Rotating electric machine and method for manufacturing stator winding of rotating electric machine

Abstract

A rotating electric machine includes: a stator core with slots arranged therein; and a stator winding mounted on the slots of the stator core, the stator winding having a bend portion connecting the slot portions adjacent to the slot portions inserted into the slots, the bend portion being composed of an inner layer side bend portion stacked along the axial direction of the stator core and arranged on the inner layer side and an outer layer side bend portion arranged on the outer layer side, the inner layer side bend portion and the outer layer side bend portion having a radial displacement portion composed of an inner diameter displacement portion, a displacement center portion and an outer diameter displacement portion, the displacement center portion of at least any one of the inner layer side bend portion and the outer layer side bend portion being linear or concave in the axial inner direction relative to a plane orthogonal to the axial direction. The enlargement of the coil end can be avoided, and the damage to the insulation coating of the coil of the stator winding can be reduced, thereby suppressing the reduction of the insulation property.

Description

Technical Field

[0001] The present application relates to a rotating electric machine and a method for manufacturing a stator winding of the rotating electric machine. Background Art

[0002] In recent years, rotating electrical machines, such as motors and generators, have been pursuing small size, high output, and high efficiency. In order to meet these requirements, distributed winding, which uses coils with a roughly rectangular cross section, is adopted, especially in automotive motors. Compared with concentrated winding, the stator of distributed winding has the characteristic of low noise due to the smooth distribution of the rotating magnetic field. In addition, by using coils with a roughly rectangular cross section, it is possible to increase the duty ratio of the coil and achieve high output compared to the case where round wires are bundled together to form the winding.

[0003] On the other hand, when a coil with a rectangular cross-section is used to form the coil end, if the corners of the rectangular cross-section are in contact with each other, there is a possibility that the surface pressure applied to the coating becomes larger and the insulation decreases. Therefore, it is necessary to three-dimensionally shape the shape of the coil end to prevent interference. In addition, not only to avoid interference, but also to cool the coil end, it is preferred to set a desired gap at the coil end. In addition, although the smaller the bending radius is when the coil end is formed, the more miniaturized the coil end can be, there is a situation where the insulating coating will be peeled off and the insulation decreases if the bending radius is reduced. In this way, there is a need to simultaneously meet the technical problems of setting an appropriate gap at the coil end, improving the reliability of the insulating coating, and miniaturizing the coil end.

[0004] In order to solve the above technical problems, for example, a structure is proposed in a rotating electric machine of Patent Document 1, in which the coil return portions at the apex of the coil end of the coil wound multiple times are stacked on concentric semicircles in the stator winding, and spaces are provided between the coil return portions that penetrate from the inner circumference to the outer circumference. It is described that by setting such a structure, interference of the coil end portions can be avoided and the cooling performance can be improved.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 5770074

[0008] However, in the rotating electric machine of patent document 1, the return bend that connects the groove parts to each other is composed of a circumferential bending part, a bevel part, an axial rising part and a radial displacement part, so there is a problem of enlargement of the coil end. That is, even if the bevel parts are aligned, the coil end will become higher by the amount of the bending radius of the axial rising part, the bending radius of the radial bending part in the radial displacement part and the coil stacking thickness. In addition, when the bending radius is reduced, the miniaturization of the coil end can be achieved in theory, but the damage to the insulating coating of the coil becomes greater, so the insulation will be reduced. In addition, although the coil end can be miniaturized by reducing the gap between the bevel parts, interference is likely to occur during assembly due to the smaller gap, which will reduce productivity. Summary of the invention

[0009] The present application is made to solve the above-mentioned technical problems, and its purpose is to provide a rotating electric machine that can avoid enlargement of coil ends, reduce damage to the insulation coating of the coil of the stator winding, and suppress the reduction of insulation.

[0010] The rotating electric machine disclosed in the present application is characterized in that it includes: an annular stator core, in which a plurality of slots opening toward the inner circumference are arranged along the circumferential direction; and a stator winding, wherein the stator winding is installed on the stator core, and the stator winding has a bend portion, which connects the slot portions adjacent to the slot portions inserted into the slots to each other, and the bend portion is composed of an inner layer side bend portion stacked along the axial direction of the stator core and arranged on the inner layer side, and an outer layer side bend portion arranged on the outer layer side, and the inner layer side bend portion and the outer layer side bend portion have a radial displacement portion composed of an inner diameter displacement portion, a displacement center portion and an outer diameter displacement portion, and the displacement center portion of at least any one of the inner layer side bend portion and the outer layer side bend portion is linear or concave in the inner direction of the axial direction relative to a plane orthogonal to the axial direction.

[0011] In addition, one of the characteristics of the manufacturing method of the stator winding of the rotating electric machine disclosed in the present application is that when the coil constituting the stator winding is wound by a winding frame with the radial direction of the stator core as the rotation center, the inner diameter side groove portion and the outer diameter side groove portion of the groove portion consisting of the inner diameter side groove portion and the outer diameter side groove portion are relatively moved along the circumferential direction, and the radial displacement portion is wound by the straight portion of the winding frame, so that the displacement center portion of the coil is formed into a straight line.

[0012] According to the rotating electric machine disclosed in the present application, by circumferentially staggering the shifted inner diameter portion and the shifted outer diameter portion of the radial shifted portion of the return portion of the coil constituting the stator winding, the length of the oblique side portion can be reduced, thereby achieving the effect of miniaturization of the coil side end. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view showing a schematic structure of the rotating electrical machine according to the first embodiment.

[0014] Figure 2 This is an external perspective view showing the structure of the stator in the first embodiment.

[0015] 3( a ) and 3 ( b ) are a perspective view showing the appearance of the coil constituting the stator winding in the first embodiment and a diagram of the AA portion.

[0016] 4( a ) and 4 ( b ) are schematic diagrams showing the structure of the rotating electrical machine according to the first embodiment.

[0017] Figure 5 This is a diagram showing the connection relationship between the coil and the inverter device in the first embodiment.

[0018] Figure 6 This is a diagram showing the connection relationship between coils in the first embodiment.

[0019] 7( a ), 7 ( b ), 7 ( c ), and 7 ( d ) are diagrams showing the structure of an inner layer turn portion among the turn portions of the coil in the first embodiment.

[0020] 8( a ) and 8 ( b ) are schematic diagrams showing the return portion of the coil in the first embodiment.

[0021] 9( a ), 9 ( b ), 9 ( c ), and 9 ( d ) are diagrams showing the structures of the inner layer turn portion and the outer layer turn portion of the turn portion of the coil in the first embodiment.

[0022] Fig.10 It is a figure which shows the formation method of the coil in Embodiment 1.

[0023] Fig.11 This is a first schematic diagram showing a method for forming a turn portion of a coil in the first embodiment.

[0024] Fig.12 This is a second schematic diagram showing the method of forming the return portion of the coil in the first embodiment.

[0025] Fig.13 Yes means Fig.12 Figure 2. A cross section of the DD section.

[0026] Fig.14 Yes means Fig.12 FIG. 5 is a diagram showing a cross-section of the portion DD of another embodiment of the present invention.

[0027] Fig.15 (a) and (b) are schematic diagrams showing a method for forming a turn portion of a coil in the first embodiment.

[0028] Fig.16 (a) and (b) are schematic diagrams showing a method for forming a turn portion of a coil in the second embodiment.

[0029] Fig.17 (a) and (b) are schematic diagrams showing a method for forming another embodiment of the return portion of the coil in the second embodiment.

[0030] Fig.18 (a) and (b) are schematic diagrams showing a method for forming still another embodiment of the return portion of the coil in the second embodiment.

[0031] 19( a ) and 19 ( b ) are schematic diagrams showing a turn portion of a coil in the third embodiment.

[0032] (Explanation of symbols)

[0033] 1 housing;

[0034] 2 Bracket;

[0035] 3. Stator;

[0036] 4 bearings;

[0037] 5. Rotating shaft;

[0038] 6 rotors;

[0039] 7 rotor core;

[0040] 8 permanent magnet;

[0041] 9 stator core;

[0042] 10 stator winding;

[0043] 11 Rotating electrical machines;

[0044] 12 coils;

[0045] 12a Winding coil;

[0046] 13 Inverter device;

[0047] 14 Neutral point;

[0048] 15 Magnetic wire;

[0049] 20a, 20b coil ends;

[0050] 21 pole tooth portion;

[0051] 22 Grooving;

[0052] 23 Grooving section;

[0053] 24 return bend;

[0054] 25 peripheral end;

[0055] 26 inner peripheral end;

[0056] 101 circumferential bending portion;

[0057] 102 bevel;

[0058] 104 radial displacement portion;

[0059] 104a inner diameter displacement portion;

[0060] 104c displaced central part;

[0061] 104b outer diameter displacement portion;

[0062] 107 Cooling space;

[0063] 108 Bevel clearance;

[0064] 110 inner layer side return bend;

[0065] 111 outer side return bend;

[0066] 120 inner diameter side cut groove portion retaining member;

[0067] 121 outer diameter side cut groove portion retaining member;

[0068] 122 inner diameter side bevel portion retaining member;

[0069] 123 outer diameter side bevel portion retaining member;

[0070] 131 Wire reel;

[0071] 131a Short side straight part;

[0072] 131b Curvilinear part;

[0073] 131c long side straight part;

[0074] 133 bobbin;

[0075] 141 inner diameter side groove limiting portion;

[0076] 142 outer diameter side groove limiting portion;

[0077] 143 bending part pressure member;

[0078] 145 inner diameter side limiting member;

[0079] 146 Outer diameter side restriction member. DETAILED DESCRIPTION

[0080] Implementation Method 1

[0081] Figure 1 It is a cross-sectional view showing a schematic structure of the rotating electrical machine according to the first embodiment. Figure 2 3(a) and 3(b) are perspective views showing the structure of the stator. FIG. 4(a) and FIG. 4(b) are schematic views showing the structure of the rotating electrical machine. In addition, Figure 5 This is a diagram showing the connection relationship between the coil and the inverter device.

[0082] First, use Figure 1 The overall structure of the rotating electrical machine according to the first embodiment will be described.

[0083] exist Figure 1 In the figure, the rotating electric machine 11 includes: a cylindrical housing 1 with a bottom; a bracket 2, the bracket 2 blocks the opening of the housing 1; a stator 3, the stator 3 is fixed to the housing 1 by fixing means such as sintering or pressing; a rotating shaft 5, the rotating shaft 5 is rotatably supported on the bottom of the housing 1 and the bracket 2 via a bearing 4; and a rotor 6, the rotor 6 is fixed to the rotating shaft 5 and is rotatably arranged on the inner circumference of the stator 3.

[0084] Here, the rotor 6 is a permanent magnet type rotor including a rotor core 7 and permanent magnets 8. The rotor core 7 is fixed to the rotating shaft 5 inserted at the axial center position. The permanent magnets 8 are buried on the outer peripheral surface side of the rotor core 7 and arranged at a specified interval in the circumferential direction to form magnetic poles.

[0085] Next, refer to Figures 2 to 5 , the structure of the stator 3 is described in detail.

[0086] In the following description, the rotation axis direction ( Figure 1 The up and down direction in the figure is defined as the axial direction, and the center direction of the shaft ( Figure 1 The left and right directions in the figure are defined as radial directions, and the rotation direction with the rotation axis as the center is defined as circumferential directions for the purpose of explanation.

[0087] like Figure 2 As shown in the external perspective view of the stator 3, the stator 3 includes a stator core 9 and a stator winding 10, which is mounted on the stator core 9 and is composed of a coil 12 formed by a conductor. Here, for the sake of convenience, the stator winding 10 is a three-phase winding in which the number of poles is eight and the number of slots of the stator core 9 is 48. That is, the slots are formed in the stator core 9 at a ratio of two per pole per phase.

[0088] FIG. 3( a ) is a perspective view showing the appearance of the coil 12 , and FIG. 3( b ) is a partial view of the coil 12 , showing the twisting manner of the notched portions 23 ( S1 to S8 ) of the coil 12 in the AA portion of FIG. 3( a ).

[0089] As shown in the schematic diagram of Fig. 4(a), the stator core 9 has: a pole tooth portion 21 extending radially inward; and slots 22 divided in the circumferential direction by the pole tooth portion 21. In addition, as shown in Fig. 4(b), the coil 12 has: a slot portion 23 (S1 to S8) mounted on the slot 22 of the stator core 9; a bend portion 24 (T1-2, T2-3, T3-4, T4-5, T5-6, T6-7, T7-8) protruding from the slot 22 of the stator core 9 and provided to different slots 22 in the circumferential direction; and an outer peripheral side end 25 (T1A) and an inner peripheral side end 26 (T8A) protruding in the axial direction from the slot 22 of the stator core 9 and used for connecting to another coil 12 of the stator winding 10. For example, when current is supplied from the outer peripheral end 25, the current flows through the slot 23 and the coil ends 20a and 20b, and is connected to another adjacent coil 12 from the inner peripheral end 26. Thus, by flowing current through the coil 12, a magnetic field can be generated.

[0090] Here, the slot portions 23 of S1 to S4 are connected by the return portion 24 across six slot pitches in the circumferential direction, and are wound at intervals equal to the pole pitch. S4 and S5 are connected via T4-5, and are connected by the return portion 24 across five slot pitches in the circumferential direction, and the slots 22 formed in the stator core 9 at a ratio of two per pole per phase are connected. Similar to S1 to S4, S5 to S8 are connected by the return portion 24 across six slot pitches. The outer circumferential side terminal 25 and the inner circumferential side terminal 26 connect the coils 12 to each other, or to the inverter device 13 as a power supply unit for supplying voltage.

[0091] Figure 5 An example of a connection diagram of the stator winding 10 is shown. U1 to U8 represent the coils 12 constituting the U phase of the three-phase AC, and are powered from the inverter device 13 through the outer peripheral side terminal 25 or the inner peripheral side terminal 26. In addition, the coils 12 joined to these end portions are connected to the neutral point 14 via the outer peripheral side terminal 25 or the inner peripheral side terminal 26. V1 to V8 represent the coils 12 constituting the V phase, and W1 to W8 represent the coils 12 constituting the W phase, and similarly, they are connected to the power supply portion and the neutral point 14 to form a three-phase winding.

[0092] In this way, Figure 2As shown, twenty-four coils 12 are arranged in one circle, and the stator core 9 is inserted from the outer diameter side to form the stator 3. In addition, in this embodiment, the structure of the stator 3 in the case where the stator core 9 is divided and inserted from the outer diameter side is described as an example, but it is also possible to insert the coil 12 from the inner diameter side of the stator 3 without a dividing surface in the circumferential direction.

[0093] Figure 6 Represents the wiring pattern in the U phase of the stator winding 10. Uin represents the power supply part of the U phase in the three-phase AC, and Uout is connected to the neutral point 14. The slot numbers represent the numbers of the forty-eight slots 22 of the stator core 9, and the numbers in the quadrilateral represent the connection order starting from Uin. The part surrounded by the ellipse represents the coil 12 shown in Figure 3(a), and the thick line represents the connection part of the end line. In this way, by continuously winding the coil 12 around two slots, the number of coils can be reduced, which has the effect of improving the productivity during assembly. Therefore, since the number of joints can be reduced, it also has the effect of improving productivity. In addition, by reducing the number of joints, the intervals between the joints are lengthened, and therefore, it also has the effect of improving the insulation between the wiring parts.

[0094] Here, the structure of the return portion 24 of the coil 12 in this embodiment will be described in detail using Figures 7(a), 7(b), 7(c), 7(d), 8(a), 8(b), 9(a), 9(b), 9(c), and 9(d). The return portion 24 is composed of a continuous conductor formed by a circumferentially bent portion 101, a bevel portion 102, and a radially displaced portion 104.

[0095] Fig. 7(a), Fig. 7(b), Fig. 7(c) and Fig. 7(d) show the structure of the inner layer side bend portion 110 corresponding to T3-4 and T7-8 shown in Fig. 3(a) among the bend portions 24 of the coil 12. In addition, for the convenience of explanation, the arc-shaped bend portion 24 is described here in a shape in which it is unfolded in a straight line. That is, the left and right directions in Fig. 7(a) are the circumferential directions, the originally arc-shaped portion is unfolded in a straight line and illustrated, the up and down directions represent the radial directions, and the paper direction represents the axial directions. In addition, Fig. 8(a) and Fig. 8(b) show schematic diagrams of the inner layer side bend portion 110 and the outer layer side bend portion 111, and Fig. 9(a), Fig. 9(b), Fig. 9(c) and Fig. 9(d) show top views and stereoscopic views of the inner layer side bend portion 110 and the outer layer side bend portion 111.

[0096] First, as shown in FIG. 7( b), the slot portion 23 of the coil 12 accommodated in the slot 22 of the stator 3 is continuously connected to the slot portion 23 of another coil 12 through the circumferentially bent portion 101, the bevel portion 102 and the radially displaced portion 104 via the axially protruding return portion 24. The slot portions 23 connected by the return portion 24 are separated from each other in the circumferential direction and accommodated in another radially different slot 22. The radially displaced portion 104 moves radially at the top of the return portion 24, and by setting it as such a structure, there is an effect of avoiding interference with the return portions 24 adjacent to each other in the circumferential direction.

[0097] Here, as shown in Fig. 8(a) and Fig. 8(b), the radial displacement portion 104 is composed of an inner diameter displacement portion 104a, a displacement center portion 104c and an outer diameter displacement portion 104b. The inner diameter displacement portion 104a and the outer diameter displacement portion 104b are staggered in the circumferential direction when viewed from the radial direction. Thus, the length A of the oblique side portion can be shortened compared to the prior art. Therefore, it has the effect of reducing the height of the return bend portion 24 and miniaturizing the coil side ends 20a, 20b.

[0098] In addition, as shown in Fig. 8(a) and Fig. 8(b), the radial displacement portion 104 is inclined relative to the axial direction. Therefore, compared with the bending inner diameter R of the inner diameter displacement portion 104a observed from the circumferential direction in the prior art, as shown in Fig. 8(a) and Fig. 8(b), the bending inner diameter R of the inner diameter displacement portion 104a observed from the circumferential direction can be significantly reduced. Therefore, by reducing the axial height required for the inner diameter displacement portion 104a to reduce the height of the return bend portion 24, there is an effect of miniaturizing the coil side ends 20a, 20b.

[0099] Furthermore, by making the displacement center portion 104c substantially linear, the height of the return bend portion 24 can be suppressed compared to the case of a uniform bending inner diameter R as in the conventional example, which has the effect of miniaturizing the coil side ends 20a and 20b.

[0100] Here, it is preferred that the inner layer side bend portion 110 and the outer layer side bend portion 111 of the bevel portion 102 are arranged straight in the radial direction. By arranging the bevel portion 102 straight in the radial direction, it is less likely to interfere with the adjacent bevel portion 102 compared to the case where it is not arranged, so the gap with the adjacent coil 12 can be reduced to suppress the height of the bend portion 24, which has the effect of miniaturizing the coil side ends 20a, 20b.

[0101] As shown in Fig. 9(a), preferably, the radial displacement portion 104 includes a circumferential movement component. By making the radial displacement portion 104 include a circumferential movement component, the length of the oblique side portion 102 extending in the circumferential direction can be shortened, which has the effect of miniaturizing the coil side ends 20a and 20b.

[0102] Here, as shown in FIG. 9( b ), it is preferred that a cooling space 107 is provided between the radially adjacent radially displaced portions 104 in the circumferential direction. The provision of the space has an effect of improving the cooling performance. In addition, by providing a fan that generates a radial fluid flow on the rotor side, the cooling performance is further improved. In addition, since the radially displaced portions 104 are spaced apart from each other, the insulation performance is also improved.

[0103] In addition, as shown in FIG9(b), a bevel gap 108 may be provided between the bevel portions 102 adjacent to each other in the circumferential direction. By providing the gap, the cooling performance is improved. In addition, by providing a fan that generates radial fluid flow on the rotor side, the cooling performance is further improved. In addition, since the bevel portions 102 are spaced apart from each other, the insulation performance is also improved.

[0104] In addition, as shown in Fig. 9(d), it is preferable that the radial movement amount of the radial displacement portion 104 is greater than the radial movement distance in the notch portion 23. By setting such a structure, compared with the case where the movement amount of the radial displacement portion 104 is the same as the radial movement amount in the notch portion 23, the interval of the continuous torsion portion can be increased, thereby reducing damage to the insulating film and having an effect of improving the reliability of the insulation.

[0105] Next, an example of a method for forming the return bend portion 24 in the first embodiment will be described. Fig.10 1 is a schematic diagram showing a state where the magnetic wire 15, which is the material of the coil 12, is wound around the winding frame 131 with the circumferential direction as the rotation center. The winding frame 131 is composed of a short side straight portion 131a, a curved portion 131b, and a long side straight portion 131c, and the short side straight portion 131a corresponds to the shift center portion 104c. The magnetic wire 15 wound around the winding tube 133 is wound around the winding frame 131 via the guide 132, thereby forming the wound coil 12a.

[0106] Fig.11 2 is a first schematic diagram showing a method for forming the return bend 24. Fig.12 This is a second schematic diagram showing a method of forming the return bend portion 24 .

[0107] First, if Fig.11 As shown, the notch 23 of the wound coil 12a is held by the outer diameter side notch holding member 121 and the inner diameter side notch holding member 120. Next, the bevel 102 is held by the inner diameter side bevel holding member 122 and the outer diameter side bevel holding member 123.

[0108] like Fig.12 As shown, here, it is preferable that the outer diameter side bevel portion retaining member 123 restricts the radial direction and the circumferential direction of the bevel portion 102. Fig.11 As shown, the outer diameter side groove portion holding member 121 and the inner diameter side groove portion holding member 120 are relatively moved in the circumferential direction, and the outer diameter side bevel portion holding member 123 and the inner diameter side bevel portion holding member 122 are rotated in the radial direction as the rotation axis while moving axially downward. The return bend portion 24 in embodiment 1 can be obtained in the following manner. Fig.13 express Fig.12 In addition, Fig.14 In another embodiment, Fig.12 DD section.

[0109] In the formation of the return bend portion 24, by adopting such a manufacturing method, since there is no need to limit the radial displacement portion 104 that damages the insulating coating after a single processing, the reliability of the insulation is improved. In addition, by limiting the bevel portion 102, the coil 12 of the stator winding 10 of the rotating electric machine 11 can be obtained by a single molding, which has the effect of improving productivity. Here, it is preferred that the outer diameter side groove portion retaining member 121 and the inner diameter side groove portion retaining member 120 limit the circumferential and radial directions of the groove portion 23. By limiting the groove portion 23, the groove portion 23 will not twist, so it is possible to increase the duty cycle of the coil 12 and achieve high output.

[0110] As described above, in this embodiment, when forming the coil 12 constituting the stator winding 10, by pre-molding the displaced central portion 104c of the radially displaced portion 104, the number of steps can be reduced compared to the case where the steps are separately molded, which has the effect of improving productivity.

[0111] In addition, in this embodiment, the case where the winding frame 131 having the short side straight portion 131a is used from the beginning is described, but Fig.15 As shown in the schematic diagram of the method for forming the bend portion of the coil, the method may also be as follows, namely, while the circumferential and radial directions of the cut groove portion 23 are restricted by the outer diameter side cut groove portion retaining member 121 or the inner diameter side cut groove portion retaining member 120, the wound coil 12a is pressurized axially by the mold 135, thereby forming a roughly linear displacement center portion 104c.

[0112] In addition, in this embodiment, the case where the structure has the return portion 24 on both sides in the axial direction is described, but it is sufficient to have the return portion connected continuously on at least one side in the axial direction. That is, even if it is applied to a structure called a segment conductor method (Japanese: セグメントコンダクト method) in which a continuous return portion is provided only on one side in the axial direction, the same effect can be obtained.

[0113] In addition, in the description of the above-mentioned embodiment, the displacement center portion 104c is roughly straight, but the same effect can be obtained even if it is not a completely straight shape, but a curved shape with a curved inner diameter R that is at least larger than the curved inner diameter R of the inner diameter displacement portion 104a and the curved inner diameter R of the outer diameter displacement portion 104b.

[0114] Thus, according to the rotating electric machine of the first embodiment, the inner diameter displacement portion and the outer diameter displacement portion of the radial displacement portion of the return portion of the coil constituting the stator winding are staggered in the circumferential direction, thereby reducing the length of the oblique side portion, thereby having the effect of miniaturizing the coil side end. As a result, the enlargement of the coil side end can be avoided, and the damage to the insulation coating of the coil of the stator winding can be reduced, thereby suppressing the reduction of insulation.

[0115] Implementation Method 2

[0116] Fig.16 This is a schematic diagram showing a method of forming a turn portion of a coil in Embodiment 2. Embodiment 2 will be described only with respect to points different from Embodiment 1.

[0117] In addition, in embodiment 1, if Fig.10 and Fig.15 As shown in FIG. 1 , a substantially linear displacement center portion 104 c is formed in a state where the coil 12 a is wound. In contrast, in Embodiment 2, first, as shown in FIG. Fig.16 As shown in (a), after the slot portion 23 of the coil 12 is moved in the circumferential direction, the slot portion 23 is restricted by the inner diameter side slot restriction portion 141 and the outer diameter side slot restriction portion 142. Fig.16 As shown in (a), the coil 12 is pressed in the axial direction by the return portion pressing member 143, thereby obtaining a substantially linear displacement center portion 104c.

[0118] By using such a forming method, the coil 12 can be made into Fig.14 The simple shape shown, therefore, has the effect of improving productivity. Fig.16 As shown in (b), since it has the effect of reducing the deviation of the upper and lower dimensions of the coil 12, that is, the B dimension, the height deviation of the bend portion 24 can be suppressed and the shape can be stabilized. Therefore, there is less interference during assembly, which can improve productivity.

[0119] also, Fig.17 1 is a schematic diagram showing another embodiment of a method for forming a coil return portion. It shows that after the coil 12 is mounted on the stator core 9 ( Fig.17 (a)) uses the bending portion pressurizing member 143 to pressurize from the axial direction ( Fig.17By setting such a structure, in addition to obtaining a substantially linear displacement center portion 104c, the oblique edge gap 108 can be reduced, thereby also having the effect of miniaturizing the coil side ends 20a, 20b.

[0120] also, Fig.18 1 is a schematic diagram showing another embodiment of a method for forming a bend portion of a coil. It shows a method for forming a bend portion 24 in a case where there are size restrictions on the inner and outer diameters of the coil ends 20a and 20b, in which the coil 12 is restricted by the inner diameter restriction member 145 and the outer diameter restriction member 146 ( Fig.18 Under (a)), by using the bending portion pressurizing member 143 to pressurize in the axial direction ( Fig.18 By using this method, the inner diameter and outer diameter of the return bend portion 24 can be reliably managed, thereby having the effect of reducing the defective rate and reducing costs.

[0121] Implementation 3

[0122] FIG. 19(a) and FIG. 19(b) are schematic diagrams of the return bend portion of the coil in Embodiment 3. Regarding Embodiment 3, only the points different from Embodiment 1 are described. In addition, here, for the convenience of description, the shape of the arc-shaped return bend portion 122 unfolded in a straight line is used for description. That is, the left and right directions in FIG. 19(a) are circumferential directions, the original arc-shaped portion is unfolded in a straight line and illustrated, the up and down directions represent the radial direction, and the paper direction represents the axial direction.

[0123] In this embodiment, as shown in Figures 19(a) and 19(b), the shifted central portion 104c of the inner layer side bend portion 110 is concave in the axial inner direction. By setting such a structure, the height of the bend portion 24 can be further reduced, which has the effect of miniaturizing the coil ends 20a and 20b.

[0124] Furthermore, the displacement center portion 104c of the outer layer side return portion 111 is substantially linear. Providing a substantially linear portion in the outer layer side return portion 111 facilitates positioning and improves productivity.

[0125] In addition, the present application describes various illustrative embodiments and examples, but the various features, methods, and functions described in one or more embodiments are not limited to the application of specific embodiments and can be applied to the embodiments alone or in various combinations.

[0126] Therefore, numerous modifications not shown are contemplated within the technical scope disclosed in the present specification, including, for example, modifications, additions, or omissions of at least one component, and also including extraction of at least one component and combination with components of other embodiments.

[0127] In addition, in the drawings, the same symbols represent the same or corresponding parts.

Claims

1. A rotating electrical machine, characterized in that: include: A ring-shaped stator core, in which a plurality of slots opening toward the inner circumference are arranged in a circumferential direction; as well as stator winding, the stator winding is installed on the stator core, The stator winding has a return portion that connects the slot portions adjacent to the slot portion inserted into the slot. The return bend portion is composed of an inner layer return bend portion stacked along the axial direction of the stator core and arranged on the inner layer side and an outer layer return bend portion arranged on the outer layer side, and the inner layer return bend portion and the outer layer return bend portion have a radial displacement portion composed of an inner diameter displacement portion, a displacement center portion and an outer diameter displacement portion, The displacement center portion of the inner layer side return portion has a concave shape that is recessed toward the inner side in the axial direction.

2. The rotating electrical machine according to claim 1, characterized in that A space penetrating in the radial direction of the stator core is provided between the radially displaced portions in the circumferentially adjacent return bend portions.

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