  532  may be arranged in the circumferential direction in a state of being in contact with each other. 
     As illustrated in  FIG. 48 , the end plate  547  of the boss forming member  543  is provided with a water channel port  574  in which the passage ends of the inlet passage  571  and the outlet passage  572  are formed. A circulation path  575  for circulating cooling water is connected to the inlet passage  571  and the outlet passage  572 . The circulation path  575  is compose of a cooling water pipe. A pump  576  and a heat radiating device  577  are provided in the circulation path  575 , and the cooling water circulates through the cooling water passage  545  and the circulation path  575  as the pump  576  is driven. The pump  576  is an electric pump. The heat radiating device  577  is, for example, a radiator that releases the heat of the cooling water to the atmosphere. 
     As illustrated in  FIG. 50 , since the stator  520  is arranged on the outside of the outer peripheral wall WA 1  and the electric module  532  is arranged on the inside of the outer peripheral wall WA 1 , the heat of the stator  520  is transferred to the outer peripheral wall WA 1  from the outside, and the heat of the electric module  532  is transferred from the inside. In this case, the stator  520  and the electric module  532  can be cooled at the same time by the cooling water flowing the cooling water passage  545 , and the heat of the heat-generating component in the rotating electric machine  500  can be efficiently released. 
     Here, the electrical configuration of the power converter will be described with reference to  FIG. 59 . 
     As illustrated in  FIG. 59 , the stator winding  521  is composed of a U-phase winding, a V-phase winding, and a W-phase winding, and an inverter  600  is connected to the stator winding  521 . The inverter  600  is composed of a full bridge circuit having the same number of upper and lower arms as the number of phases, and a series connection body composed of an upper arm switch  601  and a lower arm switch  602  is provided for each phase. These respective switches  601  and  602  are turned on/off by the drive circuit  603 , and the winding of each phase is energized by the on/off. The respective switches  601  and  602  are composed of a semiconductor switching element such as a MOSFET or an IGBT. Further, in the upper and lower arms of each phase, a charge supply capacitor  604  that supplies the charge required for switching to the respective switches  601  and  602  is connected in parallel to the series connection body of the switches  601  and  602 . 
     A control device  607  includes a microcomputer composed of a CPU and various memories, and performs energization control by turning on/off the respective switches  601  and  602  on the basis of various detected information in the rotating electric machine  500  and requests for power running and power generation. The control device  607  performs on/off control of the respective switches  601  and  602  by, for example, PWM control at a predetermined switching frequency (carrier frequency) and rectangular wave control. The control device  607  may be a built-in control device built in the rotating electric machine  500 , or an external control device provided outside the rotating electric machine  500 . 
     Incidentally, in the rotating electric machine  500  of the present embodiment, the electric time constant is small because the inductance of the stator  520  is reduced, and in a situation where the electrical time constant is small, it is desirable to increase the switching frequency (carrier frequency) and increase the switching speed. In this respect, the charge supply capacitor  604  is connected in parallel to the series connection body of the switches  601  and  602  of each phase, and thus the wiring inductance becomes low, and appropriate surge countermeasures are possible even with a configuration in which the switching speed is increased. 
     The high potential side terminal of the inverter  600  is connected to the positive electrode terminal of a DC power supply  605 , and the low potential side terminal is connected to the negative electrode terminal (ground) of the DC power supply  605 . Further, a smoothing capacitor  606  is connected to the high potential side terminal and the low potential side terminal of the inverter  600 , in parallel to the DC power supply  605 . 
     The switch module  532 A has the respective switches  601  and  602  (semiconductor switching elements), the drive circuit  603  (specifically, an electric element constituting the drive circuit  603 ), and the charge supply capacitor  604 , as heat-generating components. Further, the capacitor module  532 B has the smoothing capacitor  606  as a heat-generating component. A specific configuration example of the switch module  532 A is illustrated in  FIG. 60 . 
     As illustrated in  FIG. 60 , the switch module  532 A has a module case  611  as a housing case, and the switches  601  and  602  for one phase housed in the module case  611 , the drive circuit  603 , and the charge supply capacitor  604 . The drive circuit  603  is configured as a dedicated IC or a circuit board and is provided in the switch module  532 A. 
     The module case  611  is made of an insulating material such as resin, and is fixed to the outer peripheral wall WA 1  with its side surface in contact with the inner peripheral surface of the inner wall member  542  of the inverter unit  530 . The module case  611  is filled with a molding material such as resin. In the module case  611 , the switches  601  and  602  and the drive circuit  603 , and the switches  601  and  602  and the capacitor  604  are electrically connected by a wiring  612 , respectively. More specifically, the switch module  532 A is attached to the outer peripheral wall WA 1  via the spacer  549 , but the spacer  549  is not illustrated. 
     In a state where the switch module  532 A is fixed to the outer peripheral wall WA 1 , the side of the switch module  532 A closer to the outer peripheral wall WA 1 , that is, the side closer to the cooling water passage  545  has higher cooling performance. Therefore, the order of the arrangement of the switches  601  and  602 , the drive circuit  603 , and the capacitor  604  is determined in accordance with the cooling performance. Specifically, when comparing the amount of heat generated, the switches  601  and  602 , the capacitor  604 , and the drive circuit  603  are in the order from the largest, and therefore the switches  601  and  602 , the capacitor  604 , and the drive circuit  603  are arranged in this order from the side closer to the outer peripheral wall WA 1  in accordance with the magnitude order of the amount of heat generated. Moreover, the contact surface of the switch module  532 A is preferably smaller than the contactable surface on the inner peripheral surface of the inner wall member  542 . 
     Furthermore, although detailed illustration of the capacitor module  5328  is omitted, the capacitor module  532 B is configured such that the capacitor  606  is housed in a module case having the same shape and size as that of the switch module  532 A. Similarly to the switch module  532 A, the capacitor module  5328  is fixed to the outer peripheral wall WA 1  in a state where the side surface of the module case  611  is in contact with the inner peripheral surface of the inner wall member  542  of the inverter housing  531 . 
     The switch module  532 A and the capacitor module  532 B do not necessarily have to be arranged concentrically on the radial inside of the outer peripheral wall WA 1  of the inverter housing  531 . For example, the switch module  532 A may be arranged radially inside the capacitor module  532 B, or vice versa. 
     When the rotating electric machine  500  is driven, heat exchange is performed between the switch module  532 A and the capacitor module  532 B and the cooling water passage  545  via the inner wall member  542  of the outer peripheral wall WA 1 . As a result, the switch module  532 A and the capacitor module  532 B are cooled. 
     Each electric module  532  may have a configuration in which cooling water is drawn into the module and the cooling water is used to cool the inside of the module. Here, the water-cooled structure of the switch module  532 A will be described with reference to  FIGS. 61A and 61B .  FIG. 61A  is a vertical cross-sectional view illustrating a cross-sectional structure of the switch module  532 A in a direction crossing the outer peripheral wall WA 1 , and  FIG. 61B  is a cross-sectional view taken along a line  61 B- 61 B of  FIG. 61A . 
     As illustrated in  FIGS. 61A and 618 , as is the case with  FIG. 60 , the switch module  532 A has the module case  611 , the switches  601  and  602  for one phase, the drive circuit  603 , and the capacitor  604 , as in  FIG. 60 . In addition, the switch module  532 A has a cooling device composed of a pair of piping sections  621  and  622  and a cooler  623 . In the cooling device, the pair of piping sections  621  and  622  are composed of an inflow side piping section  621  that allows cooling water to flow in from the cooling water passage  545  of the outer peripheral wall WA 1  to the cooler  623  and an outflow side piping section  622  that allows cooling water to flow out from the cooler  623  to the cooling water passage  545 . The cooler  623  is provided in accordance with an object to be cooled, and a one-stage or multiple-stage cooler  623  is used in the cooling device. In the configurations of  FIGS. 61A and 61B , two-stage coolers  623  are provided in a direction away from the cooling water passage  545 , that is, in the radial direction of the inverter unit  530 , in a state of being separated from each other, and cooling water is supplied to those respective coolers  623  via the pair of piping sections  621  and  622 . The cooler  623  has, for example, a hollow inside. However, an inner fin may be provided inside the cooler  623 . 
     In the configuration including the two-stage coolers  623 , (1) the outer peripheral wall WA 1  side of the first-stage cooler  623 , (2) between the first-stage and second-stage coolers  623 , and (3) the opposite-to-outer peripheral wall side of the second stage cooler  623  is the place where the electric components to be cooled are placed, and each of these places is (2). (1), and (3) in order from the one with the highest cooling performance. That is, the place sandwiched between the two coolers  623  has the highest cooling performance, and in the place adjacent to any one of the coolers  623 , the place closer to the outer peripheral wall WA 1  (cooling water passage  545 ) has higher cooling performance. Taking this into consideration, in the configurations illustrated in  FIGS. 61A and 61B , the switches  601  and  602  are arranged (2) between the first-stage and second-stage coolers  623 , the condenser  604  is arranged on (1) the outer peripheral wall WA 1  side of the first-stage cooler  623 , and the drive circuit  603  is arranged on (3) the opposite-to-outer peripheral wall side of the second-stage cooler  623 . Moreover, although not illustrated, the drive circuit  603  and the capacitor  604  may be arranged in reverse. 
     In either case, in the module case  611 , the switches  601  and  602  and the drive circuit  603 , and the switches  601  and  602  and the capacitor  604  are electrically connected by a wiring  612 , respectively. Further, since the switches  601  and  602  are located between the drive circuit  603  and the capacitor  604 , the wiring  612  extending from the switches  601  and  602  toward the drive circuit  603  and the wiring  612  extending from the switches  601  and  602  toward the capacitor  604  are in a relation in which they extend in opposite directions. 
     As illustrated in  FIG. 61B , the pair of piping sections  621  and  622  are arranged side by side in the circumferential direction, that is, on the upstream side and the downstream side of the cooling water passage  545 , and cooling water flows into the cooler  623  from the inflow side piping section  621  located on the upstream side, and then the cooling water flows out from the outflow side piping section  622  located on the downstream side. Moreover, in order to promote the inflow of the cooling water into the cooling device, the cooling water passage  545  is preferably provided with a regulating section  624  that regulates the flow of cooling water, at a position between the inflow side piping section  621  and the outflow side piping section  621  when viewed in the circumferential direction. The regulating section  624  may be a blocking section that blocks the cooling water passage  545 , or a throttle section that reduces the passage area of the cooling water passage  545 . 
       FIG. 62  illustrates another cooling structure of the switch module  532 A.  FIG. 62A  is a vertical cross-sectional view illustrating a cross-sectional structure of the switch module  532 A in a direction crossing the outer peripheral wall WA 1 , and  FIG. 62B  is a cross-sectional view taken along a line  62 B- 62 B of  FIG. 62A . 
     The configurations of  FIGS. 62A and 62B  differ from the configurations of  FIGS. 61A and 61B  described above in that the pair of piping sections  621  and  622  in the cooling device are arranged differently, and a pair of piping sections  621  and  622  are arranged side by side in the axial direction. Further, as illustrated in  FIG. 62C , in the cooling water passage  545 , the passage portion communicating with the inflow side piping section  621  and the passage portion communicating with the outflow side piping section  622  are separated in the axial direction. Each of these passage portions is communicated with each other through the respective piping sections  621  and  622  and each cooler  623 . 
     In addition, the following configuration can be used as the switch module  532 A. 
     In the configuration illustrated in  FIG. 63A , the cooler  623  is changed from two stages to one stage as compared with the configuration illustrated in  FIG. 61A . In this case, the place where the cooling performance is highest in the module case  611  is different from that in  FIG. 61A , and the cooling performance is highest in the place on the outer peripheral wall WA 1  side of both sides in the radial direction (both sides in the right-left direction in the figure) of the cooler  623 , and then the cooling performance is lowered in the order of the place on the opposite-to-outer peripheral wall side of the cooler  623  and the place away from the cooler  623 . Taking this into consideration, in the configuration illustrated in  FIG. 63A , the switches  601  and  602  are arranged on the outer peripheral wall WA 1  side of both sides in the radial direction (both sides in the right-left direction in the figure) of the cooler  623 , the capacitor  604  is arranged on the opposite-to-outer peripheral wall side of the cooler  623 , and the drive circuit  603  is arranged in the place away from the cooler  623 . 
     Further, in the switch module  532 A, it is possible to change the configuration in which the switches  601  and  602  for one phase, the drive circuit  603 , and the capacitor  604  are housed in the module case  611 . For example, the module case  611  may house either one of the switches  601  and  602  for one phase and the drive circuit  603  and the capacitor  604 . 
     In  FIG. 63B , the pair of piping sections  621  and  622  and the two-stage coolers  623  are provided in the module case  611 , the switches  601  and  602  are arranged between the first-stage and second-stage coolers  623 , and the capacitor  604  or the drive circuit  603  is arranged on the outer peripheral wall WA 1  side of the first stage cooler  623 . Further, it is also possible to integrate the switches  601  and  602  and the drive circuit  603  into a semiconductor module, and to house the semiconductor module and the capacitor  604  in the module case  611 . 
     Moreover, in  FIG. 631 , in the switch module  532 A, a capacitor is preferably arranged on the side opposite to the switches  601  and  602  in at least one of the coolers  623  arranged on both sides with the switches  601  and  602  therebetween. That is, there may be a configuration in which the capacitor  604  is arranged only on one of the outer peripheral wall WA 1  side of the first-stage cooler  623  and the opposite-to-peripheral wall side of the second-stage cooler  623 , or a configuration in which the capacitor  604  is arranged on the both sides. 
     In the present embodiment, of the switch module  532 A and the capacitor module  532 B, only the switch module  532 A is configured to draw cooling water from the cooling water passage  545  into the module. However, the configuration may be changed in such a manner that cooling water is drawn into both modules  532 A and  532 B from the cooling water passage  545 . 
     Further, it is also possible to cool each electric module  532  by directly applying cooling water to the outer surface of each electric module  532 . For example, as illustrated in  FIG. 64 , by embedding the electric module  532  in the outer peripheral wall WA 1 , the cooling water is applied to the outer surface of the electric module  532 . In this case, it is conceivable to immerse a part of the electric module  532  in the cooling water passage  545 , or to expand the cooling water passage  545  further in the radial direction than in the configuration illustrated in  FIG. 58  or the like to immerse all the electric modules  532  in the cooling water passage  545 . In the case where the electric module  532  is immersed in the cooling water passage  545 , the cooling performance can be further improved by providing a fin in the module case  611  (the immersed portion of the module case  611 ) to be immersed. 
     Further, the electric module  532  includes a switch module  532 A and a capacitor module  5323 , and there is a difference in the amount of heat generated when both of them are compared. In consideration of this point, it is also possible to devise the arrangement of each electric module  532  in the inverter housing  531 . 
     For example, as illustrated in  FIG. 65 , a plurality of switch modules  532 A are arranged in the circumferential direction without being dispersed, and arranged on the upstream side of the cooling water passage  545 , that is, on the side close to the inlet passage  571 . In this case, the cooling water flowing in from the inlet passage  571  is first used for cooling the three switch modules  532 A, and then used for cooling each capacitor module  532 B. Moreover, in  FIG. 65 , the pair of piping sections  621  and  622  are arranged side by side in the axial direction as in the preceding  FIGS. 62A and 62B , but the present invention is not limited to this, and the pair of piping sections  621  and  622  may be arranged side by side in the circumferential direction as in the preceding  FIGS. 61A and 61B . 
     Next, the configuration related to the electrical connection in each electric module  532  and the bus bar module  533  will be described.  FIG. 66  is a cross-sectional view taken along a line  66 - 66  of  FIG. 49 , and  FIG. 67  is a cross-sectional view taken along a line  67 - 67  of  FIG. 49 .  FIG. 68  is a perspective view illustrating the busbar module  533  alone. Here, the configuration related to the electrical connection in each electric module  532  and the bus bar module  533  will be described with reference to each of these figures. 
     As illustrated in  FIG. 66 , in the inverter housing  531 , at positions adjacent to each other in the circumferential direction of the protruding section  573  provided on the inner wall member  542  (that is, the protruding section  573  provided with the inlet passage  571  and the outlet passage  572  communicating with the cooling water passage  545 ), three switch modules  532 A are arranged side by side in the circumferential direction, and next to them, six capacitor modules  5328  are arranged side by side in the circumferential direction. As the outline, in the inverter housing  531 , the inside of the outer peripheral wall WA 1  is equally divided into 10 regions (that is, the number of modules+1) in the circumferential direction, and one electric module  532  is arranged in each of the nine regions, and the protruding section  573  is provided in the remaining one region. The three switch modules  532 A are a U-phase module, a V-phase module, and a W-phase module. 
     As illustrated in  FIG. 66  and the above-mentioned  FIGS. 56 and 57 , each electric module  532  (switch module  532 A and capacitor module  5328 ) has a plurality of module terminals  615  extending from the module case  611 . The module terminal  615  is a module input/output terminal for performing electrical input/output in each electric module  532 . The module terminal  615  is provided so as to extend in the axial direction, and more specifically, the module terminal  615  is provided so as to extend from the module case  611  toward the back side of the rotor carrier  511  (outside the vehicle)(see  FIG. 51 ). 
     The module terminals  615  of each electric module  532  are connected to the bus bar module  533 , respectively. The number of module terminals  615  differs between the switch module  532 A and the capacitor module  5328 . The switch module  532 A is provided with four module terminals  615 , and the capacitor module  532 B is provided with two module terminals  615 . 
     Further, as illustrated in  FIG. 68 , the bus bar module  533  has an annular section  631  forming an annular shape, three external connection terminals  632  extending from the annular section  631  and enabling connection with external devices such as a power supply device and an ECU (electronic control unit), and a winding connection terminal  633  connected to the winding end of each phase in the stator winding  521 . The bus bar module  533  corresponds to a “terminal module”. 
     The annular section  631  is arranged in the inverter housing  531  at a position on the radial inside of the outer peripheral wall WA 1  and on one side in the axial direction of each electric module  532 . The annular section  631  has an annular main body formed of, for example, an insulating member such as resin, and a plurality of bus bars embedded therein. The plurality of bus bars are connected to the module terminal  615  of each electric module  532 , each external connection terminal  632 , and each phase winding of the stator winding  521 . The details will be described below. 
     The external connection terminal  632  is composed of a high potential side power terminal  632 A and a low potential side power terminal  632 B connected to the power supply device, and one signal terminal  632 C connected to an external ECU. Each of these external connection terminals  632  ( 632 A to  632 C) is provided so as to be arranged in a line in the circumferential direction and to extend n the axial direction on the radial inside of the annular section  631 . As illustrated in  FIG. 51 , in a state where the bus bar module  533  is assembled to the inverter housing  531  together with each electric module  532 , one end of the external connection terminal  632  is configured to protrude from the end plate  547  of the boss forming member  543 . Specifically, as illustrated in  FIGS. 56 and 57 , the end plate  547  of the boss forming member  543  is provided with an insertion hole  547   a , a cylindrical grommet  635  is attached to the insertion hole  547   a , and the external connection terminal  632  is provided with the grommet  635  inserted. The grommet  635  also functions as a sealed connector. 
     The winding connection terminal  633  is a terminal connected to the winding end of each phase of the stator winding  521 , and is provided so as to extend radially outward from the annular section  631 . The winding connection terminal  633  has a winding connection terminal  633 U connected to the end of the U-phase winding in the stator winding  521 , a winding connection terminal  633 V connected to the end of the V-phase winding, and a winding connection terminal  633 W connected to each connection at the end of the W-phase winding. It is preferable to provide a current sensor  634  that detects the current (U-phase current, V-phase current, W-phase current) flowing through each of these winding connection terminals  633  and each phase winding (see  FIG. 70 ). 
     Moreover, the current sensor  634  may be arranged outside the electric module  532  and around each winding connection terminal  633 , or may be arranged inside the electric module  532 . 
     Here, the connection between each electric module  532  and the bus bar module  533  will be described more specifically with reference to  FIGS. 69 and 70 .  FIG. 69  is a diagram illustrating each electric module  532  developed in a plane and schematically illustrating an electrical connection state between each electric module  532  and the bus bar module  533 .  FIG. 70  is a diagram schematically illustrating the connection between each electric module  532  and the bus bar module  533  in a state where each electric module  532  is arranged in an annular shape. Moreover, in  FIG. 69 , the path for power transmission is illustrated by a solid line, and the path of the signal transmission system is illustrated by a dashed line.  FIG. 70  illustrates only the path for power transmission. 
     The bus bar module  533  has a first bus bar  641 , a second bus bar  642 , and a third bus bar  643  as bus bars for power transmission. Of these, the first bus bar  641  is connected to the high potential side power terminal  632 A, and the second bus bar  642  is connected to the low potential side power terminal  632 B. Further, three third bus bars  643  are connected to the U-phase winding connection terminal  633 U, the V-phase winding connection terminal  633 V, and the W-phase winding connection terminal  633 W, respectively. 
     Further, the winding connection terminal  633  and the third bus bar  643  are portions that easily generate heat due to the operation of the rotating electric machine  10 . Therefore, a terminal block (not illustrated) may be interposed between the winding connection terminal  633  and the third bus bar  643 , and the terminal block may be brought into contact with the inverter housing  531  having the cooling water passage  545 . Alternatively, the winding connection terminal  633  or the third bus bar  643  may be bent into a crank shape to bring the winding connection terminal  633  or the third bus bar  643  into contact with the inverter housing  531  having the cooling water passage  545 . 
     With such a configuration, the heat generated at the winding connection terminal  633  and the third bus bar  643  can be dissipated to the cooling water in the cooling water passage  545 . 
     Moreover, in  FIG. 70 , the first bus bar  641  and the second bus bar  642  are illustrated as bus bars having an annular shape, but each of these bus bars  641  and  642  does not necessarily have to be connected in an annular shape and may have a substantially C-shape with a part discontinuous in the circumferential direction. Further, each winding connection terminal  633 U,  633 V, and  633 W may be individually connected to the switch module  532 A corresponding to each phase, and therefore may be directly connected to each switch module  532 A (actually, the module terminal  615 ) without going through the bus bar module  533 . 
     Meanwhile, each switch module  532 A has four module terminals  615  composed of a positive electrode side terminal, a negative electrode side terminal, a winding terminal, and a signal terminal. Of these, the positive electrode side terminal is connected to the first bus bar  641 , the negative electrode side terminal is connected to the second bus bar  642 , and the winding terminal is connected to the third bus bar  643 . 
     Further, the bus bar module  533  has a fourth bus bar  644  as a bus bar of the signal transmission system. The signal terminal of each switch module  532 A is connected to the fourth bus bar  644 , and the fourth bus bar  644  is connected to the signal terminal  632 C. 
     In the present embodiment, the control signal for each switch module  532 A is input from the external ECU via the signal terminal  632 C. That is, the respective switches  601  and  602  in each switch module  532 A are turned on/off by a control signal input via the signal terminal  632 C. Therefore, each switch module  532 A is connected to the signal terminal  632 C without going through a control device disposed in the rotating electric machine on the way. However, it is also possible to change this configuration in such a manner that a rotating electric machine has a built-in control device and the control signal from the control device is input to each switch module  532 A. Such a configuration is illustrated in  FIG. 71 . 
     In the configuration of  FIG. 71 , a control board  651  on which a control device  652  is mounted is provided, and the control device  652  is connected to each switch module  532 A. Further, the signal terminal  632 C is connected to the control device  652 . In this case, the control device  652  inputs a command signal related to power running or power generation from, for example, an external ECU which is a higher-level control device, and appropriately turns on/off the switches  601  and  602  of each switch module  532 A on the basis of the command signal. 
     In the inverter unit  530 , the control board  651  is preferably arranged on the further outside of the vehicle than the bus bar module  533  (back side of the rotor carrier  511 ). Alternatively, the control board  651  may be arranged between each electric module  532  and the end plate  547  of the boss forming member  543 . The control board  651  is preferably arranged in such a manner that at least a part thereof overlaps with each electric module  532  in the axial direction. 
     Further, each capacitor module  532 B has two module terminals  615  composed of a positive electrode side terminal and a negative electrode side terminal, the positive electrode side terminal is connected to the first bus bar  641 , and the negative electrode side terminal is connected to the second bus bar  642 . 
     As illustrated in  FIGS. 49 and 50 , the protruding section  573  having the inlet passage  571  and the outlet passage  572  for cooling water is provided in the inverter housing  531  at a position aligned with each electric module  532  in the circumferential direction, and the external connection terminals  632  is provided so as to be adjacent to the protruding section  573  in the radial direction. In other words, the protruding section  573  and the external connection terminal  632  are provided at the same angular position in the circumferential direction. In the present embodiment, the external connection terminal  632  is provided at a position on the radial inside of the protruding section  573 . Further, when viewed from the inside of the vehicle of the inverter housing  531 , the end plate  547  of the boss forming member  543  is provided with the water channel port  574  and the external connection terminal  632  arranged side by side in the radial direction (see  FIG. 48 ). 
     In this case, by arranging the protruding section  573  and the external connection terminal  632  side by side in the circumferential direction together with the plurality of electric modules  532 , the inverter unit  530  can be downsized, and thus the rotating electric machine  500  can be downsized. 
     Referring to  FIGS. 45 and 47  illustrating the structure of the wheel  400 , the cooling pipe H 2  is connected to the water channel port  574 , the electric wiring H 1  is connected to the external connection terminal  632 , and in that state, the electric wiring H 1  and the cooling pipe H 2  are housed in the housing duct  440 . 
     Moreover, in the above configuration, the three switch modules  532 A are arranged side by side in the circumferential direction next to the external connection terminal  632  in the inverter housing  531 , and next to them, the six capacitor modules  532 B are arranged side by side in the circumferential direction. However, this may be changed. For example, the three switch modules  532 A may be arranged side by side at a position farthest from the external connection terminal  632 , that is, a position opposite to the external connection terminal  632  with the rotating shaft  501  therebetween. Further, it is also possible to disperse each switch module  532 A in such a manner that the capacitor modules  532 B are arranged on both sides of each switch module  532 A. 
     If each switch module  532 A is arranged at the position farthest from the external connection terminal  632 , that is, a position opposite to the external connection terminal  632  with the rotating shaft  501  therebetween, a malfunction or the like caused by mutual inductance between the external connection terminal  632  and each switch module  532 A can be suppressed. 
     Next, the configuration of a resolver  660  provided as a rotation angle sensor will be described. 
     As illustrated in  FIGS. 49 to 51 , the inverter housing  531  is provided with a resolver  660  that detects the electrical angle θ of the rotating electric machine  500 . The resolver  660  is an electromagnetic induction type sensor, and includes a resolver rotor  661  fixed to the rotating shaft  501  and a resolver stator  662  arranged so as to face the radial outside of the resolver rotor  661 . The resolver rotor  661  has a disc ring shape, and is provided coaxially with the rotating shaft  501  with the rotating shaft  501  inserted. The resolver stator  662  includes an annular stator core  663  and a stator coil  664  wound around a plurality of teeth formed on the stator core  663 . The stator coil  664  includes a one-phase excitation coil and a two-phase output coil. 
     The exciting coil of the stator coil  664  is excited by a sinusoidal excitation signal, and the magnetic flux generated in the exciting coil by the excitation signal interlinks a pair of output coils. In doing so, since the relative arrangement relation between the exciting coil and the pair of output coils changes periodically in accordance with the rotation angle of the resolver rotor  661  (that is, the rotation angle of the rotation shaft  501 ), the amount of magnetic flux interlinking the pair of output coils changes periodically. In the present embodiment, the pair of output coils and the exciting coil are arranged in such a manner that the phases of the voltages generated in the pair of output coils are shifted by π/2 from each other. As a result, the output voltage of each of the pair of output coils becomes a modulated wave in which the excitation signal is modulated by the modulated waves sin θ and cos θ, respectively. More specifically, when the excitation signal is “sin Ωt”, the modulated waves are “sin θ*sin Ωt” and “cos θ *sin Ωt”, respectively. 
     The resolver  660  has a resolver digital converter. The resolver digital converter calculates the electrical angle θ by detection based on the generated modulated wave and the excitation signal. For example, the resolver  660  is connected to the signal terminal  632 C, and the calculation result of the resolver digital converter is output to an external device via the signal terminal  632 C. Further, in a case where the rotating electric machine  500  has a built-in control device, the calculation result of the resolver digital converter is input to the control device. 
     Here, the assembly structure of the resolver  660  in the inverter housing  531  will be described. 
     As illustrated in  FIGS. 49 and 51 , the boss section  548  of the boss forming member  543  constituting the inverter housing  531  has a hollow tubular shape, and on the inner peripheral side of the boss section  548 , a protruding portion  548   a  extending in a direction orthogonal to the axial direction is formed. Then, the resolver stator  662  is fixed by a screw or the like in a state of being in contact with the protruding section  548   a  in the axial direction. In the boss section  548 , the bearing  560  is provided on one side in the axial direction with the protruding section  548   a  therebetween, and the resolver  660  is coaxially provided on the other side. 
     Further, in the hollow portion of the boss section  548 , a protruding section  548   a  is provided on one side of the resolver  660  in the axial direction, and a disc ring-shaped housing cover  666  that closes the housing space of the resolver  660  is attached on the other side. The housing cover  666  is made of a conductive material such as carbon fiber reinforced plastic (CFRP). A hole  666   a  through which the rotating shaft  501  is inserted is formed in the central portion of the housing cover  666 . In the hole  666   a , a sealing material  667  that seals the airspace therebetween with the outer peripheral surface of the rotating shaft  501 . The resolver housing space is sealed by the sealing material  667 . The sealing material  667  is preferably, for example, a sliding seal made of a resin material. 
     The space in which the resolver  660  is housed is a space surrounded by the boss section  548  forming an annular shape in the boss forming member  543  and sandwiched between the bearing  560  and the housing cover  666  in the axial direction, and the circumference of the resolver  660  is surrounded by a conductive material. This makes it possible to suppress the influence of electromagnetic noise on the resolver  660 . 
     Further, as described above, the inverter housing  531  has the outer peripheral wall WA 1  and the inner peripheral wall WA 2  that together form a double wall (see  FIG. 57 ), the stator  520  is arranged on the outside of the double peripheral walls (outside the outer peripheral wall WA 1 ), the electric module  532  is arranged between the double peripheral walls (between WA 1  and WA 2 ), and the resolver  660  is arranged inside the double peripheral walls (inside the inner peripheral wall WA 2 ). Since the inverter housing  531  is a conductive member, the stator  520  and the resolver  660  are arranged so as to be separated from each other by a conductive partition wall (particularly a double conductive partition wall in the present embodiment), and the occurrence of mutual magnetic interference between the stator  520  side (magnetic circuit side) and the resolver  660  can be suitably suppressed. 
     Next, the rotor cover  670  provided on the open end side of the rotor carrier  511  will be described. 
     As illustrated in  FIGS. 49 and 51 , one side of the rotor carrier  511  in the axial direction is open, and the substantially disc ring-shaped rotor cover  670  is attached to the open end. The rotor cover  670  is preferably fixed to the rotor carrier  511  by any joining method such as welding, adhesion, or screwing. It is more preferable that the rotor cover  670  has a portion whose dimension is set smaller than the inner circumference of the rotor carrier  511  in such a manner that the movement of the magnet unit  512  in the axial direction can be suppressed. The outer diameter dimension of the rotor cover  670  matches the outer diameter dimension of the rotor carrier  511 , and the inner diameter dimension of the rotor cover  670  is slightly larger than the outer diameter dimension of the inverter housing  531 . The outer diameter dimension of the inverter housing  531  and the inner diameter dimension of the stator  520  are the same. 
     As described above, the stator  520  is fixed to the radial outside of the inverter housing  531 . At the joint portion where the stator  520  and the inverter housing  531  are joined to each other, the inverter housing  531  protrudes axially with respect to the stator  520 . In addition, the rotor cover  670  is attached so as to surround the protruding portion of the inverter housing  531 . In this case, a sealing material  671  that seals the gap between the end face of the rotor cover  670  on the inner peripheral side and the outer peripheral surface of the inverter housing  531  is provided. The housing space of the magnet unit  512  and the stator  520  is sealed by the sealing material  671 . The sealing material  671  is preferably, for example, a sliding seal made of a resin material. 
     According to the present embodiment described in detail above, the following excellent effects can be obtained. 
     In the rotating electric machine  500 , the outer peripheral wall WA 1  of the inverter housing  531  is arranged radially inside the magnetic circuit section composed of the magnet unit  512  and the stator winding  521 , and the cooling water passage  545  is formed on the outer peripheral wall WA 1 . Further, a plurality of electric modules  532  are arranged in the circumferential direction along the outer peripheral wall WA 1 , on the radial inside of the outer peripheral wall WA 1 . As a result, the magnetic circuit section, the cooling water passage  545 , and the power converter can be arranged so as to be stacked in the radial direction of the rotating electric machine  500 , and an efficient component arrangement is possible while reducing the dimensions in the axial direction. Further, the plurality of electric modules  532  constituting the power converter can be efficiently cooled. As a result, the high efficiency and downsizing of the rotating electric machine  500  can be achieved. 
     The electric module  532  (switch module  532 A, capacitor module  532 B) having heat-generating components such as a semiconductor switching element and a capacitor is provided in contact with the inner peripheral surface of the outer peripheral wall WA 1 . As a result, the heat in each electric module  532  is transferred to the outer peripheral wall WA 1 , and the electric module  532  is suitably cooled by the heat exchange in the outer peripheral wall WA 1 . 
     In the switch module  532 A, the coolers  623  are arranged on both sides of the switches  601  and  602 , respectively, and in at least one of the coolers  623  on both sides of the switches  601  and  602 , the capacitor  604  is arranged on the side opposite to the switches  601  and  602 . As a result, the cooling performance for the switches  601  and  602  can be improved, and the cooling performance of the capacitor  604  can also be improved. 
     In the switch module  532 A, the coolers  623  are arranged on both sides of the switches  601  and  602 , respectively, and in one of the coolers  623  on both sides of the switches  601  and  602 , the drive circuit  603  is arranged on the side opposite to the switches  601  and  602 , and in the other of the coolers  623 , the capacitor  604  is arranged on the side opposite to the switches  601  and  602 . As a result, the cooling performance for the switches  601  and  602  can be improved, and the cooling performance of the drive circuit  603  and the capacitor  604  can also be improved. 
     For example, in the switch module  532 A, cooling water flows into the module from the cooling water passage  545 , and the semiconductor switching element or the like is cooled by the cooling water. In this case, the switch module  532 A is cooled by heat exchange by the cooling water inside the module in addition to heat exchange by the cooling water on the outer peripheral wall WA 1 . As a result, the cooling effect of the switch module  532 A can be enhanced. 
     In the cooling system in which the cooling water flows into the cooling water passage  545  from the external circulation path  575 , the switch module  532 A is arranged on the upstream side near the inlet passage  571  of the cooling water passage  545 , and the capacitor module  532 B is arranged on the downstream side of the switch module  532 A. In this case, assuming that the cooling water flowing through the cooling water passage  545  is lower in temperature toward the upstream side, it is possible to implement a configuration in which the switch module  532 A is preferentially cooled. 
     The interval between the electric modules adjacent to each other in the circumferential direction is partially widened, and the protruding section  573  having the inlet passage  571  and the outlet passage  572  is provided in the portion where the interval is widened (second interval INT 2 ). As a result, the inlet passage  571  and the outlet passage  572  of the cooling water passage  545  can be suitably formed in the portion that is radially inside of the outer peripheral wall WA 1 . That is, in order to improve the cooling performance, it is necessary to secure the flow amount of the refrigerant, and for that purpose, it is conceivable to increase the opening areas of the inlet passage  571  and the outlet passage  572 . In this regard, as described above, by partially widening the interval between the electric modules and providing the protruding section  573 , the inlet passage  571  and the outlet passage  572  having a desired size can be suitably formed. 
     The external connection terminal  632  of the bus bar module  533  is arranged at a position radially aligned with the protruding section  573  on the radial inside of the outer peripheral wall WA 1 . That is, the external connection terminal  632  is arranged together with the protruding section  573  in the portion where the interval between the electric modules adjacent to each other in the circumferential direction is widened (the portion corresponding to the second interval INT 2 ). As a result, the external connection terminal  632  can be suitably arranged while avoiding interference with each electric module  532 . 
     In the outer rotor type rotating electric machine  500 , the stator  520  is fixed to the radial outside of the outer peripheral wall WA 1 , and a plurality of electric modules  532  are arranged on the radial inside. As a result, the heat of the stator  520  is transferred to the outer peripheral wall WA) from the radial outside, and the heat of the electric module  532  is transferred from the radial inside. In this case, the stator  520  and the electric module  532  can be cooled at the same time by the cooling water flowing the cooling water passage  545 , and the heat of the heat-generating member in the rotating electric machine  500  can be efficiently released. 
     The electric module  532  on the radial inside and the stator winding  521  on the radial outside are electrically connected by the winding connection terminal  633  of the bus bar module  533  with the outer peripheral wall WA 1  therebetween. Further, in this case, the winding connection terminal  633  is provided at a position axially separated from the cooling water passage  545 . As a result, even in a configuration in which the cooling water passage  545  is formed in an annular shape on the outer peripheral wall WA 1 , that is, the inside and outside of the outer peripheral wall WA 1  are separated by the cooling water passage  545 , the electric module  532  and the stator winding  521  can be suitably connected. 
     In the rotating electric machine  500  of the present embodiment, by reducing or eliminating the teeth (iron core) between the respective conductors  523  arranged in the circumferential direction in the stator  520 , the torque limitation caused by the magnetic saturation between the respective conductors  523  is suppressed, and the torque decrease is suppressed by making the conductor  523  flat and thin. In this case, even if the outer diameter dimension of the rotating electric machine  500  is the same, the region on the radial inside of the magnetic circuit section can be expanded by reducing the thickness of the stator  520 , and with the use of the inner region, the outer peripheral wall WA 1  having the cooling water passage  545  and the plurality of electric modules  532  provided radially inside the outer peripheral wall WA 1  can be suitably arranged. 
     In the rotating electric machine  500  of the present embodiment, the magnet magnetic flux in the magnet unit  512  is collected on the d-axis side, and thus the magnet magnetic flux on the d-axis is strengthened, and the torque can be increased accordingly. In this case, as the radial thickness dimension can be reduced (thinned) in the magnet unit  512 , the region on the radial inside of the magnetic circuit section can be expanded by reducing the thickness of the stator  520 , and with the use of the inner region, the outer peripheral wall WA 1  having the cooling water passage  545  and the plurality of electric modules  532  provided radially inside the outer peripheral wall WA 1  can be suitably arranged. 
     Further, not only the magnetic circuit section, the outer peripheral wall WA 1 , and the plurality of electric modules  532 , but also the bearing  560  and the resolver  660  can be suitably arranged in the radial direction in the same manner. 
     The wheel  400  using the rotating electric machine  500  as an in-wheel motor is mounted on a vehicle body via the base plate  405  fixed to the inverter housing  531  and a mounting mechanism such as a suspension device. Here, since the rotating electric machine  500  has been downsized, it is possible to save space even if it is assumed to be assembled to a vehicle body. 
     Therefore, it is possible to implement an advantageous configuration in expanding the installation region of the power supply device such as a battery in the vehicle and expanding the vehicle interior space. 
     A modification on an in-wheel motor will be described below. 
     (First Modification in an In-Wheel Motor) 
     In the rotating electric machine  500 , the electric module  532  and the bus bar module  533  are arranged radially inside the outer peripheral wall WA 1  of the inverter unit  530 , and the electric module  532  and the bus bar module  533  and the stator  520  are arranged radially inside and outside so as to be separated from each other by the outer peripheral wall WA 1 , respectively. In such a configuration, the position of the bus bar module  533  with respect to the electric module  532  can be arbitrarily set. Further, when connecting each phase winding of the stator winding  521  and the bus bar module  533  across the outer peripheral wall WA 1  in the radial direction, a winding connection wire (for example, the winding connection terminal  633 ) used for the connection can be arbitrarily set. 
     That is, as the position of the bus bar module  533  with respect to the electric module  532 , a configuration (α 1 ) in which the bus bar module  533  is located further outside of the vehicle in the axial direction than the electric module  532 , that is, on the back side in the rotor carrier  511  side and a configuration (α 2 ) in which the bus bar module  533  is located further inside of the vehicle in the axial direction than the electric module  532 , that is, on the front side in the rotor carrier  511  side are conceivable. 
     Further, as a position to guide the winding connection winding connection wire, a configuration (β 1 ) in which the winding connection wire is guided in the axial direction on the outside of the vehicle, that is, on the back side in the rotor carrier  511  side and a configuration (β 2 ) in which the winding connection wire is guided in the axial direction on the inside of the vehicle, that is, on the front side in the rotor carrier  511  side are conceivable. 
     Hereinafter, four configuration examples relating to the arrangement of the electric module  532 , the bus bar module  533 , and the winding connection wire will be described with reference to  FIGS. 72A to 72D .  FIGS. 72A to 72D  are vertical cross-sectional views illustrating a simplified configuration of the rotating electric machine  500 , in which the same reference signs are given to the configurations already described. The winding connection wire  637  is an electric wiring that connects each phase winding of the stator winding  521  and the bus bar module  533 , and for example, the winding connection terminal  633  described above corresponds to this. 
     In the configuration of  FIG. 72A , the above (α 1 ) is adopted as the position of the bus bar module  533  with respect to the electric module  532 , and the above (β 1 ) is adopted as the position for guiding the winding connection wire  637 . That is, the electric module  532 , the bus bar module  533 , the stator winding  521 , and the bus bar module  533  are all connected on the outside of the vehicle (the back side of the rotor carrier  511 ). This corresponds to the configuration illustrated in  FIG. 49 . 
     According to this configuration, the cooling water passage  545  can be provided on the outer peripheral wall WA 1  without fear of interference with the winding connection wire  637 . Further, the winding connection wire  637  that connects the stator winding  521  and the bus bar module  533  can be easily achieved. 
     In the configuration of  FIG. 72B , the above (α 1 ) is adopted as the position of the bus bar module  533  with respect to the electric module  532 , and the above (β 2 ) is adopted as the position for guiding the winding connection wire  637 . That is, the electric module  532  and the bus bar module  533  are connected on the outside of the vehicle (the back side of the rotor carrier  511 ), and the stator winding  521  and the bus bar module  533  are connected on the inside of the vehicle (the front side of the rotor carrier  511 ). 
     According to this configuration, the cooling water passage  545  can be provided on the outer peripheral wall WA 1  without fear of interference with the winding connection wire  637 . 
     In the configuration of  FIG. 72C , the above (α 2 ) is adopted as the position of the bus bar module  533  with respect to the electric module  532 , and the above (β 1 ) is adopted as the position for guiding the winding connection wire  637 . That is, the electric module  532  and the bus bar module  533  are connected on the inside of the vehicle (the front side of the rotor carrier  511 ), and the stator winding  521  and the bus bar module  533  are connected on the outside of the vehicle (the back side of the rotor carrier  511 ). 
     In the configuration of  FIG. 72D , the above (α 2 ) is adopted as the position of the bus bar module  533  with respect to the electric module  532 , and the above (β 2 ) is adopted as the position for guiding the winding connection wire  637 . That is, the electric module  532 , the bus bar module  533 , the stator winding  521 , and the bus bar module  533  are all connected on the inside of the vehicle (the front side of the rotor carrier  511 ). 
     According to the configurations of  FIGS. 72C and 72D , the bus bar module  533  is arranged inside the vehicle (on the front side of the rotor carrier  511 ), and thus it is considered the wiring becomes easy when adding an electric component such as a fan motor. Further, it is possible that the bus bar module  533  can be brought closer to the resolver  660  arranged further inside the vehicle than the bearing, and it is considered that wiring to the resolver  660  becomes easier. 
     (Second Modification in an In-Wheel Motor) 
     A modification of the mounting structure of the resolver rotor  661  will be described below. That is, the rotating shaft  501 , the rotor carrier  511 , and the inner ring  561  of the bearing  560  are a rotating body that rotates integrally, and a modification of the mounting structure of the resolver rotor  661  with respect to the rotating body will be described below. 
       FIGS. 73A to 73C  are block diagrams illustrating an example of a mounting structure of the resolver rotor  661  to the rotating body. In any of the configurations, the resolver  660  is provided in a closed space surrounded by the rotor carrier  511 , the inverter housing  531  and the like, and protected from external water, mud, and the like. Of  FIGS. 73A to 73C , in  FIG. 73A , the bearing  560  has the same configuration as that in  FIG. 49 . Further, in  FIGS. 73B and 73C , the bearing  560  has a configuration different from that of  FIG. 49 , and is arranged at a position away from the end plate  514  of the rotor carrier  511 . In each of these figures, two locations are illustrated as mounting locations for the resolver rotor  661 . Moreover, although the resolver stator  662  is not illustrated, for example, the boss section  548  of the boss forming member  543  should be extended to the outer peripheral side of the resolver rotor  661  or its vicinity, and the resolver stator  662  should be fixed to the boss section  548 . 
     In the configuration of  FIG. 73A , the resolver rotor  661  is attached to the inner ring  561  of the bearing  560 . Specifically, the resolver rotor  661  is provided on the axial end face of the flange  561   b  of the inner ring  561 , or is provided on the axial end face of the tubular section  561   a  of the inner ring  561 . 
     In the configuration of  FIG. 73B , the resolver rotor  661  is attached to the rotor carrier  511 . 
     Specifically, the resolver rotor  661  is provided on the inner surface of the end plate  514  in the rotor carrier  511 . Alternatively, in a configuration in which the rotor carrier  511  has a tubular section  515  extending from the inner peripheral edge portion of the end plate  514  along the rotating shaft  501 , the resolver rotor  661  is provided on the outer peripheral surface of the tubular section  515  of the rotor carrier  511 . In the latter case, the resolver rotor  661  is arranged between the end plate  514  of the rotor carrier  511  and the bearing  560 . 
     In the configuration of  FIG. 73C , the resolver rotor  661  is attached to the rotating shaft  501 . Specifically, on the rotating shaft  501 , the resolver rotor  661  is provided between the end plate  514  of the rotor carrier  511  and the bearing  560 . Alternatively, on the rotating shaft  501 , the resolver rotor  661  is arranged on the side opposite to the rotor carrier  511  with the bearing  560  therebetween. 
     (Third Modification in an In-Wheel Motor) 
     A modification of the inverter housing  531  and the rotor cover  670  will be described below with reference to  FIG. 74 .  FIGS. 74A and 74B  are vertical cross-sectional views illustrating a simplified configuration of the rotating electric machine  500 , in which the same reference signs are given to the configurations already described. Moreover, the configuration illustrated in  FIG. 74A  substantially corresponds to the configuration described with reference to  FIG. 49  and the like, and the configuration illustrated in  FIG. 74B  corresponds to the configuration in which a part of the configuration of  FIG. 74A  is modified. 
     In the configuration illustrated in  FIG. 74A , the rotor cover  670  fixed to the open end of the rotor carrier  511  is provided so as to surround the outer peripheral wall WA 1  of the inverter housing  531 . That is, the end face on the inner diameter side of the rotor cover  670  faces the outer peripheral surface of the outer peripheral wall WA 1 , and the sealing material  671  is provided between them. Further, the housing cover  666  is attached to the hollow portion of the boss section  548  of the inverter housing  531 , and the sealing material  667  is provided between the housing cover  666  and the rotating shaft  501 . The external connection terminal  632  constituting the bus bar module  533  penetrates the inverter housing  531  and extends to the inside of the vehicle (lower side in the figure). 
     Further, in the inverter housing  531 , the inlet passage  571  and the outlet passage  572  communicating with the cooling water passage  545  are formed, and the water channel port  574  including the passage ends of the inlet passage  571  and the outlet passage  572  is formed. 
     On the other hand, in the configuration illustrated in  FIG. 74B , the inverter housing  531  (specifically, the boss forming member  543 ) is formed with an annular protrusion  681  extending toward the protruding side (inside the vehicle) of the rotating shaft  501 . The rotor cover  670  is provided so as to surround the protrusion  681  of the inverter housing  531 . That is, the end face on the inner diameter side of the rotor cover  670  faces the outer peripheral surface of the protrusion  681 , and the sealing material  671  is provided between them. Further, the external connection terminal  632  constituting the bus bar module  533  penetrates the boss section  548  of the inverter housing  531  and extends into the hollow region of the boss section  548 , and also penetrates the housing cover  666  and extends to the inside of the vehicle (lower side of the figure). 
     Further, the inverter housing  531  is formed with the inlet passage  571  and the outlet passage  572  communicating with the cooling water passage  545 , those inlet passage  571  and outlet passage  572  extend into the hollow region of the boss section  548  and extend to the further inside of the vehicle (lower side of the figure) than the housing cover  666  via a relay pipe  682 . In this configuration, the piping portion extending from the housing cover  666  to the inside of the vehicle is the water channel port  574 . 
     According to the configurations of  FIGS. 74A and 748 , the rotor carrier  511  and the rotor cover  670  can be suitably rotated with respect to the housing  531  while maintaining airtightness of the internal space of the rotor carrier  511  and the rotor cover  670 . 
     Moreover, in particular, according to the configuration of  FIG. 748 , the inner diameter of the rotor cover  670  is smaller than that of the configuration of  FIG. 74A . Therefore, the inverter housing  531  and the rotor cover  670  can be provided double in the axial direction at a position further inside the vehicle than the electric module  532 , and the inconvenience caused by electromagnetic noise, which is a concern in the electric module  532 , is suppressed. Further, by reducing the inner diameter of the rotor cover  670 , the sliding diameter of the sealing material  671  can be reduced, and mechanical loss in the rotating sliding portion can be suppressed. 
     (Fourth Modification in an In-Wheel Motor) 
     A modification of the stator winding  521  will be described below.  FIG. 75  illustrates a modification on the stator winding  521 . 
     As illustrated in  FIG. 75 , in the stator winding  521 , a conductor material having a rectangular cross section is used, and is wound by a wave winding with the long side of the conductor material extending in the circumferential direction. In this case, the conductors  523  of each phase on the coil side of the stator winding  521  are arranged at predetermined pitch intervals for each phase and are connected to each other at the coil ends. The conductors  523  adjacent to each other in the circumferential direction on the coil side are in contact with each other at the end faces in the circumferential direction, or are arranged close to each other at a minute interval. 
     Further, in the stator winding  521 , the conductor material is bent in the radial direction for each phase at the coil end. More specifically, the stator winding  521  (conductor material) is bent inward in the radial direction at a different position for each phase in the axial direction, whereby interference with each other in the respective U-phase, V-phase, and W-phase windings is avoided. In the illustrated configuration, the conductors are bent at a right angle inward in the radial direction for each phase, with each phase winding being different by the thickness of the conductor material. In each of the conductors  523  arranged in the circumferential direction, the length dimension between both ends in the axial direction is preferably the same for each of the conductors  523 . 
     Moreover, in a case where the stator core  522  is assembled to the stator winding  521  to manufacture the stator  520 , a part of the annular shape of the stator winding  521  is preferably opened as a non-connection part (that is, the stator winding  521  is preferably made to be substantially C-shaped), and after assembling the stator core  522  on the inner peripheral side of the stator winding  521 , the disconnecting portions are preferably connected to each other to form the stator winding  521  in an annular shape. 
     In addition to the above, it is also possible to divide the stator core  522  into a plurality of parts (for example, three or more) in the circumferential direction, and assemble the core pieces divided into a plurality of pieces onto the inner peripheral side of the stator winding  521  formed in an annular shape. 
     (Fifteenth Modification) 
     Hereinafter, a manufacturing method of the stator in the above-described slotless outer rotor type rotating electric machine will be described. According to the stator of the present embodiment, interphase insulation is provided using three insulation sheets.  FIG. 76  is a process flow (process diagram) showing a part of the manufacturing process of the stator according to the present embodiment. In this flow, as is known, a triangle symbol indicates a work or a component, and a circle symbol indicates processes such as an assembly or a machining. 
     At step S 20 , as shown in  FIG. 77A , a recess  710  is formed at the same interval on a first insulation sheet  700  as an insulation paper. Then, a longitudinal shaped U-phase (first phase) conductor  800 U of which the cross section is rectangular in shape is placed on each recess  710 . Thus, a first assembly  810  is produced in which U-phase conductors  800 U are arranged at the same intervals on a first surface  701  of the first insulation sheet  701 . In addition to the U-phase conductor  800 U, V-phase conductor  800 V and W-phase conductor  800 W which will be described later constitute a coil side. Note that the first insulation sheet  700  has a rectangular shape in which the length dimension in the short-side direction is substantially the same as the length dimension of the U-phase conductor  800 U. Further, at step S 20 , the U-phase conductor  800 U and the first insulation sheet  700  may be fixed by a fixing means such as adhesive. 
     As shown in  FIG. 77B , at step S 21 , a recess  730  is formed at the same interval on the second insulation sheet  720  as an insulation sheet. Then, a longitudinal shaped W-phase (third phase) conductor  800 W of which the cross section is rectangular in shape is placed on each recess  730 . Thus, a second assembly  820  is produced in which W-phase conductors  800 W are arranged at the same intervals on a first surface  721  of the second insulation sheet  720 . According to the present embodiment, the number of W-phase conductors  800 W used for step S 21  is the same as that of the U-phase conductors  800 U. Also, the shape of the W-phase conductor  800 W is the same as that of the U-phase conductor  800 U. According to the present embodiment, the shape of the second insulation sheet  720  is the same as that of the first insulation sheet  700 . At step S 21 , the W-phase conductor  800 W and the second insulation sheet  720  may be fixed by a fixing means such as adhesive. 
     In the present embodiment, the first assembly  810  produced at step S 20  has the same configuration as that of the second assembly produced at step S 21 . Hence, it is not necessary to divide the manufacturing process into two steps, and two assemblies having the same configuration are produced at a single step, whereby first and second assemblies  810  and  820  may be produced. Thus, the manufacturing processes can be simplified. 
     At step S 22 , as shown in  FIG. 78A , a V-phase (second phase) conductor  800 V of which the cross section is rectangular shape is disposed on the second surface  702  of the first insulation sheet  700  that constitutes the first assembly  810  to be positioned adjacently to the U-phase conductor  800 U via the first insulation sheet  700 . Thus, the V-phase conductor  800 V is disposed between adjacently positioned recesses  720  in the first assembly  810 . According to the present embodiment, the number of V-phase conductors  800 V used for step S 22  is the same as that of the U-phase conductors  800 U. Also, the shape of the V-phase conductor  800 V is the same as that of the U-phase conductor  800 U. 
     At step S 23 , as shown in  FIG. 78B , the first assembly  810  in which the V-phase conductor  800 V is disposed and the second assembly  820  are laminated such that the second surface  702  of the first insulation sheet  700  that constitutes the first assembly  810  faces the second surface  722  of the second insulation sheet  720  that constitutes the second assembly  820 . Thus, the V-phase conductor  800 V is disposed at a portion adjacent to the W-phase conductor  800 W via the second insulation sheet  720 . Also, an interval between adjacently positioned U, V phase conductors  800 U and  800 V in the circumferential direction, an interval between adjacently positioned V, W phase conductors in the circumferential direction and an interval between adjacently positioned W, U phase conductors  800 W and  800 U in the circumferential direction are the same. 
     Further, at step S 23 , a third insulation sheet  740  as an insulation paper is made to come into contact with the first surface  701  of the first insulation sheet  700  and the U-phase conductor  800 U. Thus, a laminate body of the first assembly  810 , the second assembly  820  and the second insulation sheet  720 , that is, a flat strip-shaped winding is produced. The third insulation sheet  740  has a rectangular shape in which the length dimension in the short-side direction is substantially the same as the length dimension of the respective conductors  800 U,  800 V and  800 W. 
     At step S 24 , the laminate body produced at step S 23  is molded in an annular shape by making it rounded, thereby producing the stator winding. Specifically, for example, the stator core  760  and columnar shaped jig having the same diameter as that of the stator core  760  are used such that the laminate body is wounded around the columnar shaped jig, thereby forming the laminate body in the annular shape. The conductors  800 U,  800 V and  800 W of respective phases constituting the stator winding correspond to a linear portion with reference to  FIG. 12 . 
     At step S 25 , the stator winding produced at step S 24  is assembled to the stator core  760  such that the third insulation sheet  740  is positioned between the cylindrical shaped stator core  760  made of magnetic material, and the U-phase conductor  800 U and the first insulation sheet  700 , thereby producing the stator  770 . The stator core  760  is constituted by, for example, laminating a plurality of electromagnetic steel sheets in the axial direction. 
     At step S 26 , the stator  770  is pressed from the rotor side. Thus, as shown in  FIG. 79 , respective insulation sheets  700 ,  720  and  740  are made to be deformed by the pressing to make uniform among a total thickness dimension at a portion positioned between the W-phase conductor  800 W and the stator core  760  in the first insulation sheet  700 , the second insulation sheet  720  and the third insulation sheet  740 , a total thickness dimension at a portion positioned between the V-phase conductor  800 V and the stator core  760  in the second insulation sheet  720  and the third insulation sheet  740 , and a total thickness dimension at a portion positioned between the U-phase conductor  800 U and the stator core  760  in the third insulation sheet  740 . Thus, as shown in  FIG. 79 , a distance in the radial direction from a surface facing the rotor to the stator core  760  is made to be a uniform distance LK in the respective U, V, W phase conductors. Note that the stator  770  after the process at step S 26  is shown in  FIG. 79  as a linearly developed view for convenience reasons. 
     The stator  770  is pressed from the rotor side, thereby making the thickness dimension of the second insulation sheet  720  at a portion in the rotor side with respect to the V-phase conductor  800 V and a total thickness dimension of the first and second insulation sheets  700  and  720  at a portion in the rotor side with respect to the U-phase conductor  800 U to be uniform. Thus, the gap is suppressed from being larger. 
     Note that a termination process is performed for the respective conductors  80011 ,  800 V and  800 W after the step S 26 , thereby making the stator winding to be a star-connected wiring. Specifically, end portions of the conductors adjacently positioned in the circumferential direction are electrically connected via the coil end. Thus, a series connection body of a plurality of conductors are formed for each phase. In the above-described series connection body, first ends are electrically connected at the neutral point, and the second end is electrically connected to an inverter side. Thus, a stator winding wound by a wave winding is formed. However, with the stator winding according to the present embodiment, m=1 which is different from the stator winding  51  shown in  FIG. 12 . 
     Subsequently,  FIG. 80  illustrate a stator according to a comparative example. In  FIG. 80 , for sake of convenience, the same reference symbols are applied to configurations corresponding to the above-described configurations. 
     According to the comparative example, individual insulation sheet  900  is wound around each of the conductors  800 U,  800 V and  800 W corresponding to the respective phases. In this case, since two layers of the insulation sheet  900  are present between conductors adjacently positioned in the circumferential direction, a space occupied by the insulation sheet  900  becomes larger in the space between conductors adjacently positioned in the circumferential direction. 
     In contrast, according to the present embodiment, one layer of the insulation sheet (first insulation sheet  700 ) is present between U-phase conductor  800 U and the V-phase conductor  800 V in the circumferential direction, and also one layer of the insulation sheet (second insulation sheet  720 ) is present between the V-phase conductor  800 V and the W-phase conductor  800 W in the circumferential direction. Thus, interlayer insulation can be appropriately accomplished while minimizing the space occupied by the insulation sheet in the space between conductors adjacently positioned in the circumferential direction. As a result, the dimension of the respective conductors  800 U,  800 V, and  800 W in the circumferential direction can be larger and rated current capable of flowing through the respective conductors  800 U,  800 V and  800 W can be increased. 
     According to the present embodiment, only the third insulation sheet  740  among the first to third insulation sheets  700 ,  720  and  740  is present in the stator core  760  side of the U-phase conductor  800 U in the radial direction. Hence, a cooling ability for the U-phase conductor  800 U can be enhanced in the heat radiation path connected between a portion of the U-phase conductor  800 U in the stator core  760  side in the radial direction and the stator core  760 . 
     According to the comparative example shown in  FIG. 80 , since a portion of the W-phase conductor  800 W in the rotor side is covered by the insulation sheet  900 , the cooling ability of the W-phase conductor  800 W is decreased. In contrast, according to the present embodiment, a rotor side portion of the W-phase conductor  800 W in the radial direction is exposed. Therefore, a fluid (e.g. air) flowing through the gap between the stator  770  and the rotor enhances the cooing ability of the W-phase conductor  800 W. 
     For the V-phase conductor  800 V between the U, W phase conductors  800 U and the  800 W with respect to the radial direction, the first insulation sheet  700  is present in one side thereof in the radial direction and the second insulation sheet  720  is present in the other side thereof in the radial direction. Hence, the cooling ability of the V phase conductor  800 V is considered to be lower than the cooling ability of the U, W-phase conductors. As a result, in the case where the stator winding is energized, the temperature of the V-phase conductor  800 V is considered to be higher than the temperature of the U, W-phase conductors  800 U and  800 W. In this respect, the V-phase conductor  800 V is positioned between the U-phase conductor  800 U and the W phase conductor  800 W of which the cooling abilities are relatively high, whereby the V-phase conductor  800 V can be appropriately cooled. 
     According to the present embodiment, the configuration makes uniform among a total thickness dimension at a portion positioned between the W-phase conductor  800 W and the stator core  760  in the first insulation sheet  700 , the second insulation sheet  720  and the third insulation sheet  740 , a total thickness dimension at a portion positioned between the V-phase conductor  800 V and the stator core  760  in the second insulation sheet  720  and the third insulation sheet  740 , and a total thickness dimension at a portion positioned between the U-phase conductor  800 U and the stator core  760  in the third insulation sheet  740 . Hence, a distance in the radial direction from a surface facing the rotor to the stator core  760  is made to be uniform distance LK in the respective U, V, W phase conductors. Thus, a gap between each of the U, V, W-phase conductors  800 U,  800 V and  800 W and the rotor can be uniform, whereby a torque variation of the rotating electric machine can be reduced. 
     Note that the fifteenth modification can be changed as follows. 
     For example, in the case where the surface of the U-phase conductor  800 U is coated by the insulating coating, the stator  770  may not include the third insulation sheet  740 . 
     A temperature sensor such as a thermistor may be provided at only the V-phase conductor  800 V among the U-phase, V-phase and W-phase conductor in a state of being contacted. This is because, as described above, the temperature at V-phase conductor may be the highest among the respective conductors  800 U,  800 V,  800 W. In this configuration, the control device may lower the torque command to restrict an energization of the stator winding, when determined that a detection value of the temperature sensor exceeds the temperature threshold, thereby performing overheating protection of the stator  770 . 
     The stator winding may be configured such that two pairs of conductors constitutes each winding with a condition of m=2 as shown in  FIG. 12 . In this case, conductors in respective phases shown in  FIG. 79  may be arranged such that not one but two conductors are arranged in the circumferential direction. 
     The cross-sectional shape of each conductor in respective phases is not limited to a rectangular, but may be a circular shape, for example. 
     The configuration of the fifteenth modification can be adapted to a stator that constitutes an inner rotor type rotating electric machine. 
     OTHER EMBODIMENTS 
     For example, according to the rotating electric machine  500 , the inlet passage  571  and the outlet passage  572  of the cooling water passage  545  are provided together at the same portion. However, this configuration may be changed such that the inlet passage  571  and the outlet passage  572  are disposed at different portions in the circumferential direction. For example, the inlet passage  571  and the outlet passage  572  are disposed at 180 degrees different portions in the circumferential direction, or at least the inlet passage  571  or the outlet passage  572  may be provided in a plural number. 
     The wheel  400  according to the above-described embodiments is configured such that the rotating shaft  501  protrudes in one side of the rotating electric machine  500  in the axial direction. However, this configuration may be changed such that the rotating shaft  501  protrudes in both sides of the rotating electric machine in the axial direction. Thus, a configuration suitable for a vehicle in which at least one of front and back wheels is configured as one wheel can be accomplished. 
     As the rotating electric machine  500  used for the wheel  400 , an inner rotor type rotating electric machine can be utilized. 
     The disclosure herein is not limited to the illustrated embodiments. The disclosure includes exemplary embodiments and modifications by persons skilled in the art based on the exemplary embodiments. For example, the disclosure is not limited to the parts and/or element combinations indicated in the embodiments. The disclosure can be carried out in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which the parts and/or elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and/or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some technical scopes disclosed are indicated by the statement of the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims. 
     While the present disclosure has been described in accordance with the examples, the present disclosure should be understood such that the present disclosure is not limited to the examples and structures. The present disclosure also includes various modifications and modifications within an equivalent range. Additionally, various combinations and forms, as well as other combinations and forms further including only one element, more, or less, also fall within the category and scope of the present disclosure. 
     CONCLUSION 
     The disclosed aspects herein employ different technical means. The features and effects disclosed herein are made clearer by reference to the above-described detailed description and accompanying drawings. The present disclosure provides an armature and a manufacturing method thereof in which a space occupied by an insulation sheet is minimized in a space between conductors adjacently positioned in the circumferential direction. 
     A first aspect of the present disclosure is an armature adapted to a rotating electric machine provided with a field magnet including a plurality of magnetic poles having alternating polarities in a circumferential direction, the armature being disposed facing the field magnet. The armature includes a three-phase armature winding; and an armature core disposed opposite to the field magnet in a radial direction with the three-phase armature winding interposed therebetween, in which the armature winding includes conductors arranged in the circumferential direction at predetermined intervals in the order of a first phase, a second phase and a third phase; a first insulation sheet is arranged to sequentially pass through a field magnet side with respect to a first conductor corresponding to the first phase in a radial direction, a portion between the first conductor and a second conductor corresponding to the second phase, an armature core side with respect to the second conductor and a third conductor corresponding to the third phase in the radial direction and a portion between the third conductor and the first conductor; and a second insulation sheet is arranged to sequentially pass through a portion opposite to the first conductor with respect to the first insulation sheet in the radial direction, a field magnet side with respect to the second conductor in the radial direction, a portion between the second conductor and the third conductor, a portion between the third conductor and the first insulation sheet in the radial direction and a portion between the third conductor and the first insulation sheet in the circumferential direction. 
     According to the first aspect, one layer of the insulation sheet (first insulation sheet) is present between the first conductor and the second conductor in the circumferential direction, and also one layer of the insulation sheet (second insulation sheet) is present between the second phase conductor and the third conductor in the circumferential direction. Thus, interlayer insulation can be appropriately accomplished while minimizing the space occupied by the insulation sheet in the space between conductors adjacently positioned in the circumferential direction. 
     Further, according to the first aspect, the first and second insulation sheets are not present in the armature core side of the first conductor in the radial direction. Hence, a cooling ability of the first conductor can be enhanced by a heat radiation path connected between a portion in the armature core side in the first conductor and the armature core in the radial direction. 
     A second aspect is, in the first aspect, the armature is provided with a third insulation sheet interposed between the armature core, and the first conductor and the first insulation sheet; a distance in the radial direction from a circumferential surface in a field magnet side of each of the first conductor, the second conductor and the third conductor to the armature core is made to be uniform in a state where a total thickness dimension at a portion positioned between the third conductor and the armature core in the first insulation sheet, the second insulation sheet and the third insulation sheet, a total thickness dimension at a portion positioned between the second conductor and the armature core in the second insulation sheet and the third insulation sheet, and a total thickness dimension at a portion positioned between the first conductor and the armature core in the third insulation sheet are uniform. 
     In the second aspect, in order to enhance the insulation properties between the first conductor and the armature core, the third insulation sheet is provided to be interposed between the armature core and the first conductor and the first insulation sheet. 
     In this case, the first to third insulation sheets are present between the third conductor and the armature core, the first and second insulation sheets are present between the second conductor and the armature core, and the third insulation sheet is present between the first conductor and the armature core. When the total thickness of the first to third conductors between the third conductor and the armature core, the total thickness of the first and second insulation sheets between the second conductor and the armature core and the total thickness of the third insulation sheet between the first conductor and the armature core are different, gaps between respective first to third conductors and the field magnet are different. 
     In this respect, according to the second aspect, the distance in the radial direction from a circumferential surface in a field magnet side of each of the first conductor, the second conductor and the third conductor to the armature core is made to be uniform. Hence, gaps between respective first to third conductors and the field magnet can be uniform. As a result, for example, torque variation of the rotating electric machine can be reduced. 
     A third aspect is a manufacturing method of an armature adapted to a rotating electric machine provided with a field magnet including a plurality of magnetic poles having alternating polarities in a circumferential direction, in which the armature is disposed facing the field magnet, and the armature includes a three-phase armature winding and an armature core disposed opposite to the field magnet in a radial direction with the three-phase armature winding interposed therebetween. The manufacturing method of the armature includes: a process for producing a first assembly by arranging a first conductor corresponding to a first phase on a first surface of a first insulation sheet with intervals therebetween; a process for producing a second assembly by arranging a third conductor corresponding to a third phase on a first surface of a second insulation sheet with intervals therebetween; a process for disposing a second conductor corresponding to a second phase to be adjacent to the first conductor via the first insulation sheet on a second surface of the first insulation sheet that constitutes the first assembly; a process for producing a laminate between the first assembly in which the second conductor is disposed and the second assembly such that the second conductor is positioned to be adjacent to the third conductor via the second insulation sheet; a process for producing the armature winding by making the laminate rounded to be molded in an annular shape; and a process for producing the armature by assembling the armature winding to the armature core. 
     According to the third aspect, an armature can be produced in which one layer of the insulation sheet (first insulation sheet) is present between the first conductor and the second conductor in the circumferential direction, and also one layer of the insulation sheet (second insulation sheet) is present between the second phase conductor and the third conductor in the circumferential direction. 
     Further, according to the third aspect, an armature in which the first and second insulation sheets are not present in the armature core side of the first conductor in the radial direction can be produced. Hence, a cooling ability of the first conductor can be enhanced by a heat radiation path connected between a portion in the armature core side in the first conductor and the armature core in the radial direction. 
     A fourth aspect is the manufacturing method in the third aspect provided with a process in which the armature winding is assembled to the armature core in a state where the third insulation sheet is interposed between the first conductor and the first insulation sheet in the process for producing the armature; the armature is pressed from a field magnet side such that a distance in the radial direction from a circumferential surface in a field magnet side of each of the first conductor, the second conductor and the third conductor to the armature core is made to be uniform, thereby making a total thickness dimension at a portion positioned between the third conductor and the armature core in the first insulation sheet, the second insulation sheet and the third insulation sheet, a total thickness dimension at a portion positioned between the second conductor and the armature core in the second insulation sheet and the third insulation sheet, and a total thickness dimension at a portion positioned between the first conductor and the armature core in the third insulation sheet to be uniform. 
     According to the fourth aspect, gaps between respective first to third conductors and the field magnet can be uniform. As a result, for example, torque variation of the rotating electric machine can be reduced.