Rotating electrical machine

Abstract

A stator 20 of a rotating electrical machine 10 comprises a winding 26 having a plurality of phase coil groups that are wave-wound around a plurality of slots S of a stator core 24. A first coil and a second coil of each phase coil group switch a passing lane to an adjacent lane for each half circumference of the stator core 24, and reciprocate between an innermost lane and an outermost lane. While switching, for each slot, the layer through which first coil passes, the first coil passes through a plurality of first slots in an outward path, passes through a plurality of second slots in a return path, and passes through a layer different from the layer through which the first coil passes in the outward path in the adjacent first slot in the return path. While switching, for each slot, the layer through which second coil passes, the second coil passes through a plurality of second slots in the outward path, passes through a plurality of first slots in the return path, and passes through the same layer as the layer through which the first coil passes in the adjacent slot.

Description

Rotating electric machine

[0001] The present invention relates to a rotating electric machine, and more specifically to a rotating electric machine in which each phase of a stator winding is constituted by a plurality of coils connected in parallel.

[0002] An example of this type of prior art is disclosed in Patent Document 1. The stator of the rotating electric machine disclosed in Patent Document 1 includes a stator core having a plurality of slots, and a stator winding composed of three-phase phase windings housed in the slots and wound around the stator core. The stator winding is formed by wave winding, in which each phase winding formed by connecting ends of a plurality of conductor segments in a predetermined pattern is connected by star connection. In each slot, six phase windings are accommodated in one row in the radial direction. Each phase winding is configured by four parallel windings connected in parallel, in which in-phase phase windings are accommodated for every two circumferentially adjacent slots in each layer within the slot. Each parallel winding is equally disposed in both of the two adjacent slots in all layers within each slot, and is wound while alternating between two circumferentially adjacent slots in each layer within each slot over the entire circumferential direction at the coil end portion of the stator winding through a combination of 5-slot pitch and 7-slot pitch. With this configuration, an attempt is made to completely prevent circulating current generated between parallel windings constituting each phase winding while suppressing an increase in the axial length of the coil end portion.

[0003] Japanese Patent No. 5896250

[0004] In the stator of the rotating electric machine disclosed in Patent Document 1, two parallel windings intersect in a normal portion other than the switch portion of the parallel windings, but in the switch portion, one parallel winding wound at a 7-slot pitch straddles the other parallel winding wound at a 5-slot pitch. As described above, in Patent Document 1, every time a slot is switched, one parallel winding has to be passed over the other parallel winding, which complicates the configuration.

[0005] Therefore, a main object of the present invention is to provide a rotating electric machine that has a simple configuration and can suppress circulating current generated between parallel windings constituting each phase coil group.

[0006] According to one view of this invention, the present invention comprises a stator and a rotor rotatably mounted inside the stator and having 2 × A (A is a natural number of 2 or more) magnetic poles in the circumferential direction, the stator includes a stator core having a plurality of slots and windings having a plurality of phase coil groups (U phase, V phase, W phase) that are star-connected and wave-wound in the plurality of slots, the plurality of slots include first slots and second slots, and are provided at predetermined intervals in the circumferential direction, penetrating the stator core in the axial direction, at a ratio of 2 × B (B is a natural number) per phase and per pole, and are formed so that the windings can pass through in the radial direction in a state where they are arranged in 4 × C (C is a natural number) layers, the 4 × C layers of the plurality of slots are divided into two adjacent layers in the radial direction to form 2 × C lanes, each phase coil group includes at least one pair of first coils and second coils connected in parallel, and the first coils and second coils of each phase coil group include a plurality of corresponding first coils arranged at predetermined slot intervals A rotating electric machine is provided in which a first coil travels back and forth between the innermost lane and the outermost lane, passing through one of the slots and a plurality of corresponding second slots arranged adjacent to each first slot at predetermined intervals, switching the lane it travels through to an adjacent lane every half-circumference of the stator core; the first coil, in the forward path, passes through a plurality of first slots, switching the layer it travels through for each first slot; in the return path, it passes through a plurality of second slots, switching the layer it travels through for each second slot, such that in adjacent first slots the first coil travels through a different layer than the layer it travels through in the forward path; the second coil, in the forward path, passes through a plurality of second slots, switching the layer it travels through for each second slot, such that in adjacent first slots the first coil travels through the same layer as the layer it travels through in the forward path; and in the return path, it passes through a plurality of first slots, switching the layer it travels through for each first slot, such that in adjacent second slots the first coil travels through the same layer as the layer it travels through in the return path.

[0007] In this invention, the first coil passes through only a plurality of first slots on the outward journey without switching to a second slot midway, and passes through only a plurality of second slots on the return journey without switching to a first slot midway. The second coil passes through only a plurality of second slots on the outward journey without switching to a first slot midway, and passes through only a plurality of first slots on the return journey without switching to a second slot midway. Furthermore, the spacing between the plurality of first slots through which the first coil passes on the outward journey and the second coil passes on the return journey remains constant at a predetermined number of slots, and similarly, the spacing between the plurality of second slots through which the second coil passes on the outward journey and the first coil passes on the return journey also remains constant at a predetermined number of slots, without changing. Therefore, the first coil and the second coil can be easily wound into the corresponding slots. In addition, the slots into which the first coil and the second coil are inserted are switched between the outward and return journeys, and the layers through which the first coil and the second coil pass are also switched each time a slot is passed. Furthermore, in adjacent first and second slots, the first coil passes through different layers in the forward and return paths, while the first and second coils pass through the same layer in both the forward and return paths. As a result, in each phase coil group, the first and second coils passing through the same layer are swapped between adjacent first and second slots and the next adjacent first and second slots. For example, in the same lane, if the first and second coils are inserted in this order into the inner layer of adjacent first and second slots, then the second and first coils are inserted in this order into the inner layer of the next adjacent first and second slots, and this is repeated. Also, in the same lane, if the second and first coils are inserted in this order into the outer layer of adjacent first and second slots, then the first and second coils are inserted in this order into the outer layer of the next adjacent first and second slots, and this is repeated. Therefore, when considering the entire rotating electric machine, the positional relationship between the rotor's magnetic poles and the first coil is the same as the positional relationship between the rotor's magnetic poles and the second coil.As a result, the induced electromotive force in the first coil and the induced electromotive force in the second coil become equal, so the first and second coils are at the same potential, and circulating current can be suppressed.

[0008] Preferably, each group of phase coils further includes a first crossover wire connecting the end of the forward path of the first coil to the start of the return path, and a second crossover wire connecting the end of the forward path of the second coil to the start of the return path. In this case, by connecting the end of the forward path of the first coil to the start of the return path with the first crossover wire, the first coil can be easily reversed from the forward path to the return path. Similarly, by connecting the end of the forward path of the second coil to the start of the return path with the second crossover wire, the second coil can be easily reversed from the forward path to the return path.

[0009] Preferably, the start and end points of each phase coil group are on the innermost layer side. In this case, the busbars connected to the start points of each phase coil group can be made more compact.

[0010] More preferably, the start and end points of each phase coil group are on the outermost layer side. In this case, the rotor can be easily inserted inside the stator, regardless of whether the start point of each phase coil group is connected to a busbar or the end point of each phase coil group is connected to the neutral point.

[0011] Preferably, the number of slots sandwiched between adjacent starting points of the first coil in a group of multiple phase coils, and the number of slots sandwiched between adjacent ending points of the first coil in a group of multiple phase coils, are greater than the number of slots per pole. In this case, the distance between the starting point of one group of phase coils and the starting point of another group of phase coils can be increased, so that the jumper wires (first and second jumper wires) of one group of phase coils and the jumper wires (first and second jumper wires) of another group of phase coils do not overlap, and the jumper wires can be distributed. Therefore, localized enlargement of the coil end can be suppressed, and the stator can be made smaller.

[0012] Preferably, the number of slots sandwiched between adjacent starting points of the first coil in a group of multiple phase coils, and the number of slots sandwiched between adjacent ending points of the first coil in a group of multiple phase coils, are smaller than the number of slots per pole. In this case, the distance between the starting point of one group of phase coils and the starting point of another group of phase coils can be reduced, so the distance between the ending points of multiple groups of phase coils can be made relatively small. Therefore, it becomes easier to group the ending points of multiple groups of phase coils together at the neutral point.

[0013] More preferably, each phase coil group further includes a pair of third and fourth coils connected in parallel, the first coil, second coil, third coil and fourth coil being connected in parallel, and the pair of first and second coils and the pair of third and fourth coils being wound around the stator core in a point-symmetrical manner when viewed from the axial direction of the stator core. In this configuration, where each phase coil group includes four parallel windings of first to fourth coils connected in parallel, and the pair of first and second coils and the pair of third and fourth coils are arranged in a point-symmetrical manner when viewed from the axial direction of the stator core, the present invention is suitably used.

[0014] According to this invention, despite its simple configuration, it is possible to suppress circulating currents that occur between the parallel windings constituting each phase coil group.

[0015] This is a cross-sectional view showing a rotating electric machine according to one embodiment of the present invention. (a) is an illustrative diagram showing a stator and rotor, and (b) is a diagram showing an example of the arrangement of coils placed in the slots of the stator core. This is a wiring diagram of the stator windings. This is a diagram showing an example of a segment coil for forming a winding, where (a) is a view from the axial direction and (b) is a view from the radial direction. This is a perspective view showing the main part of the stator. This is a diagram showing an example of the wiring of the first coil of the U phase in the stator. This is a diagram showing an example of the wiring of the second coil of the U phase in the stator. This is a diagram showing an example of the wiring of the third coil of the U phase in the stator. This is a diagram showing an example of the wiring of the fourth coil of the U phase in the stator. This is a schematic diagram showing an example of the wiring pattern of the first to fourth coils of each phase coil group (U phase, V phase, W phase) in the stator. This is a schematic diagram showing another example of the wiring pattern of the first to fourth coils of each phase coil group (U phase, V phase, W phase) in the stator. This is a diagram showing another example of the wiring of the first coil of the U phase in the stator. This figure shows another example of the wiring of the second coil of the U-phase in the stator. This figure shows another example of the wiring of the third coil of the U-phase in the stator. This figure shows another example of the wiring of the fourth coil of the U-phase in the stator. This figure schematically shows another example of the wiring pattern of the first to fourth coils of each phase coil group (U-phase, V-phase, W-phase) in the stator. This figure schematically shows yet another example of the wiring pattern of the first to fourth coils of each phase coil group (U-phase, V-phase, W-phase) in the stator.

[0016] Embodiments of this invention will be described below with reference to the drawings.

[0017] Referring to Figure 1, a rotating electric machine 10 according to one embodiment of the present invention is a so-called embedded permanent magnet synchronous motor and includes a housing 12. The housing 12 includes a housing body 14 formed in a substantially cylindrical shape, a first cover 16 provided at the output end of the housing body 14, and a second cover 18 provided at the non-output end of the housing body 14.

[0018] A stator 20 and a rotor 22 are provided inside the housing 12.

[0019] The stator 20 includes a substantially cylindrical stator core 24 fixed to the housing body 14 such that its outer circumference is surrounded by the housing body 14, and a winding 26 wound around the stator core 24. The winding 26 has coil end portions E1 and E2.

[0020] The rotor 22 is rotatably mounted within the housing 12 radially inward of the stator 20 and is arranged coaxially with the stator 20. The rotor 22 is rotatably held (supported) by the first cover 16 and the housing body 14 via bearings 28 and 30. The rotor 22 includes a rotor shaft 32, a rotor core 34, and a plurality of magnets 36 (see Figure 2). The rotor shaft 32 has a hollow portion 38 extending in the axial direction and protruding from the housing 12 toward one end in the axial direction. As shown in Figure 2(a), the plurality of magnets 36 are embedded in the rotor core 34, and 2 × A (A is a natural number of 2 or more) magnetic poles are formed in the circumferential direction on the rotor 22. In this embodiment, A = 4, and the rotor 22 has eight magnetic poles P1 to P8. The polarity of two adjacent magnetic poles in the circumferential direction is different. That is, the plurality of magnetic poles P1 to P8 are arranged on the rotor 22 such that their polarities alternate. The rotor 22 rotates in sync with the rotating magnetic field generated by the stator 20. Returning to Figure 1, end plates 40 and 42 that support the rotor core 34 are positioned at both axial ends of the rotor core 34.

[0021] A third cover 44 is provided to the side of the second cover 18. The third cover 44 has a cylindrical portion 46 in its center that extends into the hollow portion 38 of the rotor shaft 32. Oil is supplied to the rotor 22 and, consequently, to the housing 12, via the cylindrical portion 46.

[0022] Stator 20 will be described in detail.

[0023] Referring to Figure 2(a), the stator core 24 of the stator 20 has a plurality of slots S. The plurality of slots S are provided at predetermined intervals in the circumferential direction at a ratio of 2 × B (B is a natural number) per phase and per pole. Each slot S is an elongated hole that penetrates the stator core 24 in the axial direction and extends radially when viewed from the axial direction, and is formed so that the windings 26 can pass through in a state where they are arranged in 4 × C (C is a natural number) layers in the radial direction. Referring to Figure 2(b), the 4 × C layers of the plurality of slots S are divided into pairs of radially adjacent layers to form 2 × C lanes. In this embodiment, B = 1, and the slots S are provided at a ratio of 2 per phase and per pole, and 6 per three phases and per pole. Since the rotor 22 has 8 poles, the stator core 24 has a total of 48 slots S (slots 1 to 48). Hereinafter, the slots S will be referred to as slot 1, slot 2, ... slot 48 as needed. In this embodiment, C=2, and each slot S has eight layers (first to eighth layers) arranged radially. Hereafter, the eight layers arranged radially will be referred to as the first layer, second layer, ... eighth layer, starting from the layer closest to the rotor 22, as needed. By dividing the eight layers of the 48 slots S into pairs of radially adjacent layers, four lanes L1 to L4 are formed. That is, lane L1 includes the first and second layers, lane L2 includes the third and fourth layers, lane L3 includes the fifth and sixth layers, and lane L4 includes the seventh and eighth layers.

[0024] Figure 2(b) shows an example of coil arrangement for slots 18 to 23 in the stator 20, which correspond to slots S for one pole of three phases. In this embodiment, slots 22 and 23 become the first and second slots for the U phase, slots 20 and 21 become the first and second slots for the V phase, respectively, and slots 18 and 19 become the first and second slots for the W phase, respectively. Thus, for the U, V, and W phases, slots S are provided at a ratio of two per pole per phase, and the first and second slots are adjacent to each other, arranged in a clockwise direction in Figure 2, with the first and second slots in that order. Looking at the stator 20 as a whole, for each phase coil group of the U, V, and W phases, the first and second slots are adjacent to each other, with multiple first slots arranged at predetermined slot intervals and multiple second slots arranged at predetermined slot intervals. Each slot S contains only coils that constitute one of the phase coil groups from the U-phase, V-phase, and W-phase.

[0025] Referring to Figure 3, the windings 26 of the stator 20 have multiple (in this embodiment, three phases) of phase coil groups (U-phase, V-phase, W-phase) that are connected in a star configuration and wound in a wave pattern around multiple slots S. Each phase coil group includes a first to fourth coil connected in parallel. The first coil and the second coil form a pair, and the third coil and the fourth coil form a pair. That is, the U-phase coil group includes the first to fourth coils U1 to U4 connected in parallel, the V-phase coil group includes the first to fourth coils V1 to V4 connected in parallel, and the W-phase coil group includes the first to fourth coils W1 to W4 connected in parallel. One end of the U-phase coil group is connected to a busbar 48u, one end of the V-phase coil group is connected to a busbar 48v, and one end of the W-phase coil group is connected to a busbar 48w. On the other hand, the other ends of the U-phase, V-phase, and W-phase coil groups are connected to a common bus ring 50 and thus to the neutral point M.

[0026] The winding 26 includes a number of segment coils 52 as shown in Figure 4. Each segment coil 52 is formed in a roughly U-shape and includes two slot wires 52a, a hairpin-side extension wire 52b connecting one end of the two slot wires 52a, and two twist-side extension wires 52c extending from the other ends of the two slot wires 52a. When the segment coils 52 are mounted on the stator core 24, the slot wires 52a are located in the slots S, and the extension wires 52b and 52c are located outside the slots S. Multiple segment coils 52 are connected in a waveform pattern by connecting the extension wire 52c of one segment coil 52 to the extension wire 52c of an adjacent segment coil 52. The extension wires 52c of adjacent segment coils 52 are connected, for example, by welding. The two slot wires 52a are arranged in a straight line and parallel to each other, and are spaced apart so that they can be inserted into two slots S arranged at a predetermined number of slot intervals in the circumferential direction. In other words, the two slot wires 52a are inserted into different slots S spaced apart by a predetermined slot pitch in the circumferential direction. In this embodiment, the two slot wires 52a have a spacing that allows them to be inserted into two slots S arranged at a distance of 6 slots apart (with 5 slots in between). By continuously connecting such segment coils 52, the slot wires 52a and thus the windings 26 can be mounted in a plurality of first slots arranged at a predetermined number of slot intervals or a plurality of second slots arranged at a predetermined number of slot intervals. In this embodiment, eight slot wires 52a are inserted into each slot S in a radially arranged eight-layer configuration. The extension wire 52b is located on the coil end E1 side of the windings 26 of the stator 20, and the extension wire 52c is located on the coil end E2 side.

[0027] Referring to Figure 5, the busbars 48u, 48v, 48w, bus ring 50, first crossover 54a, and second crossover 56a are each connected to a predetermined extension line among a number of extension lines 52c. In the example shown in Figure 5, the busbars 48u, 48v, 48w, and bus ring 50 are connected to extension lines 52c extending from slot line 52a inserted in the innermost layer (first layer) of slot S, while the first crossover 54a and second crossover 56a are connected to extension lines 52c extending from slot line 52a inserted in the outermost layer (eighth layer) of slot S.

[0028] Next, with reference to Figures 6 to 9, an example of the wiring of the first coil U1 to the fourth coil U4 of the U-phase coil group will be explained. In Figures 6 to 9, the corresponding coils are inserted into the layers of hatched slots. The connection relationships of the twisted (coil end E2) side windings are shown with solid lines, and the connection relationships of the hairpin (coil end E1) side windings are shown with dashed lines. The direction of the arrows in the figures indicates the direction from the busbar 48u to the bus ring 50 (neutral wire M). The same applies to Figures 12 to 15, which will be described later.

[0029] Figure 6 shows an example of the wiring of the first coil U1 in the stator 20.

[0030] The starting point Su1 of the forward path of the first coil U1 is connected to the busbar 48u. On the forward path, the first coil U1 starts its rotation counterclockwise from the first layer of slot 40, as viewed from the coil end E2 side. In lane L1, the first coil U1 passes through the first layer of slot 40, the second layer of slot 34, the first layer of slot 28, and the second layer of slot 22 in that order, and then moves to lane L2. In lane L2, the first coil U1 passes through the third layer of slot 16, the fourth layer of slot 10, the third layer of slot 4, and the fourth layer of slot 46 in that order, and then moves to lane L3. In lane L3, the first coil U1 passes through the fifth layer of slot 40, the sixth layer of slot 34, the fifth layer of slot 28, and the sixth layer of slot 22 in that order, and then moves to lane L4. The first coil U1 passes through the 7th layer of slot 16, the 8th layer of slot 10, the 7th layer of slot 4, and the 8th layer of slot 46 in lane L4 in that order, completing its forward path. The end point of the forward path and the start point of the return path of the first coil U1 are connected by the first jumper wire 54a. The first jumper wire 54a connects the windings inserted in slots 46 and 5, which are separated by a pitch of 7 slots.

[0031] On the return journey, the first coil U1 begins its rotation clockwise from the 8th layer of slot 5, viewed from the coil end E2 side. In lane L4, the first coil U1 passes through the 8th layer of slot 5, the 7th layer of slot 11, the 8th layer of slot 17, and the 7th layer of slot 23 in that order, and then moves to lane L3. In lane L3, the first coil U1 passes through the 6th layer of slot 29, the 5th layer of slot 35, the 6th layer of slot 41, and the 5th layer of slot 47 in that order, and then moves to lane L2. In lane L2, the first coil U1 passes through the 4th layer of slot 5, the 3rd layer of slot 11, the 4th layer of slot 17, and the 3rd layer of slot 23 in that order, and then moves to lane L1. The first coil U1 passes through the second layer of slot 29, the first layer of slot 35, the second layer of slot 41, and the first layer of slot 47 in lane L1 in that order, and then completes its return journey. The endpoint Gu1 of the return journey of the first coil U1 is then connected to the bus ring 50 and, consequently, to the neutral point M.

[0032] Figure 7 shows an example of the wiring of the second coil U2 in the stator 20.

[0033] The starting point Su2 of the outward path of the second coil U2 is connected to the busbar 48u. On the outward path, the second coil U2 starts its rotation counterclockwise from the first layer of slot 41, as viewed from the coil end E2 side. In lane L1, the second coil U2 passes through the first layer of slot 41, the second layer of slot 35, the first layer of slot 29, and the second layer of slot 23 in that order, and then moves to lane L2. In lane L2, the second coil U2 passes through the third layer of slot 17, the fourth layer of slot 11, the third layer of slot 5, and the fourth layer of slot 47 in that order, and then moves to lane L3. In lane L3, the second coil U2 passes through the fifth layer of slot 41, the sixth layer of slot 35, the fifth layer of slot 29, and the sixth layer of slot 23 in that order, and then moves to lane L4. The second coil U2 passes through the 7th layer of slot 17, the 8th layer of slot 11, the 7th layer of slot 5, and the 8th layer of slot 47 in lane L4 in that order, completing its forward path. The end point of the forward path and the start point of the return path of the second coil U2 are connected by the second crossover wire 56a. The second crossover wire 56a connects the windings inserted in slots 47 and 4, which are 5 slots apart.

[0034] On the return journey, the second coil U2 begins its rotation clockwise from the 8th layer of slot 4, viewed from the coil end E2 side. In lane L4, the second coil U2 passes through the 8th layer of slot 4, the 7th layer of slot 10, the 8th layer of slot 16, and the 7th layer of slot 22 in that order, before moving to lane L3. In lane L3, the second coil U2 passes through the 6th layer of slot 28, the 5th layer of slot 34, the 6th layer of slot 40, and the 5th layer of slot 46 in that order, before moving to lane L2. In lane L2, the second coil U2 passes through the 4th layer of slot 4, the 3rd layer of slot 10, the 4th layer of slot 16, and the 3rd layer of slot 22 in that order, before moving to lane L1. The second coil U2 passes through the second layer of slot 28, the first layer of slot 34, the second layer of slot 40, and the first layer of slot 46 in lane L1 in that order, completing its return journey. The endpoint Gu2 of the return journey of the second coil U2 is then connected to the bus ring 50 and, consequently, to the neutral point M.

[0035] Figure 8 shows an example of the wiring of the third coil U3 in the stator 20. The wiring pattern of the third coil U3 is the same as that of the first coil U1 shown in Figure 6, but shifted 24 slots (half a turn) in the circumferential direction, so its explanation is omitted.

[0036] Figure 9 shows an example of the wiring of the fourth coil U4 in the stator 20. The wiring pattern of the fourth coil U4 is the same as that of the second coil U2 shown in Figure 7, but shifted 24 slots (half a turn) in the circumferential direction, so its explanation is omitted.

[0037] A pair of first coils U1 and second coils U2, and a pair of third coils U3 and fourth coils U4 are wound around the stator core 24 (stator 20) in a way that is point-symmetrical when viewed from the axial direction of the stator core 24.

[0038] In this U-phase coil group, the first coil U1 and the second coil U2 pass through one of the following: a plurality of corresponding first slots (slots 4, 10, 16, 22, 28, 34, 40, and 46), and a plurality of corresponding second slots (slots 5, 11, 17, 23, 29, 35, 41, and 47) located adjacent to each first slot. The plurality of first slots are arranged at intervals of a predetermined number of slots (6 slots in this embodiment), and the plurality of second slots are also arranged at intervals of a predetermined number of slots (6 slots in this embodiment). Furthermore, the first coil U1 and the second coil U2 switch the lane they pass through to an adjacent lane every half-circumference of the stator core 24, and reciprocate between the innermost lane L1 and the outermost lane L4. Furthermore, the first coil U1 passes through multiple first slots in the outward journey, switching the layer it passes through for each first slot, and in the return journey, it passes through multiple second slots in the second slot, switching the layer it passes through for each second slot, so that in adjacent first slots, the first coil U1 passes through a different layer than the layer it passed through in the outward journey. The second coil U2 passes through multiple second slots in the outward journey, switching the layer it passes through for each second slot, so that in adjacent first slots, the first coil U2 passes through the same layer as the layer the first coil U1 passed through in the outward journey, and in the return journey, it passes through multiple first slots in the first slot, switching the layer it passes through for each first slot, so that in adjacent second slots, the first coil U1 passes through the same layer as the layer the first coil U1 passed through in the return journey.

[0039] Similarly, the third coil U3 and the fourth coil U4 pass through one of the corresponding multiple first slots (slots 4, 10, 16, 22, 28, 34, 40, and 46) and one of the corresponding multiple second slots (slots 5, 11, 17, 23, 29, 35, 41, and 47) located adjacent to each first slot. Furthermore, the third coil U3 and the fourth coil U4 travel back and forth between the innermost lane L1 and the outermost lane L4, switching the lane they pass through to an adjacent lane every half-circumference of the stator core 24. In addition, on the outward journey, the third coil U3 passes through multiple first slots, switching the layer it passes through for each first slot, and on the return journey, it passes through multiple second slots, switching the layer it passes through for each second slot, so that in adjacent first slots, the third coil U3 passes through a different layer than the layer it passed through on the outward journey. During the outward journey, the fourth coil U4 passes through multiple second slots, switching the layer it passes through for each second slot, so that in the adjacent first slot, it passes through the same layer as the third coil U3 passes through during the outward journey. During the return journey, the fourth coil U4 passes through multiple first slots, switching the layer it passes through for each first slot, so that in the adjacent second slot, it passes through the same layer as the third coil U3 passes through during the return journey.

[0040] Figure 10(a) shows the wiring pattern of the first coil U1 to the fourth coil U4 of the U-phase coil group. Figure 10(b) shows the wiring pattern of the first coil V1 to the fourth coil V4 of the V-phase coil group, and Figure 10(c) shows the wiring pattern of the first coil W1 to the fourth coil W4 of the W-phase coil group. In the embodiment shown in Figure 10, the starting points Su1 to Su4, Sv1 to Sv4, Sw1 to Sw4 and the ending points Gu1 to Gu4, Gv1 to Gv4, Gw1 to Gw4 of each phase coil group are on the innermost layer side.

[0041] In Figure 10, a different hatching pattern is shown for each of the four coils (coil 1 to coil 4), and the corresponding coil is inserted into the hatched layer of slot S. Also in Figure 10, the forward path of the coil is shown with a solid line, the return path with a dashed line, and the jumper lines with a dotted line. The same applies to Figures 11, 16, and 17.

[0042] As can be seen by comparing Figures 10(a) and (b), the wiring patterns of the first coils V1 to the fourth coils V4 of the V-phase coil group are the same as the wiring patterns of the first coils U1 to the fourth coils U4 of the U-phase coil group, shifted by 8 slots in the circumferential direction. Also, as can be seen by comparing Figures 10(a) and (c), the wiring patterns of the first coils W1 to the fourth coils W4 of the W-phase coil group are the same as the wiring patterns of the first coils U1 to the fourth coils U4 of the U-phase coil group, shifted by 16 slots in the circumferential direction. In other words, the first coils V1 to the fourth coils V4 of the V-phase are constructed by shifting the first coils U1 to the fourth coils U4 of the U-phase by 8 slot pitches in the circumferential direction. Furthermore, the first coils W1 to the fourth coils W4 of the W-phase are constructed by shifting the first coils U1 to the fourth coils U4 of the U-phase by 16 slot pitches in the circumferential direction. In other words, the winding method of the V-phase coil group and the W-phase coil group on the stator core 24 is the same as the winding method of the U-phase coil group on the stator core 24, except that the winding location is shifted in the circumferential direction. Therefore, the explanation of the wiring patterns of the first coil V1 to the fourth coil V4 of the V-phase coil group and the first coil W1 to the fourth coil W4 of the W-phase coil group will be omitted.

[0043] Referring to Figure 10, U-phase groups, V-phase groups, and W-phase groups are repeatedly formed in every two adjacent slots in the circumferential direction. The first U-phase coils U1 to the fourth U-phase coils U4 are inserted into the slot S of the U-phase group, the first V-phase coils V1 to the fourth V-phase coils V4 are inserted into the slot S of the V-phase group, and the first W-phase coils W1 to the fourth W-phase coils W4 are inserted into the slot S of the W-phase group.

[0044] Further, among the start points of the first coils U1, V1, W1 in the plurality of phase coil groups (U phase, V phase, W phase), the number of slots interposed between adjacent start points, that is, between start points Su1 and Sv1, between start points Su1 and Sw1, and between start points Sv1 and Sw1 is 7 or more, which is larger than the number of slots per pole (6). Further, among the end points of the first coils U1, V1, W1 in the plurality of phase coil groups (U phase, V phase, W phase), the number of slots interposed between adjacent end points, that is, between end points Gu1 and Gv1, between end points Gu1 and Gw1, and between end points Gv1 and Gw1 is also 7 or more, which is larger than the number of slots per pole (6).

[0045] According to the embodiment shown in Figure 10, the first coil U1 passes through only a plurality of first slots on the outward journey without switching to a second slot midway, and passes through only a plurality of second slots on the return journey without switching to a first slot midway. The second coil U2 passes through only a plurality of second slots on the outward journey without switching to a first slot midway, and passes through only a plurality of first slots on the return journey without switching to a second slot midway. Furthermore, the spacing between the plurality of first slots through which the first coil U1 passes on the outward journey and the second coil U2 passes on the return journey remains constant at a predetermined number of slots, and similarly, the spacing between the plurality of second slots through which the second coil U2 passes on the outward journey and the first coil U1 passes on the return journey also remains constant at a predetermined number of slots. Therefore, the first coil U1 and the second coil U2 can be easily wound around the corresponding slots S. Furthermore, the slot S into which the first coil U1 is inserted and the slot S into which the second coil U2 is inserted are switched between the forward and return paths, and the layers through which the first coil U1 and the second coil U2 pass are also switched each time they pass through slot S. Moreover, in adjacent first and second slots, the first coil U1 passes through different layers in the forward and return paths, while the first coil U1 and the second coil U2 pass through the same layer in both the forward and return paths. As a result, in the U-phase coil group, the first coil U1 and the second coil U2 passing through the same layer are swapped between certain adjacent first and second slots and the next adjacent first and second slots. For example, in the same lane, if the first coil U1 and the second coil U2 are inserted in this order into the inner layer of adjacent first and second slots, then the second coil U2 and the first coil U1 are inserted in this order into the inner layer of the next adjacent first and second slots, and this is repeated. Also, in the same lane, if the second coil U2 and the first coil U1 are inserted in this order into the outer layer of adjacent first and second slots, then the first coil U1 and the second coil U2 are inserted in this order into the outer layer of the next adjacent first and second slots, and this is repeated.Therefore, when considering the entire rotating electric machine 10, the positional relationship between the magnetic poles of the rotor 22 and the first coil U1 is the same as the positional relationship between the magnetic poles of the rotor 22 and the second coil U2. As a result, the induced electromotive force in the first coil U1 and the induced electromotive force in the second coil U2 are equal, so the first coil U1 and the second coil U2 are at the same potential, and circulating current can be suppressed. The same applies to the third coil U3 and the fourth coil U4. The same also applies to the first coils V1 to the fourth coils V4 of the V-phase coil group, and the first coils W1 to the fourth coils W4 of the W-phase coil group.

[0046] In the U-phase coil group, the first coil U1 can be easily reversed from its forward path to its return path by connecting the end point of its forward path and the start point of its return path with a first crossover wire 54a. Similarly, the second coil U2 can be easily reversed from its forward path to its return path by connecting the end point of its forward path and the start point of its return path with a second crossover wire 56a. Likewise, the first coil U3 can be easily reversed from its forward path to its return path by connecting the end point of its forward path and the start point of its return path with a first crossover wire 54a. Furthermore, the fourth coil U4 can be easily reversed from its forward path to its return path by connecting the end point of its forward path and the start point of its return path with a second crossover wire 56a. The same applies to the V-phase coil group and the W-phase coil group.

[0047] Since the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 and ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group are on the innermost layer side, the busbars 48u, 48v, and 48w connected to the starting points Su1-Su4, Sv1-Sv4, and Sw1-Sw4 of each phase coil group can be made compact.

[0048] In the embodiment shown in Fig. 10, the intervals between the starting points of one phase coil group and the starting points of another phase coil group, namely the intervals between the starting points (Su1, Su2) of the U-phase coil group, the starting points (Sv1, Sv2) of the V-phase coil group, and the starting points (Sw1, Sw2) of the W-phase coil group, and the intervals between the starting points (Su3, Su4) of the U-phase coil group, the starting points (Sv3, Sv4) of the V-phase coil group, and the starting points (Sw3, Sw4) of the W-phase coil group, can all be increased respectively. Therefore, the interval between crossover wires can be made relatively large so that the crossover wires (the first crossover wire 54a and the second crossover wire 56a) of one phase coil group do not overlap with the crossover wires (the first crossover wire 54a and the second crossover wire 56a) of another phase coil group, and the crossover wires can be dispersed. Accordingly, local enlargement of the coil end portion E2 can be suppressed, so that the stator 20 can be reduced in size.

[0049] The U-phase coil group includes 4-parallel windings formed by connecting the first coil U1 to the fourth coil U4 in parallel, the V-phase coil group includes 4-parallel windings formed by connecting the first coil V1 to the fourth coil V4 in parallel, and the W-phase coil group includes 4-parallel windings formed by connecting the first coil W1 to the fourth coil W4 in parallel. In a configuration where a pair formed of the first coils U1, V1, W1 and the second coils U2, V2, W2 and a pair formed of the third coils U3, V3, W3 and the fourth coils U4, V4, W4 are arranged point-symmetrically when viewed from the axial direction of the stator core 24, the present invention is suitably used.

[0050] An end point of an outward path and a start point of a return path that are separated by a 7-slot pitch (corresponding to 7 slots, which is more than the number of slots per pole (6 slots)) are connected by the first crossover wire 54a, and an end point of an outward path and a start point of a return path that are separated by a 5-slot pitch (corresponding to 5 slots, which is less than the number of slots per pole (6 slots)) are connected by the second crossover wire 56a. With this configuration, the arrangement of coils in two adjacent slots S can be easily interchanged.

[0051] As the segment coils of the winding 26, it is sufficient to use one type of segment coil 52.

[0052] When winding the winding 26 around the slot S, it is only necessary to move to an adjacent lane every half turn, so that the segment coils 52 can be easily connected to each other by welding.

[0053] Next, the embodiment shown in Figure 11 will be described.

[0054] Figure 11 shows another example of the wiring pattern for the first to fourth coils of each phase coil group (U phase, V phase, W phase) in the stator 20. In the embodiment shown in Figure 11, the starting points Su1 to Su4, Sv1 to Sv4, Sw1 to Sw4 and the ending points Gu1 to Gu4, Gv1 to Gv4, Gw1 to Gw4 of each phase coil group are on the innermost layer side.

[0055] The wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 11(a) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 10(a). The wiring patterns of the first coil V1 to the fourth coil V4 of the V-phase coil group shown in Figure 11(b) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 11(a), shifted by four slots in the circumferential direction. Furthermore, the wiring patterns of the first coil W1 to the fourth coil W4 of the W-phase coil group shown in Figure 11(c) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 11(a), shifted by eight slots in the circumferential direction. Therefore, the explanation of the wiring patterns for the first coil U1 to the fourth coil U4 of the U-phase coil group, the first coil V1 to the fourth coil V4 of the V-phase coil group, and the first coil W1 to the fourth coil W4 of the W-phase coil group, as shown in Figure 11, will be omitted.

[0056] Referring to Figure 11, the number of slots sandwiched between adjacent starting points of the first coils U1, V1, and W1 in the multiple phase coil groups (U phase, V phase, and W phase), for example between starting points Su1 and Sv1, and between starting points Sv1 and Sw1, is 3, which is smaller than the number of slots per pole (6). Similarly, the number of slots sandwiched between adjacent ending points of the first coils U1, V1, and W1 in the multiple phase coil groups (U phase, V phase, and W phase), for example between ending points Gu1 and Gv1, and between ending points Gv1 and Gw1, is also 3, which is smaller than the number of slots per pole (6).

[0057] According to the embodiment shown in Figure 11, since the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 and ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group are on the innermost layer side, the busbars 48u, 48v, and 48w connected to the starting points Su1-Su4, Sv1-Sv4, and Sw1-Sw4 of each phase coil group can be made compact.

[0058] In the embodiment shown in Figure 11, the distance between the starting point of one phase coil group and the starting point of another phase coil group can be reduced, that is, the distance between the starting point of the U-phase coil group (Su1, Su2), the starting point of the V-phase coil group (Sv1, Sv2), and the starting point of the W-phase coil group (Sw1, Sw2), and the distance between the starting point of the U-phase coil group (Su3, Su4), the starting point of the V-phase coil group (Sv3, Sv4), and the starting point of the W-phase coil group (Sw3, Sw4). Therefore, the spacing between the endpoints of multiple phase coil groups, namely the spacing between the endpoints of the U-phase coil group (Gu1, Gu2), the endpoints of the V-phase coil group (Gv1, Gv2), and the endpoints of the W-phase coil group (Gw1, Gw2), and the spacing between the endpoints of the U-phase coil group (Gu3, ​​Gu4), the endpoints of the V-phase coil group (Gv3, Gv4), and the endpoints of the W-phase coil group (Gw3, Gw4), can be made relatively small. Consequently, it becomes easier to group the endpoints of multiple phase coil groups Gu1, Gu2, Gv1, Gv2, Gw1, Gw2 at the neutral point M, and it also becomes easier to group the endpoints of multiple phase coil groups Gu3, Gu4, Gv3, Gv4, Gw3, Gw4 at the neutral point M.

[0059] Next, with reference to Figures 12 to 15, other examples of wiring for the first coil U1 to the fourth coil U4 of the U-phase coil group will be described.

[0060] Figure 12 shows an example of the wiring of the first coil U1 in the stator 20.

[0061] The starting point Su1 of the forward path of the first coil U1 is connected to the busbar 48u. On the forward path, the first coil U1 starts its rotation clockwise from the 8th layer of slot 4, as viewed from the coil end E2 side. In lane L4, the first coil U1 passes through the 8th layer of slot 4, the 7th layer of slot 10, the 8th layer of slot 16, and the 7th layer of slot 22 in that order, and then moves to lane L3. In lane L3, the first coil U1 passes through the 6th layer of slot 28, the 5th layer of slot 34, the 6th layer of slot 40, and the 5th layer of slot 46 in that order, and then moves to lane L2. In lane L2, the first coil U1 passes through the 4th layer of slot 4, the 3rd layer of slot 10, the 4th layer of slot 16, and the 3rd layer of slot 22 in that order, and then moves to lane L1. The first coil U1 passes through the second layer of slot 28, the first layer of slot 34, the second layer of slot 40, and the first layer of slot 46 in lane L1 in that order, completing its forward path. The end point of the forward path and the start point of the return path of the first coil U1 are connected by the first jumper wire 54b. The first jumper wire 54b connects the windings inserted in slots 41 and 46, which are 5 slots apart.

[0062] On the return journey, the first coil U1 begins its rotation counterclockwise from the first layer of slot 41, viewed from the coil end E2 side. In lane L1, the first coil U1 passes through the first layer of slot 41, the second layer of slot 35, the first layer of slot 29, and the second layer of slot 23 in that order, and then moves to lane L2. In lane L2, the first coil U1 passes through the third layer of slot 17, the fourth layer of slot 11, the third layer of slot 5, and the fourth layer of slot 47 in that order, and then moves to lane L3. In lane L3, the first coil U1 passes through the fifth layer of slot 41, the sixth layer of slot 35, the fifth layer of slot 29, and the sixth layer of slot 23 in that order, and then moves to lane L4. The first coil U1 passes through the 7th layer of slot 17, the 8th layer of slot 11, the 7th layer of slot 5, and the 8th layer of slot 47 in lane L4 in that order, and then completes its return journey. The endpoint Gu1 of the return journey of the first coil U1 is then connected to a bus ring (not shown) and, consequently, to the neutral point M.

[0063] Figure 13 shows an example of the wiring of the second coil U2 in the stator 20.

[0064] The starting point Su2 of the outward path of the second coil U2 is connected to the busbar 48u. On the outward path, the second coil U2 starts its rotation clockwise from the 8th layer of slot 5, as viewed from the coil end E2 side. In lane L4, the second coil U2 passes through the 8th layer of slot 5, the 7th layer of slot 11, the 8th layer of slot 17, and the 7th layer of slot 23 in that order, and then moves to lane L3. In lane L3, the second coil U2 passes through the 6th layer of slot 29, the 5th layer of slot 35, the 6th layer of slot 41, and the 5th layer of slot 47 in that order, and then moves to lane L2. In lane L2, the second coil U2 passes through the 4th layer of slot 5, the 3rd layer of slot 11, the 4th layer of slot 17, and the 3rd layer of slot 23 in that order, and then moves to lane L1. The second coil U2 passes through the second layer of slot 29, the first layer of slot 35, the second layer of slot 41, and the first layer of slot 47 in that order in lane L1, thus completing its forward path. The end point of the forward path and the start point of the return path of the second coil U2 are connected by the second crossover wire 56b. The second crossover wire 56b connects the windings inserted in slots 40 and 47, which are separated by a pitch of 7 slots.

[0065] On the return journey, the second coil U2 begins its rotation counterclockwise from the first layer of slot 40, viewed from the coil end E2 side. In lane L1, the second coil U2 passes through the first layer of slot 40, the second layer of slot 34, the first layer of slot 28, and the second layer of slot 22 in that order, before moving to lane L2. In lane L2, the second coil U2 passes through the third layer of slot 16, the fourth layer of slot 10, the third layer of slot 4, and the fourth layer of slot 46 in that order, before moving to lane L3. In lane L3, the second coil U2 passes through the fifth layer of slot 40, the sixth layer of slot 34, the fifth layer of slot 28, and the sixth layer of slot 22 in that order, before moving to lane L4. The second coil U2 passes through the 7th layer of slot 16, the 8th layer of slot 10, the 7th layer of slot 4, and the 8th layer of slot 46 in lane L4 in that order, completing its return journey. The endpoint Gu2 of the return journey of the second coil U2 is then connected to the bus ring and, consequently, to the neutral point M.

[0066] Figure 14 shows an example of the wiring of the third coil U3 in the stator 20. The wiring pattern of the third coil U3 is the same as that of the first coil U1 shown in Figure 12, but shifted 24 slots (half a turn) in the circumferential direction, so its explanation is omitted.

[0067] Figure 15 shows an example of the wiring of the fourth coil U4 in the stator 20. The wiring pattern of the fourth coil U4 is the same as that of the second coil U2 shown in Figure 13, but shifted 24 slots (half a turn) in the circumferential direction, so its explanation is omitted.

[0068] A pair of first coils U1 and second coils U2, and a pair of third coils U3 and fourth coils U4 are wound around the stator core 24 (stator 20) in a way that is point-symmetrical when viewed from the axial direction of the stator core 24.

[0069] In such a U-phase coil group, the first coil U1 and the second coil U2 of the U-phase coil group pass through one of the following: a plurality of corresponding first slots (slots 4, 10, 16, 22, 28, 34, 40, and 46), and a plurality of corresponding second slots (slots 5, 11, 17, 23, 29, 35, 41, and 47) located adjacent to each first slot. The plurality of first slots are arranged at intervals of a predetermined number of slots (6 slots in this embodiment), and the plurality of second slots are also arranged at intervals of a predetermined number of slots (6 slots in this embodiment). Furthermore, the first coil U1 and the second coil U2 switch the lane they pass through to an adjacent lane every half-circumference of the stator core 24, and reciprocate between the innermost lane L1 and the outermost lane L4. Furthermore, the first coil U1 passes through multiple first slots in the outward journey, switching the layer it passes through for each first slot, and in the return journey, it passes through multiple second slots in the second slot, switching the layer it passes through for each second slot, so that in adjacent first slots, the first coil U1 passes through a different layer than the layer it passed through in the outward journey. The second coil U2 passes through multiple second slots in the outward journey, switching the layer it passes through for each second slot, so that in adjacent first slots, the first coil U2 passes through the same layer as the layer the first coil U1 passed through in the outward journey, and in the return journey, it passes through multiple first slots in the first slot, switching the layer it passes through for each first slot, so that in adjacent second slots, the first coil U1 passes through the same layer as the layer the first coil U1 passed through in the return journey.

[0070] Similarly, the third coil U3 and the fourth coil U4 pass through one of the corresponding multiple first slots (slots 4, 10, 16, 22, 28, 34, 40, and 46) and one of the corresponding multiple second slots (slots 5, 11, 17, 23, 29, 35, 41, and 47) located adjacent to each first slot. Furthermore, the third coil U3 and the fourth coil U4 travel back and forth between the innermost lane L1 and the outermost lane L4, switching the lane they pass through to an adjacent lane every half-circumference of the stator core 24. In addition, on the outward journey, the third coil U3 passes through multiple first slots, switching the layer it passes through for each first slot, and on the return journey, it passes through multiple second slots, switching the layer it passes through for each second slot, so that in adjacent first slots, the third coil passes through a different layer than the layer it passed through on the outward journey. During the outward journey, the fourth coil U4 passes through multiple second slots, switching the layer it passes through for each second slot, so that in the adjacent first slot, it passes through the same layer as the third coil U3 passes through during the outward journey. During the return journey, the fourth coil U4 passes through multiple first slots, switching the layer it passes through for each first slot, so that in the adjacent second slot, it passes through the same layer as the third coil U3 passes through during the return journey.

[0071] Figure 16(a) shows the wiring pattern of the first coil U1 to the fourth coil U4 of the U-phase coil group. Figure 16(b) shows the wiring pattern of the first coil V1 to the fourth coil V4 of the V-phase coil group, and Figure 16(c) shows the wiring pattern of the first coil W1 to the fourth coil W4 of the W-phase coil group. In the embodiment shown in Figure 16, the starting points Su1 to Su4, Sv1 to Sv4, Sw1 to Sw4 and the ending points Gu1 to Gu4, Gv1 to Gv4, Gw1 to Gw4 of each phase coil group are on the outermost layer side.

[0072] As can be seen by comparing Figures 16(a) and (b), the wiring patterns of the first coil V1 to the fourth coil V4 are the same as the wiring patterns of the first coil U1 to the fourth coil U4, shifted by eight slots in the circumferential direction. Also, as can be seen by comparing Figures 16(a) and (c), the wiring patterns of the first coil W1 to the fourth coil W4 are the same as the wiring patterns of the first coil U1 to the fourth coil U4, shifted by 16 slots in the circumferential direction. In other words, the winding method of the V-phase coil group and the W-phase coil group on the stator core 24 is the same as the winding method of the U-phase coil group on the stator core 24, except that the winding location is shifted in the circumferential direction. Therefore, the explanation of the wiring patterns of the first coil V1 to the fourth coil V4 and the wiring patterns of the first coil W1 to the fourth coil W4 is omitted.

[0073] Referring to Figure 16, the number of slots sandwiched between adjacent starting points of the first coils U1, V1, and W1 in the multiple phase coil groups (U phase, V phase, W phase), i.e., between starting points Su1, Sv1, between starting points Su1, Sw1, and between starting points Sv1, Sw1, is 7 or more, which is greater than the number of slots per pole (6). Also, the number of slots sandwiched between adjacent ending points of the first coils U1, V1, and W1 in the multiple phase coil groups (U phase, V phase, W phase), i.e., between ending points Gu1, Gv1, between ending points Gu1, Gw1, and between ending points Gv1, Gw1, is 7 or more, which is greater than the number of slots per pole (6).

[0074] According to the embodiment shown in Figure 16, since the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 and ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group are on the outermost layer side, the rotor 22 can be easily inserted inside the stator 20 without being affected by configurations that connect the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 of each phase coil group to busbars 48u, 48v, 48w or configurations that connect the ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group to the neutral point M.

[0075] The spacing between the starting points of one phase coil group and the starting points of other phase coil groups, that is, the spacing between the starting points of the U-phase coil group (Su1, Su2), the V-phase coil group (Sv1, Sv2), and the W-phase coil group (Sw1, Sw2), and the spacing between the starting points of the U-phase coil group (Su3, Su4), the V-phase coil group (Sv3, Sv4), and the W-phase coil group (Sw3, Sw4), can be increased. Therefore, the spacing between the jumper wires can be made relatively large so that the jumper wires of one phase coil group (first jumper wire 54b and second jumper wire 56b) do not overlap with the jumper wires of other phase coil groups (first jumper wire 54b and second jumper wire 56b), and the jumper wires can be distributed. Therefore, localized enlargement of the coil end section E2 can be suppressed, and the stator 20 can be made smaller.

[0076] Next, the embodiment shown in Figure 17 will be described.

[0077] Figure 17 shows another example of the wiring pattern for the first to fourth coils of each phase coil group (U phase, V phase, W phase) in the stator 20. In the embodiment shown in Figure 17, the starting points Su1 to Su4, Sv1 to Sv4, Sw1 to Sw4 and the ending points Gu1 to Gu4, Gv1 to Gv4, Gw1 to Gw4 of each phase coil group are on the outermost layer side.

[0078] The wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 17(a) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 16(a). The wiring patterns of the first coil V1 to the fourth coil V4 of the V-phase coil group shown in Figure 17(b) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 17(a) shifted by four slots in the circumferential direction. Furthermore, the wiring patterns of the first coil W1 to the fourth coil W4 of the W-phase coil group shown in Figure 17(c) are the same as the wiring patterns of the first coil U1 to the fourth coil U4 of the U-phase coil group shown in Figure 17(a) shifted by eight slots in the circumferential direction. Therefore, the explanation of the wiring patterns for the first coil U1 to the fourth coil U4 of the U-phase coil group, the first coil V1 to the fourth coil V4 of the V-phase coil group, and the first coil W1 to the fourth coil W4 of the W-phase coil group, as shown in Figure 17, will be omitted.

[0079] Referring to Figure 17, in the group of phase coils (U phase, V phase, W phase), the number of slots sandwiched between adjacent starting points of the first coils U1, V1, W1, for example between starting points Su1 and Sv1, and between starting points Sv1 and Sw1, is 3, which is smaller than the number of slots per pole (6). Similarly, in the group of phase coils (U phase, V phase, W phase), the number of slots sandwiched between adjacent ending points of the first coils U1, V1, W1, for example between ending points Gu1 and Gv1, and between ending points Gv1 and Gw1, is also 3, which is smaller than the number of slots per pole (6).

[0080] According to the embodiment shown in Figure 17, since the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 and ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group are on the outermost layer side, the rotor 22 can be easily inserted inside the stator 20 without being affected by configurations that connect the starting points Su1-Su4, Sv1-Sv4, Sw1-Sw4 of each phase coil group to busbars 48u, 48v, 48w or configurations that connect the ending points Gu1-Gu4, Gv1-Gv4, Gw1-Gw4 of each phase coil group to the neutral point M.

[0081] The distance between the starting point of one phase coil group and the starting point of another phase coil group, that is, the distance between the starting point of the U-phase coil group (Su1, Su2), the starting point of the V-phase coil group (Sv1, Sv2), and the starting point of the W-phase coil group (Sw1, Sw2), and the distance between the starting point of the U-phase coil group (Su3, Su4), the starting point of the V-phase coil group (Sv3, Sv4), and the starting point of the W-phase coil group (Sw3, Sw4), can be reduced. Therefore, the spacing between the endpoints of multiple phase coil groups, namely the spacing between the endpoints of the U-phase coil group (Gu1, Gu2), the endpoints of the V-phase coil group (Gv1, Gv2), and the endpoints of the W-phase coil group (Gw1, Gw2), and the spacing between the endpoints of the U-phase coil group (Gu3, ​​Gu4), the endpoints of the V-phase coil group (Gv3, Gv4), and the endpoints of the W-phase coil group (Gw3, Gw4), can be made relatively small. Consequently, it becomes easier to group the endpoints of multiple phase coil groups Gu1, Gu2, Gv1, Gv2, Gw1, Gw2 at the neutral point M, and it also becomes easier to group the endpoints of multiple phase coil groups Gu3, Gu4, Gv3, Gv4, Gw3, Gw4 at the neutral point M.

[0082] In the above embodiment, two slots were allocated per phase and per pole. That is, a total of six slots were allocated per pole: two slots for the U phase, two slots for the V phase, and two slots for the W layer (see Figure 2). However, the number of slots per three-phase pole is not limited to six.

[0083] In the above-described embodiment, the number of slots in the stator 20 was 48, but it is not limited to this, and the number of slots may be, for example, 72.

[0084] In the above-described embodiment, the number of poles was 8, but it is not limited to this, and for example, it may be 6 or 12 poles.

[0085] In the embodiment described above, the number of layers in one slot was 8, but this is not limited to this.

[0086] In the embodiment described above, there were four coils in parallel for one phase, but the system is not limited to this. For example, there may be two coils in parallel for one phase.

[0087] Preferred embodiments of the present invention have been described above, but it is clear that various modifications are possible without departing from the scope and spirit of the invention. The scope of the present invention is limited only to the appended claims.

[0088] 10 Rotating electric machine 12 Housing 20 Stator 22 Rotor 24 Stator core 26 Winding 32 Rotor shaft 34 Rotor core 36 Magnets 48u, 48v, 48w Busbar 50 Bus ring 52 Segment coils 54a, 54b First jumper wires 56a, 56b Second jumper wires E1, E2 Coil end sections L1, L2, L3, L4 Lanes M Neutral point P1-P8 Magnetic poles S Slots Su1, Su2, Su3, Su4 Starting point of U-phase coil group Sv1, Sv2, Sv3, Sv4 Starting point of V-phase coil group Sw1, Sw2, Sw3, Sw4 Starting point of W-phase coil group Gu1, Gu2, Gu3, Gu4 End point of U-phase coil group Gv1, Gv2, Gv3, Gv4: End points of the V-phase coil group Gw1, Gw2, Gw3, Gw4: End points of the W-phase coil group U1, V1, W1: First coil U2, V2, W2: Second coil U3, V3, W3: Third coil U4, V4, W4: Fourth coil

Claims

1. The rotor comprises a stator and a rotor rotatably mounted inside the stator and having 2 × A (A is a natural number of 2 or more) magnetic poles in the circumferential direction, the stator includes a stator core having a plurality of slots and windings having a plurality of phase coil groups (U phase, V phase, W phase) connected in a star configuration and wave-wound in the plurality of slots, the plurality of slots include a first slot and a second slot, penetrates the stator core in the axial direction and is provided at predetermined intervals in the circumferential direction at a ratio of 2 × B (B is a natural number) per phase and per pole, and is formed so that the windings can pass through in the radial direction in a state where they are arranged in 4 × C (C is a natural number) layers, the plurality of slots are divided into 2 × C lanes by dividing the 4 × C layers into pairs of radially adjacent layers, and each phase coil group includes at least one pair of first coils and second coils connected in parallel. The first coil and the second coil of each phase coil group pass through one of the corresponding plurality of first slots arranged at predetermined slot intervals and the corresponding plurality of second slots adjacent to each first slot and arranged at predetermined slot intervals, switching the lane they pass through to the adjacent lane every half-circumference of the stator core, and reciprocating between the innermost lane and the outermost lane; the first coil passes through the plurality of first slots in the forward path, switching the layer it passes through for each first slot; and in the return path, it passes through the plurality of second slots, switching the layer it passes through for each second slot, such that in adjacent first slots the first coil passes through a different layer than the layer it passed through in the forward path; A rotating electric machine wherein, in the forward path, the second coil passes through a plurality of second slots, switching the layer it passes through for each second slot, so that in adjacent first slots it passes through the same layer as the first coil passes through in the forward path, and in the return path, the second coil passes through a plurality of first slots, switching the layer it passes through for each first slot, so that in adjacent second slots it passes through the same layer as the first coil passes through in the return path.

2. The rotating electric machine according to claim 1, wherein each group of phase coils further includes a first jumper wire connecting the end of the forward path of the first coil to the start of the return path, and a second jumper wire connecting the end of the forward path of the second coil to the start of the return path.

3. The rotating electric machine according to claim 2, wherein the starting and ending points of each phase coil group are on the innermost layer side.

4. The rotating electric machine according to claim 2, wherein the starting and ending points of each phase coil group are on the outermost layer side.

5. The rotating electric machine according to claim 3 or 4, wherein the number of slots sandwiched between adjacent starting points of the first coil in the plurality of phase coil groups and the number of slots sandwiched between adjacent ending points of the first coil in the plurality of phase coil groups are greater than the number of slots per pole.

6. The rotating electric machine according to claim 3 or 4, wherein the number of slots sandwiched between adjacent starting points of the first coil in the plurality of phase coil groups and the number of slots sandwiched between adjacent ending points of the first coil in the plurality of phase coil groups are smaller than the number of slots per pole.

7. The rotating electric machine according to any one of claims 1 to 6, wherein each group of phase coils further includes a pair of third and fourth coils connected in parallel, the first coil, the second coil, the third coil and the fourth coil are connected in parallel, and the pair of first and second coils and the pair of third and fourth coils are wound around the stator core in a point-symmetric manner when viewed from the axial direction of the stator core.

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