JP6009519B2 - Rotating electric machine and method of manufacturing rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine and a method for manufacturing the rotating electrical machine.

  In a rotating electrical machine, a rotating magnetic field is generated by supplying AC power to a stator winding, and the rotor is rotated by this rotating magnetic field. In addition, AC energy can be output from the coil by converting mechanical energy applied to the rotor into electrical energy. Thus, the rotating electrical machine operates as an electric motor or a generator. As a stator of such a rotating electric machine, a configuration is known in which an external connection side lead-out portion is arranged to extend in the axial direction above the stator core, and neutral wires are arranged on both sides thereof (for example, Patent Document 1). reference).

JP 2011-015459 A

  When this type of rotating electrical machine is mounted on an automobile, it is required to be downsized because it is mounted in a narrow and limited space. In order to secure a gap between the upper end of the coil end and the mission portion, it is desirable to narrow a convex region such as a neutral wire route. However, this type of rotating electric machine has a problem that the core back and the coil end become large and project in the axial direction and the radial direction.

According to the first aspect of the present invention, a rotating electrical machine includes a stator core in which a plurality of slots arranged in the circumferential direction are formed, and a stator coil with an insulation coating inserted into the slots of the stator core. And a rotor disposed so as to be rotatable with a predetermined gap with respect to the stator core, and the stator coil has a rectangular cross-section conductor formed into a substantially U shape in advance. A main coil of a plurality of phases to which a plurality of segment coils are connected; a first sub-coil including a lead wire that is pulled out from the slot and to which an AC terminal is attached; and is connected to one end of each of the main coils; A second subcoil including a neutral wire drawn from the slot and connected to the other end of each of the main coils, wherein the lead wire and the neutral wire are a plurality of straight portions. And from the bend Is composed of a conductor made a folded structure, and the lead wire is first conductor portion that is bent from the slot in a radial direction along the Rutotomoni coil end rising obliquely to the coil end direction, the coil A second conductor portion bent in a radial direction so as to bend along the coil end on the end, and the neutral wire has a region where the axial height of the neutral wire changes at the coil end. An insulating film is formed in a conductor region which is bent in a radial direction and in which the straight portion and the bent portion are formed.
According to the second aspect of the present invention, in the method for manufacturing a rotating electrical machine, the insulating film is provided on the conductor of the stator coil before forming, and the forming process is performed in order to bend the conductor while bringing the forming pin into contact with the conductor. A plurality of the bent portions are formed by performing a plurality of times.

  According to the present invention, the core back and the coil end can be reduced in size.

1 is a schematic diagram illustrating an overall configuration of a rotating electrical machine according to a first embodiment of the present invention. It is a perspective view which shows the stator of the rotary electric machine which concerns on the 1st Embodiment of this invention. 3 is a perspective view of a stator core 132. FIG. It is a figure which shows the electromagnetic steel plate 133. FIG. It is a figure which shows the cross section of the rotor 150 and the stator 130. It is a perspective view which shows the stator coil 138. FIG. It is a figure which shows a star connection. It is a perspective view which shows stator coil 138U. It is a perspective view which shows stator coil 138U1. It is a perspective view which shows stator coil 138U2. It is a figure explaining the connection method of the segment coil. FIG. 10 is an enlarged view of a portion of the lead wire 500U1 shown in FIG. It is a figure explaining the forming process of the lead wire 500U1, and is the figure which looked at the lead wire 500U1 from the center side of the stator core 132. It is a figure explaining forming processing of outgoing line 500U1, and is a figure which looked at outgoing line 500U1 along the axial direction. It is a figure which shows lead wire 500U1 of U1 phase coil, and lead wire 500U2 of U2 phase coil. It is a figure which shows the part of the neutral wire connection part 712 of FIG. It is a figure which shows the lead wire of U1 phase and U1 phase connected to AC terminal 41U. It is a figure which shows the neutral wires 712U2, 712V2, and 712W2 connected by the neutral wire connection part 712. It is a figure which shows the connection structure of the stator coil in 2nd Embodiment. It is a figure which shows the bridge line 400U.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
-First embodiment-
(Overall configuration of rotating electrical machine)
The rotating electrical machine according to the present embodiment is a rotating electrical machine that is suitable for use in driving an automobile. Here, a so-called electric vehicle using a rotating electric machine includes a hybrid type electric vehicle (HEV) having both an engine and a rotating electric machine, and a pure electric vehicle (EV) that runs only by the rotating electric machine without using an engine. However, since the rotating electrical machine described below can be used for both types, the description will be made based on the rotating electrical machine used for a hybrid type vehicle as a representative.

  FIG. 1 is a schematic diagram showing an overall configuration of a rotating electrical machine 100 according to an embodiment of the present invention. In FIG. 1, the inside of the rotating electrical machine 100 is shown by making a part of the rotating electrical machine 100 into a cross section. As shown in FIG. 1, the rotating electrical machine 100 is disposed inside the case 10, and includes a housing 112, a stator 130 having a stator core 132 fixed to the housing 112, and the inside of the stator. And a rotor 150 disposed rotatably. The case 10 includes an engine case and a transmission case.

  The rotating electrical machine 100 is a three-phase synchronous motor with a built-in permanent magnet. The rotating electrical machine 100 operates as an electric motor that rotates the rotor 150 when a three-phase alternating current is supplied to the stator coil 138 wound around the stator core 132. Further, when the rotating electrical machine 100 is driven by an engine, it operates as a generator and outputs three-phase AC generated power. That is, the rotating electrical machine 100 has both a function as an electric motor that generates rotational torque based on electric energy and a function as a generator that generates electric power based on mechanical energy. Functions can be used selectively.

  The stator 130 is fixed to the housing 112. The stator 130 is fixedly held in the case 10 by a flange 115 provided on the housing 112 being fastened to the case 10 by bolts 12. The rotor 150 fixed to the shaft 118 is supported by the bearings 14 </ b> A and 14 </ b> B of the case 10, and is rotatably held inside the stator core 132.

  FIG. 2 is a perspective view showing the stator 130 attached to the housing 112. The housing 112 is formed in a cylindrical shape by drawing a steel plate (such as a high-tensile steel plate) having a thickness of about 2 to 5 mm. A flange 115 is provided at one end of the housing 112 in the axial direction, and is folded and bolted to the case 10 as described above (see FIG. 1). The flange 115 is formed integrally with the housing 112 by drawing. Note that the stator 130 may be directly fixed to the case 10 without providing the housing 112.

  The stator 130 is fixed to the inner peripheral side of the housing 112, and has a cylindrical stator core 132 and a stator coil 138 attached to the stator core 132. FIG. 3 is a perspective view of the stator core 132. The stator core 132 is formed by laminating a plurality of electromagnetic steel plates 133 as shown in FIG. The electromagnetic steel sheet 133 has a thickness of about 0.05 to 1.0 mm and is formed by punching or etching. The laminated electromagnetic steel sheets 133 are fixed by welding. In the example shown in FIG. 3, the weld 200 shows it. The electromagnetic steel plates 133 stacked by this welding are connected, and deformation of the electromagnetic steel plates 133 due to the tightening force when press-fitted into the housing 112 is suppressed.

  A plurality of slots 420 extending in the axial direction are formed in the stator core 132 so as to be equally spaced in the circumferential direction. The number of slots 420 is, for example, 72 in this embodiment. As shown in FIG. 2, the stator coil 138 is accommodated in the slot 420. In the example shown in FIG. 3, the slot 420 is an open slot, and an opening is formed on the inner peripheral side of the stator core. The circumferential width of the opening is substantially the same as or slightly smaller than the coil mounting portion of each slot 420 in which the stator coil 138 is mounted.

  Insulating paper 300 is disposed in each slot 420. The insulating paper 300 is disposed in the slot 420 and the coil ends 140a and 140b. By disposing the insulating paper 300 (so-called slot liner) in the slot 420, the insulating paper 300 is disposed between the coils inserted into the slot 420 and between the coil and the inner surface of the slot 420. The withstand voltage between the inner surface of 420 is improved.

  Further, the insulating paper 300 disposed on the coil ends 140a and 140b is annularly disposed between the coils for interphase insulation and interconductor insulation at the coil ends 140a and 140b. As described above, in the rotating electrical machine 100 according to the present embodiment, since the insulating paper 300 is disposed inside the slot 420 and at the coil ends 140a and 140b, even if the insulating coating of the coil is damaged or deteriorated, Necessary withstand voltage can be maintained. The insulating paper 300 is an insulating sheet of heat-resistant polyamide paper, for example, and has a thickness of about 0.1 to 0.5 mm.

  Teeth 430 are formed between the slots 420, and each tooth 430 is integrated with an annular core back 440. The stator core 132 is an integral core in which the teeth 430 and the core back 440 are integrally molded. The teeth 430 serve to guide the rotating magnetic field generated by the stator coil 138 to the rotor 150 and generate a rotating torque in the rotor 150.

  The stator core 132 shown in FIG. 3 is fitted and fixed to the inside of the cylindrical housing 112 by shrink fitting. As a specific assembling method, for example, a stator core 132 is first arranged, and a housing 112 that has been heated in advance and expanded in inner diameter by thermal expansion is fitted into the stator core 132. Next, the housing 112 is cooled to shrink the inner diameter, whereby the outer peripheral portion of the stator core 132 is tightened by the heat shrinkage.

  The stator core 132 has an inner diameter dimension of the housing 112 that is smaller than an outer diameter dimension of the stator core 132 by a predetermined value so that the stator core 132 does not idle with respect to the housing 112 due to a reaction caused by the torque of the rotor 150 during operation. Set to. As a result, the stator core 132 is firmly fixed in the housing 112 by shrink fitting. The difference between the outer diameter of the stator core 132 and the inner diameter of the housing 112 at room temperature is called a tightening allowance. By setting this allowance assuming the maximum torque of the rotating electrical machine 100, the housing 112 has a predetermined tightening force. Thus, the stator core 132 can be held. The stator core 132 is not limited to being fitted and fixed by shrink fitting, but may be fitted and fixed to the housing 112 by press fitting.

  FIG. 5 is a diagram illustrating the rotor 150, and is a view illustrating a cross section of the rotor 150 and the stator 130. In addition, in order to avoid complexity, the stator coil 138 and the insulating paper 300 housed in the shaft 118 and the slot 420 are omitted. As shown in FIG. 5, the rotor 150 includes a rotor core 152 and permanent magnets 154 held in magnet insertion holes formed in the rotor core 152.

  In the rotor core 152, rectangular parallelepiped magnet insertion holes are formed at equal intervals in the circumferential direction in the vicinity of the outer peripheral portion. A permanent magnet 154 is embedded in each magnet insertion hole and fixed with an adhesive or the like. The width of the magnet insertion hole in the circumferential direction is larger than the width of the permanent magnet 154 in the circumferential direction, and magnetic gaps 156 are formed on both sides of the permanent magnet 154. The magnetic gap 156 may be embedded with an adhesive, or may be solidified integrally with the permanent magnet 154 with a resin.

  The permanent magnet 154 forms a field pole of the rotor 150. In the present embodiment, one magnetic pole is formed by one permanent magnet 154, but one magnetic pole may be formed by a plurality of permanent magnets. By increasing the number of permanent magnets for forming each magnetic pole to a plurality, the magnetic flux density of each magnetic pole emitted from the permanent magnet increases, and the magnet torque can be increased.

  The magnetization direction of the permanent magnet 154 is directed in the radial direction, and the direction of the magnetization direction is reversed for each field pole. That is, if the surface on the stator side of the permanent magnet 154 for forming a certain magnetic pole is magnetized to the N pole and the surface on the shaft side is magnetized to the S pole, the stator side of the permanent magnet 154 that forms the adjacent magnetic pole is assumed. The surface is magnetized so as to be the south pole and the shaft side surface is the north pole. In this embodiment, the 12 permanent magnets 154 are magnetized so as to change the magnetization direction alternately for each magnetic pole at equal intervals in the circumferential direction, so that the rotor 150 forms 12 magnetic poles. ing.

  The permanent magnet 154 may be magnetized and embedded in the magnet insertion hole of the rotor core 152, or may be inserted into the magnet insertion hole of the rotor core 152 before being magnetized, and then magnetized by applying a strong magnetic field. You may do it.

  However, the magnetized permanent magnet 154 has a strong magnetic force. If the magnet is magnetized before the permanent magnet 154 is fixed to the rotor 150, the permanent magnet 154 is strongly attracted to the rotor core 152 when the permanent magnet 154 is fixed. A force is generated, and this suction force hinders work. Moreover, there is a possibility that dust such as iron powder adheres to the permanent magnet 154 due to the strong attractive force. Therefore, in order to improve the productivity of the rotating electrical machine 100, it is desirable that the permanent magnet 154 is magnetized after being inserted into the magnet insertion hole of the rotor core 152. Here, as the permanent magnet 154, a neodymium-based, samarium-based sintered magnet, a ferrite magnet, a neodymium-based bond magnet, or the like can be used, but the residual magnetic flux density of the permanent magnet 154 is 0.4 to 1. About 3T is desirable, and a neodymium magnet is more suitable.

  In the present embodiment, the auxiliary magnetic pole 160 is formed between the permanent magnets 154 forming the magnetic pole. The auxiliary magnetic pole 160 acts so that the magnetic resistance of the q-axis magnetic flux generated by the stator coil 138 is reduced. The auxiliary magnetic pole 160 causes the magnetic resistance of the q-axis magnetic flux to be much smaller than the magnetic resistance of the d-axis magnetic flux, so that a large reluctance torque is generated.

  When a rotating magnetic field is generated in the stator 130 by supplying the three-phase alternating current to the stator coil 138, the rotating magnetic field acts on the permanent magnet 154 of the rotor 150 to generate magnet torque. Since the above-described reluctance torque is generated in the rotor 150 in addition to the magnet torque, both the above-described magnet torque and reluctance torque act on the rotor 150 as rotational torque, and a large rotational torque is generated. Can be obtained.

(Description of stator coil)
FIG. 6 is a perspective view showing a stator coil 138 for three phases. The stator coils 138 are connected in a star connection configuration as shown in FIG. In the present embodiment, a two-star stator coil 138 in which two star connections are connected in parallel is employed. That is, it has a U1 phase, V1 phase and W1 phase star connection, and a U2 phase, V2 phase and W2 phase star connection, and the U1 and U2 phase lead wires are combined together by an AC terminal 41U. The V1 and V2 phase lead wires are grouped together by an AC terminal 41V, and the W1 and W2 phase lead wires are grouped together by an AC terminal 41W. N1 and N2 are neutral points of the respective star connections.

  The stator coil 138 is wound in a distributed winding manner. The distributed winding is a winding method in which the phase-wound coil is wound around the stator core 132 so that the phase-wound coil is accommodated in two slots 420 that are separated across the plurality of slots 420. In the present embodiment, distributed winding is adopted as the winding method, so that the formed magnetic flux distribution is closer to a sine wave than concentrated winding, and has a feature that reluctance torque is likely to be generated. Therefore, this rotating electrical machine 100 has improved controllability using field-weakening control and reluctance torque, and can be used over a wide rotational speed range from a low rotational speed to a high rotational speed, and is suitable for an electric vehicle. Excellent motor characteristics can be obtained.

  The stator coil 138 may have a round cross section or a square shape. However, there is a tendency for the efficiency to be improved by using the cross-section inside the slot 420 as effectively as possible and reducing the space in the slot. Is desirable. The square shape of the cross section of the stator coil 138 may be a shape in which the circumferential direction of the stator core 132 is short and the radial direction is long, or conversely, the circumferential direction is long and the radial direction is short. It may be. In this embodiment, the stator coil 138 is a rectangular coil in which the rectangular cross section of the stator coil 138 is long in the circumferential direction of the stator core 132 and short in the radial direction of the stator core 132 in each slot 420. It is used. Moreover, the outer periphery of this flat coil is covered with an insulating film.

  As shown in FIG. 2, the stator coil 138 shown in FIG. 6 has a total of six coils (U 1, U 2, V 1, V 2, W 1, W 2) attached in close contact with the stator core 132. The six coils constituting the stator coil 138 are arranged at appropriate intervals by the slot 420. As shown in FIG. 6, on one coil end 140a side of the stator coil 138, AC terminals 41U, 41V, 41W which are input / output terminals for UVW three phases, and neutral wire connecting portions 711, 712, Is arranged.

  In order to improve workability in assembling the rotating electrical machine 100, the AC terminals 41U, 42V, and 43W for receiving the three-phase AC power protrude from the coil end 140a outward in the axial direction of the stator core 132. Is arranged. The stator 130 is connected to a power converter (not shown) via the AC terminals 41U, 42V, and 43W, so that AC power is supplied.

  As shown in FIGS. 2 and 6, the coil ends 140a and 140b, which are portions protruding outward in the axial direction from the stator core 132, are arranged in an orderly manner as a whole, leading to a reduction in the size of the entire rotating electrical machine. effective. Further, the orderly arrangement of the coil ends 140a and 140b is desirable from the viewpoint of improving the reliability with respect to the insulation characteristics.

  FIG. 8 is a perspective view showing a U-phase stator coil 138 </ b> U wound around the stator core 132. FIGS. 9 and 10 are perspective views showing a U1-phase stator coil 138U1 and a U2-phase stator coil 138U2 constituting the stator coil 138U. As can be seen from FIGS. 9 and 10, the stator coil 138 is a segment type coil formed by connecting a plurality of U-shaped segment coils 28 to each other. The segment coil 28 has a top portion 28c disposed at one coil end 140a. Further, both end portions 28E and 28E of the segment coil 28 are connected to the other segment coil 28 at the other coil end 140b.

  FIG. 11 is a diagram for explaining a method of connecting the segment coils 28. The segment coil 28 before being attached to the slot 420 of the stator core 132 is preliminarily formed into a U-shape composed of a mountain-shaped top portion 28c and a straight portion 28b as shown in the upper side of the figure. Each segment coil 28 is inserted into the slot 420 from the coil end 140a side of the stator core 132 (see FIG. 2). After insertion into the slot 420, the straight portion 28b protruding to the opposite side of the stator core 132 (coil end 140b side in FIG. 2) is bent in the direction of the adjacent segment coil to be connected, and the end portion 28E is further downward in the figure. Bend to the side. Then, the end portion 28E and the end portion 28E of the adjacent segment coil 28 are connected by welding or the like.

  In this way, a main coil to which a plurality of segment coils 28 are connected is formed. And the subcoil containing a lead wire and the subcoil containing a neutral wire are connected to the both ends of the main coil comprised by the segment coil 28, and one phase coil is formed. Thus, in the main coil, the segment coil 28 which is a preformed conductor is used, thereby ensuring insulation between the conductors and not placing a burden on the insulating film.

  In the U1-phase stator coil 138U1 shown in FIG. 9, the subcoil 701U1 to which the AC terminal 41U is connected has a portion that is housed in the slot of the stator core 132, and a lead wire 500U1 that is drawn from the slot. . In the stator coil 138 in the present embodiment, the secondary coil 701U1 is housed in the outermost layer of the slot. The lead wire 500U1 has a bent portion 501U1 bent so as to be bent, and a terminal portion 502U1 to which the AC terminal 41U is connected. The secondary coil 701U1 is connected to the end 28E of the segment coil 28 provided at one end of the U1-phase main coil on the coil end 140b side. Further, a sub coil 702U1 having a neutral wire 711U1 is connected to the segment coil 28 provided at the other end of the main coil.

  On the other hand, also in the case of the U2-phase stator coil 138U2 shown in FIG. 10, the subcoil 701U2 to which the AC terminal 41U is connected includes a portion housed in the slot of the stator core 132 and a lead wire 500U2 drawn from the slot. Have. The subcoil 701U2 is housed in the innermost layer of the slot. The lead wire 500U2 has a bent portion 501U2 bent so as to be bent, and a terminal portion 502U2 to which the AC terminal 41U is connected. The bent portion 501U2 is drawn out in the opposite direction to the bent portion 501U1 of the U1 phase. The secondary coil 701U2 is connected to the end 28E of the segment coil 28 provided at one end of the U2-phase main coil on the coil end 140b side. Further, a sub coil 702U2 having a neutral wire 712U2 is connected to the segment coil 28 provided at the other end of the main coil.

  Terminal portions 502U1 and 502U2 are bent from coil end 140a in the outer peripheral direction of stator core 132 so as to be substantially perpendicular to coil end 140a. Although not described, the U-phase, V-phase, and W-phase stator coils have the same configuration as the U-phase coil, and the U-phase, V-phase, and W-phase stator coils have a predetermined slot pitch in the circumferential direction. They are shifted one by one. As shown in FIG. 6, the AC terminals 41U, 41V, and 41W are arranged in one place so as to be connected to the cable, and all face in the same direction (a direction substantially perpendicular to the coil end 140a). They are arranged parallel to each other.

  The AC terminals 41U, 41V, 41W are gathered in a circumferential width within a predetermined number of slots of the stator core 132. For example, when 3 slots per phase are secured to ensure mutual insulation, it is possible to aggregate the slots within a total of about 9 slots, but the number is not limited to 9 slots. As shown in FIG. 6, AC terminals 41U, 41V, and 41W have their terminal portions bent so that their phases are substantially parallel to each other. Since each of the U, V, and W phases is arranged so that the terminal portions are aligned in parallel, the rigidity of the terminal portions can be increased. At this time, when the terminal portions to which excessive tension or compressive force is applied are adjacent to each other, the tensile compressive force is absorbed, and the occurrence of fatigue failure in the terminal portion can be suppressed.

  As shown in FIG. 6, the portion where the AC terminals 41U, 41V, and 41W are provided is gathered in one place for connection with the cable, and the convex region such as the neutral coil routing on the coil end 140a is narrowed. And secure a gap with the mission part. Moreover, it has a simple structure in consideration of ensuring insulation between conductors and manufacturing workability while concentrating them at one place.

  Furthermore, as shown in FIG. 2, the coil end 140a is made low by narrowing the protruding region of the neutral wires 711U1 and 712U2 on the coil end 140a. Therefore, the neutral wires 711U1, 711V, and 711W of the U1, V1, and W1 phases are connected to the left side of the AC terminals 41U, 41V, and 41W on the coil end 140a while being connected to the U2 phase and the V2 phase. And the neutral wire 712U2 of the W2 phase is routed and connected to the right side of the AC terminals 41U, 41V, 41W in the figure on the coil end 140a.

  In the present embodiment, the lead wires 500U1 and 500U2 and the neutral wires 711U1 and 712U2 drawn from the coil end 140a are bent so that the scooping on the coil end 140a has a shorter path. The core back 440 is made small to reduce the winding resistance. Below, the bending shape in the lead wires 500U1 and 500U2 and the bending shape of the neutral wires 711U1 and 712U2 will be described.

  FIG. 12 is an enlarged view of a portion of the lead line 500U1 shown in FIG. The AC terminal 41U is not shown. The lead wire 500U1 illustrated in FIG. 12 includes a first conductor portion 511U1, a second conductor portion 512U1, and the terminal portion 502U1 described above. The first conductor portion 511U1 is a portion that rises obliquely upward from the straight portion (the portion inserted into the slot 420) of the sub-coil 701U1 and extends above the top portion 28c of the segment coil 28, along the top portion 28c. It draws an arc.

  Further, the second conductor portion 512U1 is a conductor portion that is wound around the plurality of top portions 28c (see FIG. 6). In FIG. 12, only two segment coils are shown, so there are also two top portions 28c. Actually, however, as shown in FIG. 6, a large number of top portions 28c are arcuate at the coil end 140a. Are aligned. Further, the terminal portion 502U1 is bent so as to be bent at a substantially right angle from the second conductor portion 512U1 to the outer peripheral direction of the coil end 140a. In the example shown in FIG. 12, the terminal portion 502U1 is once raised upward from the second conductor portion 512U1 and then bent in the outer peripheral direction so that the wide surface of the flat wire faces upward and downward.

  In the present embodiment, a forming process (automatic forming process) is used for forming the lead wire 500U1 having a complicated shape as shown in FIG. Conventionally, a forming process is not used for forming a rectangular wire having an insulating coating, and it has been formed into a more abbreviated shape using mold forming. In addition, about shaping | molding of the segment coil 28, shaping | molding using a type | mold is used similarly to the past.

  13 and 14 are diagrams for explaining the forming process of the lead wire 500U1. 13 is a view as seen from the center side of the stator core 132, and FIG. 14 is a view as seen along the axial direction from above the coil end 140a. As can be seen from FIGS. 13 and 14, the lead wire 500U1 is bent three-dimensionally (three-dimensionally), and it is very difficult to mold using the mold having such a shape.

  In the example shown in FIGS. 13 and 14, bending by forming is performed in the order of FIGS. 13, 14 (a), and 14 (b). In addition, P1-P12 has shown the position of the shaping | molding pin at the time of performing a forming process, and a bending process is performed in order of P1-P12. In FIG. 13, bending is performed by applying a pin to a surface where the width of the flat wire is narrow. The sub-coil 701U1 is bent in the order of the pin positions P1, P2, and P3, and a portion that becomes the first conductor portion 511U1, the second conductor portion 512U1, and the terminal portion 502U1 is formed.

  Next, in FIG. 14, bending is performed by applying a pin to a surface where the width of the flat wire is wide. The final shape of the first conductor portion 511U1 is formed by bending the pin positions P4, P5, P6, P7, and P8 in this order. The first conductor portion 511U1 is curved in the coil end radial direction. Next, the final shape of the second conductor portion 512U1 is formed by bending the pin positions P9, P10, and P11 in this order. Finally, the terminal portion 502U1 is formed by bending 90 degrees at the pin position P12.

  Thus, since the lead wire 500U1 is bent by forming, as shown in FIG. 12, a straight portion between a plurality of bent portions B with which the forming pin abuts and a bent portion B adjacent to the bent portion B is provided. S. An indentation of the forming pin is formed at the pin contact portion of the bent portion B. By performing a plurality of bends in this way, even if the bent portion 501U1 has a complicated curved shape, it can be accurately approximated by a broken line. Note that at least two or more bent portions B are formed in the second conductor portion 512U1 wound so as to be bent near the top of the coil end 140a so as to better approximate the ideal shape.

  FIG. 15 is a diagram showing a lead wire 500U1 of the U1-phase coil and a lead wire 500U2 of the U2-phase coil. The terminal portion 502U1 of the lead wire 500U1 and the terminal portion 502U2 of the lead wire 500U2 are connected to a common AC terminal 41U. Due to the arrangement of the AC terminal 41U, the lengths of the lead wires 500U1 and 500U2 are different. Moreover, since the folding part 501U1 and the bending part 501U2 are different in the position of scooping, the bent shape is also different. As shown in FIG. 15, since the shape when the lead wire 500U1 of the U1 phase coil and the lead wire 500U2 of the U2 phase coil are connected by the AC terminal 41U becomes a trapezoid, the rigidity can be increased. Thereby, the natural frequency of the coil itself can be lowered as compared with the cantilever structure.

  FIG. 16 is a diagram showing a portion of the neutral wire connecting portion 712 in FIG. The neutral wire connecting portion 712 is a portion where the neutral wire 712U2 of the U2 phase, the neutral wire 712V2 of the V2 phase, and the neutral wire 712W2 of the W2 phase are connected, and the neutral point N2 of FIG. It is a part corresponding to. The slots in which the U2, V2, and W2-phase subcoils 702U2, 702V2, and 702W2 are inserted are shifted by a predetermined slot interval. Accordingly, the lengths of the neutral wires 712U2, 712V2, and 712W2 are different, and the shape is also different. They are different from each other.

  When the AC terminal 41U is connected as shown in FIG. 15, the insulating film 600 is formed on the bent portions 501U1 and 501U2 which are portions drawn out from the slots of the auxiliary coils 701U1 and 701U2 as shown in FIG. In this part, sufficient withstand voltage is ensured. As the insulating film 600, for example, an insulating powder coating film is suitable. As a coating material (powder) used for insulating powder coating, an epoxy resin for electrical insulation is used. Similarly, when three neutral wires 712U2, 712V2, and 712W2 are connected as shown in FIG. 16, an insulating film 600 is applied to the drawn portions as shown in FIG.

-Second Embodiment-
19 and 20 are diagrams for explaining a second embodiment of the present invention. In the first embodiment described above, the stator coil 138 has a two-star connection structure. However, in the second embodiment, a similar star coil 28 is used as shown in FIG. . When the U-phase coil is viewed, the coils denoted by reference numerals U1 and U2 have the same configuration as the U1-phase coil and U2-phase coil shown in FIG. 7, and the coil U1 and the coil U2 are connected by the bridge line 400U. is there. The same applies to the V phase and the W phase. The U-phase, V-phase, and W-phase coils connected by the bridge lines 400U, 400V, and 400W are connected at a neutral point N.

  FIG. 20 shows the bridge line 400U, but the bridge lines 400U and 400W have the same structure. Here, the bridge line 400U will be described as an example. The bridge line 400U includes straight conductor portions 703a and 703b inserted into the slots, and a connecting portion 500 that connects the straight conductor portions 703a and 703b. The connecting portion 500 is a portion that is pulled out of the slot, and includes skewed portions 500a and 500b that are pulled out from the slot, and a scooping portion 500c that is wound around the coil end. The oblique portions 500a and 500b are disposed in the gap between the group of segment coils 28.

  A conductor drawn out from the straight conductor portion 703b, such as the skew portion 500b, is bent in the opposite direction and then connected to the skew portion 500a. In the present embodiment, in addition to the lead wire and the neutral wire described in the first embodiment, a forming process is applied to forming the connecting portion 500 of the bridge wire 400U. By forming the bridge line 400U having such a complicated shape by forming, a connecting portion 500 formed by a bent line close to an ideal curve can be easily obtained. That is, the connection part 500 is comprised by the linear part and the bending part.

In the embodiment described above, the following operational effects are obtained.
(1) As shown in FIGS. 6, 8, 9, and 10, the stator coil 138 </ b> U <b> 1 includes a main coil in which a plurality of segment coils 28 in which a conductor having a rectangular cross section is formed in a substantially U shape is connected, and a slot 420. A lead wire 500U1 to which the AC terminal 41U is pulled out and attached is included, a subcoil 701U1 connected to one end of the main coil, a neutral wire 711U1 drawn from the slot, and the other end of the main coil at the other end A secondary coil 702U1 to be connected. The stator coil 138 shown in FIG. 6 is provided with six sets of such phase coils U1, U2, V1, V2, W1, and W2. For example, the lead wire 500U1 of the subcoil 701U1 and the neutral wire 711U1 of the second subcoil 702U1 are formed of a conductor having a bent structure including a plurality of straight portions S and bent portions B.

  By using the lead wire 500U1 and the neutral wire 711U1 as a conductor having a bent structure, the shapes of the lead wire 500U1 and the neutral wire 711U1 can be made closer to the ideal shape. Thereby, useless scooping can be suppressed, and the amount of coil used and the winding resistance can be reduced. Further, the size of the scooping on the coil end 140a can be reduced, and the coil end 140a and the core back 440 can be reduced.

(2) Furthermore, the lead wire 500U1 is connected to the first conductor portion 511U1, which is the first conductor region from the slot to the top 28c of the segment coil 28, and the terminal connection provided at the tip of the lead wire. The terminal portion 502U1 is a region, and the second conductor portion 512U1 is a coil end winding region between the terminal portion 502U1 and the first conductor portion 511U1. Then, by bending the second conductor portion 512U1 three-dimensionally so that two or more bent portions B are formed, the shape of the second conductor portion 512U1 that crawls on the coil end 140a is brought close to an ideal shape. Can do. As a result, it is possible to suppress an increase in the height of the entire coil end caused by scooping the lead wire 500U1.

(3) Further, in the case of a winding structure using bridge wires 400U to 400W as shown in FIG. 19, as shown in FIG. 20, the connecting portion 500 has a bent structure composed of a plurality of straight portions and bent portions. By comprising with a conductor, the shape of the conductor wound around the coil end can be brought closer to the ideal shape, and the entire coil end can be prevented from being enlarged.

(4) The bent portion is formed by a forming process that bends the conductor while bringing the forming pin into contact with the conductor. A folding structure can be easily formed and printed by using an automatic forming machine. When forming is performed, an indentation by a forming pin is formed in the bent portion on the conductor surface. Although the total number of segment coils 28 is large, they are classified into several types of shapes. Further, since the shape is relatively simple, it is suitable from the viewpoint of cost to use the mold using the mold as in the prior art for forming the segment coil 28. On the other hand, the number of lead wires and neutral wires is only 12 even in the case of a 2-star connection stator coil, and the shapes thereof are different and the shapes are complicated. Therefore, it is very expensive to mold each of them with a mold.

  On the other hand, when a lead wire or a neutral wire is bent by forming, any shape can be easily handled, and the wire can be freely formed into any shape. Furthermore, productivity can be increased by dividing the process of forming lead wires and neutral wires using NC forming and the step of forming a plurality of segment coils with a mold. Moreover, it is possible to manufacture a coil having a reduced shape and a stable shape.

(5) By making all the bending radii of the bent portions the same size, the bending can be continuously performed with the same molding pin, and the setup for pin replacement can be omitted, thereby improving productivity. You can plan. In addition, since the bent portion is the same bend, damage to the enamel film of the coil can be made uniform, resulting in a coil with excellent insulation.

(6) Furthermore, by forming the insulating film 600 in the conductor region where the straight portion and the bent portion are formed, a sufficient withstand voltage can be obtained in combination with the insulating coating of the conductor.

(7) The stator coil 138 has a winding structure in which the lead wire and the neutral wire are drawn from the innermost side or the outermost side of the slot, so that the lead wire and the neutral wire are wound around. The length can be reduced and the coil end 140a and the core back 440 can be made small. In the present embodiment, the lead line 41U, the lead line 41V1, and the lead line 41W are arranged in parallel at positions perpendicular to the axial direction, and the neutral line 711 and the neutral line 712 are arranged as the lead line 41U and the lead line. The winding structure is such that 41V1 and the lead wire 41W are arranged in the circumferentially opposite direction. By doing so, the lead wire and the neutral wire are drawn out from the innermost side or the outermost side of the slot, and the convex region of the routing is narrowed to ensure a gap with the mission unit. In addition, it has a simple structure in consideration of ensuring insulation between conductors and manufacturing workability while concentrating the lead wires in one place.

  The above description is merely an example, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiment and the items described in the claims. For example, in the above-described embodiment, the rotating electric machine having a permanent magnet in the rotor has been described as an example. However, the present invention can be similarly applied to a stator of a rotating electric machine such as an induction motor. Further, the present invention can be applied to other than the rotating electric machine for driving the vehicle.

  28: segment coil, 28c: top, 41U, 41V, 41W: AC terminal, 100: rotating electric machine, 130: stator, 132: stator core, 138, 138U, 138U1, 138U2: stator coil, 140a140b: coil End, 150: Rotor, 400U: Bridge wire, 420: Slot, 500: Connection portion, 500U1, 500U2: Lead wire, 501U1, 501U2: Bending portion, 502U1, 502U2: Terminal portion, 511U1: First conductor portion, 512U1 : Second conductor portion, 600: insulating film, 701U1, 701U2, 702U1, 702U2: secondary coil, 711U1, 711V1, 711W1, 712U2, 712V2, 712W2: neutral wire, B: bent portion, S: straight portion, P1 P12: Pin position

Claims (4)

A stator core having a plurality of slots arranged in the circumferential direction, and a stator having a stator coil with an insulating coating inserted into the slots of the stator core;
In a rotating electrical machine comprising: a rotor disposed rotatably with a predetermined gap with respect to the stator core;
The stator coil is
A multi-phase main coil in which a plurality of segment coils formed in advance in a substantially U shape with a rectangular cross-section conductor are connected;
A first subcoil connected to one end of each of the main coils, including a lead wire that is pulled out of the slot and to which an AC terminal is attached;
A second subcoil including a neutral wire drawn from the slot and connected to the other end of each of the main coils,
The lead wire and the neutral wire are composed of a conductor having a bent structure composed of a plurality of straight portions and bent portions,
The lead wire comprises: a first conductor portion that is bent from the slot in a radial direction along the Rutotomoni coil end rising obliquely to the coil end direction, the diameter so as to curve along the upper coil end to the coil end A second conductor portion bent in a direction ,
In the neutral wire, a region where the axial height of the neutral wire changes at the coil end is bent in the radial direction ,
An electrical rotating machine, wherein an insulating film is formed in a conductor region where the straight portion and the bent portion are formed. In the rotating electrical machine according to claim 1,
The rotating electrical machine, wherein the second conductor portion has two or more bent portions. In the rotating electrical machine according to claim 1 or 2,
The main coil of each phase is obtained by connecting two divided main coils with a bridge coil,
The bridge coil has a connection region drawn out of the slot so as to straddle the two slots,
The rotating electrical machine according to claim 1, wherein the connecting region is formed of a conductor having a bent structure including a plurality of straight portions and bent portions. It is a manufacturing method of the rotary electric machine according to claim 1,
Provide the insulating film on the conductor of the stator coil before molding,
A method of manufacturing a rotating electrical machine, wherein a plurality of the bent portions are formed by sequentially performing a plurality of forming processes for bending the conductor while bringing a forming pin into contact with the conductor.

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