Rotating electric machines

Abstract

The present invention provides a new rotating electric machine, which can suppress the height increase of the coil end portion on the side where the turning portion is located, and can improve the cooling performance around the turning portion of the segmented coil. The segmented coil (31) includes: a first straight portion (34r) inserted into a specific slot (22); a second straight portion (34a) inserted into another specific slot (22) different from the specific slot (22); and a turning portion (33), which extends from an end surface of the stator core (21) to the outside in the axial direction of the stator core (21), has a top portion (33c) connecting the first straight portion (34r) and the second straight portion (34a), and at each end portion (33c) of the segmented coil (31). In the slot (22), straight portions (34r, 34a) of a plurality of segment coils (31) are inserted and arranged in a stacked manner from the inner circumference to the outer circumference in the radial direction, and a curved portion (37) is formed between the straight portions (34r, 34a) of the segment coils (31) stacked in the radial direction and the curved portion (33), and the curved portion (37) makes the top portion (33c) of the curved portion (33) tilt in a direction close to the end surface of the stator core (21).

Description

Technical Field

[0001] The present invention relates to a rotating electric machine, and more particularly to a rotating electric machine having a stator, the stator including a stator core having a plurality of slots and a plurality of segment coils received in the slots of the stator core. Background Art

[0002] In electric vehicles and hybrid vehicles, a driving force is obtained by a rotating electric machine, and as the rotating electric machine, a rotating electric machine having a stator is used, and the stator includes: a stator core having a plurality of slots; and a plurality of copper segment coils received in the slots of the stator core. A rotating electric machine including such a stator is described in, for example, Japanese Patent Application Laid-Open No. 2017-189020 (Patent Document 1).

[0003] The rotating electric machine described in Patent Document 1 includes: a stator core having a plurality of slots extending in the axial direction on the inner circumferential surface; and a copper segment coil inserted into the slots, wherein a parallel portion substantially parallel to the end face portion of the stator core is formed at the top of a portion on a bent side (referred to as a turn portion) of a coil end portion of the segment coil protruding in the axial direction from the end face portion of the stator core.

[0004] Furthermore, with the parallel portion as a boundary, an intermediate inclined portion having an inclination of one predetermined angle is formed in one intermediate inclined portion, and an intermediate inclined portion having two inclinations of two different predetermined angles is formed in the other intermediate inclined portion.

[0005] According to the segment coil having such a structure, it is possible to provide a stator for a rotating electric machine which avoids mechanical interference between adjacent coils at the bent-side coil end of the segment coil and suppresses the length of the coil end.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-189020 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, in this type of rotating electric machine, when the spatial distance between the turn portion of the bent side coil end of the segmented coil protruding from the end face portion of the stator core and the turn portion of the bent side coil end of the adjacent segmented coil is small, the heat generated by the coil when current is passed through is difficult to dissipate into a cooling medium such as air or oil, so the resistance of the coil increases, which may lead to a decrease in the performance of the rotating electric machine.

[0011] As a countermeasure, there is a method of increasing the contact area between the cooling medium and the turning portion by increasing the spatial distance between the end surface of the stator core and the turning portion of the segment coil, but there is a problem that the height of the turning portion, that is, the length of the bending side coil end portion increases, which hinders miniaturization. Therefore, there is a need for a rotating electric machine that can sufficiently cool the bending side coil end portion without increasing the length of the bending side coil end portion.

[0012] An object of the present invention is to solve the above-mentioned problems in such a rotating electrical machine.

[0013] That is, an object of the present invention is to provide a new rotating electrical machine capable of suppressing the length of the coil end portion on the side where the turn portion is located from increasing and improving the cooling performance around the turn portion of the segment coil.

[0014] Technical solutions to solve problems

[0015] The present invention is characterized in that

[0016] The segment coil includes: a first straight portion inserted into a specific slot; a second straight portion inserted into another specific slot different from the specific slot; and a turn portion, which extends from one end surface portion of the stator core to the outside in the axial direction of the stator core and has a top portion connecting the first straight portion and the second straight portion, wherein the straight portions of the plurality of segment coils are inserted and arranged in each slot in a stacked manner from the inner peripheral side to the outer peripheral side in the radial direction, and a bent portion is formed between the straight portions of the segment coils stacked in the radial direction and the turn portion, and the bent portion makes the turn portion tilt in a direction in which the top of the turn portion approaches the end surface of the stator core.

[0017] Effects of the Invention

[0018] According to the present invention, the turning portion extending from the end surface portion of the stator core is bent radially outward, thereby forming a sufficient gap between the turning portions of each segment coil, and the cooling medium can easily enter the gap, or the substantial contact area between the coil and the cooling medium is increased, thereby achieving improved cooling performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view showing a cross section in the axial direction of a rotating electrical machine to which the present invention is applied.

[0020] Figure 2 Observed from above Figure 1 A perspective view of a stator of a rotating electrical machine is shown.

[0021] Figure 3 Yes means Figure 2 A front view of the shape of the segmented coil is shown.

[0022] Figure 4 is to Figure 2 The diagram is an enlarged cross-sectional view showing a portion of an end surface portion of the stator core, which is a surface perpendicular to the axis of the stator core.

[0023] Figure 5 It is an explanatory diagram for explaining the arrangement state of each segment coil inserted in the slot.

[0024] Figure 6 It is an enlarged perspective view for explaining the relationship between the shape of the turning portion of the segment coil and the slot.

[0025] Figure 7 It is a description of the composition Figure 2 FIG. 1 is an enlarged perspective view of an arrangement state of a first coil group of coils shown.

[0026] Figure 8 It is a description of the composition Figure 2 An enlarged perspective view of the arrangement of the first coil group and the second coil group of coils shown.

[0027] Fig. 9 This is an enlarged cross-sectional view of one slot cut along a plane in the axial direction of the stator core in the first embodiment of the present invention.

[0028] Fig.10 Observe from different perspectives Figure 8 An enlarged perspective view of the first coil group and the second coil group shown.

[0029] Fig.11 This is an enlarged cross-sectional view of one slot cut along a plane in the axial direction of the stator core in the second embodiment of the present invention.

[0030] Fig.12 It is an explanatory diagram for explaining the length of the turning portion of each of the segment coil located on the inner circumference side and the segment coil located on the outer circumference side.

[0031] Fig.13 It means that the Fig.12 FIG. 1 is an explanatory diagram of the reason for the length of the turn portion of the segment coil on the outer peripheral side shown. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present invention will be described in detail using the drawings, but the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention.

[0033] Figure 11 is a cross-sectional view of a rotating electrical machine 100 to which the present invention is applied. The rotating electrical machine 100 of this embodiment is mounted on a vehicle such as an electric vehicle without an internal combustion engine or a hybrid vehicle with an internal combustion engine, and includes a function as a motor that generates driving force and a function as a generator that generates electricity when the vehicle is braked, etc. In addition, the generated electricity is stored in a battery, etc., mounted on the vehicle.

[0034] The rotating electrical machine 100 mainly includes a rotor 10 and a stator 20. The rotor 10 and the stator 20 are accommodated in an accommodation space formed by a circular housing 14 with openings on both sides, and a front cover 15 and a rear cover 16 that close the openings on both sides of the housing 14. The front cover 15 and the rear cover 16 are fixed to the housing 14 with bolts 17.

[0035] The rotor 10 includes, for example, a substantially cylindrical rotor core 11 formed by laminating a plurality of flat electromagnetic steel sheets in the direction of the axis L, and a drive shaft 12 fixed to the center of the rotor core 11. Although not shown in the figure, the rotor core 11 includes a plurality of magnet insertion holes provided at equal angles in the circumferential direction, and a plurality of magnets (neodymium magnets, ferrite magnets) inserted and fixed to the magnet insertion holes.

[0036] The drive shaft 12 is rotatably supported by two bearings 13 located at both ends, and rotates integrally with the rotor core 11 around the axis L of the rotor core 11. The bearings 13 are arranged inside the front cover 15 and the rear cover 16. The bearing 13 on the front cover 15 side is supported by a retainer 18, and the retainer 18 is fixed to the front cover 15 with bolts 19. In addition, the drive shaft 12 applies a rotational force to a drive wheel (not shown) via a speed reduction mechanism (not shown), and also applies a rotational force from the drive wheel.

[0037] The stator 20 includes, for example, a substantially annular stator core 21 formed by laminating a plurality of flat electromagnetic steel sheets in the direction of the axis L, and a coil 30 wound around the stator core 21 .

[0038] The rotor core 11 is rotatably arranged inside the stator core 21 with a small gap in the radial direction D2 of the stator core 21, and the axis L of the stator core 21 coincides with the axis L of the rotor core 11. The rotating electric machine of this structure is well known, and further description thereof is omitted.

[0039] Figure 2 Yes Take out Figure 1 The stator 20 of the rotating electrical machine 100 is shown in FIG. 1 as viewed from obliquely above. Figure 2 In the embodiment, the inner circumference of the annular stator core 21 has a plurality of slit-like slots 22 arranged at equal angles in the circumferential direction D1 and extending radially outward in the radial direction D2 (see Figure 4 ).

[0040] When viewed from the direction of the axis L of the stator core 21, the slot 22 penetrates from one end surface portion 21a to the other end surface portion 21b along the direction of the axis L of the stator core 21. In addition, the inner peripheral surface of the stator core 21 has an opening portion (slit) 22a that is continuous along the direction of the axis L from one end surface portion 21a to the other end surface portion 21b.

[0041] The stator core 21 has, for example, 48 slots 22 formed at equal angles in the circumferential direction D1, and the coil 30 is disposed in each slot 22. In this way, the slots 22 are formed in the stator core 21 in a radial shape with the axis L as the center.

[0042] In addition, if Figure 2 As shown, the coil 30 of the stator 20 is composed of a first coil group 30A arranged on the inner circumference side and a second coil group 30B arranged on the outer circumference side of the first coil group 30A in the radial direction D2 of the stator core 21. The first coil group 30A and the second coil group 30B are a collection of copper segment coils 31A and 31B.

[0043] In the direction of the axis L of the stator core 21, one coil end portion 35A, 35B of the coil 30 is formed by a turn portion 33 (see FIG. 1 ) of the segment coils 31A, 31B constituting the first coil group 30A and the second coil group 30B. Figure 3 ) In addition, the other coil ends 36A, 36B of the coil 30 are composed of a connecting portion 32 that connects the predetermined segment coils 31A, 31B of the same phase.

[0044] Here, the turning portion 33 is the bending side coil end portions 35A and 35B, the connecting portion 32 is the connecting side coil end portions 36A and 36B, and therebetween is the slot insertion portion 34 (see Figure 3 ). In addition, Figure 3 As shown in FIG. 1 , the groove insertion portion 34 is sometimes also described as a straight line portion 34 .

[0045] In addition, the connecting side coil ends 36A and 36B adjacent to each coil group are connected by TIG welding the connecting portions 32 connecting the segment coils 31A and 31B in sequence. That is, the connecting portions 32 of the adjacent segment coils 31A of the first coil group 30A are connected in sequence, and the connecting portions 32 of the adjacent segment coils 31B of the second coil group 30B are connected in sequence. These structures are also well known, so further description is omitted.

[0046] Furthermore, in order to improve the cooling performance of the bent coil end portion 35 protruding from one end surface portion 21 a of the stator core 21 in the direction of the axis L of the stator core 21 , the shape of the turn portion 33 of the segment coil 31 constituting the coil 30 becomes important.

[0047] (Example 1)

[0048] Hereinafter, the structure of turn portion 33 of segment coil 31 which is a feature of rotating electrical machine 100 according to the present embodiment will be described in detail with reference to the drawings.

[0049] Figure 3 2 shows the shapes of the segment coils 31A and 31B. The segment coils 31A and 31B are formed in substantially the same shape, so the structures of the segment coils 31A and 31B will be described in summary. However, the segment coils 31A and 31B are characterized by the bend portion 33 that is bent outward in the radial direction when inserted into the slot 22. Fig. 9 The details are explained in detail in .

[0050] exist Figure 3 In the embodiment, segment coil 31 includes a pair of straight portions 34a and 34r disposed in slot 22, and a turn portion 33 is formed so as to connect one side of the pair of straight portions 34a and 34r. In addition, the other side of the pair of straight portions 34a and 34r is opened to form connecting portions 32a and 32r. Thus, a bent side coil end 35 and a connecting side coil end 36 are formed.

[0051] The turn portion 33 has a top portion 33 c formed near the center thereof. The top portion 33 c is formed so that when the segment coils 31 are assembled to the stator core 21 , the top portions 33 c of the segment coils 31 (plurality) assembled to the stator core 21 are arranged in parallel with the core end surface portion 21 a .

[0052] Furthermore, one side of the top portion 33c is connected to the straight portion 34a via the intermediate inclined portion 33ba, and the other side of the top portion 33c is connected to the straight portion 34r via the intermediate inclined portion 33br. Therefore, when the segment coil 31 is arranged in the slot 22, the turn portion 33 has a "mountain-shaped" shape when viewed from the radial direction.

[0053] In addition, the connection portion 33aa between the intermediate inclined portion 33ba and the straight portion 34a, and the connection portion 33ar between the intermediate inclined portion 33br and the straight portion 34r are bent, thereby connecting the pair of straight portions 34a and 34r via the intermediate inclined portion 33ba, the top portion 33c, and the intermediate inclined portion 33br. Therefore, the segment coil 31 is formed into a substantially "U" shape by the pair of straight portions 34a and 34r and the turn portion 33 bent so as to connect the pair of straight portions 34a and 34r.

[0054] Here, in a state where segment coil 31 is arranged in two slots 22 separated by a predetermined pitch, a pair of straight line portions 34a and 34r have a straight line portion 34a located at the front side in the clockwise direction and a straight line portion 34r located at the rear side in the clockwise direction.

[0055] As described later, in the slot 22, the straight portions 34a and 34r of the segment coils 31A and 31B forming the first coil group 30A and the second coil group 30B are arranged in a radially stacked manner. Figure 4 As shown, use Figure 4 This is explained.

[0056] In one groove 22, the straight portion 34r is arranged in an odd-numbered layer, and the straight portion 34a is arranged in an even-numbered layer. In the present embodiment, the innermost layer of the groove 22 is the first layer, and the layers are the second, third, and fourth layers as they go toward the outer circumference.

[0057] like Figure 4 As shown, the coil 30 has a first coil group 30A disposed on the inner circumference side of the radial direction D2 and a second coil group 30B disposed on the outer circumference side of the first coil group 30A. In addition, in the embodiment of the present invention, there are two coil groups consisting of the first coil group 30A and the second coil group 30B, but of course, there may be more than three coil groups as in Patent Document 1.

[0058] In addition, from the viewpoint of suppressing the reduction of the space factor, the coil 30 is preferably composed of segment coils 31A and 31B composed of rectangular wires with a rectangular cross-sectional shape. Of course, a coil with a circular cross-sectional shape may also be used depending on the specifications of the rotating electrical machine. In the present embodiment, segment coils 31A and 31B composed of rectangular wires are used.

[0059] like Figure 4 As shown, an insulating member 40 made of insulating paper or the like is arranged on the inner peripheral wall surface of each slot 22, covering the circumference of the segment coils 31A and 31B constituting the first coil group 30A and the second coil group 30B. A pair of straight portions 34a and 34r of the segment coils 31A and 31B are inserted and arranged in the slot 22 extending in the direction of the axis L of the stator core 21 in a stacked manner in the radial direction D2.

[0060] Of the pair of straight portions 34a and 34r of the first segment coil 31A constituting the first coil group 30A, the straight portion 34r located on the innermost circumferential side of the slot 22 when viewed in the radial direction D2 of the stator core 21 is the first layer. Also, the straight portion 34a of the second segment coil 31A constituting the first coil group 30A, which is located outside the straight portion 34r of the first layer on the innermost circumferential side, is the second layer adjacent to the first layer on the outer side in the radial direction D2 of the stator core 21.

[0061] Thus, the first segment coil 31A and the second segment coil 31A are segment coils of the same shape, and the straight portions 34r, 34a of each segment coil 31A are arranged at a predetermined interval in the plurality of slots 22 annularly arranged in the stator core 21, and a collection of these constitutes the first coil group 30A.

[0062] Similarly, of the pair of straight portions 34a and 34r of the third segment coil 31B constituting the second coil group 30B, the straight portion 34r located outside the second layer when viewed in the radial direction D2 of the stator core 21 is the third layer. In addition, the straight portion 34a of the fourth segment coil 31B constituting the second coil group 30B is the fourth layer adjacent to the third layer on the outside in the radial direction D2 of the stator core 21.

[0063] Thus, the third segment coil 31B and the fourth segment coil 31B are segment coils of the same shape, and the straight portions 34r, 34a of the segment coils 31B are arranged at a predetermined interval in the plurality of slots 22 annularly arranged in the stator core 21, and a collection of these constitutes the second coil group 30B.

[0064] However, since segment coil 31B is arranged on the outer peripheral side, the length (wire length) of turn portion 33 is formed longer than that of segment coil 31A arranged on the inner peripheral side.

[0065] Thus, in the present embodiment, straight line portions 34r of segment coils 31A and 31B are arranged in odd-numbered layers, and straight line portions 34a of segment coils 31A and 31B are arranged in even-numbered layers. As described above, a pair of straight line portions 34a and 34r of each segment coil 31A and 31B are arranged in different slots 22 spaced apart at a predetermined pitch in the circumferential direction D1 of stator core 21.

[0066] Figure 5 The arrangement relationship of the segment coils 31A and 31B when viewing the slot 22 from the inside to the outside in the radial direction is shown.

[0067] In the slot 22 (region L) on the left, the segment coil 31A of the first coil group 30A is shown, with the display of the segment coil 31B of the second coil group 39B omitted. In addition, in the slot 22 (region R) on the right, the segment coil 31B of the second coil group 30B is shown, with the display of the segment coil 31A of the first coil group 30A omitted.

[0068] As shown in region (L), straight portion 34r of first segment coil 31A forming the first layer, which is located on the innermost circumference side of slot 22, extends to the slot 22 after the next predetermined pitch (right side in the figure) via intermediate inclined portion 33br on the upper right side when viewed in the drawing. On the other hand, straight portion 34a of second segment coil 31A formed in the second layer adjacent to the outer circumference side in the radial direction of the first layer extends from the slot 22 before the predetermined pitch (left side in the figure) toward the lower oblique side via intermediate inclined portion 33ba when viewed in the drawing.

[0069] Similarly, as shown in region (R), straight portion 34r of third segment coil 31B formed in the third layer on the outer peripheral side of the second layer of slot 22 extends from the right upper side via intermediate inclined portion 33br to the slot 22 after the next predetermined pitch (right side in the figure) when viewed in the drawing. On the other hand, straight portion 34a of fourth segment coil 31B formed in the fourth layer adjacent to the outer peripheral side in the radial direction of the third layer extends from the slot 22 before the predetermined pitch (left side in the figure) toward the oblique lower side via intermediate inclined portion 33ba when viewed in the drawing.

[0070] Thus, in segment coils 31A and 31B, straight line portions 34r of odd-numbered layers stacked on slots 22 extend from the upper right side via intermediate inclined portion 33br to the slot 22 after the next predetermined pitch (right side in the figure) when viewed in the drawing, and straight line portions 34a of even-numbered layers extend from the slot 22 before the predetermined pitch (left side in the figure) from the lower right side via intermediate inclined portion 33ba when viewed in the drawing.

[0071] Figure 6 Indicates that Figure 4 The structure of the turn portion 33 is shown in a state where one segment coil 31 is inserted into the slot 22. Here, the segment coil 31B of the second coil group 30B is shown. As described above, the cross section of the segment coil 31B is formed in a rectangular shape in order to increase the space factor.

[0072] The segment coil 31B constituting the second coil group 30B is configured to have a turn portion 33 protruding from the slot 22 in the direction of the axis L of the stator core 21 and a pair of straight portions 34a and 34r passing through two predetermined slots 22. The rotary electric machine 100 of the present embodiment is characterized by the shape of the turn portion 33 of the segment coil 31 wound around the slot 22 of the stator core 21.

[0073] The open ends of the pair of straight portions 34a, 34r of the segment coil 31B penetrate the slot 22 in the direction of the axis L of the stator core 21, and protrude outward from the end surface portion 21b of the stator core 21 on the opposite side to the end surface portion 21a along the direction of the axis L. The open end protruding in the direction of the axis L from the end surface portion 21b of the stator core 21 on the opposite side to the turn portion 33 becomes a connection side coil end portion 36. Figure 2 As shown, they are connected in sequence by the connecting portion 32.

[0074] like Figure 6 As shown, turn portion 33 of segment coil 31B has top portion 33 c which is farthest from end surface portion 21 a of stator core 21 when viewed in the direction of axis L and is constituted by “one side” substantially parallel to end surface portion 21 a .

[0075] The turn portion 33 has a pair of intermediate inclined portions 33ba and 33br connected to both ends of the top portion 33c and extending obliquely downward in the drawing so as to approach the end surface portion 21a of the stator core 21. Each of the intermediate inclined portions 33ba and 33br is connected to a pair of straight portions 34a and 34r via connecting portions 33aa and 33ar.

[0076] As described above, when one straight portion 34r of segment coil 31A of first coil group 30A is the first layer, the other straight portion 34a is the second layer. Similarly, when one straight portion 34r of segment coil 31B of second coil group 30B is the third layer, the other straight portion 34a is the fourth layer.

[0077] Therefore, the middle inclined portion 33br, the top 33c and the middle inclined portion 33ba from one straight portion 34r (odd-numbered layer) to another straight portion 34a (even-numbered layer) are inclined one layer from the inner peripheral side to the outer peripheral side when viewed from a viewpoint orthogonal to the end surface portion 21a of the stator core 21.

[0078] In addition, if Figure 6 As shown in FIG. 1 , the entire turn portion 33 is bent into a "mountain-shaped" shape with the top portion 33c as the vertex. Furthermore, the top portion 33c and the intermediate inclined portions 33ba, 33br constituting the turn portion 33 are formed into an inclined shape that is bent outward in the radial direction toward the end surface portion 21a starting from the curved portions 37a, 37r so as to be located outside in the radial direction D2 of the stator core 21 relative to the pair of straight portions 34a, 33r.

[0079] That is, the top 33c and the pair of intermediate inclined portions 33ba, 33br constituting the turn portion 33 are bent obliquely with the bent portions 37a, 37r as the starting point so as to expand radially outwardly more toward the top 33c. In addition, the segment coils 31A, 31B are pre-formed into the above-mentioned shape before being inserted into the slots 22.

[0080] Therefore, as described above, the top 33c and the pair of intermediate inclined portions 33ba, 33br constituting the turn portion 33 are inclined one layer from the inner peripheral side to the outer peripheral side in the radial direction D2 of the stator core 21 when viewed from a viewpoint orthogonal to the end surface portion 21a of the stator core 21. In addition to this, with respect to the axis L, the top 33c and the intermediate inclined portions 33ba, 33br are inclined so as to be away from the axis L and closer to the end surface portion 21a in the radial direction outward, starting from the curved portions 37a, 37r.

[0081] Then, segment coils 31 formed in this way are inserted into and arranged in respective slots 22. Figure 7 In order to facilitate understanding of the shape of the segment coil 31 constituting the coil 30 , the second coil group 30B is shown removed.

[0082] like Figure 7 As shown in FIG. 1 , a pair of straight portions 34a and 34r of each segment coil 31A of the first coil group 30A is arranged in a pair of slots 22 spaced apart at a predetermined pitch in the circumferential direction D1 of the stator core 21. Figure 7 In the example shown, a pair of straight portions 34a, 34r of each segment coil 31A is arranged in a pair of slots 22 separated by six pitches. One straight portion 34r of the pair of straight portions 34a, 34r of each segment coil 31A is arranged at the innermost position in the radial direction D2 of the stator core 21 relative to the other straight portion 34a (see Figure 4 ).

[0083] Thus, a pair of straight portions 34a, 34r of each segment coil 31 of the first coil group 30A is arranged in a pair of slots 22 spaced apart at a predetermined pitch in the circumferential direction D1 of the stator core 21. In the present embodiment, 48 segment coils 31A are sequentially arranged in the 48 slots 22 of the stator core 21.

[0084] The ends (connection-side coil ends) of a pair of straight portions 34a and 34r of each segment coil 31A disposed in the slot 22 on the side opposite to the turn portion 33 are sequentially connected by the connection portions 32a and 32r, thereby forming a first coil group 30A with a plurality of segment coils 31A. Of course, the second coil group 30B also has the same structure.

[0085] Figure 8 Enlarged representation of the composition Figure 2The illustrated coils 30 are a part of the first coil group 30A and the second coil group 30B. In addition, in some slots 22, the fourth-layer segment coil 31B located on the outermost peripheral side is omitted.

[0086] like Figure 8 As shown, with respect to the turning portion 33 of the segment coil 31A constituting the first coil group 30A disposed on the inner circumference side of the slot 22, the turning portion 33 of the segment coil 31B constituting the second coil group 30B is disposed outside the first coil group 30A in the radial direction D2 of the stator core 21. Furthermore, each of the segment coils 31A and 31B is inclined so as to expand outward in the radial direction D2 with the bent portions 37a and 37r as starting points.

[0087] Thus, the coil 30 wound on the stator 20 is composed of the first coil group 30A and the second coil group 30B, and is wound around the slots 22 of the stator core 21 in a "wave-wound distributed winding". As described above, it is of course possible to have three or more coil groups.

[0088] Next, based on Fig. 9 The specific shape of the turn portion 33 that is a feature of this embodiment will be described in detail. Fig. 9 In the embodiment, the plane extending in the radial direction in the direction of the axis L is cut Figure 4 Since slots 22 are included in the embodiment, cross sections of a plurality of segment coils 31 are shown. Hereinafter, portions related to the present embodiment will be described.

[0089] like Fig. 9 As shown, in the same slot 22, Figure 5 In the arrangement shown, the segment coils 31A and 31B are arranged such that the straight portion 34r (first layer) of the first segment coil 31A of the first coil group 30A is arranged radially outward from the inner circumference, and the straight portion 34a (second layer) of the second segment coil 31A is arranged outside the straight portion 34r (first layer).

[0090] Furthermore, straight portion 34r (third layer) of third segment coil 31B of second coil group 30B is arranged outside straight portion 34a (second layer) of second segment coil 31A, and straight portion 34a (fourth layer) of fourth segment coil 31B is arranged outside the straight portion 34r (third layer) of second segment coil 31A.

[0091] Therefore, with the paper surface as the boundary, the middle inclined portion 33br connected to the straight portion 34r of the first and third layers extends in a manner protruding toward the front side of the paper surface, and conversely, the middle inclined portion 33ba connected to the straight portion 34a of the second and fourth layers is formed to extend in a manner connected to the straight portion 34a of the groove 22 from the inner side of the paper surface.

[0092] In addition, Fig. 9In the figure, in the segment coil 31A constituting the first coil group 30A, the bent portion of the straight portion 34r arranged at the odd-numbered layers is marked as a bent portion 37rA, and the bent portion of the straight portion 34a arranged at the even-numbered layers is marked as a bent portion 37aA. In the segment coil 31B constituting the second coil group 30B, the bent portion of the straight portion 34r arranged at the odd-numbered layers is marked as a bent portion 37rB, and the bent portion of the straight portion 34a arranged at the even-numbered layers is marked as a bent portion 37aB.

[0093] Furthermore, in the same slot 22, a turning portion 33 of the bent side coil end 35 is formed, which is formed into an inclined shape in which the straight portions 34a, 34r of the stacked segment coils 31 are bent outward in the radial direction D2 of the stator core 21 relative to the direction of the axis L, with the bent portions 37aA, 37rA and the bent portions 37aB, 37rB as starting points.

[0094] That is, the top 33c and the pair of intermediate inclined portions 33ba, 33br constituting the turn portion 33 are inclined in a direction gradually away from the axis L toward the outside starting from the curved portions 37aA, 37rA and 37aB, 37rB. In this case, the top 33c is farthest from the axis L.

[0095] Here, if Fig. 9 As shown, the straight portion 34r of the first segment coil 31A constituting the first layer of the first coil group 30A disposed on the innermost circumference side in the radial direction D2 of the slot 22 is formed in a shape without forming the curved portion 37rA. That is, the straight portion 34r is formed in a shape extending substantially parallel to the axis L and connected to the intermediate inclined portion 33br.

[0096] Furthermore, as necessary, a configuration may be adopted in which bent portion 37rA is formed in straight portion 34r of first segment coil 31A constituting the first layer of first coil group 30A.

[0097] Furthermore, in the same slot 22, the more the straight portions 34a and 34r of the segment coils 31A and 31B are located on the outer peripheral side in the radial direction D2 of the slot 22, the larger the inclination angle θ of the curved portions 37aA, 37rB, and 37aB of the straight portions 34a and 34r of the segment coils 31A and 31B stacked in the radial direction D2 is set. Here, the inclination angle θ refers to the angle formed by the line segment from the curved portions 37aA, 37rB, and 37aB as the starting point to the top 33c of the turn portion 33 and the axis L of the stator core 21.

[0098] like Fig. 9As shown in FIG. 1 , the inclination of bent portion 37rA of straight portion 34r forming the first layer of first segment coil 31A is as described above, and the inclination angle θ is “θ=0°”, that is, parallel to axis L. Furthermore, the inclination of bent portion 37aA of straight portion 34a forming the second layer of second segment coil 31A adjacent to the first layer is “θ=θ1” with respect to the first layer.

[0099] Similarly, the inclination of bent portion 37rA of straight portion 34r of third segment coil 31B forming the third layer adjacent to the second layer is set at an inclination angle θ of "θ=θ2" with respect to the first layer. Also, the inclination of bent portion 37aA of straight portion 34a of the fourth layer of fourth segment coil 31B forming the third layer adjacent to the third layer is set at an inclination angle θ of "θ=θ3" with respect to the first layer.

[0100] Therefore, the inclination angle θ1 of the curved portion 37aA of the second layer, the inclination angle θ2 of the curved portion 37rB of the third layer, and the inclination angle θ3 of the curved portion 37aB of the fourth layer have a relationship of "θ1<θ2<θ3". For example, in the present embodiment, "θ1=5°", "θ2=7.5°", and "θ3=10°" are set. In addition, the inclination angle θ is not limited to this, and an appropriate angle can be selected.

[0101] In addition, the angle difference Δθ between each inclination angle θ1, θ2, and θ3 is set to an equal angle of "2.5°", but it can also be set to unequal angles. In addition, the angle difference Δθ can be set larger as it is located on the outside, or the angle difference Δθ can be set larger as it is located on the inside.

[0102] Here, the curved portion 37aA of the second-layer straight portion 34a, the curved portion 37rB of the third-layer straight portion 34r, and the curved portion 37aB of the fourth-layer straight portion 34a are formed so as to be closer to the end surface portion 21a of the stator core 21 as viewed in the direction of the axis L, as they are located on the outer peripheral side of the radial direction D2 of the slot 22. Similarly, the top portion 33c is also formed so as to be closer to the end surface portion 21a of the stator core 21 as viewed in the direction of the axis L, as the turn portion 33 is located on the outer peripheral side of the radial direction D2 of the slot 22.

[0103] This has the effect of shortening the length of the turning portion of segment coil 31B located on the outer peripheral side. Fig.12 , Fig.13 is described in.

[0104] Fig.10 Observe from different perspectives Figure 8 FIG. 1 shows a first coil group 30A and a second coil group 30B. Fig.10As shown in the figure, two segment coils 31A and 31B adjacent to each other in the circumferential direction D1 of the stator core 21 are shown facing each other with a gap G in the radial direction D2 of the stator core 21 between two tops 33c adjacent to each other in the circumferential direction D1. Through the gap G, the cooling medium can smoothly flow into the turn portion 33, and the coil 30 can be effectively cooled.

[0105] As described above, the rotating electrical machine 100 of the present embodiment includes the stator core 21 , the plurality of slots 22 provided in the stator core 21 , and the segment coils 31A and 31B arranged in the slots 22 .

[0106] In addition, if Figure 3 As shown, segment coils 31A and 31B include a pair of straight portions 34a and 34r disposed in different slots 22 and a turn portion 33 connecting the pair of straight portions 34a and 34r. Turn portion 33 includes a pair of intermediate inclined portions 33ba and 33br connected to straight portions 34a and 34r.

[0107] In addition, curved portions 37a and 37r are provided between the straight portions 34a and 34r and the turn portion 33, and the inclination angle θ of the curved portions 37a and 37r is set to be larger as they are located on the outer peripheral side of the radial direction D2 of the cut groove 22. As described above, the inclination angle θ1 of the curved portion 37aA formed in the second-layer straight portion 34a, the inclination angle θ2 of the curved portion 37rB formed in the third-layer straight portion 34r, and the inclination angle θ3 of the curved portion 37aB formed in the fourth-layer straight portion 34a have a relationship of "θ1<θ2<θ3".

[0108] In this way, bent portions 37a and 37r are bent so that turn portion 33 is inclined in a direction away from axis L as segment coils 31A and 31B are located on the outer peripheral side in radial direction D2 of slot 22. That is, as segment coil 31 is located on the outer peripheral side in radial direction D2 of slot 22, top portion 33c and intermediate inclined portions 33ba and 33br are bent so as to come closer to end surface portion 21a of stator core 21 as viewed in the direction of axis L.

[0109] Thus, in the two segment coils 31A and 31B constituting the first coil group 30A and the second coil group 30B, the space between the top portion 33C and the intermediate inclined portions 33ba and 33br forming each turn portion 33 can be expanded outward in the radial direction D2.

[0110] Therefore, sufficient gaps are formed between the turns 33 adjacent to each other in the circumferential direction D1 of the stator core 21 to avoid mechanical interference, and the coolant can easily enter the gaps, or the substantial contact area between the coil and the coolant is increased, thereby improving the cooling performance.

[0111] Furthermore, two top portions 33c adjacent to each other in the circumferential direction D1 face each other in the radial direction D2 with a gap G. This makes it easier for the coolant to enter the gap G, or the contact area between the coil 30 and the coolant increases, thereby improving the cooling effect.

[0112] In addition, if Fig.10 As shown, the segment coils 31A and 31B adjacent to each other in the circumferential direction D1 of the stator core 21 face each other with a gap G in the radial direction D2 of the stator core 21 between two top portions 33 c adjacent to each other in the circumferential direction D1 .

[0113] Thus, as described above, mechanical interference between the segment coils 31A and 31B adjacent to each other in the circumferential direction D1 of the stator core 21 can be avoided more effectively and reliably.

[0114] As described above, according to the rotary electric machine 100 of the present embodiment, the interference of the turn portions 33 of the bent-side coil ends 35A and 35B can be avoided without increasing the length of the coil end portions 35, thereby improving the cooling performance.

[0115] (Example 2)

[0116] Next, the second embodiment of the present invention is described. In the first embodiment, the inclination angle θ1 of the curved portion 37aA formed in the second layer of the straight portion 34a, the inclination angle θ2 of the curved portion 37rB formed in the third layer of the straight portion 34r, and the inclination angle θ3 of the curved portion 37aB formed in the fourth layer of the straight portion 34a have a relationship of "θ1<θ2<θ3".

[0117] In contrast, in the second embodiment, it is characterized in that the inclination angle θ1 of the curved portion 37aA formed in the straight portion 34a of the second layer, the inclination angle θ2 of the curved portion 37rB formed in the straight portion 34r of the third layer, and the inclination angle θ3 of the curved portion 37aB formed in the straight portion 34a of the fourth layer have a relationship of "θ1=θ2=θ3".

[0118] like Fig.11 As shown in FIG. 1 , the inclination of bent portion 37rA of straight portion 34r forming the first layer of first segment coil 31A is as described above, and the inclination angle θ is “θ=0°”, that is, parallel to axis L. Furthermore, the inclination of bent portion 37aA of straight portion 34a forming the second layer of second segment coil 31A adjacent to the first layer is “θ=θ1” with respect to the first layer.

[0119] Similarly, the inclination of bent portion 37rA of straight portion 34r of third segment coil 31B forming the third layer adjacent to the second layer is set at an inclination angle θ of "θ=θ2" with respect to the first layer. Also, the inclination of bent portion 37aA of straight portion 34a of the fourth layer of fourth segment coil 31B forming the third layer adjacent to the third layer is set at an inclination angle θ of "θ=θ3" with respect to the first layer.

[0120] The inclination angle θ1 of the second curved portion 37aA, the inclination angle θ2 of the third curved portion 37rB, and the inclination angle θ3 of the fourth curved portion 37aB have a relationship of "θ1 = θ2 = θ3". For example, in this embodiment, "θ1 = θ2 = θ3 = 10°" is set.

[0121] As described above, even when inclination angle θ is set to be the same, since turn portion 33 is configured to be inclined outward in the radial direction, a large space exists for each of segment coils 31A and 31B.

[0122] Thus, sufficient gaps are formed between the turns 33 adjacent to each other in the circumferential direction D1 of the stator core 21 to avoid mechanical interference, and the coolant can easily enter the gaps, or the substantial contact area between the coil and the coolant is increased, thereby improving the cooling performance.

[0123] Furthermore, two top portions 33c adjacent to each other in the circumferential direction D1 face each other in the radial direction D2 with a gap G. This makes it easier for the coolant to enter the gap G, or the contact area between the coil 30 and the coolant increases, thereby improving the cooling effect.

[0124] In addition, similarly to the first embodiment, two top portions 33c adjacent to each other in the circumferential direction D1 face each other with a gap G in the radial direction D2 of the stator core 21. Thus, as described above, mechanical interference between the segment coils 31A and 31B adjacent to each other in the circumferential direction D1 of the stator core 21 can be more effectively and reliably avoided.

[0125] Next, the wire lengths of turn portions 33 of segment coil 31A on the inner circumference side and segment coil 31B on the outer circumference side will be described.

[0126] like Fig.12 As shown in FIG. 1 , with respect to the wire length of the turn portion 33 of the segment coil 31A located on the inner circumference side and the wire length of the turn portion 33 of the segment coil 31B located on the outer circumference side, the wire length of the segment coil 31B located on the outer circumference side with a longer radius is longer. Therefore, the coil resistance increases accordingly, and the heat generation also increases. If there is only one segment coil 31B, there is no influence to the extent of the left side, but if a plurality of segment coils 31B, for example, n segment coils 31B, are connected in series for use, the coil resistance increases by n times, which may not be negligible.

[0127] On the other hand, in the first embodiment and the second embodiment, in the segment coil 31A constituting the first coil group 30A, the bent portion of the straight portion 34r arranged at the odd-numbered layers is set as the bent portion 37rA, and the bent portion of the straight portion 34a arranged at the even-numbered layers is set as the bent portion 37aA, and in the segment coil 31B constituting the second coil group 30B, the bent portion of the straight portion 34r arranged at the odd-numbered layers is set as the bent portion 37rB, and the bent portion of the straight portion 34a arranged at the even-numbered layers is set as the bent portion 37aB, the following relationship is established.

[0128] That is, Fig.13 As shown, the formation positions of the curved portion 37aA of the second layer straight portion 34a, the curved portion 37rB of the third layer straight portion 34r, and the curved portion 37aB of the fourth layer straight portion 34a are determined so that the closer they are to the end face portion 21a of the stator core 21 as viewed in the direction of the axis L, the further they are located on the outer peripheral side of the radial direction D2 of the slot 22.

[0129] Therefore, the relationship between the length "S1" from the bending point of the curved portion 37aA of the second layer straight portion 34a to the end face portion 21a of the stator coil 21, the length "S2" from the bending point of the curved portion 37rB of the third layer straight portion 34r to the end face portion 21a of the stator coil 21, and the length "S3" from the bending point of the curved portion 37aB of the fourth layer straight portion 34a to the end face portion 21a of the stator coil 21 has the relationship of "S3<S2<S1".

[0130] Therefore, the length from bends 37aB and 37rB of segment coil 31B located on the outer circumference to end surface portion 21a of stator coil 21 is shortened. This provides the following effects: the line length of bend 33 of segment coil 31B located on the outer circumference can be shortened, the coil resistance can be suppressed from increasing, and the heat generation can be suppressed. In the present embodiment, the positions of bends 37rA, 37aA, 37rB, and 37aB are determined so that the lengths of bends 33 of segment coil 31A on the inner circumference and segment coil 31B on the outer circumference are set to be substantially the same.

[0131] As described above, according to the present invention, the segment coil includes: a first straight portion inserted into a specific slot; a second straight portion inserted into another specific slot different from the specific slot; and a turn portion extending from one end surface portion of the stator core toward the outside in the axial direction of the stator core and having a top portion bent so as to connect the first straight portion and the second straight portion, wherein the straight portions of the plurality of segment coils are inserted and arranged in each slot so as to be stacked from the inner peripheral side to the outer peripheral side in the radial direction, and a bent portion is formed between the straight portions of the radially stacked segment coils and the turn portion, and the bent portion inclines the turn portion in a direction in which the top portion of the turn portion approaches the end surface of the stator core.

[0132] As a result, the turn portion extending from the end surface portion of the stator core is bent radially outward, thereby forming a sufficient gap between the turn portions of each segment coil, allowing the cooling medium to easily enter the gap, or the actual contact area between the coil and the cooling medium is increased, thereby achieving improved cooling performance.

[0133] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments are embodiments described in detail in order to easily explain the present invention, and are not limited to all structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and in addition, the structure of other embodiments can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0134] Description of Reference Numerals

[0135] 21…stator core, 22…slot, 30…coil, 30A…first coil group, 30B…second coil group, 31A…segment coil, 31B…segment coil, 33…turning portion, 33aa…connecting portion, 33ar…connecting portion, 33ba…intermediate inclined portion, 33br…intermediate inclined portion, 33c…top portion, 34a…straight portion, 34r…straight portion, 37aA…bend portion, 37rA…bend portion, 37aB…bend portion, 37rB…bend portion, 100…rotating electric machine, D1…circumferential direction, D2…radial direction, G…gap, L…axis line.

Claims

1. A rotating electric machine having a stator, wherein the stator comprises a stator core having a plurality of slots and a plurality of segment coils respectively received in the slots of the stator core, wherein: The segmented coil comprises: Inserted into the first straight line portion of the specific groove; A second straight line portion inserted into another specific groove different from the specific groove; and a turn portion extending from one end surface portion of the stator core to the outside in the axial direction of the stator core and having a top portion bent so as to connect the first straight portion and the second straight portion, In each of the slots, the linear portions of the plurality of segment coils are inserted and arranged so as to be stacked from the inner circumference to the outer circumference in the radial direction, and A curved portion is formed between the straight portion and the curved portion of each of the segment coils stacked in the radial direction, and the curved portion is inclined at an angle such that the top of the curved portion approaches the end surface of the stator core and forms a gap for the cooling medium to pass through in order to avoid mechanical interference between adjacent curved portions. The position of each of the bent portions, which is a starting point of the inclination of the turn portion, is determined so that the segment coil located on the outer peripheral side of the slot is closer to the end surface portion of the stator core.

2. The rotating electrical machine according to claim 1, characterized in that: The turn portion of each of the segment coils is inclined more greatly as the segment coil is located on the outer peripheral side of the slot.

3. The rotating electrical machine according to claim 1, characterized in that: The turn portion of each of the segment coils is inclined at the same angle regardless of the position of the segment coil in the slot.

4. The rotating electrical machine according to claim 2 or 3, characterized in that: The plurality of segment coils at least form a first coil group disposed on the inner circumference side of the stator core and a second coil group disposed on the outer circumference side of the first coil group. The line length of the turn portion of the segment coil of the first coil group and the line length of the turn portion of the segment coil of the second coil group are determined to be substantially the same.

5. The rotating electrical machine according to claim 2 or 3, characterized in that: The plurality of segment coils at least form a first coil group disposed on the inner circumference side of the stator core and a second coil group disposed on the outer circumference side of the first coil group. In the turning portion of the segment coil, the top portion is formed between the intermediate inclined portions connecting the first straight portion and the second straight portion. The two mutually adjacent turn portions of the segment coils forming the first coil group and the second coil group face each other with a gap therebetween in the radial direction of the stator core.

6. A rotating electric machine having a stator, wherein the stator comprises a stator core having a plurality of slots and a plurality of segment coils respectively received in the slots of the stator core, wherein: The segmented coil comprises: A first straight portion inserted into the specific first groove; a second straight portion inserted into a specific second groove different from the specific first groove; and a turning portion having a top portion bent so as to connect the first straight portion and the second straight portion, The plurality of segment coils at least form a first coil group disposed on the inner circumference side of the stator core and a second coil group disposed on the outer circumference side of the first coil group. In the first slot and the second slot, the first straight portion of the segment coil forming the first coil group is arranged as the first layer on the innermost circumference side of the first slot and the second slot, and the second straight portion of the segment coil forming the first coil group is arranged as the second layer on the outer circumference side of the first layer of the first slot and the second slot. In the first slot and the second slot, the first straight portion of the segment coil forming the second coil group is arranged as a third layer on the outer peripheral side of the second layer of the first slot and the second slot, and the second straight portion of the segment coil forming the second coil group is arranged as a fourth layer on the outer peripheral side of the third layer of the first slot and the second slot, A curved portion is formed between the curved portions extending from the straight portion from the second layer to the fourth layer, and the curved portion is bent at an angle starting from the curved portion and extending from the line segment to the top in a radial direction outwardly away from the axis of the stator core so as to avoid mechanical interference between adjacent curved portions and form a gap for the cooling medium to pass through. The position of each of the bent portions, which is a starting point of the inclination of the turn portion, is determined so that the segment coil located on the outer peripheral side of the slot is closer to the end surface portion of the stator core.

7. The rotating electrical machine according to claim 6, characterized in that: When the angle formed by the line segment from the curved portion to the top of the turn portion and the axis of the stator core is defined as the inclination angle θ, The line segment to the top of the second layer is inclined at an inclination angle θ1, the line segment to the top of the third layer is inclined at an inclination angle θ2, the line segment to the top of the fourth layer is inclined at an inclination angle θ3, and The inclination angles θ1, θ2, and θ3 have a relationship of θ1<θ2<θ3.

8. The rotating electrical machine according to claim 6, characterized in that: When the angle formed by the line segment from the curved portion to the top of the turn portion and the axis of the stator core is defined as the inclination angle θ, The line segment to the top of the second layer is inclined at an inclination angle θ1, the line segment to the top of the third layer is inclined at an inclination angle θ2, the line segment to the top of the fourth layer is inclined at an inclination angle θ3, and The inclination angles θ1, θ2, and θ3 have a relationship of θ1=θ2=θ3.

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