stata

Abstract

To provide a stator that can suppress the generation of circulating current even when the effective number of turns is not an integer, thereby increasing the output of a rotating electric machine while reducing vibration and noise. [Solution] The stator of the present disclosure includes a third segment coil in which a pair of legs are inserted into one 2·i layer and the other 2·i+1 layer on the opposite side of one side in the circumferential direction of predetermined first and second slots spaced 7 slots apart, with the legs protruding from one end of the stator core, forming a jumper wire between the 2·i layer and the 2·i+1 layer, and at one end of the stator core, two legs protruding from one 2·i layer and the other 2·i-1 layer on one side in the circumferential direction of first and second slots spaced 5 slots apart are twisted so that their tips are joined together.

Description

Technical Field

[0001] The present disclosure relates to a stator including a stator core including a plurality of slots and a plurality of stator coils wound around the stator core.

Background Art

[0002] Conventionally, a stator is known that includes a stator core having a plurality of slots arranged in the circumferential direction, and three-phase (U-phase, V-phase, W-phase) stator coils wound around the stator core (see, for example, Patent Document 1). In this stator, the three-phase stator coils each include a multiple of four parallel windings (parallel coils) connected in parallel, and are connected by a Y-connection. Each parallel winding is formed by inserting a pair of straight portions (legs) of a plurality of U-shaped conductor segments (segment coils) into corresponding slots so as to protrude from one end (twisted side) in the axial direction of the stator core, and twisting each straight portion in the circumferential direction to join the tips of two corresponding straight portions. In other words, the multiple conductor segments include a first conductor segment having a pair of linear sections that are inserted into two first slots spaced five slots apart, a second conductor segment having a pair of linear sections that are inserted into two second slots spaced seven slots apart on either side of the first slot, and a third conductor segment having a pair of linear sections that are inserted into predetermined first and second slots spaced six slots apart. The pair of linear sections of the first conductor segment are inserted into one 2·i-1 layer (where i=3,2,1 in the example of Patent Document 1) and the other 2·i layer on one side (winding start side) of the two first slots in the circumferential direction. The pair of linear sections of the second conductor segment are inserted into one 2·i-1 layer and the other 2·i layer on one side of the two second slots in the circumferential direction, such that the second conductor segment straddles the corresponding first conductor segment. Furthermore, a pair of legs of the third conductor segment are inserted into one 2·i layer and the other 2·i+1 layer on one side of predetermined first and second slots spaced six slots apart in the circumferential direction, forming a jumper wire (57) that spans between the 2·i layer and the 2·i+1 layer at the other end of the stator core (opposite the twisted side). Also, at one end of the stator core, two legs protruding from one 2·i layer and the other 2·i-1 layer on one side of two slots spaced six slots apart in the circumferential direction are twisted together so that their ends are joined.As a result, in each parallel winding, the linear portions of the conductor segments are evenly distributed in both the first and second slots adjacent to each other in the circumferential direction. This eliminates the timing difference in the generation of induced voltages at each magnetic pole of the parallel winding in response to the passage of the rotor's magnets, thereby preventing the generation of circulating currents in each parallel winding. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 5896250 (Figures 13A-15) [Overview of the project] [Problems that the invention aims to solve]

[0004] In a rotating electric machine including a stator as described in Patent Document 1, the output characteristics change depending on the number of turns (hereinafter referred to as "effective number of turns") obtained by dividing the number of linear sections (number of layers) in one slot by the number of parallel windings (number of parallels), and the mounting side of the rotating electric machine may require a stator with a non-integer number of turns (for example, 1.5 or 2.5). Furthermore, according to the stator described in Patent Document 1, even if the effective number of turns is a non-integer, it is possible to prevent the generation of circulating current between multiple parallel windings. However, in the stator described in Patent Document 1, since each of the multiple stator coils is wound around the stator core by full-section winding, it is not easy to increase the output of the rotating electric machine including the stator or to reduce the vibration and noise of the rotating electric machine.

[0005] Therefore, the primary objective of this disclosure is to provide a stator that can suppress the generation of circulating current even when the effective number of turns is not an integer, thereby increasing the output of a rotating electric machine while reducing vibration and noise. [Means for solving the problem]

[0006] The stator of this disclosure includes a stator core including a plurality of slots formed circumferentially spaced apart so as to extend radially, and a plurality of segment coils having pairs of legs inserted into different slots and forming a plurality of stator coils by electrical connections between the tips of the corresponding legs. In such a stator, when the number of poles is "p" and the number of slots is "n", n = 6·p. Each plurality of stator coils includes 4·m parallel coils (where "m" is an integer of 1 or more) connected in parallel. An even number of legs are inserted radially into one slot. The plurality of segment coils include a first segment coil, a second segment coil, and a third segment coil. A pair of legs of the first segment coil are inserted so as to protrude from one end of the stator core into one 2·i-1 layer (where "i" is an integer of 1 or more, i=1,...,imax) on one side of two first slots spaced 6 slots apart in the circumferential direction and into the other 2·i layer. A pair of legs of the second segment coil are inserted so as to protrude from one end of the stator core into one 2·i-1 layer and the other 2·i layer on one side of two second slots spaced 8 slots apart on both sides of the first slot, and the second segment coil straddles the corresponding first segment coil. A pair of legs of the third segment coil are inserted so as to protrude from one end of the stator core into one 2·i layer and the other 2·i+1 layer on the opposite side of predetermined first and second slots spaced 7 slots apart, and the third segment coil forms a jumper wire between the 2·i layer and the 2·i+1 layer. Furthermore, at one end of the stator core, two legs protruding from one 2·i layer and the other 2·i-1 layer on one side of first and second slots spaced 5 slots apart are twisted so that their ends are joined together.

[0007] In other words, each parallel coil is basically formed by inserting a second segment coil into two second slots spaced eight slots apart, so as to straddle a first segment coil inserted into two first slots spaced six slots apart, and joining the corresponding legs at one end of the stator core at a five-slot pitch. This makes it possible to cancel out the circulating current generated by the timing difference in the generation of induced voltages at each magnetic pole of the parallel coil in response to the passage of the rotor magnets within each parallel winding, even if the effective number of turns is not an integer, thereby suppressing the flow of circulating current in the stator coil. Furthermore, in the stator of this disclosure, the legs of the first to third segment coils forming one phase of the stator coil are inserted into every three adjacent slots in the circumferential direction, and each of the multiple stator coils is wound around the stator core by short-section winding. As a result, a rotating electric machine including this stator can achieve higher output and reduce vibration and noise compared to a rotating electric machine including a stator in which the stator coils are wound around the stator core by full-section winding, and can omit skew and other measures to reduce torque ripple. As a result, the stator of this disclosure can suppress the generation of circulating current even when the effective number of turns is not an integer, thereby increasing the output of the rotating electric machine while reducing vibration and noise.

[0008] Other stators in this disclosure include a stator core comprising a plurality of slots formed circumferentially spaced so as to extend radially, and a plurality of segment coils having pairs of legs inserted into different slots and forming a plurality of stator coils by electrical connections between the tips of the corresponding legs. In such a stator, when the number of poles is "p" and the number of slots is "n", n = 6·p. Each plurality of stator coils comprises 4·m parallel coils (where "m" is an integer of 1 or more) connected in parallel. An even number of legs are inserted radially into a single slot. The plurality of segment coils comprises a first segment coil, a second segment coil, and a third segment coil. The pair of legs of the first segment coil are inserted into one 2·i-1 layer (where "i" is an integer greater than or equal to 1, i=1, ..., imax) and the other 2·i layer on one side of two first slots spaced four slots apart in the circumferential direction, with the pair of legs protruding from one end of the stator core. The pair of legs of the second segment coil are inserted into one 2·i-1 layer and the other 2·i layer on one side of two second slots spaced six slots apart on either side of the first slot in the circumferential direction, with the pair of legs protruding from one end of the stator core, and the second segment coil straddles the corresponding first segment coil. A pair of legs of the third segment coil are inserted so as to protrude from one end of the stator core into one 2·i layer and the other 2·i+1 layer on the opposite side of the circumferential direction of predetermined first and second slots spaced five slots apart, and the third segment coil forms a jumper wire between the 2·i layer and the 2·i+1 layer. Furthermore, at one end of the stator core, two legs protruding from one 2·i layer and the other 2·i-1 layer on the circumferential direction of the first and second slots spaced seven slots apart are twisted so that their ends are joined together.

[0009] In other words, each parallel coil is basically formed by inserting a second segment coil into two second slots spaced six slots apart, straddling a first segment coil inserted into two first slots spaced four slots apart, and then joining the corresponding legs at one end of the stator core at a seven-slot pitch. This makes it possible to cancel out the circulating current generated by the timing difference in the induced voltage generated at each magnetic pole of the parallel coil in response to the passage of the rotor magnets, even if the effective number of turns is not an integer, within each parallel winding, thereby suppressing the flow of circulating current in the stator coil. In addition, in other stators of this disclosure, the legs of the first to third segment coils forming a single-phase stator coil are inserted into every three adjacent slots in the circumferential direction, and each of the multiple stator coils is wound around the stator core by short-section winding. As a result, a rotating electric machine including this stator can achieve higher output and reduce vibration and noise compared to a rotating electric machine including a stator in which the stator coil is wound around the stator core by full-section winding. In addition, this stator eliminates the need for skew and other elements to reduce torque ripple. As a result, the stator of this disclosure can suppress the generation of circulating current even when the effective number of turns is not an integer, thereby increasing the output of the rotating electric machine while reducing vibration and noise. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing the status of this disclosure. [Figure 2] This is a schematic diagram showing an example of a stator coil of the stator described herein. [Figure 3] This is a schematic diagram showing the segment coils that form the stator coil of the stator of the present disclosure. [Figure 4] This is an explanatory diagram illustrating an example of how the segment coils are assembled to the stator core of the stator according to the present disclosure. [Figure 5] This is a plan view showing the stator of this disclosure. [Figure 6] This is a schematic diagram showing other stator coils applicable to the stator of this disclosure. [Figure 7] This is an explanatory diagram illustrating another configuration of the segment coils to the stator core of the stator of the present disclosure. [Modes for carrying out the invention]

[0011] Next, with reference to the drawings, embodiments for carrying out the invention of this disclosure will be described.

[0012] Figure 1 is a perspective view showing the stator 1 of this disclosure. The stator 1 shown in the figure, together with a rotor (not shown), constitutes a three-phase AC motor (rotating electric machine) used, for example, as a driving source or generator for electric vehicles or hybrid vehicles. In this embodiment, the stator 1 includes an annular stator core 2, a stator coil 3u (U-phase coil), a stator coil 3v (V-phase coil), and a stator coil 3w (W-phase coil).

[0013] The stator core 2 of the stator 1 is formed in an annular shape by, for example, stacking multiple electromagnetic steel sheets formed in a substantially annular shape by press working and connecting them in the stacking direction, or by, for example, press-molding and sintering ferromagnetic powder. As shown in Figure 1, the stator core 2 includes a central hole 2o in which the rotor is arranged, a plurality of teeth portions 2t that extend radially from the annular outer circumference (yoke portion) toward the axis and are adjacent to each other at a certain interval in the circumferential direction, and a plurality of slots 20 (for example, 48 in this embodiment) formed between adjacent teeth portions 2t. Each of the plurality of slots 20 extends radially from the stator core 2 and is arranged circumferentially at a certain interval, opening through the central hole 2o. In addition, an insulator (insulating paper), not shown, is placed inside each slot 20. Furthermore, the stator 1 has the same number of magnetic poles as the rotor (eight in this embodiment), and when the number of magnetic poles (number of poles) of the stator 1 is "p" and the number of slots 20 is "n", the relationship n = 6·p holds.

[0014] The stator coils 3u, 3v, and 3w are each formed by electrically joining multiple segment coils (coil wires) 4. As shown in Figure 2, the stator coil 3u includes four parallel coils U1, U2, U3, and U4 that are electrically connected in parallel. The stator coil 3v includes four parallel coils V1, V2, V3, and V4 that are electrically connected in parallel with each other, and the stator coil 3w includes four parallel coils W1, W2, W3, and W4 that are electrically connected in parallel with each other. The stator coils 3u, 3v, and 3w are then connected to each other by a star connection (Y connection), as shown in Figure 2. That is, the parallel coils U1-U4, V1-V4, and W1-W4 are connected to each other by a so-called 4Y connection.

[0015] The segment coil 4 is an electrical conductor formed by bending a flat rectangular wire, for example, which has an insulating coating made of enamel resin deposited on its surface, in the flatwise direction and the edgewise direction. In this embodiment, the segment coil 4 includes a first segment coil 4a, a second segment coil 4b, a third segment coil 4c, and a fourth segment coil 4d, as shown in Figure 3. The first to third segment coils 4a, 4b, and 4c are formed in a substantially U-shape and each has a pair (two) of legs 40 and a connecting wire portion 41 that connects the pair of legs 40. Furthermore, a crank portion 42 is formed in the connecting wire portion 41 of the first to third segment coils 4a, 4b, and 4c so as to extend diagonally between two flatwise bends. The two legs 40 of the first-third segment coils 4a, 4b, and 4c are inserted into different slots 20 from the other end of the stator core 2 so as to protrude from one end (the lower end in Figure 1) of the stator core 2, and the connecting wires 41 of the first-third segment coils 4a, 4b, and 4c are aligned at the other end of the stator core 2. The fourth segment coil 4d is formed in a roughly S-shape and includes both ends that extend straight and parallel to each other, and an oblique portion that extends obliquely between these ends along the connecting wires 41 of the first and second segment coils 4a and 4b.

[0016] In this embodiment, the first to fourth segment coils 4a, 4b, 4c, and 4d are assembled to the stator core 2 such that an even number (six in this embodiment) of legs 40 and the fourth segment coil 4d protrude radially adjacent to each of the multiple slots 20, and multiple layers are formed by the multiple legs 40 etc. that protrude from each of the multiple slots 20 and are adjacent to each other in the circumferential direction of the stator core 2. Hereinafter, the layer of multiple legs 40 etc. (tip portions) adjacent to each other in the circumferential direction on the outermost circumference of the stator core 2 will be called the "first layer", the layers radially inward will be called the "second layer", "third layer", ... and the layer of multiple legs 40 adjacent to each other in the circumferential direction on the innermost circumference will be called the "sixth layer". The number of "layers" in the stator 1 corresponds to the number of legs 40 arranged in each slot 20.

[0017] Next, referring to Figure 4, the assembly method of the first to third segment coils 4a, 4b, and 4c to the stator core 2 will be described using the stator coil 3u as an example. As shown in Figure 4, the pair of legs 40 of the first segment coil 4a (see the circles in Figure 4) are inserted from the other end of the stator core 2 (the front end of the paper in Figure 4) so ​​as to protrude from one end of the stator core 2 (the back end of the paper in Figure 4) into one 2·i-1 layer (where "i" is an integer of 1 or more, i=1, ..., imax (in this embodiment, imax=3)) and the other 2·i layer on one side (the end end of the winding) of two first slots 21 that are spaced 6 slots apart in the circumferential direction of the stator core 2.

[0018] More specifically, as shown in FIG. 4, a pair of legs 40 of the first segment coil 4a that forms the parallel coil U1 of the stator coil 3u are inserted into the first layer of slot 42 and the second layer of slot 48, the first layer of slot 18 and the second layer of slot 24, the third layer of slot 30 and the fourth layer of slot 36, the fifth layer of slot 42 and the sixth layer of slot 48, and the fifth layer of slot 18 and the sixth layer of slot 24. Further, a pair of legs 40 of the first segment coil 4a that forms the parallel coil U2 are inserted into the first layer of slot 30 and the second layer of slot 36, the third layer of slot 42 and the fourth layer of slot 48, the third layer of slot 18 and the fourth layer of slot 24, and the fifth layer of slot 30 and the sixth layer of slot 36, as shown in FIG. 4.

[0019] Furthermore, as shown in FIG. 4, a pair of legs 40 of the first segment coil 4a that forms the parallel coil U3 are inserted into the first layer of slot 24 and the second layer of slot 30, the third layer of slot 36 and the fourth layer of slot 42, the third layer of slot 12 and the fourth layer of slot 18, and the fifth layer of slot 24 and the sixth layer of slot 30. Also, a pair of legs 40 of the first segment coil 4a that forms the parallel coil U4 are inserted into the first layer of slot 36 and the second layer of slot 42, the first layer of slot 12 and the second layer of slot 18, the third layer of slot 24 and the fourth layer of slot 30, the fifth layer of slot 36 and the sixth layer of slot 42, and the fifth layer of slot 12 and the sixth layer of slot 18, as shown in FIG. 4.

[0020] The pair of legs 40 (refer to the ○ marks in FIG. 4) of the second segment coil 4b are inserted from the other end side of the stator core 2 so as to protrude from one end of the stator core 2 to one side (the winding end side) in the circumferential direction of two second slots 22 that are separated by only eight slots on both sides of the first slot 21, and the jumper portion 41 of the second segment coil 4b straddles the jumper portion 41 of the corresponding first segment coil 4a (refer to FIG. 1). More specifically, as shown in FIG. 4, the pair of legs 40 of the second segment coil 4b that form the parallel coil U1 of the stator coil 3u are inserted into the first layer of slot No. 29 and the second layer of slot No. 37, the third layer of slot No. 41 and the fourth layer of slot No. 1, the third layer of slot No. 17 and the fourth layer of slot No. 25, and the fifth layer of slot No. 29 and the sixth layer of slot No. 37. Also, as shown in FIG. 4, the pair of legs 40 of the second segment coil 4b that form the parallel coil U2 are inserted into the first layer of slot No. 41 and the second layer of slot No. 1, the first layer of slot No. 17 and the second layer of slot No. 25, the third layer of slot No. 29 and the fourth layer of slot No. 37, the fifth layer of slot No. 41 and the sixth layer of slot No. 1, and the fifth layer of slot No. 17 and the sixth layer of slot No. 25.

[0021] Furthermore, as shown in FIG. 4, the pair of legs 40 of the second segment coil 4b that form the parallel coil U3 are inserted into the first layer of slot No. 35 and the second layer of slot No. 43, the first layer of slot No. 11 and the second layer of slot No. 19, the third layer of slot No. 23 and the fourth layer of slot No. 31, the fifth layer of slot No. 35 and the sixth layer of slot No. 43, and the fifth layer of slot No. 11 and the sixth layer of slot No. 19. Also, as shown in FIG. 4, the pair of legs 40 of the second segment coil 4b that form the parallel coil U4 are inserted into the first layer of slot No. 23 and the second layer of slot No. 31, the third layer of slot No. 35 and the fourth layer of slot No. 43, the third layer of slot No. 11 and the fourth layer of slot No. 19, and the fifth layer of slot No. 23 and the sixth layer of slot No. 31.

[0022] The pair of legs 40 of the third segment coil 4c (see circles in Figure 4) are inserted so as to protrude from one end of the stator core 2 into one 2·i layer and the other 2·i+1 layer on the opposite side (winding start side) of predetermined first and second slots 21 and 22 that are spaced 7 slots apart, and the third segment coil 4c forms a jumper wire between the 2·i layer and the 2·i+1 layer. That is, the parallel coil U1 of the stator coil 3u includes two third segment coils 4c. The pair of legs 40 of one of the third segment coils 4c of the parallel coil U1 are inserted into the second layer of slot 13 and the third layer of slot 6, as shown in Figure 4, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). As shown in Figure 4, the pair of legs 40 of the other third-segment coil 4c of the parallel coil U1 are inserted into the fourth layer of slot 12 and the fifth layer of slot 5, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer).

[0023] The parallel coil U2 of the stator coil 3u includes two third-segment coils 4c. A pair of legs 40 of one of the third-segment coils 4c of the parallel coil U2 are inserted into the second layer of slot 12 and the third layer of slot 5, as shown in Figure 4, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). A pair of legs 40 of the other third-segment coil 4c of the parallel coil U1 are inserted into the fourth layer of slot 13 and the fifth layer of slot 6, as shown in Figure 4, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer). The parallel coil U3 of the stator coil 3u includes two third-segment coils 4c. As shown in Figure 4, a pair of legs 40 of one of the third-segment coils 4c of the parallel coil U1 are inserted into the second layer of slot 6 and the third layer of slot 47, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). A pair of legs 40 of the other third-segment coil 4c of the parallel coil U1 are inserted into the fourth layer of slot 7 and the fifth layer of slot 48, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer). The parallel coil U4 of the stator coil 3u includes two third-segment coils 4c. A pair of legs 40 of one of the third-segment coils 4c of the parallel coil U4 are inserted into the second layer of slot 7 and the third layer of slot 48, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). The pair of legs 40 of the other third-segment coil 4c of the parallel coil U1 are inserted into the fourth layer of slot 6 and the fifth layer of slot 47, as shown in Figure 4, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer).

[0024] The first to third segment coils 4a, 4b, and 4c that form the parallel coils V1-V4 of the stator coil 3v are assembled with a 4-slot offset in the circumferential direction (to the left in Figure 4) relative to the first to third segment coils 4a, 4b, and 4c that form the parallel coils U1-U4 of the U phase. Similarly, the first to third segment coils 4a, 4b, and 4c that form the parallel coils W1 and W2 of the stator coil 3w are assembled with a 4-slot offset in the circumferential direction relative to the first to third segment coils 4a, 4b, and 4c that form the parallel coils U1 and U2 of the U phase, on the opposite side (to the right in Figure 4) from the parallel coils V1 and V2. Furthermore, the first-to-third segment coils 4a, 4b, and 4c that form the parallel coils W3 and W4 of the stator coil 3w are assembled with a 4-slot offset in the circumferential direction from the parallel coils U1 and U2 (to the left in Figure 4) relative to the first-to-third segment coils 4a, 4b, and 4c that form the parallel coils V3 and V4 of the V phase.

[0025] As can be seen from Figure 4, the inclination direction of the connecting wire portion 41 (crank portion 42) of the first and second segment coils 4a and 4b with respect to the radial direction of the stator core 2 is the same. In contrast, the inclination direction of the connecting wire portion 41 (crank portion 42) of the third segment coil 4c with respect to the radial direction of the stator core 2 is opposite to that of the first and second segment coils 4a and 4b, as shown in Figures 4 and 5. In this embodiment, the first and second segment coils 4a and 4b each include three types of segment coils with different spacings in the circumferential direction of a pair of legs 40, as can be seen from Figures 4 and 5, and the third segment coil 4c each includes two types of segment coils with different spacings in the circumferential direction of a pair of legs 40.

[0026] The fourth segment coil 4d (see the square in Figure 4) is inserted into the first or sixth layer (2·imax layer) of a predetermined first or second slot 21, 22 so as to protrude from both ends of the stator core 2. In this embodiment, the parallel coils U1-U4, V1-V4, W1-W4 of the stator coil 3u each include two fourth segment coils 4d. The fourth segment coil 4d of parallel coil U1 is inserted into the first layer of slot 5 and the sixth layer of slot 13. The fourth segment coil 4d of parallel coil U2 is inserted into the first layer of slot 6 and the sixth layer of slot 12. The fourth segment coil 4d of parallel coil U3 is inserted into the first layer of slot 48 and the sixth layer of slot 6. The fourth segment coil 4d of parallel coil U4 is inserted into the first layer of slot 47 and the sixth layer of slot 7.

[0027] The fourth segment coil 4d of parallel coil V1 is inserted into the first layer of slot 9 and the sixth layer of slot 17. The fourth segment coil 4d of parallel coil V2 is inserted into the first layer of slot 10 and the sixth layer of slot 16. The fourth segment coil 4d of parallel coil V3 is inserted into the first layer of slot 4 and the sixth layer of slot 10. The fourth segment coil 4d of parallel coil V4 is inserted into the first layer of slot 3 and the sixth layer of slot 11. The fourth segment coil 4d of parallel coil W1 is inserted into the first layer of slot 1 and the sixth layer of slot 9. The fourth segment coil 4d of parallel coil W2 is inserted into the first layer of slot 2 and the sixth layer of slot 8. The fourth segment coil 4d of parallel coil W3 is inserted into the first layer of slot 8 and the sixth layer of slot 14. The fourth segment coil 4d of parallel coil W4 is inserted into the first layer of slot 7 and the sixth layer of slot 15.

[0028] After the assembly of the first to fourth segment coils 4a, 4b, 4c, and 4d to the stator core 2 is complete, the legs 40 of the first to third segment coils 4a, 4b, and 4c and the fourth segment coil 4d that protrude from one end (torsion side) of the stator core 2 are subjected to twisting using a twisting device (not shown). In this embodiment, each pair of legs 40 of the first to third segment coils 4a, 4b, and 4c are twisted to opposite sides so that they are spaced apart from each other in the circumferential direction (see dashed lines in Figure 4). In addition, the portion of each fourth segment coil 4d that protrudes from one end (torsion side) of the stator core 2 is twisted toward the legs 40 of the corresponding first or second segment coils 4a and 4b that protrude from and are twisted from the first or second slots 21 and 22, which are spaced five slots apart.

[0029] Furthermore, at one end of the stator core 2, as can be seen in Figure 4, the tips of the two legs 40 of the first-third segment coils 4a, 4b, and 4c, which are twisted and protruding from one side (winding end side) of the circumferential direction of the first and second slots 21 and 22, which are spaced five slots apart (for example, the second layer of slot 13 and the first layer of slot 18), are electrically joined together by welding (for example, laser welding). Also at one end of the stator core 2, the tips of the legs 40 of the fourth segment coil 4d, which is twisted and protruding from the first and second slots 21 and 22, which are spaced five slots apart, are electrically joined together by welding. Prior to welding, the insulating coating is removed from the tips of each leg 40, etc., so that the conductive material is exposed.

[0030] As a result, multiple connecting wires 45 are formed on one end of the stator core 2, connecting the tips of the corresponding two legs 40 of the first to third segment coils 4a, 4b, and 4c. As can be seen from Figure 4, the direction in which each connecting wire 45 crosses layers on one end of the stator core 2 (from layer 2·i to layer 2·i-1) is opposite to the direction in which the connecting wires 41 of the first to third segment coils 4a, 4b, and 4c cross layers on the other end of the stator core 2 (opposite the twisted side) (from layer 2·i-1 to layer 2·i). Once the joining of the tips of the corresponding legs 40 is complete, the first to fourth segment coils 4a, 4b, 4c, and 4d are wound around the first and second layers, the third and fourth layers, and the fifth and sixth layers using a wave winding method.

[0031] Furthermore, as shown in Figure 1, the portion of each fourth segment coil 4d protruding from the other end (opposite side from the torsion side) of the stator core 2 extends diagonally along the connecting wire portion 41 of the adjacent second segment coil 4b or along the fourth segment coil 4d, and its tip extends parallel to the axis of the stator core 2. Then, as shown in Figure 4, the fourth segment coils 4d inserted into the first layer of slots 5 and 6 and the sixth layer of slots 6 and 7 are used as lead wires Pu1, Pu2, Pu3, and Pu4 of parallel coils U1, U2, U3, and U4, protruding from the other end of the stator core 2 and electrically connected to the U-phase power lines via a busbar unit (not shown). Furthermore, the fourth segment coils 4d inserted into the sixth layer of slots 13 and 12, and the first layer of slots 48 and 47, are used as neutral wires Nu1, Nu2, Nu3, and Nu4 for parallel coils U1, U2, U3, and U4, respectively, as shown in Figure 4. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown).

[0032] Furthermore, the legs 40 inserted into the first layer of slots 9 and 10, and the sixth layer of slots 10 and 11, are used as lead wires Pv1, Pv2, Pv3, and Pv4 of parallel coils V1, V2, V3, and V4, as shown in Figure 4. They protrude from the other end of the stator core 2 and are electrically connected to the V-phase power lines via a busbar unit (not shown). In addition, the legs 40 inserted into the sixth layer of slots 17 and 16, and the first layer of slots 4 and 3, are used as neutral wires Nv1, Nv2, Nv3, and Nv4 of parallel coils V1, V2, V3, and V4, as shown in Figure 4. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown). Furthermore, the legs 40 inserted into the first layer of slots 1 and 2, and the sixth layer of slots 14 and 15, are used as lead wires Pw1, Pw2, Pw3, and Pw4 of parallel coils W1, W2, W3, and W4, as shown in Figure 4. They protrude from the other end of the stator core 2 and are electrically connected to the W-phase power lines via a busbar unit (not shown). In addition, the legs 40 inserted into the sixth layer of slots 9 and 8, and the first layer of slots 8 and 7, are used as neutral wires Nw1, Nw2, Nw3, and Nw4 of parallel coils W1, W2, W3, and W4, as shown in Figure 4. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown). As a result, multiple stator coils 3u, 3v, and 3w are wound around the stator core 2 in a distributed winding manner.

[0033] In the multiple stator coils 3u, 3v, and 3w wound around the stator core 2, the joints between the tips of numerous legs 40 and the like are arranged radially in predetermined numbers to form an annular first coil end portion that protrudes outward from the end face of one end (twisted side) of the stator core 2. As described above, in the stator 1, the corresponding legs 40 and the like are joined at a 5-slot pitch on one end of the stator core 2, so the first coil end portion can be made low-profile (the amount protruding from the end face of one end of the stator core 2 can be shortened).

[0034] Furthermore, in multiple stator coils 3u, 3v, 3w, the connecting wire portions 41 of the first to third segment coils 4a, 4b, 4c form an annular second coil end portion that protrudes outward from the other end (opposite side from the twisted side) of the stator core 2. In the second coil end portion, the connecting wire portion 41 of the second segment coil 4b straddles the connecting wire portion 41 of the first segment coil 4a. By doubling the overlap of the connecting wire portions 41, the increase in axial length in the stator 1 can be effectively suppressed.

[0035] As described above, the stator 1 includes a plurality of first segment coils 4a, each having a pair of legs 40 inserted into two first slots 21 spaced six slots apart; a plurality of second segment coils 4b, each having a pair of legs 40 inserted into two second slots 22 spaced eight slots apart on either side of the first slots 21; and a plurality of third segment coils 4c, each having a pair of legs 40 inserted into predetermined first and second slots 21 and 22 spaced seven slots apart. The pair of legs 40 of the first segment coils 4a are inserted so as to protrude from one end of the stator core 2 into one 2·i-1 layer and the other 2·i layer on one side (winding end side) of the two first slots 21 in the circumferential direction. The pair of legs 40 of the second segment coil 4b are inserted so as to protrude from one end of the stator core 2 into one 2·i-1 layer and the other 2·i layer on one side of the two second slots 22 in the circumferential direction, and the second segment coil 4b straddles the corresponding first segment coil 4a. The pair of legs 40 of the third segment coil 4c are inserted so as to protrude from one end of the stator core 2 into one 2·i layer and the other 2·i+1 layer on the opposite side (winding start side) of a given first and second slot 21,22 in the circumferential direction, and the third segment coil 4c forms a jumper wire between the 2·i layer and the 2·i+1 layer. Furthermore, at one end of the stator core 2, the two legs 40 protruding from one 2·i layer and the other 2·i-1 layer on one side of the first and second slots 21,22, which are spaced five slots apart in the circumferential direction, are twisted together so that their ends are joined.

[0036] In other words, each parallel coil U1-U4, V1-V4, W1-W4 is basically formed by inserting a second segment coil 4b into two second slots 22 spaced 8 slots apart, so as to straddle a first segment coil 4a inserted into two first slots 21 spaced 6 slots apart, and then joining the corresponding legs 40 at one end of the stator core 2 at a 5-slot pitch. As a result, even if the effective number of turns obtained by dividing the number of legs 40 in one slot 20 (number of layers = 6) by the number of parallel coils U-U4 (number of parallel = 4) is a non-integer (1.5 in this embodiment), the circulating current generated due to the timing difference in the generation of induced voltages at each magnetic pole of the parallel coils U1-U4, V1-V4, W1-W4 in response to the passage of the rotor's magnets can be canceled out within each parallel coil U1-U4, V1-V4, W1-W4, thereby suppressing the flow of circulating current to the stator coils 3u, 3v, 3w.

[0037] Taking the parallel coil U1 as an example, eight magnetic poles are formed in the parallel coil U1. As shown in Figure 4, in the magnetic poles (windings) formed in the range from slot 5 to slot 13, the legs 40 or fourth segment coil 4d are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (see the triangle in Figure 4) (two each in slots 5 and 13, and one each in slots 6 and 12). Similarly, in the magnetic poles formed in the range from slot 17 to slot 25, the legs 40 are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (one each in slots 17 and 25, and two each in slots 18 and 24). Furthermore, in the magnetic poles formed in the range from slot 29 to slot 37, the legs 40 are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (two each in slots 29 and 37, and one each in slots 30 and 36). Furthermore, in the magnetic poles formed in the range from slot 41 to slot 1, the legs 40 are evenly arranged on both sides in the circumferential direction with respect to the center of the magnetic pole (one each in slots 41 and 1, and two each in slots 42 and 48). Therefore, in these magnetic poles, there is no timing difference in the generation of induced voltage in response to the passage of a magnet.

[0038] On the other hand, in the magnetic poles formed in the range from slot 12 to slot 18, the legs 40 are biased to the other side in the circumferential direction relative to the magnetic pole center (the winding start side, the left side in Figure 4) (one each in slots 12 and 17, and two each in slots 13 and 18). Also, in the magnetic poles formed in the range from slot 36 to slot 42, the legs 40 are biased to the other side in the circumferential direction relative to the magnetic pole center (one each in slots 36 and 41, and two each in slots 37 and 42). As a result, in these magnetic poles, the timing of the generation of induced voltage in response to the passage of a magnet is shifted, for example, to the delayed side. In contrast, in the magnetic poles formed in the range from slot 24 to slot 30, the legs 40 are biased to one side in the circumferential direction relative to the magnetic pole center (the winding end side, the right side in Figure 4) (two each in slots 24 and 29, and one each in slots 25 and 30). Furthermore, in the magnetic poles formed in the range from slot 48 to slot 6, the legs 40 or fourth segment coil 4d are arranged to one side in the circumferential direction relative to the magnetic pole center (two each in slots 48 and 5, and one each in slots 1 and 6). As a result, in these magnetic poles, the timing of the generation of induced voltage in response to the passage of a magnet is shifted, for example, to the leading side. Therefore, it can be understood that the parallel coil U1 can cancel out the circulating current caused by the shift in the timing of induced voltage generation in the magnetic poles formed in the range from slot 12 to slot 18 and in the range from slot 36 to slot 42, and the circulating current caused by the shift in the timing of induced voltage generation in the magnetic poles formed in the range from slot 24 to slot 30 and in the range from slot 48 to slot 6. Then, in stator 1, similar to parallel coil U1, the circulating current caused by the timing of induced voltage generation cancels out within each parallel coil U2-U4, V1-V4, and W1-W4.

[0039] In addition, in the stator 1, the legs 40 of the first to third segment coils 4a, 4b, and 4c, which form a single-phase stator coil 3u, 3v, or 3w, and the fourth segment coil 4d are inserted into every three adjacent slots 20 in the circumferential direction, and each of the multiple stator coils 3u, 3v, and 3w is wound around the stator core 2 by short-segment winding. For example, in the U-layer stator coil 3u, as shown in Figure 4, the legs 40 of the first to third segment coils 4a, 4b, and 4c are inserted at a 4-slot pitch, with 12 legs 40 each into slots 20 7, 6, and 5; slots 20 1, 47, and 48; slots 20 43, 42, and 41; slots 20 37, 36, and 35; slots 20 31, 30, and 29; slots 20 25, 24, and 23; slots 20 19, 18, and 17; and slots 20 13, 12, and 11. As a result, a rotating electric machine including stator 1 can achieve higher output (power) and reduced vibration and noise compared to a rotating electric machine including a stator in which the stator coil is wound around the stator core by full-slot winding. In addition, stator 1 eliminates the need for skew and other measures to reduce torque ripple of the 6th order × number of pole pairs (e.g., 24th order). As a result, stator 1 can suppress the generation of circulating current even if the effective number of turns is not an integer, thereby increasing the output of the rotating electric machine while reducing vibration and noise.

[0040] Furthermore, each stator coil 3u, 3v, 3w includes multiple fourth-segment coils 4d. Each fourth-segment coil 4d is inserted into the first or sixth layer (2·imax layer) of a predetermined first or second slot 21, 22 so as to protrude from both ends of the stator core 2. At one end of the stator core 2, the fourth-segment coils 4d protruding from the first and second slots 21, 22, which are spaced five slots apart, and the legs 40 are twisted together so that their ends are joined. In addition, some of the multiple fourth-segment coils 4d protrude from the other end of the stator core 2 opposite to the one end and are connected to power lines to which power is applied. Furthermore, some of the multiple fourth-segment coils 4d protrude from the other end of the stator core 2 and are connected to the neutral point. This allows the lead wires Pu1-Pw4 and neutral wires Nu1-Nw4 to be concentrated on the other end of the stator core 2 (opposite the twisted side), simplifying the routing of power lines and the structure of the busbar unit. However, the multiple stator coils 3u, 3v, and 3w do not necessarily have to be connected by a Y connection; they may be connected by a delta connection or an open connection, and may be composed of parallel coils U1-U4, V1-V4, and W1-W4 connected as shown in Figure 6.

[0041] Furthermore, as can be seen from Figures 1 and 4, in the stator 1, the fourth segment coil 4d, which is used as a lead wire Pu1, neutral wire Nu1, etc., can be concentrated within a relatively narrow area of ​​the first coil end. This makes it possible to position the stator 1 inside a case, etc., so that the legs 40, which are used as lead wires Pu1, neutral wire Nu1, etc., are not submerged in the coolant (cooling oil) when the rotating electric machine including the stator 1 is cooled by the coolant (cooling oil). As a result, the stator 1 can significantly reduce the cost required for insulating the exposed conductor parts of lead wires Pu1, neutral wire Nu1, etc. In addition, in the stator 1, the tips of the legs 40, etc., which are inserted into the sixth layer on the innermost circumference side are not joined together, eliminating the need to shift (protrude) the legs 40, etc., which are inserted into the sixth layer towards the axis of the central hole 2o. Therefore, it becomes possible to assemble the rotor to the central hole 2o of the stator core 2 from both one end and the other end of the stator core 2.

[0042] Furthermore, in stator 1, the number of layers in each slot 20, 2·imax, may be an even number greater than 6, and the number of parallel coils in each stator coil 3u, 3v, 3w may be a multiple of 4 = 4·m (where "m" is an integer greater than or equal to 1). Also, the combination of the number of layers in each slot 20, 2·imax, and the number of parallel coils in each stator coil 3u, 3v, 3w, 4·m (2·imax, 4·m) is not limited to (6,4) in the above embodiment, but may be any of (10,4), (14,4), and (12,8), for example.

[0043] Figure 7 is an explanatory diagram illustrating another assembly configuration of the segment coil 4 to the stator core 2 of the stator 1 that satisfies the relationship n=6·p.

[0044] The stator coils 3u, 3v, and 3w, which are wound around the stator core 2 in the manner shown in Figure 7, are formed by electrically joining a plurality of first, second, third, and fourth segment coils 4a', 4b', 4c', and 4d', respectively. Furthermore, the stator coil 3u includes four parallel coils U1, U2, U3, and U4 that are electrically connected in parallel. In addition, the stator coil 3v includes four parallel coils V1, V2, V3, and V4 that are electrically connected in parallel with each other, and the stator coil 3w includes four parallel coils W1, W2, W3, and W4 that are electrically connected in parallel with each other. The parallel coils U1-U4, V1-V4, and W1-W4 are connected to each other by a so-called 4Y connection.

[0045] The two legs 40 of the first-third segment coils 4a', 4b', and 4c' are inserted into different slots 20 from the other end of the stator core 2 so that they protrude from one end of the stator core 2 (the lower end in Figure 1), and the connecting wires 41 of the first-third segment coils 4a', 4b', and 4c' are aligned at the other end of the stator core 2. Furthermore, the first-third segment coils 4a', 4b', and 4c' are assembled to the stator core 2 such that an even number (in this case, six) of legs 40 protrude radially adjacent from each of the multiple slots 20. In addition, multiple layers (six layers in this embodiment) are formed by the multiple legs 40 that protrude from each of the multiple slots 20 and are adjacent to each other in the circumferential direction of the stator core 2.

[0046] As shown in Figure 7, the pair of legs 40 of the first segment coil 4a' (see the circles in Figure 4) are inserted from the other end of the stator core 2 (the front end of the paper in Figure 4) so ​​as to protrude from one end of the stator core 2 (the back end of the paper in Figure 4). This is done by inserting the legs 40 of the first segment coil 4a' (see the circles in Figure 4) into one 2·i-1 layer (where "i" is an integer greater than or equal to 1, i=1, ..., imax (in this embodiment, imax=3)) and the other 2·i layer on one side (the end end of the winding) of two first slots 21 that are spaced 4 slots apart in the circumferential direction of the stator core 2. More specifically, the pair of legs 40 of the first segment coil 4a' that forms the parallel coil U1 of the stator coil 3u are inserted into the first layer of slot 27 and the second layer of slot 31, the first layer of slot 3 and the second layer of slot 7, the third layer of slot 15 and the fourth layer of slot 19, the fifth layer of slot 27 and the sixth layer of slot 31, as well as the fifth layer of slot 3 and the sixth layer of slot 7, as shown in Figure 7. Additionally, the pair of legs 40 of the first segment coil 4a' that forms the parallel coil U2 are inserted into the first layer of slot 15 and the second layer of slot 19, the third layer of slot 27 and the fourth layer of slot 31, the third layer of slot 3 and the fourth layer of slot 7, as shown in Figure 7.

[0047] Furthermore, as shown in Figure 7, the pair of legs 40 of the first segment coil 4a' that forms the parallel coil U3 are inserted into the first layer of slot 9 and the second layer of slot 13, the third layer of slot 21 and the fourth layer of slot 25, the third layer of slot 45 and the fourth layer of slot 1, and the fifth layer of slot 9 and the sixth layer of slot 13. Also, as shown in Figure 7, the pair of legs 40 of the first segment coil 4a' that forms the parallel coil U4 are inserted into the first layer of slot 21 and the second layer of slot 25, the first layer of slot 45 and the second layer of slot 1, the third layer of slot 9 and the fourth layer of slot 13, the fifth layer of slot 21 and the sixth layer of slot 25, and the fifth layer of slot 45 and the sixth layer of slot 1.

[0048] The pair of legs 40 of the second segment coil 4b' (see circles in Figure 7) are inserted from the other end of the stator core 2 so as to protrude from one end of the stator core 2 into one 2·i-1 layer and the other 2·i layer on one side (winding end side) of two second slots 22 spaced 6 slots apart on both sides of the first slot 21, and the connecting wire portion (not shown) of the second segment coil 4b' spans the connecting wire portion (not shown) of the corresponding first segment coil 4a'. More specifically, the pair of legs 40 of the second segment coil 4b' forming the parallel coil U1 of the stator coil 3u are inserted into the first layer of slot 14 and the second layer of slot 20, the third layer of slot 26 and the fourth layer of slot 32, the third layer of slot 2 and the fourth layer of slot 8, and the fifth layer of slot 14 and the sixth layer of slot 20, as shown in Figure 7. Furthermore, as shown in Figure 7, the pair of legs 40 of the second segment coil 4b' that forms the parallel coil U2 are inserted into the first layer of slot 26 and the second layer of slot 32, the first layer of slot 2 and the second layer of slot 8, the third layer of slot 14 and the fourth layer of slot 20, the fifth layer of slot 26 and the sixth layer of slot 32, and the fifth layer of slot 2 and the sixth layer of slot 8.

[0049] Furthermore, as shown in Figure 7, the pair of legs 40 of the second segment coil 4b' that forms the parallel coil U3 are inserted into the first layer of slot 20 and the second layer of slot 26, the first layer of slot 44 and the second layer of slot 2, the third layer of slot 8 and the fourth layer of slot 14, the fifth layer of slot 20 and the sixth layer of slot 26, and the fifth layer of slot 44 and the sixth layer of slot 2. Also, as shown in Figure 7, the pair of legs 40 of the second segment coil 4b' that forms the parallel coil U4 are inserted into the first layer of slot 8 and the second layer of slot 14, the third layer of slot 20 and the fourth layer of slot 26, the third layer of slot 44 and the fourth layer of slot 2, and the fifth layer of slot 8 and the sixth layer of slot 14.

[0050] The pair of legs 40 of the third segment coil 4c' (see circles in Figure 7) are inserted so as to protrude from one end of the stator core 2 into one 2·i layer and the other 2·i+1 layer on the opposite side (winding start side) of predetermined first and second slots 21 and 22 that are spaced 5 slots apart in the circumferential direction, and the third segment coil 4c' forms a jumper wire between the 2·i layer and the 2·i+1 layer. That is, the parallel coil U1 of the stator coil 3u includes two third segment coils 4c'. The pair of legs 40 of one of the third segment coils 4c' of the parallel coil U1 are inserted into the second layer of slot 44 and the third layer of slot 39, as shown in Figure 7, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). The pair of legs 40 of the other third-segment coil 4c′ of the parallel coil U1 are inserted into the fourth layer of slot 43 and the fifth layer of slot 38, as shown in Figure 7, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer).

[0051] The parallel coil U2 of the stator coil 3u includes two third-segment coils 4c'. A pair of legs 40 of one of the third-segment coils 4c' of the parallel coil U2 are inserted into the second layer of slot 43 and the third layer of slot 38, as shown in Figure 7, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). A pair of legs 40 of the other third-segment coil 4c' of the parallel coil U1 are inserted into the fourth layer of slot 44 and the fifth layer of slot 39, as shown in Figure 7, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer). The parallel coil U3 of the stator coil 3u includes two third-segment coils 4c'. As shown in Figure 7, a pair of legs 40 of one of the third segment coils 4c' of the parallel coil U1 are inserted into the second layer of slot 37 and the third layer of slot 32, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). A pair of legs 40 of the other third segment coil 4c' of the parallel coil U1 are inserted into the fourth layer of slot 38 and the fifth layer of slot 33, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer). The parallel coil U4 of the stator coil 3u includes two third segment coils 4c'. A pair of legs 40 of one of the third segment coils 4c' of the parallel coil U4 are inserted into the second layer of slot 38 and the third layer of slot 33, forming a jumper wire between the second layer (2·i layer) and the third layer (2·i+1 layer). The pair of legs 40 of the other third-segment coil 4c′ of the parallel coil U1 are inserted into the fourth layer of slot 37 and the fifth layer of slot 32, as shown in Figure 7, forming a jumper wire between the fourth layer (2·i layer) and the fifth layer (2·i+1 layer).

[0052] The first to third segment coils 4a', 4b', and 4c' that form the parallel coils V1-V4 of the stator coil 3v are assembled with a 4-slot offset in the circumferential direction (to the left in Figure 7) relative to the first to third segment coils 4a', 4b', and 4c' that form the parallel coils U1-U4 of the U phase. Similarly, the first to third segment coils 4a', 4b', and 4c' that form the parallel coils W1 and W2 of the stator coil 3w are assembled with a 4-slot offset in the circumferential direction relative to the first to third segment coils 4a', 4b', and 4c' that form the parallel coils U1 and U2 of the U phase, on the opposite side from the parallel coils V1 and V2. Furthermore, the first-third segment coils 4a', 4b', and 4c' that form the parallel coils W3 and W4 of the stator coil 3w are assembled with a circumferential offset to the opposite side of the parallel coils U1 and U2 from the first-third segment coils 4a', 4b', and 4c' that form the parallel coils V3 and V4 of the V phase.

[0053] As can be seen from Figure 7, the inclination direction of the connecting wire portion 41 (crank portion 42) of the first and second segment coils 4a' and 4b' with respect to the radial direction of the stator core 2 is the same. In contrast, as can be seen from Figure 7, the inclination direction of the connecting wire portion 41 (crank portion 42) of the third segment coil 4c' with respect to the radial direction of the stator core 2 is the opposite direction to that of the first and second segment coils 4a' and 4b'. In this embodiment, as can be seen from Figure 7, the first and second segment coils 4a' and 4b' each include three types of segment coils with different spacings in the circumferential direction of a pair of leg portions 40, etc., and the third segment coil 4c' each includes two types of segment coils with different spacings in the circumferential direction of a pair of leg portions 40, etc.

[0054] The fourth segment coil 4d' (see the square in Figure 7) is inserted into the first or sixth layer (2·imax layer) of a predetermined first or second slot 21, 22 so as to protrude from both ends of the stator core 2. In this embodiment, the parallel coils U1-U4, V1-V4, W1-W4 of the stator coil 3u each include two fourth segment coils 4d'. The fourth segment coil 4d' of parallel coil U1 is inserted into the first layer of slot 38 and the sixth layer of slot 44. The fourth segment coil 4d' of parallel coil U2 is inserted into the first layer of slot 39 and the sixth layer of slot 43. The fourth segment coil 4d' of parallel coil U3 is inserted into the first layer of slot 33 and the sixth layer of slot 37. The fourth segment coil 4d' of parallel coil U4 is inserted into the first layer of slot 32 and the sixth layer of slot 38.

[0055] The fourth segment coil 4d' of parallel coil V1 is inserted into the first layer of slot 42 and the sixth layer of slot 48. The fourth segment coil 4d' of parallel coil V2 is inserted into the first layer of slot 43 and the sixth layer of slot 47. The fourth segment coil 4d' of parallel coil V3 is inserted into the first layer of slot 4 and the sixth layer of slot 10. The fourth segment coil 4d' of parallel coil V4 is inserted into the first layer of slot 3 and the sixth layer of slot 11. The fourth segment coil 4d' of parallel coil W1 is inserted into the first layer of slot 34 and the sixth layer of slot 40. The fourth segment coil 4d' of parallel coil W2 is inserted into the first layer of slot 43 and the sixth layer of slot 47. The fourth segment coil 4d' of parallel coil W3 is inserted into the first layer of slot 41 and the sixth layer of slot 45. The fourth segment coil 4d' of parallel coil W4 is inserted into the first layer of slot 40 and the sixth layer of slot 46.

[0056] After the assembly of the first to fourth segment coils 4a', 4b', 4c', and 4d' to the stator core 2 is complete, the legs 40 of the first to third segment coils 4a', 4b', and 4c' and the fourth segment coil 4d' that protrude from one end (torsion side) of the stator core 2 are subjected to torsion using a torsion processing device (not shown). The pair of legs 40 of each first to third segment coil 4a', 4b', and 4c' are twisted in opposite directions so that they are spaced apart from each other in the circumferential direction (see dashed lines in Figure 7). In addition, the portion of each fourth segment coil 4d' that protrudes from one end (torsion side) of the stator core 2 is twisted toward the legs 40 of the corresponding first or second segment coils 4a', 4b' that protrude from and are twisted from the first or second slots 21, 22 which are spaced seven slots apart.

[0057] Furthermore, at one end of the stator core 2, as can be seen in Figure 7, the tips of the two legs 40 of the first-third segment coils 4a', 4b', and 4c', which are twisted and protruding from one side (winding end side) of the circumferential direction of the first and second slots 21 and 22, which are spaced 7 slots apart (for example, the second layer of slot 7 and the first layer of slot 14), are electrically joined by welding. Also at one end of the stator core 2, the tips of the legs 40 of the fourth segment coil 4d', which is twisted and protruding from the first and second slots 21 and 22, which are spaced 7 slots apart, are electrically joined by welding. Prior to welding, the insulating coating is removed from the tips of each leg 40, etc., so that the conductive material is exposed.

[0058] As a result, multiple connecting wires 45 are formed on one end of the stator core 2, connecting the tips of the corresponding two legs 40 of the first to third segment coils 4a', 4b', and 4c'. As can be seen from Figure 7, the direction in which each connecting wire 45 crosses layers on one end of the stator core 2 (from layer 2·i to layer 2·i-1) is opposite to the direction in which the connecting wires 41 of the first to third segment coils 4a', 4b', and 4c' cross layers on the other end of the stator core 2 (opposite the twisted side) (from layer 2·i-1 to layer 2·i). Once the joining of the tips of the corresponding legs 40 is complete, the first to fourth segment coils 4a', 4b', 4c', and 4d' are wound around the first and second layers, the third and fourth layers, and the fifth and sixth layers using a wave winding method.

[0059] Furthermore, the portion of each fourth segment coil 4d' protruding from the other end (opposite side from the torsion side) of the stator core 2 extends diagonally along the connecting wire portion 41 of the adjacent second segment coil 4b' or the fourth segment coil 4d', and its tip extends parallel to the axis of the stator core 2 (see Figure 1). Then, as shown in Figure 7, the fourth segment coils 4d' inserted into the first layer of slots 38 and 39 and the sixth layer of slots 37 and 38 are used as lead wires Pu1, Pu2, Pu3, and Pu4 of parallel coils U1, U2, U3, and U4, protruding from the other end of the stator core 2 and electrically connected to the U-phase power lines via a busbar unit (not shown). Furthermore, the fourth segment coils 4d' inserted into the sixth layer of slots 44 and 43, and the first layer of slots 33 and 32, are used as neutral wires Nu1, Nu2, Nu3, and Nu4 for parallel coils U1, U2, U3, and U4, respectively, as shown in Figure 7. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown).

[0060] Furthermore, the legs 40 inserted into the first layer of slots 42 and 43, and the sixth layer of slots 41 and 42, are used as lead wires Pv1, Pv2, Pv3, and Pv4 of parallel coils V1, V2, V3, and V4, as shown in Figure 7. They protrude from the other end of the stator core 2 and are electrically connected to the V-phase power lines via a busbar unit (not shown). In addition, the legs 40 inserted into the sixth layer of slots 48 and 47, and the first layer of slots 37 and 36, are used as neutral wires Nv1, Nv2, Nv3, and Nv4 of parallel coils V1, V2, V3, and V4, as shown in Figure 7. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown). Furthermore, the legs 40 inserted into the first layer of slots 34 and 35, and the sixth layer of slots 45 and 44, are used as lead wires Pw1, Pw2, Pw3, and Pw4 of parallel coils W1, W2, W3, and W4, as shown in Figure 7. They protrude from the other end of the stator core 2 and are electrically connected to the W-phase power lines via a busbar unit (not shown). In addition, the legs 40 inserted into the sixth layer of slots 40 and 39, and the first layer of slots 41 and 40, are used as neutral wires Nw1, Nw2, Nw3, and Nw4 of parallel coils W1, W2, W3, and W4, as shown in Figure 7. They protrude from the other end of the stator core 2 and are electrically connected to the neutral point via a busbar unit (not shown). As a result, multiple stator coils 3u, 3v, and 3w are wound around the stator core 2 in a distributed winding manner.

[0061] In the configuration shown in Figure 7, where multiple stator coils 3u, 3v, 3w are wound around the stator core 2, the joints between the ends of numerous leg portions 40 and the like are arranged radially in predetermined numbers to form an annular first coil end portion that protrudes outward from the end face of one end (twist side) of the stator core 2. Furthermore, in the configuration shown in Figure 7, where multiple stator coils 3u, 3v, 3w are wound around the stator core 2, the connecting wire portions 41 of the first to third segment coils 4a', 4b', 4c' form an annular second coil end portion that protrudes outward from the end face of the other end (opposite side from the twist side) of the stator core 2. In the second coil end portion, the connecting wire portion 41 of the second segment coil 4b' straddles the connecting wire portion 41 of the first segment coil 4a', but by limiting the overlap of the connecting wire portions 41 to two, the increase in the axial length of the stator 1 to which the configuration shown in Figure 7 is applied can be effectively suppressed.

[0062] As described above, the stator 1 to which the embodiment shown in Figure 7 is applied includes a plurality of first segment coils 4a' having a pair of legs 40 inserted into two first slots 21 spaced 4 slots apart, a plurality of second segment coils 4b' having a pair of legs 40 inserted into two second slots 22 spaced 6 slots apart on both sides of the first slots 21, and a plurality of third segment coils 4c' having a pair of legs 40 inserted into predetermined first and second slots 21, 22 spaced 5 slots apart. The pair of legs 40 of the first segment coils 4a' are inserted so as to protrude from one end of the stator core 2 into one 2·i-1 layer and the other 2·i layer on one side (winding end side) of the two first slots 21 in the circumferential direction. The pair of legs 40 of the second segment coil 4b' are inserted so as to protrude from one end of the stator core 2 into one 2·i-1 layer and the other 2·i layer on one side of the two second slots 22 in the circumferential direction, and the second segment coil 4b' straddles the corresponding first segment coil 4a'. The pair of legs 40 of the third segment coil 4c' are inserted so as to protrude from one end of the stator core 2 into one 2·i layer and the other 2·i+1 layer on the opposite side (winding start side) of a given first and second slot 21,22 in the circumferential direction, and the third segment coil 4c' forms a jumper wire between the 2·i layer and the 2·i+1 layer. Furthermore, at one end of the stator core 2, two legs 40 protruding from one 2·i layer and the other 2·i-1 layer on one side in the circumferential direction of the first and second slots 21 and 22, which are spaced 7 slots apart, are twisted so that their tips are joined together.

[0063] In other words, each parallel coil U1-U4, V1-V4, W1-W4 shown in Figure 7 is basically formed by inserting a second segment coil 4b' into two second slots 22 spaced six slots apart, so as to straddle a first segment coil 4a' inserted into two first slots 21 spaced four slots apart, and then joining the corresponding legs 40 at one end of the stator core 2 at a seven-slot pitch. As a result, even if the effective number of turns obtained by dividing the number of legs 40 in one slot 20 (number of layers = 6) by the number of parallel coils U-U4 (number of parallel = 4) is a non-integer (1.5 in this embodiment), the circulating current generated by the timing difference in the generation of induced voltages at each magnetic pole of the parallel coils U1-U4, V1-V4, W1-W4 in response to the passage of the rotor's magnets can be canceled out within each parallel coil U1-U4, V1-V4, W1-W4, thereby suppressing the flow of circulating current to the stator coils 3u, 3v, 3w.

[0064] Taking the parallel coil U1 as an example, eight magnetic poles are formed in the parallel coil U1. As shown in Figure 7, in the magnetic poles (windings) formed in the range from slot 38 to slot 44, the legs 40 or fourth segment coil 4d' are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (see the triangle in Figure 7) (two each in slots 38 and 44, and one each in slots 39 and 43). Similarly, in the magnetic poles formed in the range from slot 2 to slot 8, the legs 40 are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (one each in slots 2 and 8, and two each in slots 3 and 7). Furthermore, in the magnetic poles formed in the range from slot 14 to slot 20, the legs 40 are evenly distributed on both sides in the circumferential direction with respect to the magnetic pole center (two each in slots 14 and 20, and one each in slots 15 and 19). Furthermore, in the magnetic poles formed in the range from slot 26 to slot 32, the legs 40 are evenly arranged on both sides in the circumferential direction with respect to the center of the magnetic pole (one each in slots 26 and 32, and two each in slots 27 and 31). Therefore, in these magnetic poles, there is no timing difference in the generation of induced voltage in response to the passage of a magnet.

[0065] On the other hand, in the magnetic poles formed in the range from slot 43 to slot 3, the legs 40 etc. are biased to the other side in the circumferential direction relative to the magnetic pole center (the winding start side, the left side in Figure 7) (one each in slots 43 and 2, and two each in slots 44 and 3). Also, in the magnetic poles formed in the range from slot 19 to slot 27, the legs 40 are biased to the other side in the circumferential direction relative to the magnetic pole center (one each in slots 19 and 26, and two each in slots 20 and 27). As a result, in these magnetic poles, the timing of the generation of induced voltage in response to the passage of a magnet is shifted, for example, to the delayed side. In contrast, in the magnetic poles formed in the range from slot 7 to slot 15, the legs 40 are biased to one side in the circumferential direction relative to the magnetic pole center (the winding end side, the right side in Figure 7) (two each in slots 7 and 14, and one each in slots 8 and 15). Furthermore, in the magnetic poles formed in the range from slot 31 to slot 39, the legs 40 or the fourth segment coil 4d' are arranged to be biased to one side in the circumferential direction with respect to the magnetic pole center (two each in slots 31 and 38, and one each in slots 32 and 39). As a result, in these magnetic poles, the timing of the generation of induced voltage in response to the passage of the magnet is shifted, for example, to the leading side. Therefore, it can be understood that the parallel coil U1 can cancel out the circulating current caused by the shift in the timing of the generation of induced voltage in the magnetic poles formed in the range from slot 43 to slot 3 and in the range from slot 19 to slot 27, and the circulating current caused by the shift in the timing of the generation of induced voltage in the magnetic poles formed in the range from slot 7 to slot 15 and in the range from slot 31 to slot 39. In the configuration shown in Figure 7, similar to the parallel coil U1, the circulating current caused by the timing of the induced voltage generation cancels out within each of the parallel coils U2-U4, V1-V4, and W1-W4.

[0066] Furthermore, in the stator 1 to which the embodiment shown in Figure 7 is applied, the legs 40 of the first to third segment coils 4a', 4b', 4c' that form a single-phase stator coil 3u, 3v, or 3w, and the fourth segment coil 4d' are inserted into every three adjacent slots 20 in the circumferential direction, and each of the multiple stator coils 3u, 3v, 3w is wound around the stator core 2 by short-segment winding. For example, in the U-layer stator coil 3u, as shown in Figure 7, the legs 40 of the first to third segment coils 4a', 4b', 4c' are inserted at a 4-slot pitch, with 12 legs 40 inserted into slots 20 39, 38, and 37; slots 20 33, 32, and 31; slots 20 27, 26, and 25; slots 20 21, 20, and 19; slots 20 15, 14, and 13; slots 20 9, 8, and 7; slots 20 3, 2, and 1; and slots 20 45, 44, and 43. As a result, a rotating electric machine including a stator 1 to which the embodiment shown in Figure 7 is applied can have higher output (power) and reduced vibration and noise compared to a rotating electric machine including a stator in which the stator coil is wound around the stator core by full-slot winding. In addition, according to the embodiment shown in Figure 7, skew and other measures to reduce torque ripple of the 6th order × pole pair order (e.g., 24th order) can be omitted. As a result, in the stator 1 to which the embodiment shown in Figure 7 is applied, the generation of circulating current can be suppressed even if the effective number of turns is not an integer, thereby increasing the output of the rotating electric machine and reducing vibration and noise.

[0067] Furthermore, each stator coil 3u, 3v, 3w shown in Figure 7 includes a plurality of fourth-segment coils 4d'. Each fourth-segment coil 4d' is inserted into the first or sixth layer (2·imax layer) of a predetermined first or second slot 21, 22 so as to protrude from both ends of the stator core 2. At one end of the stator core 2, the fourth-segment coils 4d' protruding from the first and second slots 21, 22, which are spaced 7 slots apart, and the legs 40 are twisted together so that their ends are joined. In addition, a portion of the plurality of fourth-segment coils 4d' protrudes from the other end of the stator core 2 opposite to the one end and is connected to a power line to which power is applied. Furthermore, a portion of the plurality of fourth-segment coils 4d' protrudes from the other end of the stator core 2 and is connected to the neutral point. This allows the lead wires Pu1-Pw4 and neutral wires Nu1-Nw4 to be concentrated on the other end of the stator core 2 (opposite the twisted side), simplifying the routing of power lines and the structure of the busbar unit. However, in the stator 1 to which the embodiment shown in Figure 7 is applied, the multiple stator coils 3u, 3v, and 3w do not necessarily have to be connected by a Y connection, but may be connected by a delta connection or an open connection, and may be composed of parallel coils U1-U4, V1-V4, and W1-W4 connected as shown in Figure 6.

[0068] Furthermore, in the embodiment shown in Figure 7, the fourth segment coil 4d', which is used as a lead wire Pu1, neutral wire Nu1, etc., can be concentrated within a relatively narrow range at the first coil end. As a result, when the rotating electric machine including the stator 1 to which the embodiment shown in Figure 7 is applied is cooled by a coolant (cooling oil), the legs 40 used as lead wires Pu1, neutral wire Nu1, etc., can be positioned inside the case, etc., so that they are not submerged in the liquid. Consequently, in the stator 1 to which the embodiment shown in Figure 7 is applied, the cost required for insulating the exposed conductors of lead wires Pu1, neutral wire Nu1, etc., can be significantly reduced. In addition, in the stator 1 to which the embodiment shown in Figure 7 is applied, the tips of the legs 40, etc., which are inserted into the sixth layer on the innermost circumference side are not joined together, eliminating the need to shift (protrude) the legs 40, etc., which are inserted into the sixth layer towards the axis of the central hole 2o. Therefore, it becomes possible to assemble the rotor to the central hole 2o of the stator core 2 from both one end and the other end of the stator core 2.

[0069] Furthermore, in the stator 1 to which the embodiment shown in Figure 7 is applied, the number of layers in each slot 20, 2·imax, may be an even number greater than 6, and the number of parallel coils in each stator coil 3u, 3v, 3w may be a multiple of 4 = 4·m (where "m" is an integer greater than or equal to 1). Also, the combination of the number of layers in each slot 20, 2·imax, and the number of parallel coils in each stator coil 3u, 3v, 3w, 4·m (2·imax, 4·m) is not limited to (6,4) in the above embodiment, but may be any of (10,4), (14,4), and (12,8), for example.

[0070] Furthermore, the invention disclosed herein is not limited in any way to the embodiments described above, and it goes without saying that various modifications can be made within the scope of this disclosure. Moreover, the embodiments described above are merely one specific form of the invention described in the summary of the invention, and do not limit the elements of the invention described in the summary of the invention. [Industrial applicability]

[0071] The invention disclosed herein can be used in industries such as stator manufacturing. [Explanation of Symbols]

[0072] 1 Stator, 2 Stator core, 2o Center hole, 2t Teeth section, 20 Slot, 21 First slot, 22 Second slot, 3u, 3v, 3w Stator coil, 4 Segment coil, 4a, 4a' First segment coil, 4b, 4b' Second segment coil, 4c, 4c' Third segment coil, 4d' Fourth segment coil, 40 Leg section, 41, 45 Jumper wire section, 42 Crank section, Nu1, Nu2, Nu3, Nu4, Nv1, Nv2, Nv3, Nv4, Nw1, Nw2, Nw3, Nw4 Neutral wire, Pu1, Pu2, Pu3, Pu4, Pv1, Pv2, Pv3, Pv4, Pw1, Pw2, Pw3, Pw4 Lead wires, U1, U2, U3, U4, V1, V2, V3, V4, W1, W2, W3, W4 parallel coils.

Claims

1. A stator comprising a stator core including a plurality of slots formed circumferentially spaced apart so as to extend radially, and a plurality of segment coils having pairs of legs inserted into different slots and forming a plurality of stator coils by electrical joining of the tips of the corresponding legs, Let the number of poles be "p" and the number of slots be "n", then n = 6 * p, Each of the aforementioned multiple stator coils includes 4·m parallel coils (where "m" is an integer of 1 or more) connected in parallel. An even number of the legs are inserted into one of the slots, arranged in the radial direction. The plurality of segment coils are A first segment coil is inserted into one of the 2.i-1 layers (where "i" is an integer greater than or equal to 1, i = 1, ..., imax) and the other 2.i layer of two first slots spaced six slots apart, such that the pair of legs protrude from one end of the stator core. The pair of legs are inserted into the 2.i-1 layer on one side and the 2.i layer on the other side of the circumferential direction of the two second slots, which are spaced eight slots apart on both sides of the first slot, so as to protrude from one end of the stator core, and the second segment coil spans the corresponding first segment coil, The stator core includes a third segment coil in which the pair of legs are inserted into one 2.i layer and the other 2.i+1 layer on the opposite side in the circumferential direction of predetermined first and second slots spaced seven slots apart, so as to protrude from one end of the stator core, and a jumper wire is formed between the 2.i layer and the 2.i+1 layer. A stator in which, at one end of the stator core, two legs protruding from one 2.i layer and the other 2.i-1 layer in the circumferential direction of the first and second slots, which are spaced five slots apart, are twisted and their tips are joined together.

2. In the stator according to claim 1, The plurality of segment coils include a plurality of fourth segment coils inserted into the first layer or 2.imax layer of a predetermined first or second slot so as to protrude from both ends of the stator core. At one end of the stator core, the fourth segment coil and the leg portion, which protrude from the first and second slots spaced five slots apart, are twisted together so that their tips are joined. A portion of the plurality of fourth segment coils protrudes from the other end of the stator core opposite to the one end and is connected to a power line to which power is applied.

3. In the stator according to claim 2, The aforementioned multiple stator coils are connected by a Y-connection, A portion of the plurality of fourth segment coils protrudes from the other end of the stator core and is connected to the neutral point of the stator.

4. In the stator according to claim 1 or 2, A stator in which the combination of the number of layers in the slot (2 imax) and the number of parallel coils (4 m) is one of the following: (6, 4), (10, 4), (14, 4), and (12, 8).

5. A stator comprising a stator core including a plurality of slots formed circumferentially spaced apart so as to extend radially, and a plurality of segment coils having pairs of legs inserted into different slots and forming a plurality of stator coils by electrical joining of the tips of the corresponding legs, Let the number of poles be "p" and the number of slots be "n", then n = 6 * p, Each of the aforementioned multiple stator coils includes 4·m parallel coils (where "m" is an integer of 1 or more) connected in parallel. An even number of the legs are inserted into one of the slots, arranged in the radial direction. The plurality of segment coils are A first segment coil is inserted into one of the 2.i-1 layers (where "i" is an integer greater than or equal to 1, i = 1, ..., imax) and the other 2.i layer of two first slots spaced four slots apart, such that the pair of legs protrude from one end of the stator core. The pair of legs are inserted into the 2.i-1 layer on one side and the 2.i layer on the other side of the circumferential direction of the two second slots, which are spaced six slots apart on both sides of the first slot, so as to protrude from one end of the stator core, and the second segment coil spans the corresponding first segment coil, The stator core includes a third segment coil in which the pair of legs are inserted into one 2.i layer and the other 2.i+1 layer on the opposite side in the circumferential direction of predetermined first and second slots spaced five slots apart, with the legs protruding from one end of the stator core, and a jumper wire is formed between the 2.i layer and the 2.i+1 layer. A stator in which, at one end of the stator core, two legs protruding from one 2.i layer and the other 2.i-1 layer in the circumferential direction of the first and second slots, which are spaced seven slots apart, are twisted and their tips are joined together.

6. In the stator according to claim 5, The plurality of segment coils include a plurality of fourth segment coils inserted into the first layer or 2.imax layer of a predetermined first or second slot so as to protrude from both ends of the stator core. At one end of the stator core, the fourth segment coil and the leg portion, which protrude from the first and second slots spaced five slots apart, are twisted together so that their tips are joined. A portion of the plurality of fourth segment coils protrudes from the other end of the stator core opposite to the one end and is connected to a power line to which power is applied.

7. In the stator according to claim 6, The aforementioned multiple stator coils are connected by a Y-connection, A portion of the plurality of fourth segment coils protrudes from the other end of the stator core and is connected to the neutral point of the stator.

8. In the stator according to claim 5 or 6, A stator in which the combination of the number of layers in the slot (2 imax) and the number of parallel coils (4 m) is one of the following: (6, 4), (10, 4), (14, 4), and (12, 8).

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