Stator winding for rotary electric machine and rotary electric machine

Abstract

This stator winding (1) for a rotary electric machine is wound around a plurality of layers on a stator (10) of the rotary electric machine (50). The stator winding (1) comprises a plurality of flat element wires (2), and the plurality of flat element wires (2) are wound in a concentrated manner on teeth (13) of the stator (10) by a flatwise bending method. A transposition part (3) that transposes the arrangement of the plurality of flat element wires (2) by 180° is provided between a layer end part (AE) in which an A-layer, which is one layer on the teeth (13) side of the outermost circumference, is wound, and a layer start part (BS) of a B-layer, which is the next layer wound onto the A-layer.

Description

Stator winding of rotating electric machine and rotating electric machine

[0001] The present disclosure relates to a stator winding for a rotating electric machine and a rotating electric machine.

[0002] Conventionally, electric motors have been proposed in which a stator core is provided with multiple teeth, stator windings are wound around these teeth in a concentrated manner, and power is supplied to the stator windings to generate torque in a rotor configured across an air gap, thereby causing the rotor to rotate.Also proposed is a generator in which a rotor arranged across an air gap from the stator is rotated by external power, thereby outputting generated power from the stator windings.

[0003] Stator windings used in rotating electric machines such as electric motors and generators are generally loosely wound windings, in which arbitrary wire strands are wound in any order, for relatively small rotating electric machines, but large, high-capacity rotating electric machines use form-wound windings. This is because in large-capacity rotating electric machines, the current flowing through each winding increases, which requires a larger cross-sectional area of ​​the winding, and the higher voltage requires an insulating layer. Form-wound windings are made up of multiple bundles of rectangular wire strands with a rectangular cross section.

[0004] When a stator winding made up of multiple flat wires is wound around a stator multiple times, i.e., when wound in multiple layers, if the wires are positioned in the same position in the cross section of all the stator windings, an induced voltage difference will occur between the wires due to the magnetic flux linking between them. Normally, the wires are connected together at the end of the stator winding each time one tooth or multiple teeth are wound, and this voltage difference induced between the wires generates a circulating current between the wires, resulting in reduced efficiency and a rise in the temperature of the winding.

[0005] For this reason, for example, Patent Document 1 discloses an example in which the stator winding of a rotating electric machine, in which each stator winding is made up of multiple flat wires, is concentratedly wound around the teeth of the stator, and the stator winding made up of multiple flat wires is twisted (transposed). That is, the stator winding of the rotating electric machine disclosed in Patent Document 1 aims to reduce circulating current loss by twisting the arrangement of each wire by 180° as it is wound around one tooth.

[0006] International Publication No. WO2021 / 024518

[0007] In a rotating electric machine, improving the winding space factor enables a reduction in winding resistance, an increase in the number of turns, etc., and improves efficiency. Therefore, since the transposition parts in the stator winding of the rotating electric machine disclosed in Patent Document 1 cause a larger winding bulge compared to the winding parts other than the transposition parts, a device is devised to position the transposition parts in the outermost layer and at the coil end parts in order to improve the winding space factor.

[0008] When the stator winding is wound around the stator teeth in a concentrated manner, if only one layer is wound around the stator teeth, transposition is possible without reducing the winding space factor, which is effective even when the transposition portion is positioned as described in Patent Document 1. However, if the stator winding is wound in multiple layers, that is, if another stator winding is wound on top of an already wound stator winding, it is necessary to separate the winding into a winding on the tip side of the tooth and a winding on the bottom side, and then finally form the transposition portion, which results in a problem of significantly reduced workability.

[0009] Furthermore, the stator winding of the rotating electric machine disclosed in Patent Document 1 is wound around a rectangular wire by edgewise bending, i.e., by bending the short side of the cross section of the rectangular wire. Therefore, compared to a stator winding wound around a rectangular wire by flatwise bending, i.e., a stator winding wound by bending the long side of the cross section of the rectangular wire, the stator winding of Patent Document 1 has the problem of increased winding bulge and a reduced winding space factor.

[0010] An object of the present disclosure is to provide a stator winding for a rotating electric machine that is easier to work with and has an improved winding space factor than conventional stator windings.

[0011] A stator winding for a rotating electric machine according to the present disclosure is wound in multiple layers around a stator of the rotating electric machine. The stator winding includes multiple flat wires that are wound in a concentrated manner around the teeth of the stator using a flatwise bending method. The stator winding for the rotating electric machine includes a transposition portion that transposes the arrangement of the multiple flat wires by 180° between a layer end portion of layer A, which is a layer closer to the teeth than the outermost periphery, and a layer start portion of layer B, which is the next layer wound around layer A.

[0012] In the stator winding of the rotating electric machine disclosed herein, a plurality of flat rectangular wires are wound in a concentrated manner around the teeth of the stator using a flatwise bending method, and a transposition portion is provided between the end of one layer and the start of the next layer, thereby improving workability and the winding space factor compared to conventional methods.

[0013] 1. is a schematic configuration diagram showing a stator winding of a rotary electric machine according to embodiment 1. FIG. 1 is a diagram showing a first example of the stator winding and transposition parts of FIG. 1. FIG. 2 is a diagram showing a second example of the stator winding of FIG. 1. FIG. 3 is a diagram showing a third example of the stator winding of FIG. 1. FIG. 4 is a diagram showing a schematic view of the direction of main interlinkage magnetic flux linking the stator winding of FIG. 1. FIG. 5 is a diagram showing a stator winding of a comparative example. FIG. 16 is a schematic configuration diagram showing a stator winding of a rotary electric machine according to embodiment 2. FIG. 17 is a diagram showing transposition parts when the stator winding of FIG. 8 has three layers. FIG. 18 is a diagram showing transposition parts when the stator winding of FIG. 8 has four layers. FIG. 19 is a diagram showing transposition parts when the stator winding of FIG. 8 has five layers. FIG. 19 is a schematic configuration diagram showing a stator winding for which an electromagnetic field analysis is performed according to embodiment 2. FIG. 20 is a diagram showing average loss when the number and positions of transposition parts of FIG. 12 are changed. FIG. 21 is a diagram showing loss of each flat rectangular wire when the number and positions of transposition parts of FIG. 12 are changed. 21 is a diagram showing the loss of each flat wire when the number and position of the transposition parts in FIG. 12 are changed. FIG. 22 is a diagram showing the loss of each flat wire when the number and position of the transposition parts in FIG. 12 are changed. FIG. 23 is a diagram showing the loss of each flat wire when the number and position of the transposition parts in FIG. 12 are changed. FIG. 24 is a diagram showing the loss of each flat wire when the number and position of the transposition parts in FIG. 12 are changed. FIG. 25 is a diagram showing the schematic configuration of a stator winding of a rotary electric machine according to embodiment 3. FIG. 26 is a diagram showing the schematic configuration of a stator winding of a rotary electric machine according to embodiment 4. FIG. 27 is a diagram showing the configuration of a rotary electric machine according to embodiment 5. FIG. 28 is a diagram showing the phase ring conductor of FIG.

[0014] Embodiment 1. FIG. 1 is a schematic diagram showing the configuration of a stator winding of a rotating electric machine according to embodiment 1, and FIG. 2 is a diagram showing a first example of the stator winding of FIG. 1 and a transposition portion. FIG. 3 is a diagram showing a second example of the stator winding of FIG. 1, and FIG. 4 is a diagram showing a third example of the stator winding of FIG. 1. FIGS. 5 and 6 are each a diagram showing a schematic diagram of the direction of main interlinkage magnetic flux that interlinks with the stator winding of FIG. 1. FIG. 7 is a diagram showing a stator winding of a comparative example. A rotating electric machine 50 according to embodiment 1 includes a stator 10 and a rotor 20. The rotor 20 has a plurality of permanent magnets 27 provided on the surface of a rotor core 26 (see FIG. 21). The stator 10 includes a stator core 11 having a plurality of teeth 13 arranged outside the rotor 20 with gaps 21 between them, and a stator winding 1 wound around each tooth 13. The stator core 11 includes teeth 13 and a core back 12 that supports the teeth 13. The rotating electrical machine 50 is an electric motor or a generator.

[0015] As shown in FIG. 2 , the stator winding 1 includes a plurality of flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. FIG. 2 shows an example of a stator winding 1 made up of eight flat wires 2. The flatwise bending method involves bending the long sides 6a of the flat wires 2, which have a long side width wl longer than the short side width ws of the short sides 6b in the cross section. The stator winding 1 is wound in a concentrated manner around the teeth 13 of the stator 10, and the first layer LA1 is wound in the order of winding numbers 1 to 10 from the winding start portion COS. In FIG. 1 , winding numbers 1 to 10 are assigned to the cross section of the stator winding 1. Winding numbers 11 to 20 are also assigned to the cross section of the stator winding 1. Between the layer end LE1 of the first layer LA1, which is assigned winding number 10, and the layer start LS2 of the second layer LA2, which is assigned winding number 11, the arrangement of the flat wires 2 of the stator winding 1 is transposed by 180° by the transposition unit 3. The second layer LA2 of the stator winding 1 is formed by winding the flat wires 2 around the outer periphery of the first layer LA1 in the order of winding numbers 11 to 20, with the arrangement of the flat wires 2 transposed by 180°. The layer end LE2 of the second layer LA2, which is assigned winding number 20, is the winding end COE of the stator winding 1. The winding start COS is also the layer start LS1 of the stator winding 1. The stator winding 1 can also be expressed as being wound flatwise around the flat wires 2. Winding or winding by the "flatwise bending method" will be expressed as "flatwise" winding or winding as appropriate. Furthermore, the flatwise bending method will be referred to as flatwise bending, and the edgewise bending method will be referred to as edgewise bending, as appropriate.

[0016] While Figure 1 shows an example in which the stator winding 1 has two layers, i.e., two layers, the stator winding 1 may have three or more layers. If the layer immediately before the transposition portion 3 is arranged is referred to as layer A and the layer immediately after the transposition portion 3 is arranged as layer B, the transposition portion 3 can be expressed as follows: The transposition portion 3 transposes the arrangement of the plurality of flat wires 2 by 180° between the layer end portion (i.e., layer A end portion AE) of layer A, which is one layer closer to the teeth 13 than the outermost periphery, and the layer start portion (i.e., layer B start portion BS) of layer B, which is the next layer wound around layer A. In Figure 1, layer A, layer B, layer A end portion AE, and layer B start portion BS are the first layer LA1, second layer LA2, layer end portion LE1, and layer start portion LS2, respectively.

[0017] 2 shows an example in which the number of flat wires 2 is eight. In the first layer LA1 of the stator winding 1, each flat wire 2 is assigned a wire number from 1 to 8. The flat wires 2 with odd wire numbers 1, 3, 5, and 7 are arranged on the tip side of the teeth 13, i.e., the rotor 20 side, while the flat wires 2 with even wire numbers 2, 4, 6, and 8 are arranged on the core back 12 side of the stator core 11. Furthermore, since each flat wire 2 is bent using the flatwise bending method and wound around the teeth 13, the long side 6a of each flat wire 2, which has a long side width wl, faces the teeth 13. Furthermore, the short side 6b of each flat wire 2, which has a short side width ws, faces the rotor 20 or the core back 12.

[0018] The positions of the flat wires 2 in the second layer LA2 of the stator winding 1 transposed 180° by the transposition portion 3 are changed to wire numbers 8 to 1, compared to wire numbers 1 to 8, which were the positions of the flat wires 2 in the first layer LA1 of the stator winding 1 before transposition. More specifically, the positions of the flat wires 2 in the first layer LA1 are changed to wire numbers 8 to 1. After transposition, the flat wire 2 in the second layer LA2 is disposed in the position of the flat wire 2 in the first layer LA1 with wire number 1. Similarly, after transposition, the flat wires 2 in the second layer LA2 are disposed in the positions of the flat wires 2 in the first layer LA1 with wire numbers 3, 5, and 7. After transposition, the flat wire 2 in the second layer LA2 with wire numbers 7 is disposed in the position of the flat wire 2 in the first layer LA1 with wire number 2. Similarly, after transposition, the flat wires 2 with wire numbers 5, 3, and 1 in the second layer LA2 are arranged at the positions of the flat wires 2 with wire numbers 4, 6, and 8 in the first layer LA1. Rotation of the arrangement positions of the flat wires 2 shown in Figure 2 is called 180° transposition.

[0019] 1 shows an example in which the winding start COS and winding end COE of the stator winding 1 are on the air gap 21 side and the stator winding 1 is configured with two layers, but the positions of the winding start COS and winding end COE of the stator winding 1 are not limited to this. The winding start COS and winding end COE of the stator winding 1 may be located on the core back side. Furthermore, the stator winding 1 may have two or more layers, but the transposition portion 3, which is the portion where the transposition occurs, transposes between the layer end (layer A end AE), which is the end of the winding of one layer, and the layer start (layer B start BS), which is the start of the winding of the next layer.

[0020] Here, the stator winding 1 may be formed by arranging a plurality of flat wires 2 each having a rectangular cross section so that the long sides 6a of the rectangular cross section are in contact with each other as shown in Fig. 3, or by arranging a plurality of flat wires 2 so that the short sides 6b of the rectangular cross section are in contact with each other as shown in Fig. 4. Furthermore, as shown in Fig. 2, a plurality of flat wires 2 may be arranged in the direction in which the long sides 6a of the rectangular cross section are in contact with each other, and a plurality of flat wires 2 may also be arranged in the direction in which the short sides 6b are in contact with each other.

[0021] The stator winding 1 can also be described as having a transposition section 3 in which the arrangement position of each flat wire 2, i.e., the wire arrangement, is transposed by 180° between the layer end section (layer A end section AE), which is the end of the winding of one layer, and the layer start section (layer B start section BS), which is the start of the winding of the layer following that layer.

[0022] This can also be expressed as the arrangement of corresponding flat wires 2 in the stator winding 1 being shifted by 180° between one flatwise wound layer and an adjacent layer. A 180° shift in the arrangement of corresponding flat wires 2 in the stator winding 1 means that, when multiple flat wires 2 are arranged so that the long sides 6a of their rectangular cross sections are in contact, the arrangement order of adjacent flat wires 2 from the side closest to the teeth 13 of the stator 10 is reversed. Furthermore, when multiple flat wires 2 are arranged so that the short sides 6b of their rectangular cross sections are in contact, the arrangement of corresponding flat wires 2 in the stator winding 1 is reversed between adjacent flat wires 2.

[0023] When the voltage is increased to realize a larger capacity of the rotating electric machine 50, it is necessary to improve the insulation reliability between the stator winding 1 and the stator core 11, and therefore the insulating coating of the stator winding 1 must be thicker. Furthermore, when the current is increased to realize a larger capacity of the rotating electric machine 50, it is necessary to increase the cross-sectional area of ​​the stator winding 1 to reduce the winding resistance of the stator winding 1 and reduce copper loss. However, increasing the cross-sectional area of ​​the stator winding 1 increases eddy current loss within the winding conductor, resulting in increased loss. In the rotating electric machine 50, the main interlinkage magnetic flux, which is the main interlinkage magnetic flux, is in the direction indicated by arrow 22a in FIG. 5 . When this main interlinkage magnetic flux interlinks with the stator winding 1, eddy current loss occurs within the winding if the winding has a large cross-section. For this reason, the stator winding 1 is divided into multiple strands, i.e., rectangular strands 2, to reduce eddy current loss.

[0024] 7 shows a comparative example of a stator winding 61 in which a typical stator winding is divided into multiple flat wires 2. Generally, as in the comparative example stator winding 61, this is often addressed by increasing the division in the radial direction R of the rotating electric machine 50 and decreasing the division in the circumferential direction Φ of the rotating electric machine 50 so as to reduce the interlinkage magnetic flux in the direction indicated by arrow 22a in one flat wire 2. For this reason, edgewise bending is generally employed for the flat wire 2 when the stator winding 61 is wound around the teeth 13 of the stator 10.

[0025] Because the flat wire 2 of the stator winding is made of a metal such as copper, when it is wound around the teeth 13 while being bent edgewise, the stator winding 61 bulges, reducing the winding space factor within the stator slots. The reduction in winding space factor due to edgewise bending is particularly problematic in large rotating electric machines where each flat wire 2 is large. Therefore, flatwise bending of the flat wire 2 improves workability and the winding space factor. However, when flatwise bending is performed, many interlinking magnetic fluxes interlink with the flat wire 2, resulting in large eddy current loss. Therefore, the flat wire 2 must be divided into multiple segments in the radial direction R within the stator winding 1. For this reason, the stator winding 1 of the first embodiment shows an example in which the number of flat wires 2 in the radial direction R of the rotating electric machine 50, i.e., the number of radial divisions, is two, and the number of flat wires 2 in the circumferential direction Φ, i.e., the number of circumferential divisions, is four.

[0026] In the rotating electric machine 50 of the first embodiment, which is a rotating electric machine with concentrated stator windings, the sublinkage magnetic flux, which is the flux linkage magnetic flux in the direction of the arrow 22b shown in Fig. 6, i.e., the flux linkage magnetic flux in a direction that is 90° different from the direction of the arrow 22a in Fig. 5, is also relatively large. For this reason, when edgewise bending is employed as in the stator winding 61 of the comparative example, eddy current loss due to this sublinkage magnetic flux becomes large. In contrast, in the stator winding 1 of the first embodiment, which employs flatwise bending, eddy current loss due to the sublinkage magnetic flux becomes small.

[0027] In addition to copper loss and eddy current loss, circulating current loss also occurs as a type of loss in the stator winding 1. When there is interlinkage magnetic flux between the flat wires 2, a difference in voltage is induced between the flat wires 2. Circulating current is a current that flows in response to this induced voltage difference so that the flat wires 2 in the stator winding 1 are at the same potential at the collective connection that collectively connects them. The loss caused by the flow of this circulating current is circulating current loss.

[0028] 5 and 6 , if there were no transposition portion 3, a circulating current would be generated between the flat wires 2 in the stator winding 1. A known method for reducing this circulating current is to transpose (twist) the stator winding. This involves shifting the arrangement of the flat wires 2 by 180° as shown in FIG. 2 to homogenize the magnetic flux linking between the flat wires 2. Therefore, the stator winding 1 of embodiment 1 includes a transposition portion 3 that transposes the arrangement of the flat wires 2 by 180°, thereby reducing the circulating current and circulating current loss.

[0029] When multiple layers are wound around the teeth 13 of the stator 10 in a concentrated manner, as in the stator winding 1 of embodiment 1, the winding is generally performed starting from the innermost layer. In this case, if a transposition portion is provided in the middle of an inner layer, i.e., the layer on the tooth 13 side, rather than at the layer start or end, a bulge occurs in the stator winding wound over the transposition portion, reducing the winding space factor. For this reason, in the stator winding 1 of embodiment 1, by performing the transposition at the winding end portion of the layer (layer A end portion AE of layer A), the effect on the stator winding 1 wound over the transposition portion can be reduced, thereby preventing a reduction in the winding space factor. The stator winding 1 of embodiment 1 shown in FIG. 1 is an example in which the transposition portion 3 is located closer to the core back 12 than the end faces of the stator windings 1 on the core back 12 side, as indicated by winding numbers 9, 10, 11, and 12.

[0030] In this way, in the stator winding 1 of embodiment 1, the plurality of flat rectangular wires 2 included in the stator winding 1 are wound around the teeth 13 by flatwise bending, and therefore, compared to conventional stator windings in which the wires are wound around the teeth 13 by edgewise bending, the workability of the stator winding 1 can be improved, and the winding space factor can be improved. Furthermore, the stator winding 1 of embodiment 1 is provided with a transposition portion 3 that is transposed 180° at the winding end portion of the layer (layer A end portion AE of layer A), and therefore, circulating current loss can be reduced.

[0031] As described above, the stator winding 1 of the rotating electric machine of the first embodiment is wound in multiple layers around the stator 10 of the rotating electric machine 50. The stator winding 1 includes multiple flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 of the rotating electric machine includes a transposition portion 3 that transposes the arrangement of the multiple flat wires 2 by 180° between a layer end portion (layer A end portion AE) where winding of layer A, which is one layer closer to the teeth 13 than the outermost periphery, ends and a layer start portion (layer B start portion BS) of layer B, which is the next layer wound around layer A. In the stator winding 1 of the rotating electric machine of the first embodiment, a plurality of flat wires 2 are wound in a concentrated manner around the teeth 13 of the stator 10 by flatwise bending, and a transposition portion 3 is provided between the layer end portion of one layer (layer A end portion AE of layer A) and the layer start portion of the next layer (layer B start portion BS of layer B), thereby improving workability and the winding space factor compared to conventional methods.

[0032] The rotating electric machine 50 of the first embodiment also includes a stator 10 and a rotor 20. The rotor 20 has a plurality of permanent magnets 27 provided on the surface of a rotor core 26. The rotor 20 may include one or more rotors 20. In the case of a plurality of rotors, the plurality of permanent magnets 27 are provided on the surface of any one of the rotor cores 26. Furthermore, the plurality of permanent magnets 27 may not be provided on the surface, but may be embedded inside the rotor core 26. The stator 10 includes a stator core 11 having a plurality of teeth 13 arranged on the outside of the rotor 20 via an air gap 21, and a stator winding 1 wound around each tooth 13. The stator winding 1 is wound in multiple layers around the stator 10 of the rotating electric machine 50 and includes a plurality of flat wires 2, which are concentratedly wound around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 includes a transposition portion 3 that transposes the arrangement of the plurality of flat wires 2 by 180° between a layer end portion (layer A end portion AE) where winding of layer A, which is one layer closer to the teeth 13 than the outermost periphery, has ended and a layer start portion (layer B start portion BS) of layer B, which is the next layer to be wound around layer A. With this configuration, the rotating electric machine 50 of embodiment 1 has a plurality of flat wires 2 wound concentrically around the teeth 13 of the stator 10 by the flatwise bending method, and includes the transposition portion 3 between the layer end portion of one layer (layer A end portion AE of layer A) and the layer start portion of the next layer (layer B start portion BS of layer B). This improves the workability of the stator winding 1 compared to conventional methods, and improves the winding space factor of the stator winding 1.

[0033] Second Embodiment. FIG. 8 is a schematic diagram showing the stator winding of a rotating electric machine according to a second embodiment, and FIG. 9 is a diagram showing the transposition portion when the stator winding of FIG. 8 has three layers. FIG. 10 is a diagram showing the transposition portion when the stator winding of FIG. 8 has four layers, and FIG. 11 is a diagram showing the transposition portion when the stator winding of FIG. 8 has five layers. FIG. 12 is a schematic diagram showing the stator winding for which an electromagnetic field analysis is performed according to the second embodiment, and FIG. 13 is a diagram showing the average loss when the number and position of the transposition portions of FIG. 12 are changed. FIGS. 14 to 18 are diagrams showing the loss of each rectangular wire when the number and position of the transposition portions of FIG. 12 are changed, respectively. A rotating electric machine 50 according to the second embodiment differs from the rotating electric machine 50 according to the first embodiment in that the number of layers of the stator winding 1 is three or more. The following mainly describes the differences from the rotating electric machine 50 according to the first embodiment.

[0034] As shown in Fig. 2, the stator winding 1 includes a plurality of flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 is wound in a concentrated manner around the teeth 13 of the stator 10, and the first layer LA1 is formed by winding the windings in the order of winding numbers 1 to 10 from the winding start portion COS. In Fig. 8, winding numbers 1 to 10 are assigned to the cross section of the stator winding 1. Winding numbers 11 to 30 are also assigned to the cross section of the stator winding 1. The second layer LA2, from winding numbers 11 to 20, is also wound around the outer periphery of the first layer LA1 without being transposed. Between the layer end LE2 of the second layer LA2, which is assigned winding number 20, and the layer start LS3 of the third layer LA3, which is assigned winding number 21, the arrangement of the plurality of flat wires 2 of the stator winding 1 is transposed by 180° by a transposition portion 3. In the third layer LA3 of the stator winding 1, the arrangement of the plurality of flat wires 2 is transposed by 180°, and the stator winding 1 is formed by being wound around the outer periphery of the second layer LA2 in the order of winding numbers 21 to 30. The layer end LE3 of the third layer LA3, which is assigned winding number 30, is the winding end portion COE of the stator winding 1. There is one transposition portion 3 of the stator winding 1 for each tooth 13.

[0035] The stator winding 1 shown in Fig. 8 is an example in which the transposition portion 3 is located between the layer end portion LE2 of the second layer LA2 and the layer start portion LS3 of the third layer LA3. In Fig. 8, the A layer, the B layer, the A layer end portion AE, and the B layer start portion BS correspond to the second layer LA2, the third layer LA3, the layer end portion LE2, and the layer start portion LS3, respectively. The stator winding 1 of embodiment 2 shown in Fig. 8 is an example in which the transposition portion 3 is located closer to the core back 12 than the end faces of the stator windings 1 indicated by winding numbers 1, 2, 19, 20, 21, and 22 on the core back 12 side.

[0036] FIG. 9 shows a schematic diagram of the position of the transposition portion 3 when the stator winding 1 has three layers. In the case of a three-layer stator winding 1, the second layer LA2 corresponds to the central layer portion 4, which is the central layer. In the case of the three-layer stator winding 1 shown in FIGS. 8 and 9, the transposition portion 3 is provided outside the central layer portion 4, which is the central portion of the multiple layers of the stator winding 1, between the layer A end portion AE (layer end portion LE2 of the second layer LA2) of layer A and the layer B start portion BS (layer start portion LS3 of the third layer LA3) of layer B. In FIG. 9, the stator winding after transposition is indicated by the reference numeral 1a. Note that the stator winding after transposition is also indicated by the reference numeral 1a in FIGS. 10 and 11.

[0037] 10 and 11 show schematic diagrams illustrating the positions of the transposition portions 3 when the number of layers of the stator winding 1 is four and five, respectively. The four-layer stator winding 1 has a first layer LA1 through a fourth layer LA4 wound around the teeth 13. The five-layer stator winding 1 has a first layer LA1 through a fifth layer LA5 wound around the teeth 13. In the case of a four-layer stator winding 1, the second layer LA2 and the third layer LA3 correspond to the central layer 4, which is the central layer. In the case of a five-layer stator winding 1, the third layer LA3 corresponds to the central layer 4, which is the central layer. In the case of the four-layer stator winding 1 shown in FIG. 10 , the transposition portion 3 is provided outside the central layer 4, which is the central portion of the multiple layers of the stator winding 1, between the layer A end portion AE of layer A (the layer end portion of the third layer LA3) and the layer B start portion BS of layer B (the layer start portion of the fourth layer LA4). In the case of the five-layer stator winding 1 shown in FIG. 11 , the transposition portion 3 is provided outside the central layer portion 4, which is the central portion of the multiple layers of the stator winding 1, between the layer A end portion AE (layer end portion of the third layer LA3) of layer A and the layer B start portion BS (layer start portion of the fourth layer LA4) of layer B.

[0038] When a stator winding 1 having multiple layers is transposed in one location, i.e., when it has one transposition portion 3, it will be explained using the results of electromagnetic field analysis that loss is smaller when the transposition portion 3 is provided between two layers outside the central layer 4 or within the central layer 4 than when the transposition portion 3 is provided inside the central layer 4. When the transposition portion 3 is provided outside the central layer 4 or between two layers within the central layer 4, this is the case when the transposition portion 3 is provided outside the central layer 4, including the central layer 4.

[0039] FIG. 12 shows the schematic configuration of the stator winding 1 of a rotating electric machine for which electromagnetic field analysis was performed. The stator winding 1 shown in FIG. 12 is composed of a total of six flat wires 2 arranged in three rows and two columns, and is wound in four layers around the teeth 13 of a single stator 10. Each layer has the same number of turns. Starting from the tooth 13, the first layer LA1, second layer LA2, third layer LA3, and fourth layer LA4 are wound. The second layer LA2 and third layer LA3 correspond to the central layer 4. FIG. 13 shows the results of electromagnetic field analysis of six rotating electric machines equipped with the stator winding 1 shown in FIG. 12. The vertical axis of FIG. 13 represents the average loss of the six standardized flat wires 2. The six samples S1 to S6 each have different locations and numbers of 180° transpositions. Sample S1 represents a case without transposition. Sample S2 is a case where transposition occurs between each layer, and a total of three transposition parts 3 are provided between the first layer LA1 and the second layer LA2, between the second layer LA2 and the third layer LA3, and between the third layer LA3 and the fourth layer LA4. In Fig. 13, the space between the first layer LA1 and the second layer LA2 is denoted as "1-2," the space between the second layer LA2 and the third layer LA3 is denoted as "2-3," and the space between the third layer LA3 and the fourth layer LA4 is denoted as "3-4."

[0040] Sample S3 has one transposition portion 3 between the second layer LA2 and the third layer LA3. Sample S4 has a total of two transposition portions 3, one between the first layer LA1 and the second layer LA2 and one between the third layer LA3 and the fourth layer LA4. Sample S5 has one transposition portion 3 between the first layer LA1 and the second layer LA2. Sample S6 has one transposition portion 3 between the third layer LA3 and the fourth layer LA4. Note that the flat wires 2 of the stator winding 1 are collectively connected each time the winding is completed around one tooth 13. The average loss on the vertical axis is normalized by the average loss value of sample S2, i.e., when 180° transposition is performed between all layers.

[0041] The dislocation between the second layer LA2 and the third layer LA3, labeled "2-3," is a dislocation within the central layer 4. The dislocation between the first layer LA1 and the second layer LA2, labeled "1-2," is a dislocation inside the central layer 4. The dislocation between the third layer LA3 and the fourth layer LA4, labeled "3-4," is a dislocation outside the central layer 4.

[0042] FIG. 13 shows that the average loss of sample S6, where the translocation 3 is located outside the central layer 4, is lower than the average loss of sample S5, where the translocation 3 is located inside the central layer 4. When the number of layers is even, there are two layers in the central layer 4, so sample S3, where the translocation occurs within the central layer 4, has a lower average loss than sample S6. Sample S4, where the translocation occurs in two places, has an average loss roughly equivalent to that of sample S2, where the translocation occurs between all layers. Sample S1, where there is no translocation, has a larger circulating current loss than the other samples S2 to S6. FIG. 13 shows the case where the number of layers in the stator winding 1 is four. However, even when the number of layers in the stator winding 1 is three or five or more, as long as the stator winding 1 has only one translocation 3, similar to samples S5 and S6, the loss is smaller when the translocation 3 is located outside the central layer 4 rather than inside the central layer 4.

[0043] Figures 14 to 18 compare the losses generated by the flat wires 2 in samples S2 to S6, respectively. The loss on the vertical axis is normalized by the average loss value of sample S2 shown in Figure 13. Samples S5 and S6 are compared. Sample S5, which is transposed inside the central layer 4, exhibits increased losses in the flat wires 2 with wire numbers 2 and 4. In contrast, sample S6, which is transposed outside the central layer 4, exhibits reduced losses in the flat wires 2 with wire numbers 2 and 4. This indicates that when transposition is performed at a single location, transposition between layers outside the central layer 4 of the stator winding 1 can reduce losses. Sample S3, which is transposed within the central layer 4, exhibits reduced losses in the flat wires 2 with wire numbers 2 and 4 compared to sample S5. Figures 14 to 18 show the case where the stator winding 1 has four layers. However, even when the number of layers in the stator winding 1 is three or five or more, if the stator winding 1 has only one transposition portion 3, the loss in the flat wires 2 with wire number 2 and wire number 4 is smaller when the transposition portion 3 is provided on the outside including the central layer 4 than when the transposition portion 3 is provided on the inside of the central layer 4, as in samples S5 and S6.

[0044] The stator winding 1 of embodiment 2 has a plurality of flat wires 2 wound in a concentrated manner around the teeth 13 of the stator 10 by flatwise bending, and has a transposition portion 3 between an A-layer end portion AE of one layer, that is, an A-layer, and a B-layer start portion BS of the next layer, that is, a B-layer, and therefore has the same effect as the stator winding 1 of embodiment 1. Furthermore, the stator winding 1 of embodiment 2 has the transposition portion 3 located outside a central layer portion 4, which is the center of the multiple layers of the stator winding 1, between an A-layer end portion AE of layer A and a B-layer start portion BS of layer B, and therefore can reduce losses more than when the transposition portion 3 is located inside the central layer portion 4.

[0045] The rotating electric machine 50 of the second embodiment includes the stator winding 1 of the second embodiment, and therefore, similarly to the rotating electric machine 50 of the first embodiment, the workability of the stator winding 1 is improved compared to the conventional art, and the winding space factor of the stator winding 1 is improved. Furthermore, due to the effect of the stator winding 1 of the second embodiment, the rotating electric machine 50 of the second embodiment can reduce losses more than when the transposition portion 3 is provided inside the central layer portion 4.

[0046] Embodiment 3. Figure 19 is a schematic diagram showing the configuration of a stator winding of a rotating electric machine according to embodiment 3. A rotating electric machine 50 according to embodiment 3 differs from rotating electric machines 50 according to embodiments 1 and 2 in that the number of layers of the stator winding 1 is an even number of four or more, and the outermost layer has more turns than the other layers. The following mainly describes the differences from rotating electric machines 50 according to embodiments 1 and 2.

[0047] As shown in FIG. 2 , the stator winding 1 includes a plurality of flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 is wound in a concentrated manner around the teeth 13 of the stator 10, with the first layer LA1 being wound in the order of winding numbers 1 to 10 from the winding start portion COS. In FIG. 19 , winding numbers 1 to 10 are assigned to the cross section of the stator winding 1. Winding numbers 11 to 44 are also assigned to the cross section of the stator winding 1. The second layer LA2 is wound around the outer periphery of the first layer LA1 without transposition from winding number 11 to winding number 20. The third layer LA3 is wound around the outer periphery of the second layer LA2 without transposition from winding number 21 to winding number 30. Between the layer end LE3 of the third layer LA3, which is assigned winding number 30, and the layer start LS4 of the fourth layer LA4, which is assigned winding number 31, the arrangement of the plurality of flat wires 2 of the stator winding 1 is transposed by 180° by a transposition portion 3. In the fourth layer LA4 of the stator winding 1, the arrangement of the plurality of flat wires 2 is transposed by 180°, and the stator winding 1 is formed by being wound around the outer periphery of the third layer LA3 in the order of winding numbers 31 to 44. The layer end LE4 of the fourth layer LA4, which is assigned winding number 44, is the winding end portion COE of the stator winding 1. There is one transposition portion 3 of the stator winding 1 for each tooth 13. 19 is an example in which the transposition portion 3 is arranged closer to the core back 12 than the end faces of the stator windings 1 on the core back 12 side, as indicated by winding numbers 9, 10, 11, 12, and 30. Note that the transposition portion 3 may also be arranged closer to the core back 12 than the end faces of the stator windings 1 on the core back 12 side, as indicated by winding numbers 31 and 32.

[0048] The stator winding 1 shown in FIG. 19 is an example in which a transposition portion 3 is disposed between the layer end portion LE3 of the third layer LA3 and the layer start portion LS4 of the fourth layer LA4. In FIG. 19, layer A, layer B, layer A end portion AE, and layer B start portion BS correspond to the third layer LA3, fourth layer LA4, layer end portion LE3, and layer start portion LS4, respectively. The transposition portion 3 is located between winding numbers 30 and 31, and between the third layer LA3 and fourth layer LA4. The second layer LA2 and the third layer LA3 correspond to the central layer portion 4, which is the central layer. In other words, the stator winding 1 of embodiment 3 has a 180° transposition between the layers outside the central layer portion 4. The stator winding 1 shown in FIG. 19 corresponds to sample S6 shown in FIGS. 13 and 18. In the case of a stator winding 1 in which the number of turns varies from layer to layer as shown in FIG. 19 , by performing a 180° transposition between two layers in which the number of turns on the outer side is smaller than that on the inner side, the loss reduction effect is enhanced as in sample S6 compared to sample S5 shown in FIG. 13 .

[0049] Although the stator winding 1 of the third embodiment has a larger number of turns in the outermost layer than the other layers, the number of layers of the stator winding 1 is an even number of four or more, and other configurations are similar to those of the stator winding 1 of the second embodiment, and therefore, the same effects as those of the stator winding 1 of the second embodiment are achieved. Furthermore, the rotating electric machine 50 of the third embodiment is equipped with the stator winding 1 of the third embodiment, and therefore, the same effects as those of the rotating electric machine 50 of the second embodiment are achieved.

[0050] Embodiment 4. Figure 20 is a schematic diagram showing the configuration of a stator winding of a rotating electric machine according to embodiment 4. A rotating electric machine 50 according to embodiment 4 differs from the rotating electric machines 50 according to embodiments 2 and 3 in that the number of layers of the stator winding 1 is an even number equal to or greater than four, and a transposition portion 3 is provided between two layers of a central layer portion 4. The following mainly describes the differences from the rotating electric machines 50 according to embodiments 2 and 3.

[0051] As shown in Fig. 2, the stator winding 1 includes a plurality of flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 is wound in a concentrated manner around the teeth 13 of the stator 10, and the first layer LA1 is formed by winding the windings in the order of winding numbers 1 to 10 from the winding start portion COS. In Fig. 20, winding numbers 1 to 10 are assigned to the cross section of the stator winding 1. Winding numbers 11 to 38 are also assigned to the cross section of the stator winding 1. The second layer LA2, from winding numbers 11 to 20, is also wound around the outer periphery of the first layer LA1 without transposition. Between the layer end LE2 of the second layer LA2, which is assigned winding number 20, and the layer start LS3 of the third layer LA3, which is assigned winding number 21, the arrangement of the plurality of flat wires 2 of the stator winding 1 is transposed by 180° by a transposition portion 3. In the third layer LA3 of the stator winding 1, the arrangement of the plurality of flat wires 2 is transposed by 180°, and the third layer LA3 is wound around the outer periphery of the second layer LA2 in the order of winding numbers 21 to 30. In the fourth layer LA4, winding numbers 31 to 38 are also wound around the outer periphery of the third layer LA3 with the transposition maintained, thereby forming the stator winding 1. The layer end LE4 of the fourth layer LA4, which is assigned winding number 38, is the winding end portion COE of the stator winding 1. There is one transposition portion 3 in the stator winding 1 for each tooth 13. The stator winding 1 of the fourth embodiment shown in FIG. 20 is an example in which the transposition portion 3 is arranged closer to the core back 12 than the end face on the core back 12 side of the stator windings 1 indicated by winding numbers 1, 2, 19, 20, 21, 22, 37, and 38.

[0052] The stator winding 1 shown in FIG. 20 is an example in which a transposition portion 3 is disposed between two layers in the central layer portion 4, i.e., between the layer end portion LE2 of the second layer LA2 and the layer start portion LS3 of the third layer LA3. In FIG. 20, layer A, layer B, layer A end portion AE, and layer B start portion BS correspond to the second layer LA2, the third layer LA3, the layer end portion LE2, and the layer start portion LS3, respectively. The transposition portion 3 is located between winding numbers 20 and 21, and between the second layer LA2 and the third layer LA3. The second layer LA2 and the third layer LA3 correspond to the central layer portion 4, which is a central layer. That is, in the stator winding 1 of embodiment 4, the transposition portion 3 is provided in the central layer portion 4, between the layer A end portion AE of layer A and the layer B start portion BS of layer B. The stator winding 1 shown in FIG. 20 corresponds to sample S3 shown in FIGS. 13 and 15. When the number of layers of the stator winding 1 is an even number of four or more as shown in FIG. 20, by performing a 180° transposition between the two layers of the central layer portion 4, the loss reduction effect is higher as in sample S3 compared to samples S5 and S6 shown in FIG.

[0053] As shown in FIG. 20 , even when the number of layers of the stator winding 1 is four (an even number greater than three) and the number of turns in the outermost layer is fewer than the others, transposition between two layers in the central layer 4 can achieve results similar to those of sample S3 shown in FIGS. 13 and 15 . That is, when the number of layers of the stator winding 1 is an even number greater than four, if the transposition part 3 is provided between the A-layer end AE of layer A and the B-layer start BS of layer B in the central layer 4, loss can be reduced more than that of samples S5 and S6, and the same loss reduction effect as that of sample S2, in which transposition is performed between each layer, can be achieved. Note that, as shown in FIG. 1 , when the number of layers of the stator winding 1 is an even number of two, both the first layer LA1 and the second layer LA2 can also be referred to as the central layer 4. The stator winding 1 shown in FIG. 1 has the transposition part 3 provided between the first layer LA1 and the second layer LA2, and therefore the transposition part 3 is provided between the A-layer end AE of layer A and the B-layer start BS of layer B in the central layer 4. Therefore, the stator winding 1 shown in FIG. 1 provides results similar to those of sample S3 shown in FIGS.

[0054] The stator winding 1 of embodiment 4 has a plurality of flat wires 2 wound in a concentrated manner around the teeth 13 of the stator 10 by flatwise bending, and has a transposition portion 3 between the layer A end portion AE of layer A, which is one layer, and the layer B start portion BS of layer B, which is the next layer, and therefore has the same effect as the stator winding 1 of embodiments 1 to 3. Furthermore, the stator winding 1 of embodiment 4 has a transposition portion 3 between the layer A end portion AE of layer A and the layer B start portion BS of layer B in the two-layer central layer portion 4, and therefore can reduce loss more than samples S5 and S6, and achieves the same loss reduction effect as sample S2, in which transpositions are performed between each layer.

[0055] The rotating electric machine 50 of the fourth embodiment includes the stator winding 1 of the fourth embodiment, and therefore, like the rotating electric machines 50 of the first to third embodiments, the workability of the stator winding 1 is improved compared to the prior art, and the winding space factor of the stator winding 1 is improved. Furthermore, due to the effect of the stator winding 1 of the fourth embodiment, the rotating electric machine 50 of the fourth embodiment can reduce losses more than samples S5 and S6, and can obtain the same loss reduction effect as sample S2 in which transposition is performed between each layer.

[0056] 1, 8, 19, and 20, the transposition part 3 is provided on the core back 12 side of the stator 10, but the transposition part 3 may also be provided on the air gap 21 side. However, if the transposition part 3 is provided on the air gap 21 side, it is necessary to move the transposition part 3 toward the air gap 21 side to prevent contact between the transposition part 3 and the rotor 20, which reduces workability compared to when the transposition part 3 is provided on the core back 12 side. For this reason, it is desirable to set the winding start position, i.e., the winding start part COS, so that the transposition part 3 is located on the core back 12 side.

[0057] Fifth Embodiment. FIG. 21 is a diagram showing the configuration of a rotating electric machine according to a fifth embodiment, and FIG. 22 is a diagram showing the phase ring conductors of FIG. 21. A rotating electric machine 50 according to the fifth embodiment is an example of a rotating electric machine to which multiple-phase power is applied. The rotating electric machine 50 according to the fifth embodiment shown in FIG. 21 is, for example, a three-phase rotating electric machine, and is an example having four U-phase stator windings, four V-phase stator windings, and four W-phase stator windings. The first to fourth U-phase stator windings are designated by the symbols 1Ua, 1Ub, 1Uc, and 1Ud. Similarly, the first to fourth V-phase stator windings are designated by the symbols 1Va, 1Vb, 1Vc, and 1Vd, and the first to fourth W-phase stator windings are designated by the symbols 1Wa, 1Wb, 1Wc, and 1Wd. Where appropriate, the reference numeral 1 will be used collectively for the stator windings, and 1Ua to 1Ud, 1Va to 1Vd, and 1Wa to 1Wd will be used to distinguish between them. A rotating electric machine 50 of embodiment 5 shown in Figure 21 includes a rotor 20 having a plurality of permanent magnets 27 provided on the surface of a rotor core 26, and a stator 10 arranged outside the rotor 20 with an air gap 21 between them. The stator 10 includes a stator core 11 having a plurality of teeth 13 arranged outside the rotor 20 with an air gap 21 between them, and a stator winding 1 wound around each tooth 13.

[0058] The direction of the rotation axis 25 of the rotor 20 is the axial direction Z, the direction from the rotation axis 25 to the outside is the radial direction R, and the direction of rotation around the rotation axis 25 is the circumferential direction Φ. The core back 12 of the stator core 11 supports 12 teeth 13.

[0059] Generally, in rotating electrical machines, stator windings 1 of the same phase are wound around multiple teeth 13 of a stator 10. In this case, the stator winding 1 wound around one tooth 13 must be routed to other teeth 13, which reduces workability. In particular, since the stator winding 1 made up of multiple flat wires 2 is relatively large in size, it requires space to route the stator winding 1, which reduces workability.

[0060] Therefore, as shown in Figure 22, each time the stator winding 1 is wound around one tooth 13, connecting conductors 31 connected to ring conductors 32 are connected to the ends of the stator winding 1, i.e., the winding start portion COS and the winding end portion COE, respectively, and finally, by connecting the connecting conductors 31 of the stator windings 1 of the same phase with the ring conductor 32, it is possible to prevent deterioration in workability due to routing of the stator winding 1. In Figure 22, the first U-phase stator winding 1Ua and the second U-phase stator winding 1Ub are shown with dashed lines. One end of the stator winding 1Ua is connected to a terminal 35 via the connecting conductor 31. The other end of the stator winding 1Ua is connected to one end of the second U-phase stator winding 1Ub via the connecting conductor 31, the ring conductor 32, and again via the connecting conductor 31. The connecting conductors 31 and the ring conductor 32 form a phase ring conductor 30. The connection conductor 31 and the ring conductor 32 are connected after all the stator windings 1 have been wound.

[0061] 21 shows only the U-phase phase ring conductor 30, and omits the V-phase and W-phase phase ring conductors 30. The other end of the second U-phase stator winding 1Ub is connected to one end of the third U-phase stator winding 1Uc by a second ring conductor 32. The other end of the third U-phase stator winding 1Uc is connected to one end of the fourth U-phase stator winding 1Ud by a third ring conductor 32. Note that one ends of the fourth stator windings 1Ud, 1Vd, and 1Wd are connected to the ring conductor 32 for forming the neutral point, but the ring conductor 32 and connecting conductor 31 for forming the neutral point are omitted.

[0062] Because the connecting conductors 31 and ring conductors 32 that make up the phase ring conductor 30 are made up of bus bars, even if the flat wires 2 of the stator winding 1 are divided at the teeth 13 of the stator 10, they are all connected together by the connecting conductors 31. For this reason, if each stator winding 1 does not have the transposition portion 3 shown in the first to fourth embodiments, a large circulating current loss will occur.

[0063] However, by applying each stator winding 1 having the transposition portion 3 shown in Embodiments 1 to 4 to the stator winding of a rotating electric machine through which power of multiple phases flows, circulating current loss is reduced, and it becomes possible to connect the stator windings 1 together at their ends using connecting conductors 31. By connecting the stator windings 1 of the same phase using phase ring conductors 30, it is possible to prevent the aforementioned deterioration in workability due to the routing of the stator windings 1.

[0064] The rotating electric machine 50 of the fifth embodiment is provided with the stator winding 1 of the first to fourth embodiments, and therefore has the same effects as the rotating electric machine 50 of the first to fourth embodiments.

[0065] As described above, the rotating electric machine 50 of the fifth embodiment includes a stator 10 and a rotor 20, and is a rotating electric machine to which multiple phases of electric power are applied. The rotor 20 has multiple permanent magnets 27 provided on the surface of a rotor core 26. The stator 10 includes a stator core 11 having multiple teeth 13 arranged on the outside of the rotor 20 with gaps 21 between them, and a stator winding 1 wound around each tooth 13. The rotating electric machine 50 further includes a ring conductor 32 that connects the multiple stator windings 1, to which electric power of the same phase is applied, via connecting conductors 31. The stator winding 1 is wound in multiple layers around the stator 10 of the rotating electric machine 50 and includes multiple flat wires 2, which are wound in a concentrated manner around the teeth 13 of the stator 10 using a flatwise bending method. The stator winding 1 has a transposition portion 3 that transposes the arrangement of the plurality of flat wires 2 by 180° between the layer end portion (layer A end portion AE) where winding of layer A, which is one layer closer to the teeth 13 than the outermost periphery, has ended and the layer start portion (layer B start portion BS) of layer B, which is the next layer to be wound around layer A. With this configuration, the rotating electric machine 50 of embodiment 5 has the plurality of flat wires 2 wound concentrically around the teeth 13 of the stator 10 by the flatwise bending method, and has the transposition portion 3 between the layer end portion of one layer (layer A end portion AE of layer A) and the layer start portion of the next layer (layer B start portion BS of layer B). This improves the workability of the stator winding 1 compared to conventional methods, and improves the winding space factor of the stator winding 1.

[0066] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0067] 1, 1a... stator winding, 1Ua, 1Ub, 1Uc, 1Ud... stator winding, 1Va, 1Vb, 1Vc, 1Vd... stator winding, 1Wa, 1Wb, 1Wc, 1Wd... stator winding, 2... flat wire, 3... transposition portion, 4... central layer portion, 10... stator, 11... stator core, 12... core back, 13... teeth, 20... rotor, 21... gap, 26... rotor core, 27...Permanent magnet, 32...Ring conductor, 31...Connecting conductor, 50...Rotating electric machine, AE...Layer A end portion, BS...Layer B start portion, COS...Winding start portion, COE...Winding end portion, LA1...First layer, LA2...Second layer, LA3...Third layer, LA4...Fourth layer, LA5...Fifth layer, LS1, LS2, LS3, LS4...Layer start portion, LE1, LE2, LE3, LE4...Layer end portion

Claims

1. A stator winding of a rotating electric machine wound in multiple layers around the stator of the rotating electric machine, the stator winding comprising a plurality of flat rectangular wires, the plurality of flat rectangular wires being concentratedly wound around the teeth of the stator using a flatwise bending method, and a transposition section for transposing the arrangement of the plurality of flat rectangular wires by 180 degrees between a layer end portion where layer A, one of the layers closer to the teeth than the outermost circumference, has ended and a layer start portion of layer B, the next layer to be wound around layer A.

2. A stator winding for a rotating electric machine as described in claim 1, wherein, when the number of layers of the stator winding is three or more, the transposition portion is provided between the layer end portion of the layer A and the layer start portion of the layer B on the outside including a central layer portion which is the center of the plurality of layers of the stator winding.

3. A stator winding for a rotating electric machine as described in claim 1, wherein, when the number of layers of the stator winding is an even number equal to or greater than three, the transposition portion is provided between the layer end portion of the layer A and the layer start portion of the layer B in a central layer portion which is the center of the plurality of layers of the stator winding.

4. A stator winding for a rotating electric machine as described in any one of claims 1 to 3, wherein the stator of the rotating electric machine has a core back supporting the teeth, and the transposition portion is provided on the core back side between the layer end portion of the A layer and the layer start portion of the B layer.

5. A stator winding for a rotating electric machine according to any one of claims 1 to 4, wherein the transposition portion is one for each of the teeth.

6. A stator winding for a rotating electric machine as claimed in any one of claims 1 to 5, wherein the stator winding comprises connecting conductors to which all of the flat rectangular wires are connected at a winding start portion, which is the start portion of the first layer wound around the tooth, and at a winding end portion, which is the end portion of the last layer wound around the tooth.

7. A rotating electric machine having a stator and a rotor, wherein the rotor has a plurality of permanent magnets provided on the surface or inside of a rotor core, and the stator comprises a stator core having a plurality of teeth arranged on the outside of the rotor with gaps between them, and a stator winding of a rotating electric machine according to any one of claims 1 to 6 wound around each of the teeth.

8. A rotating electric machine comprising a stator and a rotor, and through which multiple phases of electric power are passed, wherein the rotor has multiple permanent magnets provided on the surface or inside of a rotor core, and the stator comprises a stator core having multiple teeth arranged on the outside of the rotor with gaps between them, and a stator winding of the rotating electric machine according to claim 6 wound around each of the teeth, and further comprising a ring conductor connecting the multiple stator windings through which electric power of the same phase is passed via the connecting conductor.

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