Rotating electric machine and electric drive system

Abstract

To provide a rotary electric machine that can reduce the difference between the height of a first segment conductor and the height of a second segment conductor.SOLUTION: A rotary electric machine comprises a first segment conductor 121 with a first slot pitch and a second segment conductor 122 with a second slot pitch less than the first slot pitch. The second segment conductor 122 comprises a first leg 122A and a second leg 122B. The first leg 122A comprises a slot insertion part 122A0 and a first linear part 122A2 that is connected to the slot insertion part 122A0 while configuring a coil end part. The second leg 122B comprises a slot insertion part 122B0 and a second linear part 122B2 that is connected to the slot insertion part 122B0 while configuring a coil end part. The second linear part 122B2 is formed so as to be longer than the first linear part 122A2.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine and an electric drive system using the rotating electric machine. [Background technology]

[0002] As a background art of this technical field, a rotating electric machine described in JP 2020-54052 A (Patent Document 1) is known. The stator of the rotating electric machine of Patent Document 1 includes a stator core and a coil wound around the stator core. The coil includes a basic coil segment having a pair of first legs and a first transition portion arranged on the side of the first end face of the stator core, and a transition coil segment having a pair of second legs and a second transition portion arranged so that the first transition portion is located between the first end face (see Abstract above). Furthermore, Patent Document 1 describes a configuration in which the basic coil segment is composed of a main coil segment and a sub-coil segment, and the main coil segment is inserted into two slots where a pair of first legs are located 6 pitches apart, and the sub-coil segment is inserted into two slots where a pair of first legs are located 5 pitches apart (see paragraph 0023 and FIG. 4). In the stator of the rotating electric machine of Patent Document 1, a plurality of main coil segments and one sub-coil segment are connected in series to form one coil assembly, and multiple (four) coil assembly are arranged radially around the stator core (see paragraph 0022 and Figure 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-54052 A Summary of the Invention [Problem to be solved by the invention]

[0004] The main coil segments and sub-coil segments of Patent Document 1 will be referred to as segment conductors in the following description. Furthermore, the main coil segments will be distinguished as first segment conductors and the sub-coil segments as second segment conductors as necessary.

[0005] When manufacturing first and second segment conductors having different slot pitches, it is not preferable to change the bending angle between the first leg and the oblique side portion connecting the first leg and the second leg, and the bending angle between the oblique side portion and the second leg, between the first and second segment conductors, because this increases the number of inspections required for bending. If the bending angle between the oblique side portion and the first leg and the bending angle between the oblique side portion and the second leg are not changed between the first and second segment conductors, the height of the first and second segment conductors will differ, resulting in problems such as a complicated jig used in winding a coil around a stator core using the first and second segment conductors and a difficulty in improving the accuracy of bending the segment conductors due to the complicated winding work.

[0006] An object of the present invention is to provide a rotating electric machine capable of reducing the difference in height between a first segment conductor and a second segment conductor. [Means for solving the problem]

[0007] In order to achieve the above object, a rotating electric machine according to the present invention comprises: a stator core having a plurality of slots; a coil wound around the stator core, the coil including a plurality of segment conductors each having a slot insertion portion disposed inside the slot and a first coil end portion protruding from one end face in the axial direction with respect to the stator core; a stator having a a rotor disposed across a gap from the stator, The first coil end portion has a straight portion connected to the slot insertion portion and a slant portion formed in a mountain shape with a central portion as an apex, the plurality of segment conductors include first segment conductors inserted into two slots arranged at a first slot pitch, and second segment conductors inserted into two slots arranged at a second slot pitch smaller than the first slot pitch, the second segment conductor is formed such that a second straight portion forming the straight portion on one slot side is longer than a first straight portion forming the straight portion on the other slot side, The protruding height of the central portion of the first segment conductor from the end face of the stator core and the protruding height of the central portion of the second segment conductor from the end face of the stator core are formed to be approximately equal. Effect of the Invention

[0008] According to the present invention, it is possible to provide a rotating electric machine in which the difference in height between the first segment conductor and the second segment conductor can be reduced.

[0009] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view (longitudinal cross-sectional view) showing a cross section of a rotating electric machine 1 according to the present invention that is parallel to and includes a central axis Ax. [Diagram 2] FIG. 1 is a diagram showing a stator core 11 that constitutes a stator 10 of a rotating electric machine 1 according to the present invention, and is a plan view of the stator core 11 as viewed from the axial direction. [Diagram 3] FIG. 2 is a diagram showing a rotor core 31 constituting a rotor 30 of a rotating electric machine 1 according to the present invention, and is a plan view of the rotor core 31 as viewed from the axial direction. [Figure 4A] 1 is a diagram showing a state in which a first coil segment 121 and a second coil segment 122 constituting a coil 12 according to an embodiment of the present invention are assembled to a stator core 11. FIG. [Figure 4B]1 is a plan view showing an outline of the shape characteristics of a first conductor segment 121 before being assembled to a stator core 11. FIG. [Figure 4C] 13 is a plan view showing an outline of the shape characteristics of a second conductor segment 122 before being assembled to a stator core 11. FIG. [Diagram 5] FIG. 4 is a perspective view showing the appearance of a coil end portion. [Figure 6] 13 is a plan view showing the shape of an output segment conductor 123. FIG. [Figure 7] 1 is a plan view of a stator 10 of a rotating electric machine 1 as viewed from a first coil end portion side (end surface 11S1 side). [Figure 8] 1 is a partial cross-sectional view of a slot portion 112 of a stator core 11 into which a first segment conductor 121 and a first segment conductor 122 are inserted. [Figure 9] 1A and 1B are diagrams illustrating an embodiment in which a stator core 11 is manufactured by stacking thin steel plates, and the stacked steel plates are joined by welding. [Figure 10] 4C are views for explaining an embodiment in which twisted portions 121CD and 122CD shown in FIG. 4A and FIG. 4C are formed at a welded portion W. FIG. [Figure 11] 1 is a diagram showing a schematic configuration of a hybrid electric vehicle 500 equipped with a rotating electric machine 1 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same reference numerals are used to designate the same components in each drawing to avoid duplication of description. Even if the same reference numerals are used, when the content is different from that of other drawings, the different parts will be described.

[0012] In the following description, the radial direction of the rotor 30 of the rotating electric machine 1 is indicated by r, the direction along the rotating shaft 32 of the rotor 30 (axial direction) is indicated by z, and the rotation direction of the rotor 30 is indicated by θ. The axis line (central axis line) passing through the center of the rotating shaft 32 is indicated by Ax. That is, the axial direction coincides with the direction along the central axis line Ax of the rotating shaft 22. The rotation direction θ coincides with the circumferential direction centered on the central axis line Ax.

[0013] In the following description, the up-down direction, vertical direction, and horizontal direction may be specified. These directions are set based on each drawing, and do not specify the up-down direction, vertical direction, and horizontal direction in the mounted state of the rotating electric machine 1. Note that a cross section of the rotating electric machine 1 cut in a direction perpendicular to the axial direction is called a horizontal cross section, and a cross section of the rotating electric machine 1 cut in the axial direction is called a longitudinal cross section (rz cross section).

[0014] [Example 1] A rotating electric machine 1 according to an embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig. 1 is a cross-sectional view (longitudinal cross-sectional view) of the rotating electric machine 1 according to the present invention, which is parallel to and includes the central axis Ax. Fig. 2 is a diagram showing a stator core 11 constituting a stator 10 of the rotating electric machine 1 according to the present invention, and is a plan view of the stator core 11 as viewed from the axial direction. Fig. 3 is a diagram showing a rotor core 31 constituting a rotor 30 of the rotating electric machine 1 according to the present invention, and is a plan view of the rotor core 31 as viewed from the axial direction. Note that the rotating shaft 32 is omitted from Fig. 3.

[0015] The rotating electric machine 1 according to this embodiment can be used, for example, as a traction motor for an electric vehicle that runs on the power of the rotating electric machine alone, or for a hybrid electric vehicle that is driven by both an engine and a rotating electric machine.

[0016] 1, the rotating electric machine 1 includes a stator 10, a rotor 30, and a housing 50. The stator 10 is held inside the housing 50, and includes a stator core 11 and a stator winding (coil) 12.

[0017] The stator core 11 is a component of the stator 10, and is formed by laminating electromagnetic steel sheets (thin sheets). As shown in Fig. 2, the stator core 11 has a yoke 113 having an annular shape, a plurality of teeth 111 protruding from the yoke 113 toward the rotor 30 in a comb-tooth shape, and a plurality of slots 112 formed between the plurality of teeth 111. The slots 112 form a storage space for the coils 12. In this embodiment, a stator core 11 having 48 slots is illustrated.

[0018] The coil 12 inserted into the slot 112 and wound around the stator core 11 is made up of three-phase U, V, and W windings.

[0019] 1, the rotor 30 is rotatably arranged on the inner periphery side of the stator core 11 via an air gap Gp. The rotor 30 includes a rotor core 31 fixed to a rotating shaft 32, a plurality of permanent magnets 33 fixed to the rotor core 31 and constituting magnetic poles, and non-magnetic end plates 34A, 34B attached to both end faces of the rotor core 31 in the axial direction. The rotor 30 is rotatably arranged by the rotating shaft 32 being journaled by bearings 61A, 61B provided on end brackets 51A, 51B. The rotating shaft 31 may also be called a drive shaft or a shaft.

[0020] The rotor core 31 is made by laminating thin steel plates, and mainly serves to form a magnetic path and strength members. The lamination direction of the steel plates (laminated steel plates) coincides with the axial direction. End plates 34A, 34B are structural members arranged at both axial ends of rotor core 32 to fix the steel plates that form rotor core 32 in the axial direction. Alternatively, the laminated steel plates may be fixed by welding, in which case end plates 34A, 34B may not be used. Electromagnetic steel plates are usually used for the laminated steel plates.

[0021] The housing 50 has a pair of end brackets 51A, 51B provided with bearings 61A, 61B, and a side surface portion 52, and contains the stator 10 and the rotor 30. The rotor 30, which is integral with the rotating shaft 32, is rotatably supported by the housing 50 via the bearings 61A, 61B.

[0022] In this embodiment, the rotating electric machine 1 is driven by a three-phase AC current. For this purpose, the rotating shaft 32 is provided with a resolver (rotation angle sensor) 35 that detects the pole position and rotation speed of the rotor 30. Based on the output from the resolver 35, a control circuit and a drive circuit (not shown) generate control signals and drive signals for a power module (not shown) to perform a switching operation.

[0023] In this embodiment, an embedded magnet motor is exemplified as the rotating electric machine 1, but is not limited to an embedded magnet motor. As shown in Fig. 3, a plurality of magnet storage sections 36 are provided in the rotor core 31 along the circumferential direction, and magnets 37 are inserted and fixed in the holes 36. The magnet storage sections 36 are formed of holes (magnet insertion holes).

[0024] In this embodiment, a configuration in which one pole is composed of three magnets 37 is exemplified, but the number of magnets 37 constituting one pole is not limited to 3. For example, one pole may be composed of one flat magnet, or one pole may be composed of two flat magnets arranged in a V shape.

[0025] Furthermore, the rotor 30 of this embodiment has eight magnetic poles (number of poles=8). As described above, the stator 10 has 48 slots (number of slots=48), and three-phase coils 12 are wound (number of phases=3). The rotating electric machine 1 of this embodiment is a three-phase, eight-pole, 48-slot rotating electric machine. In this case, the number of slots per pole per phase (NSPP), calculated by (number of slots) / ((number of poles)×(number of phases)), is 2.

[0026] Next, the configuration of the coil segments 121, 122 that constitute the coil 12 of this embodiment will be described with reference to FIGS. 4A to 4C.

[0027] FIG. 4A is a diagram showing a state in which a first coil segment 121 and a second coil segment 122 constituting the coil 12 are assembled to the stator core 11 in one embodiment of the coil 12 according to the present invention. The coil 12 includes a plurality of segment conductors 121, 122 and is wound around the stator core 11. The coil 12 is arranged as a wave winding, straddling a plurality of slots, and mechanically makes one revolution around the stator core 11. The segment conductor is a coil member with a rectangular cross section, and an insulating layer made of enamel or the like is provided on the outer periphery.

[0028] The multiple segment conductors 121, 122 include a first segment conductor 121 inserted into two slots 112 arranged at a first slot pitch, and a second segment conductor 122 inserted into two slots arranged at a second slot pitch smaller than the first slot pitch. A plurality of first segment conductors 121 are provided consecutively at the first slot pitch. The second segment conductor 122 is provided at the second slot pitch as the last segment conductor following the multiple first segment conductors 121 to adjust for a shortage in the number of slots.

[0029] In this embodiment, a configuration in which the first slot pitch is set to 6 and the second slot pitch is set to 5 for an 8-pole, 48-slot rotating electric machine 1 is exemplified.

[0030] Here, the first segment conductor 121 and the second segment conductor 122 will be described with reference to Fig. 4B and Fig. 4C. Fig. 4B is a plan view showing an outline of the shape characteristics of the first segment conductor 121 before being assembled to the stator core 11. Fig. 4C is a plan view showing an outline of the shape characteristics of the second segment conductor 122 before being assembled to the stator core 11.

[0031] 4B, the first conductor segment 121 has a pair of first and second legs 121A and 121B, and an oblique side portion 121C formed in a generally mountain-like shape with a vertex 121CC at the center and connecting the first and second legs 121A and 121B. That is, the oblique side portion 121C has a first oblique side portion 121CA descending from the vertex 121CC on the first leg 121A side and a second oblique side portion 121CB descending from the vertex 121CC on the second leg 121B side, with the vertex 121CC as a boundary. The first oblique side portion 121CA is bent at an angle θ121A (=θ1) at a bent portion 121A1 with respect to the first leg 121A. The second oblique side portion 121CB is bent at an angle θ121B (=θ1) at a bent portion 121B1 with respect to the second leg portion 121B.

[0032] The length k121A of the first leg 121A and the length k121B of the second leg 121B are both equal to k1. The angle θ121A that the first hypotenuse portion 121CA makes with the first leg 121A and the angle θ121B that the second hypotenuse portion 121CB makes with the second leg 121B are both equal to θ1. Since the first segment conductor 121 is inserted across two slots arranged at the first slot pitch, there is a spacing d1 between the pair of first leg 121A and second leg 121B that allows six teeth 111 (see FIG. 2) to fit therein.

[0033] Reference numeral 121x denotes a center line of the first conductor segment 121 that passes through the vertex 121CC of the hypotenuse portion 121C. The distance between the first leg 121A and the center line 121x and the distance between the second leg 122A and the center line 121x are both d2 and are equal.

[0034] 4C, the second conductor segment 122 has a pair of first and second legs 122A and 122B, and an oblique side portion 122C connecting the first and second legs 122A and 122B. The oblique side portion 122C is formed in a generally mountain shape having a vertex 122CC, and has a first oblique side portion 122CA descending from the vertex 122CC on the first leg 122A side and a second oblique side portion 122CB descending from the vertex 122CC on the second leg 122B side, with the vertex 121CC as a boundary. The first oblique side portion 122CA is bent at an angle θ122A (=θ1) at a bent portion 122A1 with respect to the first leg 122A. The second oblique side portion 122CB is bent at an angle θ122B (=θ1) at a bent portion 122B1 with respect to the second leg portion 122B.

[0035] The second conductor segment 122 is inserted across two slots arranged at the second slot pitch, and therefore has a distance d3 between the pair of first leg portion 122A and second leg portion 122B, which allows five teeth 111 (see FIG. 2) to be accommodated. In other words, d3 is smaller than d1 (d3 <d1)。

[0036] On the other hand, the angle θ122A between the first hypotenuse portion 122CA and the first leg portion 122A and the angle θ122B between the second hypotenuse portion 122C and the second leg portion 122B are both equal to θ1, and the angles θ122A and θ122B in the second segment conductor 122 are equal to the angles θ121A and θ121B in the first segment conductor 121.

[0037] Therefore, the length k122B of the second leg 122B is k2, which is longer than the length k122A (=k1) of the first leg 122A by the difference Δk between k2 and k1 (k2>k1). In this case, the length k122A of the first leg 122A of the second segment conductor 122 is k1, which is equal to the length k121A of the first leg 121A and the length k121B of the second leg 121B of the first segment conductor 121.

[0038] The line segment 122x passes through the vertex 122CC of the hypotenuse portion 122C, and the distance d4 between the second leg 122A and the line segment 122x is smaller than the distance d2 between the first leg 122A and the line segment 122x. The distance d2 between the first leg 122A and the line segment 122x is equal to the distance d2 between the first leg 121A of the first segment conductor 121 and the center line 121x.

[0039] 4B and 4C, twisted portions 121CD, 122CD are provided on the oblique side portion 121C of the first conductor segment 121 and the oblique side portion 122C of the second conductor segment 122. The first conductor segment 121 and the second conductor segment 122 are arranged so that the multiple conductor segments overlap in the radial direction. At this time, twisted portions (radial bent portions) 121CD, 122CD are formed in the conductor segments as indicated by dashed lines T in FIG. 7 to avoid interference between the multiple conductor segments.

[0040] Returning to Fig. 4A for further explanation, the first conductor segment 121 and the second conductor segment 122 in the states shown in Fig. 4B and Fig. 4C are inserted into the slots 112 of the fixed core 11. In this embodiment, they are inserted into the slots 112 from the end face 11S1 side of the fixed core 11.

[0041] The first leg 121A of the first segment conductor 121 inserted into the slot 112 is bent at a bending portion 121A3 to the opposite side to the second leg 121B, at a portion 121A4 on the tip (lower end) 121A6 side of the first leg 121A with respect to a slot insertion portion 121A0 arranged inside the slot 112. The second leg 121B of the first segment conductor 121 is bent at a bending portion 121B3 to the opposite side to the first leg 121A, at a portion 121B4 on the tip (lower end) 121B6 side of the second leg 121B with respect to a slot insertion portion 121B0 arranged inside the slot 112. The portion 121A4 bent at the bending portion 121A3 forms a third oblique side of the first segment conductor 121, and the portion 121B4 bent at the bending portion 121B3 forms a fourth oblique side of the first segment conductor 121.

[0042] Furthermore, the first leg 121A is bent at a bent portion 121A5 such that the tip (lower end) 121A6 side of the first leg 121A is bent relative to the third oblique side 121A4 in a direction along the slot insertion portion 121A0. The second leg 121B is bent at a bent portion 121B5 such that the tip (lower end) 121B6 side of the second leg 121B is bent relative to the fourth oblique side 121B4 in a direction along the slot insertion portion 121B0.

[0043] The first leg 122A of the second segment conductor 122 inserted into the slot 112 is bent at a bending portion 122A3 to the opposite side to the second leg 122B, at a portion 122A4 on the tip (lower end) 122A6 side of the first leg 122A with respect to a slot insertion portion 122A0 arranged inside the slot 112. The second leg 122B of the second segment conductor 122 is bent at a bending portion 122B3 to the opposite side to the first leg 122A, at a portion 122B4 on the tip (lower end) 122B6 side of the second leg 122B with respect to a slot insertion portion 122B0 arranged inside the slot 112. The portion 122A4 bent at the bending portion 122A3 constitutes a third oblique side of the second segment conductor 122, and the portion 122B4 bent at the bending portion 122B3 constitutes a fourth oblique side of the second segment conductor 122.

[0044] Furthermore, the first leg 122A is bent at a bent portion 122A5 on the side of a tip (lower end) 122A6 of the first leg 122A relative to the third oblique side 122A4 in a direction along the slot insertion portion 122A0. The second leg 122B is bent at a bent portion 122B5 on the side of a tip (lower end) 122B6 of the second leg 122B relative to the fourth oblique side 122B4 in a direction along the slot insertion portion 122B0.

[0045] A portion of the first leg 121A of the first segment conductor 121 from the bent portion 121A5 to the tip 121A6 side is welded to a portion of the second leg 121B of an adjacent first segment conductor 121. On the other hand, a portion of the second leg 121B from the bent portion 121B5 to the tip 121B6 side is welded to a portion of the first leg 122A of the adjacent second segment conductor 122 from the bent portion 122A5 to the tip 122A6 side.

[0046] The coil 12 has a slot insertion portion 121A0 disposed inside the slot 112, and a first coil end portion protruding from an end face 11S1 of the stator core 11. The first coil end portion is mainly constituted by oblique side portions 121C and 122C of the segment conductors 121 and 122, and includes straight line portions 121A2, 121B2, 122A2, and 122B2 connected to the slot insertion portions 121A0, 121B0, 122A0, and 122B0.

[0047] The straight portion 121A2 is a portion that, together with the slot insertion portion 121A0, constitutes the first leg 121A of the first segment conductor 121 (first straight portion of the first segment conductor 121). The straight portion 121B2 is a portion that, together with the slot insertion portion 121B0, constitutes the second leg 121B of the first segment conductor 121 (first straight portion of the first segment conductor 121). The straight portion 122A2 is a portion that, together with the slot insertion portion 122A0, constitutes the first leg 122A of the second segment conductor 122 (first straight portion of the second segment conductor 122). The straight portion 122B2 is a portion that, together with the slot insertion portion 122B0, constitutes the second leg 122B of the second segment conductor 122 (second straight portion of the second segment conductor 122).

[0048] In the first coil end portion, either the first segment conductor 121 or the second segment conductor 122 constitutes the coil end portion by itself.

[0049] The coil 12 has a second coil end portion protruding from an end surface 11S2 of the stator core 11 on the side opposite to the side where the first coil end portion of the stator core 11 is formed. In the second coil end portion, the first leg 121A and the second leg 121B of the two first segment conductors 121 are connected to each other, or the second leg 121B of the first segment conductor 121 and the first leg 122A of the second segment conductor 122 are connected to each other, thereby forming a coil end portion. The third oblique side portion 121A4 and the fourth oblique side portion 121B4 of the first segment conductor 121 and the third oblique side portion 122A4 and the fourth oblique side portion 122B4 of the second segment conductor 122 are formed in a second coil end portion. In addition, the welded portion W of the two segment conductors is formed in the second coil end portion.

[0050] The second segment conductor 122 is formed such that the second straight portion 122B2 forming a straight portion on one slot 112 side is longer than the first straight portion 122A2 forming a straight portion on the other slot 112 side. The second straight portion 122B2 of the second segment conductor 122 has a height h22 from the end face 11S1 of the stator core 11 in the second leg portion 122B (see FIG. 4C) to the portion exposed to the outside of the stator core 11, i.e., from the end face 11S1 to the bent portion 122B1, which is greater than the height h21 from the end face 11S1 to the bent portion 122A1 in the first straight portion 122A2 of the second segment conductor 122 (h22>h21). In addition, the height h21 from the end face 11S1 to the bent portion 122A1 in the first straight portion 122A2 of the second segment conductor 122 is equal to the height h21 from the end face 11S1 to the bent portion 121A1 in the first straight portion 121A2 of the first segment conductor 121, and the height h21 from the end face 11S1 to the bent portion 121B1 in the second straight portion 121B2 of the first segment conductor 121.

[0051] In addition, the protruding height h121 from the end face 11S1 of the stator core 11 at the first coil end portion of the first segment conductor 121 and the protruding height h122 from the end face 11S1 of the stator core 11 at the first coil end portion of the second segment conductor 122 are formed to be equal (h121=h122=h1).

[0052] The stator 10 of the rotating electrical machine 1 of this embodiment has the following features. A stator core 11 having a plurality of slots 112; a coil 12 wound around the stator core 11, the coil 12 including a plurality of segment conductors 121 and 122 each having slot insertion portions 121A0, 121B0, 122A0, and 122B0 disposed inside the slot 112 and a coil end portion (first coil end portion) protruding from an end surface 11S1 of the stator core 11; A stator 10 having A rotating electric machine 1 including a stator 10 and a rotor 30 disposed with a gap therebetween, The coil end portion includes straight portions 121A2, 121B2, 122A2, and 122B2 that are connected to the slot insertion portions 121A0, 121B0, 122A0, and 122B0, and oblique side portions 121C and 122C that are formed in a mountain shape with vertices 121CC and 122CC at the center, the plurality of segment conductors 121, 122 include a first segment conductor 121 inserted into two slots 112 arranged at a first slot pitch, and a second segment conductor 122 inserted into two slots 112 arranged at a second slot pitch smaller than the first slot pitch; The second segment conductor 122 is formed such that a second straight portion 122B2 forming the straight portion on one slot side is longer than a first straight portion 122A2 forming the straight portion on the other slot side, The protruding height h121 from the end face 11S1 of the stator core 11 at the center of the first conductor segment 121 and the protruding height h122 from the end face 11S1 of the stator core 11 at the center of the second conductor segment 122 are formed to be equal.

[0053] According to this embodiment, the heights of the first coil end portions are uniform, so that the positioning accuracy of the coil 12, i.e., the first segment 121 and the second segment conductor 122, using the jig 70 (see FIG. 4A) is improved, and the first segment 121 and the second segment conductor 122 can be bent with high accuracy. In addition, when the first segment 121 and the second segment conductor 122 are positioned by the jig 70 and bent, the first segment 121 and the second segment conductor 122 are less likely to move in the axial direction, so that damage to the insulating coating of the first segment 121 and the second segment conductor 122 (movement of the insulating paper) can be suppressed. In addition, the improved processing accuracy when bending the first segment 121 and the second segment conductor 122 can reduce the occurrence of defects when welding the welded portion W.

[0054] In this embodiment, since the bending angles (θ121A, θ121B, θ122A, θ122B) of the first segment conductor 121 and the second segment conductor 122 are the same, it is possible to suppress an increase in the number of inspections. In addition, it is possible to suppress variations in the winding resistance, etc., thereby improving the yield rate and reliability.

[0055] The rotating electric machine 1 of this embodiment includes the stator 10 of the rotating electric machine 1 described above, and a rotor 30 arranged with a gap between the stator 10 and the rotor 30, and the number of slots per pole per phase (NSPP) is 2. In this case, the coil 12 includes a first segment conductor 121 and a second segment conductor 122 that is a deformed coil member with respect to the first segment conductor 121.

[0056] Next, the lead segment conductor 123 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a perspective view showing the appearance of a coil end portion. Fig. 6 is a plan view showing the shape of the lead segment conductor 123. The coil 12 includes an output segment conductor 123 that constitutes an output wire. The output segment conductor 123 includes a first output portion 123A accommodated in the slot 112, a second output portion 123B located at the first coil end portion, and a bent portion 123C provided between the first output portion 123A and the second output portion 123B. The first output portion 123A is linear and parallel to the axial direction. The second output portion 123B is connected to the first output portion 123A via the bent portion 123C, and is linear and parallel to the axial direction.

[0057] The first and second output portions 123A and 123B are located at different radial positions with respect to the stator core 11 such that the second output portion 123B is located on the inner circumferential side of the first output portion 123A. In addition, the output segment conductor 123 is disposed closer to the second straight portion 122B than to the first straight portion 122A of the second segment conductor 122.

[0058] That is, the rotating electric machine 1 of this embodiment has the following features. The coil 12 includes an output segment conductor 123 that constitutes an output wire, The lead segment conductor 123 includes a first lead portion 123A that is housed in the slot 112 and is linearly shaped parallel to the axial direction, and a second lead portion 123B that is connected to the first lead portion 123A via a bent portion 123C, is linearly shaped, and is located at a first coil end portion. The first lead portion 123A and the second lead portion 123B are positioned differently in the radial direction with respect to the stator core 11 such that the second lead portion 123B is positioned on the inner circumferential side with respect to the first lead portion 123A. The lead-out segment conductor 123 is disposed closer to the second straight portion 122B of the second segment conductor 122 than to the first straight portion 122A.

[0059] This allows the bent portion 123C of the lead segment conductor 123 to be disposed below the second oblique side portion 122CB of the second segment conductor 122 and between the end face 11S1 of the stator core 11 and the second oblique side portion 122CB. A larger gap (gap based on Δk in FIG. 4C ) is formed below the second oblique side portion 122CB of the second segment conductor 122 than below the first oblique side portion 122CA, thereby suppressing interference between the second segment conductor 122 and the lead segment conductor 123.

[0060] FIG. 7 is a plan view of the stator 10 of the rotating electric machine 1 as viewed from the first coil end portion side (end surface 11S1 side). In the rotating electric machine 1 of this embodiment, the lead segment conductor 123 includes inner circumference side lead segment conductors 123-1 to 123-6 that are housed in the slots 112 at positions on the inner circumference side of the stator core 11, and outer circumference side lead segment conductors 123-7 to 123-12 that are housed in the slots 112 at positions on the outer circumference side of the stator core 11.

[0061] By arranging at least one of the lead segment conductors 123-1 to 123-12 with respect to the second segment conductor 122 as described above, it is possible to suppress interference between the second segment conductor 122 and the lead segment conductor 123 at the lead segment conductor 123. By arranging all of the lead segment conductors 123-1 to 123-12 with respect to the second segment conductor 122 as described above, it is possible to reduce the height of the coil end portion (first coil end portion) and thereby reduce the size of the rotating electric machine 1.

[0062] FIG. 8 is a partial cross-sectional view of the stator core 11 into which the first conductor segment 121 and the second conductor segment 122 have been inserted.

[0063] Inside the slots, insulators 80 are arranged between the stator core 11 and the slot insertion portions 121A0 and 121B0 of the first segment conductor 121 and between the two adjacent slot insertion portions 121A0. The insulators 80 are made of, for example, varnish. Similarly to the first segment conductor 121, insulators 80 are arranged between the stator core 11 and the slot insertion portions 122A0 and 122B0 of the second segment conductor 122 and between the two adjacent slot insertion portions 122A0 and 122B0.

[0064] That is, in the rotating electric machine 1 of this embodiment, insulators 80 are arranged inside the slots 112, between the stator core 11 and the slot insertion portions 121A0, 121B0, 122A0, and 122B0 of the segment conductors 121 and 122, and between two adjacent slot insertion portions 121A0, 121B0, 122A0, and 122B0.

[0065] The insulator 80 is made of a non-conductive material such as varnish, insulating paper, etc. The segment conductors 121, 122 are insulated by enamole or the like, but by disposing the insulator 80, the insulation of the stator core 11 can be further improved, and the reliability of the rotating electric machine 1 can be improved.

[0066] FIG. 9 is a diagram illustrating an embodiment in which the stator core 11 is manufactured by stacking thin steel plates, and the stacked steel plates are joined by welding.

[0067] The stator core 11 of this embodiment is formed by stacking steel plates (e.g., electromagnetic steel plates) 11P. The stacked steel plates have welded portions 11W where they are fixed by welding. The welded portions 11W of the stator core 11 are disposed closer to the second straight portion 121A of the second segment conductor 122 than the first straight portion 121A.

[0068] That is, in the rotating electric machine 1 of this embodiment, The stator core 11 is formed by laminating steel plates 11P and has welded portions 11W where the laminated steel plates 11P are fixed by welding. The welded portion 11W of the stator core 11 is disposed closer to the second straight portion 122B2 of the second conductor segment 122 than to the first straight portion 122A2.

[0069] The welded portion 11W may expand due to heat input during welding. In this embodiment, the gap h5 formed between the second oblique side portion 122CB and the end face 11S1 of the stator core 11 on the second straight portion 122B2 side is larger than the gap h6 formed between the first oblique side portion 122CA and the end face 11S1 of the stator core 11 on the first straight portion 122A2 side of the second segment conductor 122, so that interference with the expanding welded portion 11W can be easily avoided. Alternatively, even if the welded portion 11W expands, it becomes easy to arrange the lead segment conductors 123-1 to 123-12, etc., between the expanded end face 11S1 and the second oblique side portion 122CB.

[0070] FIG. 10 is a diagram for explaining an embodiment in which the twisted portions 121CD and 122CD of FIG. 4A and FIG. 4C are formed in the welded portion W. In FIG.

[0071] The segment conductors 121 and 122 have second coil end portions 121A6, 121B6, 122A6 and 122B6 protruding from an end face 11S2 opposite to the end face 11S1 of the stator core 11. The second coil end portions 121A6, 121B6, 122A6 and 122B6 of the segment conductors 121 and 122 are connected to the second coil end portions 121A6, 121B6, 122A6 and 122B6 of the other segment conductors 121 and 122 by welding on the side of the end face 11S2 opposite to the stator core 11.

[0072] In the present embodiment, it has been described that the first segment conductor 121 and the second segment conductor 122 can be positioned with high accuracy by the jig 70, and the first segment conductor 121 and the second segment conductor 122 can be bent with high accuracy. In the present embodiment, the position of the welded portion W can be determined with high accuracy, so that the twisted portions 121CD, 122CD provided at the oblique side portion 121C of the first segment conductor 121 and the oblique side portion 122C of the second segment conductor 122 can be provided at the welded portion W. In other words, the twisted portions 121CD, 122CD bent in the radial direction can be provided at the joints W formed by welding the second coil end portions 121A6, 121B6, 122A6, 122B6 of the segment conductors 121, 122 to the second coil end portions 121A6, 121B6, 122A6, 122B6 of the other segment conductors 121, 122.

[0073] That is, in this embodiment, the legs of the segment conductors 121, 122 on the side of the welded portion W are aligned, so that the coil 12 can be twisted on the side of the welded portion W, and the weldability of the coil 12 can be improved.

[0074] Therefore, the rotating electrical machine 1 of this embodiment has the following features. The segment conductors 121 and 122 have second coil end portions 121A6, 121B6, 122A6, and 122B6 protruding from an end face 11S2 of the stator core 11 opposite to an end face 11S1 of the stator core 11, The second coil end portions 121A6, 121B6, 122A6, and 122B6 of the segment conductors 121 and 122 are connected to the second coil end portions 121A6, 121B6, 122A6, and 122B6 of the other segment conductors 121 and 122 by welding on the opposite end face 11S2 side of the stator core 11, The joints between the second coil end portions 121A6, 121B6, 122A6, and 122B6 of the segment conductors 121 and 122 and the second coil end portions 121A6, 121B6, 122A6, and 122B6 of the other segment conductors 121 and 122 by welding are provided with twisted portions 121CD and 122CD bent in the radial direction.

[0075] In this embodiment, the degree of freedom in the arrangement of the twisted portions 121CD and 122CD is increased, and thus the degree of freedom in the design of the rotating electrical machine 1 is improved.

[0076] [Example 2] The rotating electric machine 1 of this embodiment can be applied to a pure electric vehicle that runs on the power of the rotating electric machine only, or a hybrid electric vehicle that is driven by both an engine and a rotating electric machine, but the following description will be given using a hybrid electric vehicle as an example.

[0077] The vehicle 500 is equipped with an engine 520, a first rotating electric machine 1-1, a second rotating electric machine 1-2, and a battery 580. When the vehicle 500 requires driving force from the first rotating electric machine 1-1 and the second rotating electric machine 1-2, the battery 580 supplies DC power to the first rotating electric machine 1-1 and the second rotating electric machine 1-2 via a power conversion device 600. Furthermore, the battery 580 receives DC power from the first rotating electric machine 1-1 and the second rotating electric machine 1-2 during regenerative running. The exchange of DC power between the battery 580 and the first rotating electric machine 1-1 and the second rotating electric machine 1-2 is performed via the power conversion device 600. Although not shown, the vehicle 500 is equipped with a battery that supplies low-voltage power (for example, 14-volt power), and supplies DC power to a control circuit described below.

[0078] The first rotating electric machine 1-1 and the second rotating electric machine 1-2 have substantially the same structure, and can be configured with the above-mentioned rotating electric machine 1. However, the structure relating to the first segment conductor 121 and the second segment conductor 122 does not need to be provided in both the first rotating electric machine 1-1 and the second rotating electric machine 1-2, and may be provided in only one of them.

[0079] Rotational torque from the engine 520 and the first rotating electric machine 1-1 and the second rotating electric machine 1-2 is transmitted to the front wheels 510 via the transmission 530 and a differential gear 560. The transmission 530 is controlled by a transmission control device 534. The engine 520 is controlled by an engine control device 524. The battery 580 is controlled by a battery control device 584. The transmission control device 534, the engine control device 524, the battery control device 584, the power conversion device 600, and the integrated control device 570 are connected to each other by a communication line 574.

[0080] The integrated control device 570 is a higher-level control device than the transmission control device 534, the engine control device 524, the power conversion device 600, and the battery control device 584, and receives information indicating the respective states of the transmission control device 534, the engine control device 524, the power conversion device 600, and the battery control device 584 from them via a communication line 574. The integrated control device 570 calculates control commands for each device based on the acquired information. The calculated control commands are transmitted to each device via the communication line 574.

[0081] The battery 580 is composed of a secondary battery such as a lithium ion battery or a nickel metal hydride battery, and outputs high voltage DC power of 250 V to 600 V or more. The battery control device 584 outputs the charge / discharge status of the battery 580 and the status of each unit cell battery constituting the battery 580 to the integrated control device 570 via the communication line 574.

[0082] When the integrated control device 570 determines that the battery 580 needs to be charged based on information from the battery control device 584, it issues a command to the power conversion device 600 to perform power generation operation. The integrated control device 570 mainly manages the output torque of the engine 520, the first rotating electric machine 1-1, and the second rotating electric machine 1-2, and performs calculation processing of the total torque and the torque distribution ratio of the output torque of the engine 520 and the output torque of the first rotating electric machine 1-1 and the second rotating electric machine 1-2, and transmits a control command based on the result of this calculation processing to the transmission control device 534, the engine control device 524, and the power conversion device 600. Based on the torque command from the integrated control device 570, the power conversion device 600 controls the first rotating electric machine 1-1 and the second rotating electric machine 1-2 so that a torque output or generated power is generated as commanded.

[0083] The power conversion device 600 is provided with power semiconductors that configure inverter circuits for operating the first rotating electric machine 1-1 and the second rotating electric machine 1-2. The power conversion device 600 controls the switching operation of the power semiconductors based on commands from the integrated control device 570. The switching operation of the power semiconductors causes the first rotating electric machine 1-1 and the second rotating electric machine 1-2 to operate as electric motors or generators.

[0084] When the first rotating electric machine 1-1 and the second rotating electric machine 1-2 are operated as electric motors, DC power from a high-voltage battery 580 is supplied to a DC terminal of an inverter of the power conversion device 600. The power conversion device 600 controls the switching operation of the power semiconductors to convert the supplied DC power into three-phase AC power and supplies the converted power to the first rotating electric machine 1-1 and the second rotating electric machine 1-2. On the other hand, when the first rotating electric machine 1-1 and the second rotating electric machine 1-2 are operated as generators, the rotors of the first rotating electric machine 1-1 and the second rotating electric machine 1-1 are rotated by a rotational torque applied from the outside, and three-phase AC power is generated in the stator windings of the first rotating electric machine 1-1 and the second rotating electric machine 1-2. The generated three-phase AC power is converted to DC power by the power conversion device 600, and this DC power is supplied to the battery 580, thereby charging the high-voltage battery 580.

[0085] In this embodiment, an electric drive system including rotating electric machines 1-1, 1-2 that generate driving force for a vehicle and a power conversion device 600 may include a rotating electric machine 1 having a stator 30 in which a coil 12 includes a first segment conductor 121 and a second segment conductor 122, and a rotor 30 rotatably arranged on the inner side of the stator core 11 via a gap.

[0086] That is, the electric drive system of this embodiment is as follows: An electric drive system including a rotating electric machine and a power conversion device that generate driving force for a vehicle, The rotating electric machine is a rotating electric machine 1 according to the present embodiment.

[0087] The rotating electric machine 1 of this embodiment can be made smaller and less expensive, and is suitable for use as a main engine motor for an automobile.

[0088] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. For example, the above-mentioned embodiment is described in detail to easily explain the present invention, and the present invention is not necessarily limited to the embodiment having all the configurations described. In addition, it is possible to delete a part of the configuration of the embodiment, or to add another configuration. [Explanation of symbols]

[0089] 1...rotating electric machine, 10...stator, 11...stator core, 11P...steel plate, 11S1...end surface of stator core 11, 11W...welding portion, 12...coil, 80...insulator, 112...slot, 121...segment conductor (first segment conductor), 122...segment conductor (second segment conductor), 121A0, 121B0, 122A0, 122B0...slot insertion portion of segment conductor, 121A2, 121B2, 122A2, 122B2...straight portion of coil end portion, 121A6, 121B6, 122A6, 122B6...second coil end portion, 121C, 122C...hypothetic side portion, 121CC, 122CC...apex of coil end portion, 121CD, 122CD...twisted portion, 122A2...first straight portion, 122B2...second straight portion, 123...output segment conductor, 123-1 to 123-6...inner circumference side output segment conductor, 123-7 to 123-12...outer circumference side output segment conductor, 123A...first output portion, 123B...second output portion, 123C...bent portion.

Claims

1. a stator core having a plurality of slots; a coil wound around the stator core, the coil including a plurality of segment conductors each having a slot insertion portion disposed inside the slot and a first coil end portion protruding from one end face in the axial direction with respect to the stator core; a stator having a a rotor disposed across a gap from the stator, The first coil end portion has a straight portion connected to the slot insertion portion and an oblique side portion formed in a mountain shape with a central portion as an apex, the plurality of segment conductors include first segment conductors inserted into two slots arranged at a first slot pitch, and second segment conductors inserted into two slots arranged at a second slot pitch smaller than the first slot pitch, the second segment conductor is formed such that a second straight portion forming the straight portion on one slot side is longer than a first straight portion forming the straight portion on the other slot side, a protruding height of the central portion of the first segment conductor from the end face of the stator core and a protruding height of the central portion of the second segment conductor from the end face of the stator core are formed to be substantially equal to each other.

2. 2. The rotating electric machine according to claim 1, A rotating electric machine with two slots per pole and phase.

3. 2. The rotating electric machine according to claim 1, The coil includes an output segment conductor constituting an output wire, the lead segment conductor includes a first lead portion that is accommodated in the slot and is linearly parallel to the axial direction, and a second lead portion that is linearly connected to the first lead portion via a bent portion and is located in the first coil end portion, the first lead portion and the second lead portion are positioned differently in a radial direction with respect to the stator core such that the second lead portion is positioned on an inner circumferential side with respect to the first lead portion, the lead segment conductor is disposed closer to the second straight portion than to the first straight portion of the second segment conductor.

4. 4. The rotating electric machine according to claim 3, The rotary electric machine includes an inner circumference side lead segment conductor that is accommodated in the slot at a position on the inner circumference side of the stator core, and an outer circumference side lead segment conductor that is accommodated in the slot at a position on the outer circumference side of the stator core.

5. 2. The rotating electric machine according to claim 1, A rotating electric machine, wherein an insulator is arranged inside the slot, between the stator core and the slot insertion portion of the segment conductor, and between two adjacent slot insertion portions.

6. 2. The rotating electric machine according to claim 1, The stator core is formed by laminating steel plates and has welded portions where the laminated steel plates are fixed by welding, a rotating electric machine in which the welded portion of the stator core is disposed closer to the second straight portion than to the first straight portion of the second segment conductor.

7. 2. The rotating electric machine according to claim 1, the plurality of segment conductors each have a second coil end portion protruding from an end face of the stator core opposite to the end face of the stator core, the second coil end portion of the segment conductor is connected to the second coil end portion of another segment conductor by welding on the opposite end face side of the stator core, a twisted portion bent in a radial direction is provided at a joint between the second coil end portion of the segment conductor and the second coil end portion of the other segment conductor by welding.

8. An electric drive system including a rotating electric machine and a power conversion device that generate driving force for a vehicle, An electric drive system comprising the rotating electric machine according to claim 1 as the rotating electric machine.

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