Stator and manufacturing method thereof

Abstract

To suppress dispersion in specific frequencies of stators.SOLUTION: A stator mounted on a rotary electric machine comprises: a stator core composed of multiple plate groups built up onto each other with multiple slots formed; and a stator coil composed of multiple segment conductors to be inserted into the slots and to be assembled into the stator core. The plate group includes multiple first groove parts and multiple second groove parts wider than the first groove parts as groove parts comprising the slots. At least one of the multiple slots is configured using the first groove part and the second groove part.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a stator provided in a rotating electric machine and a method for manufacturing a stator provided in a rotating electric machine. [Background technology]

[0002] Rotating electric machines such as electric motors and generators have a stator consisting of a stator core and a stator coil, and a rotor housed inside the stator (see Patent Documents 1 to 4). In addition, a stator coil consisting of multiple segment coils has been proposed as a stator coil wound around a stator core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2020-518218 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-129450 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-77125 [Patent Document 4] Japanese Patent Application Publication No. 2020-114078 Summary of the Invention [Problem to be solved by the invention]

[0004] The segment coils that make up the stator coil are inserted into multiple slots formed in the stator core. The gaps between the slots and the segment coils are filled with varnish, which is then hardened to secure the segment coils to the slots. However, securing the segment coils with varnish causes variations in the stator's natural frequency, i.e., its natural value. It is difficult to fill the entire slot with varnish, and the locations where the segment coils are secured with varnish cannot be uniformly determined, resulting in variations in the natural frequency of each manufactured stator. Therefore, there is a need to suppress variations in the natural frequency of stators.

[0005] An object of the present invention is to suppress variations in the natural frequency of the stator. [Means for solving the problem]

[0006] In one embodiment, the stator is provided in a rotating electric machine, and includes a stator core including a plurality of plates that are rotated and stacked on each other, and a plurality of slots formed therein; Multiple a stator coil that is assembled to the stator core and that is made up of a plurality of segment conductors that are inserted into the slots; do. The aforementioned Multiple Plate Group Each of is the above Multiple The grooves constituting the slot include a plurality of first grooves and a plurality of second grooves that are wider than the first grooves. do. At least one of the plurality of slots arranged in the axial direction of the stator core The first groove portion and the second groove portion are used The first groove portions included in each of the plate groups do not overlap with each other in the axial direction of the stator core.

[0007] A method for manufacturing a stator according to one embodiment is a method for manufacturing a stator provided in a rotating electric machine, and includes a core laminating step of laminating a plurality of core plates to form a stator core made up of a plurality of plate groups that are rotated one on top of the other, and a coil inserting step of inserting a conductor group made up of a plurality of segment conductors into a plurality of slots formed in the stator core. do. The aforementioned Multiple Plate Group Each of is the above Multiple The grooves constituting the slot include a plurality of first grooves and a plurality of second grooves that are wider than the first grooves. do. At least one of the plurality of slots arranged in the axial direction of the stator core The first groove portion and the second groove portion are used The first groove portions included in each of the plate groups do not overlap with each other in the axial direction of the stator core. [Effects of the Invention]

[0008] According to the present invention, the plate group includes a plurality of first grooves and a plurality of second grooves that are wider than the first grooves as grooves that define the slots, and at least one of the plurality of slots is configured using the first grooves and the second grooves, thereby suppressing variations in the natural frequency of the stator. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a vehicle on which a rotating electric machine is mounted. [Figure 2] 1 is a cross-sectional view showing an example of the configuration of a rotating electric machine; [Figure 3] 3 is a cross-sectional view showing the stator core taken along line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view showing the stator along the line AA in FIG. 2. [Figure 5] FIG. 2 is a cross-sectional view showing a stator core equipped with a U-phase winding. [Figure 6] FIG. 2 is an oblique view showing an example of a segment coil. [Figure 7] FIG. 2 is a perspective view showing an example of a stator. [Figure 8]10A and 10B are diagrams illustrating an example of a connection structure of a segment coil. [Figure 9] FIG. 2 is a diagram showing an example of a connection state of a stator coil. [Figure 10] 10A to 10C are diagrams illustrating an example of a method for manufacturing a stator. [Figure 11] 10A and 10B are diagrams illustrating an example of a state in which a plate stacking step is performed. [Figure 12] 1A and 1B are diagrams showing an example of a core block manufactured through a plate stacking process. [Figure 13] 1A and 1B are diagrams showing an example of a core block manufactured through a plate stacking process. [Figure 14] FIG. 10 is a diagram illustrating an example of an execution status of a block transposition process. [Figure 15] 1A and 1B are diagrams showing an example of a stator core manufactured through a block lamination process. [Figure 16] FIG. 10 is a diagram illustrating an example of a state in which a coil insertion process is being performed. [Figure 17] FIG. 3 is a cross-sectional view showing the stator along the line AA in FIG. 2. [Figure 18] FIG. 18 is a cross-sectional view taken along line X1-X1 of FIG. [Figure 19] FIG. 18 is a cross-sectional view taken along line X2-X2 in FIG. [Figure 20] FIG. 18 is a cross-sectional view taken along line X3-X3 in FIG. [Figure 21] 10A and 10B are diagrams showing an example of width dimensions of a segment coil, a first groove portion, and a second groove portion. [Figure 22] FIG. 10 is a diagram showing a core block of a first modified example. [Figure 23] FIG. 10 is a diagram showing a core block of a second modified example. [Figure 24] FIG. 4 is a diagram showing a first groove portion provided in a core block. [Figure 25] FIG. 2 is a diagram showing a first groove portion into which a segment coil is inserted. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. In the following description, identical or substantially identical configurations and elements are designated by the same reference numerals and will not be described repeatedly.

[0011] [Examples of use of rotating electrical machines] FIG. 1 is a diagram showing a vehicle 11 equipped with a rotating electric machine 10. As shown in FIG. 1, the vehicle 11 is provided with an electric axle 14 including the rotating electric machine 10 housed in an axle case 12, a differential mechanism 13, and the like. The rotating electric machine 10 and the differential mechanism 13 are connected via a gear train (not shown), and wheels 16 are connected to the differential mechanism 13 via axles 15. A battery 18 is connected to the rotating electric machine 10, which is a motor generator, via an inverter 17, which is a power conversion device. Note that, although the rotating electric machine 10 provided on the electric axle 14 is shown as an example of a rotating electric machine, the present invention is not limited thereto and may be a rotating electric machine provided in a transmission or the like, or may be a rotating electric machine provided in a device other than a vehicle.

[0012] [Rotating Electrical Machine Structure] Fig. 2 is a cross-sectional view showing an example of the configuration of a rotating electric machine 10. The rotating electric machine 10 shown in Fig. 2 is provided with a stator 20 according to one embodiment. As shown in Fig. 2, the rotating electric machine 10 has a motor case 21 that constitutes part of the axle case 12. The motor case 21 includes a cylindrical case body 22 with a bottom, and an end cover 23 that closes the open end of the case body 22. The stator 20, which is fixed inside the case body 22, has a cylindrical stator core 24 made of a plurality of laminated electromagnetic steel plates, and a three-phase stator coil SC wound around the stator core 24.

[0013] A bus bar unit 25 is connected to the stator coil SC. This bus bar unit 25 has three power bus bars 26-28 connected to three power points Pu, Pv, and Pw of the stator coil SC, a neutral bus bar 29 connecting three neutral points Nu, Nv, and Nw of the stator coil SC to each other, and an insulating member 30 that holds these bus bars 26-29. Furthermore, ends of the power bus bars 26-28 protrude to the outside from the motor case 21, and power cables 31 extending from the inverter 17 are connected to each of the power bus bars 26-28.

[0014] A cylindrical rotor 32 is rotatably housed in the center of the stator core 24. The rotor 32 has a cylindrical rotor core 33 made of a plurality of laminated electromagnetic steel plates, a plurality of permanent magnets 34 provided in the rotor core 33, and a rotor shaft 35 fixed to the center of the rotor core 33. One end of the rotor shaft 35 is supported by a bearing 36 provided in the case body 22, and the other end of the rotor shaft 35 is supported by a bearing 37 provided in the end cover 23.

[0015] [Stator structure] FIG. 3 is a cross-sectional view of the stator core 24 taken along line AA in FIG. 2, and FIG. 4 is a cross-sectional view of the stator 20 taken along line AA in FIG. 2. FIG. 5 is a cross-sectional view of the stator core 24 provided with a U-phase winding (hereinafter referred to as U-phase coil Cu), and FIG. 6 is a perspective view of an example of a segment coil 40. As will be described later, the stator coil SC is composed of a V-phase winding (hereinafter referred to as V-phase coil Cv) and a W-phase winding (hereinafter referred to as W-phase coil Cw) in addition to the U-phase coil Cu. The U-phase coil Cu, V-phase coil Cv, and W-phase coil Cw shown in the figure have the same coil structure and are assembled to the stator core 24 with their phases shifted by 120° from one another.

[0016] As shown in FIG. 3, a plurality of teeth T are formed at predetermined intervals in the circumferential direction on the inner periphery of the stator core 24. That is, a plurality of slots S1 to S48 are formed at predetermined intervals in the circumferential direction on the inner periphery of the stator core 24. As shown in FIG. 4, a segment coil (segment conductor) 40 is housed in each of the slots S1 to S48, and the stator coil SC is formed by connecting the plurality of segment coils 40 to each other. As shown in FIGS. 4 and 5, the segment coils 40 that form the U-phase coil Cu are housed in slots S1, S2, S7, S8, etc., the segment coils 40 that form the V-phase coil Cv are housed in slots S3, S4, S9, S10, etc., and the segment coils 40 that form the W-phase coil Cw are housed in slots S5, S6, S11, S12, etc.

[0017] As shown in FIG. 6, the segment coil 40, which is bent into a substantially U-shape, has a pair of coil sides 41 spaced apart at a predetermined pitch. One coil side 41 is housed in one of the slots (e.g., slot S7), and the other coil side 41 is housed in another slot (e.g., slot S13) spaced apart at a predetermined pitch. The segment coil 40 also has end portions 42 connecting the pair of coil sides 41 to each other and joint ends 43 extending from each of the pair of coil sides 41. The segment coil 40 is made of rectangular wire made of a conductive material such as copper, and the segment coil 40, except for the tip of the joint end 43, is provided with an insulating coating such as enamel or resin coating. The shape of the end portions 42 that make up the segment coil 40 is not limited to the shape shown in the figure, and they can be bent into various shapes depending on the assembly position relative to the stator core 24.

[0018] Here, Fig. 7 is a perspective view showing an example of the stator 20, and Fig. 8 is a diagram showing an example of the connection structure of the segment coils 40. As shown in Figs. 4 and 7, a plurality of segment coils 40 are assembled in each of the slots S1 to S48 of the stator core 24. Also, as shown in Figs. 7 and 8, the joint end 43 of the segment coil 40 is arranged to protrude from one end face 45 of the stator core 24 toward the power line side, and the end portion 42 of the segment coil 40 is arranged to protrude from the other end face 46 of the stator core 24 toward the reaction power line side.

[0019] As shown in Figure 8, the joint end 43 protruding from one end surface 45 of the stator core 24 is bent so as to contact the joint end 43 of another segment coil 40, forming a conductor joint 47. Then, by welding each conductor joint 47 by TIG welding or the like, the multiple segment coils 40 are connected to one another via the conductor joint 47. That is, the U-phase coil Cu is formed by multiple segment coils 40, the V-phase coil Cv is formed by multiple segment coils 40, and the W-phase coil Cw is formed by multiple segment coils 40. The welded conductor joint 47 is then subjected to an insulating process in which a resin coating or the like is formed to cover the conductor.

[0020] FIG. 9 is a diagram showing an example of the wiring state of the stator coil SC. As shown in FIG. 9, the stator coil SC is composed of a U-phase coil Cu, a V-phase coil Cv, and a W-phase coil Cw. The U-phase coil Cu is composed of multiple segment coils 40 connected in series. One end of the U-phase coil Cu is a power point Pu, and the other end of the U-phase coil Cu is a neutral point Nu. The V-phase coil Cv is composed of multiple segment coils 40 connected in series. One end of the V-phase coil Cv is a power point Pv, and the other end of the V-phase coil Cv is a neutral point Nv. The W-phase coil Cw is composed of multiple segment coils 40 connected in series. One end of the W-phase coil Cw is a power point Pw, and the other end of the W-phase coil Cw is a neutral point Nw. The neutral point Nu of the U-phase coil Cu, the neutral point Nv of the V-phase coil Cv, and the neutral point Nw of the W-phase coil Cw are connected to one another, and the phase coils Cu, Cv, and Cw form a stator coil SC.

[0021] [Stator manufacturing method] Next, a method for manufacturing the stator 20 according to one embodiment will be described. Fig. 10 is a diagram showing an example of the method for manufacturing the stator 20. Fig. 11 is a diagram showing an example of the state of execution of the plate stacking step S100, and Figs. 12 and 13 are diagrams showing an example of a core block 51 manufactured through the plate stacking step S100. Fig. 14 is a diagram showing an example of the state of execution of the block rolling step S110, and Fig. 15 is a diagram showing an example of a stator core 24 manufactured through the block rolling step S110.

[0022] <Plate stacking process, block rolling process> 10, the manufacturing process for stator 20 includes a plate laminating process S100 in which core plates 50 are laminated to manufacture core block 51, and a block rolling process S110 in which core blocks 51 are rolled to manufacture stator core 24. The two processes, plate laminating process S100 and block rolling process S110, constitute a core laminating process in which a plurality of core plates 50 are laminated to form stator core 24.

[0023] 11, in the plate stacking process S100, an annular core plate 50 is punched out of rolled electromagnetic steel sheet material by a press device (not shown), and a plurality of core plates 50 are stacked to manufacture a core block (plate group) 51. Note that, in order to join the stacked core plates 50 to one another, each core plate 50 is subjected to crimping, welding, adhesive processing, or the like.

[0024] As shown in Figures 12 and 13, a plurality of grooves 61, 62 corresponding to the slots S1 to S48 described above are formed in the inner periphery of the core block 51. The grooves 61, 62 formed in the core block 51 include a plurality of first grooves 61 each having a width dimension set to "W1" and a plurality of second grooves 62 each having a width dimension set to "W2" which is wider than "W1". As shown by the range α, the first grooves 61 are The first angle is A plurality of second groove portions 62 are formed over a predetermined angle (120°), and as shown in the range β, The second angle is A plurality of them are formed over a predetermined angle (240°).

[0025] 13, the first groove 61 has a pair of side surfaces 63 arranged parallel to each other, a bottom surface 64 arranged perpendicular to the pair of side surfaces 63, and an opening 65 that opens radially inward of the core block 51 and has an engaging claw 65a. Similarly, the second groove 62 has a pair of side surfaces 66 arranged parallel to each other, a bottom surface 67 arranged perpendicular to the pair of side surfaces 66, and an opening 68 that opens radially inward of the core block 51 and has an engaging claw 68a.

[0026] In the following description, the three core blocks 51 constituting the stator core 24 will be denoted by reference numerals 51a, 51b, and 51c to distinguish them from one another. The core blocks 51a, 51b, and 51c have the same shape. As shown in FIGS. 14 and 15 , in the block rotating step S110, the three core blocks 51a, 51b, and 51c are stacked in the thickness direction, and the core blocks 51a, 51b, and 51c are joined together to manufacture the stator core 24. As shown in FIG. 14 , in the block rotating step S110, the core blocks 51a, 51b, and 51c are stacked while being rotated by 120°. By rotating (rotationally stacking) the core blocks 51a, 51b, and 51c in this manner, the first groove portions 61 of the core blocks 51a, 51b, and 51c are arranged so as not to overlap each other in the thickness direction, as shown by the range α in FIG. 14 .

[0027] That is, the first groove portions 61 of the core block 51a are arranged to overlap the second groove portions 62 of the other core blocks 51b and 51c, the first groove portions 61 of the core block 51b are arranged to overlap the second groove portions 62 of the other core blocks 51a and 51c, and the first groove portions 61 of the core block 51c are arranged to overlap the second groove portions 62 of the other core blocks 51a and 51b. In the block rolling step S110, in order to join the core blocks 51a, 51b, and 51c to one another, each core block 51a, 51b, and 51c is subjected to crimping, welding, adhesive bonding, or the like. The thickness direction shown in FIGS. 14 and 15 is the thickness direction of the core blocks 51a, 51b, and 51c, and is a direction that coincides with or is parallel to the center line C1 of the core blocks 51a, 51b, and 51c.

[0028] In the above description, the core blocks 51a, 51b, and 51c are formed by stacking the core plates 50, and then the core blocks 51a, 51b, and 51c are rotated to form the stator core 24. However, this is not a limitation. For example, the stator core 24 may be formed from the core blocks 51a, 51b, and 51c by continuously stacking all of the core plates 50 constituting the stator core 24 and rotating the orientation of the core plates 50 every time a predetermined number of core plates are stacked. That is, in the above description, the plate stacking step S100 and the block rotating step S110 are set separately. However, this is not a limitation. A single core stacking step may be set in which the stator core 24 is formed by continuously stacking the core plates 50.

[0029] <Coil assembly process, coil insertion process> Fig. 16 is a diagram showing an example of the execution status of the coil insertion process. Fig. 16 also shows the stator core 24 and a portion of a coil group 70, which will be described later. As shown in Fig. 10, the manufacturing process of the stator 20 includes a coil assembly process S120 in which a plurality of segment coils 40 are combined to form the coil group 70, and a coil insertion process S130 in which the coil group 70 is inserted into the slots S1 to S48 of the stator core 24.

[0030] As shown in Fig. 16, in the coil insertion process S130, a coil group (conductor group) 70 consisting of multiple segment coils 40 assembled in the coil assembly process S120 is inserted into the slots S1 to S48 of the stator core 24. The stator core 24 is mounted on a bed 72 of a press machine 71, and the joint ends 43 of the coil group 70 are inserted into the slots S1 to S48 of the stator core 24. Then, a slide 73 of the press machine 71 is lowered to press the coil group 70 in the direction of arrow P, thereby inserting the coil sides 41 of the coil group 70 into the slots S1 to S48 of the stator core 24. As shown in the enlarged portion of Fig. 16, an insulating sheet 74 such as aramid paper, also known as an insulator, is provided between the slots S1 to S48 and the segment coil 40.

[0031] <Coil bending process, coil welding process, varnish impregnation process> As shown in FIG. 10, the manufacturing process for the stator 20 includes a coil insertion process S130, followed by a coil bending process S140, a coil welding process S150, and a varnish impregnation process S160. As shown in FIG. 8, in the coil bending process S140, the joint ends 43 of the segment coils 40 protruding from one end surface 45 of the stator core 24 are bent, and multiple conductor joints 47 are formed by the joint ends 43 of the segment coils 40. In the coil welding process S150, the conductor joints 47 are welded by TIG welding or the like, thereby joining the multiple segment coils 40 that make up the coil group 70 and completing the stator coil SC. In the varnish impregnation process S160, varnish made of resin, organic solvent, or the like is permeated into the gap between the stator core 24 and the stator coil SC and cured, thereby firmly fixing the stator coil SC to the stator core 24.

[0032] [Structure for holding segment coils by stator core] Fig. 17 is a cross-sectional view showing the stator 20 along line AA in Fig. 2. Fig. 18 is a cross-sectional view taken along line X1-X1 in Fig. 17, Fig. 19 is a cross-sectional view taken along line X2-X2 in Fig. 17, and Fig. 20 is a cross-sectional view taken along line X3-X3 in Fig. 17. Fig. 21 is a diagram showing an example of the width dimensions of the segment coil 40, the first groove portion 61, and the second groove portion 62. Fig. 21 also shows the width dimensions of the segment coil 40, the first groove portion 61, and the second groove portion 62 before the coil group 70 is inserted into the stator core 24.

[0033] As shown in Fig. 14 above, the stator core 24 having slots S1 to S48 is manufactured by rotating (rotationally stacking) each core block 51 by 120°, using core blocks 51 having first groove portions 61 and second groove portions 62. Therefore, as shown in Fig. 18, in the X1-X1 cross section, the slots S7 to S13 of the stator core 24 are formed by the first groove portions 61 of the core block 51a and the second groove portions 62 of the core blocks 51b and 51c. Note that although Fig. 18 only shows the slots S7 to S13, the slots S1 to S16 are similarly formed by the first groove portions 61 of the core block 51a and the second groove portions 62 of the core blocks 51b and 51c.

[0034] 19, in the X2-X2 cross section, slots S23 to S29 of the stator core 24 are defined by the first groove portions 61 of the core block 51b and the second groove portions 62 of the core blocks 51a and 51c. Although only slots S23 to S29 are shown in FIG. 19, slots S17 to S32 are similarly defined by the first groove portions 61 of the core block 51b and the second groove portions 62 of the core blocks 51a and 51c. Furthermore, as shown in FIG. 20, in the X3-X3 cross section, slots S39 to S45 of the stator core 24 are defined by the first groove portions 61 of the core block 51c and the second groove portions 62 of the core blocks 51a and 51b. Although only slots S39 to S45 are shown in FIG. 20, slots S33 to S48 are similarly defined by the first groove portions 61 of the core block 51c and the second groove portions 62 of the core blocks 51a and 51b.

[0035] As shown in FIG. 21, the width of the segment coil 40 inserted into the slots S1 to S48, i.e., the width of the coil side 41 and the insulating sheet 74 covering it, is set to "Wc." The width of the first groove 61, which forms part of each slot S1 to S48, is set to "W1," and the width of the second groove 62, which forms part of each slot S1 to S48, is set to "W2." The width Wc of the segment coil 40 is set larger than the width W1 of the first groove 61. In other words, an interference wa is provided between the first groove 61 and the segment coil 40, and the side 63 of the first groove 61 is pressed by the coil side 41 during coil insertion. Meanwhile, the width Wc of the segment coil 40 is set smaller than the width W2 of the second groove 62. In other words, no interference is provided between the second groove 62 and the segment coil 40, and the side 66 of the second groove 62 is not pressed strongly by the coil side 41 during coil insertion.

[0036] As mentioned above, a clamping margin wa is provided between the first groove portion 61 and the segment coil 40, and as shown by the arrows in the enlarged portions of Figures 18 to 20, a compressive stress acts on both the first groove portion 61 and the segment coil 40. In other words, the clamping margin wa allows the first groove portion 61 and the segment coil 40 to be firmly fastened together, thereby suppressing variations in the natural value, or natural frequency, of mass-produced stators 20. Furthermore, because the segment coil 40 can suppress the runout of each tooth T, it is also possible to increase the natural frequency of the stator 20.

[0037] However, configuring the slots S1 to S48 only with the first groove portions 61 significantly increases the insertion resistance of the coil group 70 into the stator core 24, which increases the load on the press machine 71. For this reason, the slots S1 to S48 of the stator core 24 are configured by combining the first groove portions 61 and the second groove portions 62. This makes it possible to prevent an excessive increase in the insertion resistance of the coil group 70 into the stator core 24, reduce the load on the press machine 71, and suppress increases in manufacturing equipment costs.

[0038] Furthermore, because the stator core 24 is formed by rotating the core blocks 51, the slots S1 to S48, each consisting of the first groove portion 61 and the second groove portion 62, can be formed using core plates 50 of the same shape. This makes it possible to avoid an increase in the number of parts, thereby suppressing an increase in the manufacturing cost of the stator 20. Note that the fact that the multiple core plates 50 constituting the stator core 24 have the same shape means that the positions, numbers, and shapes of the first groove portions 61 and second groove portions 62 formed in each core plate 50 are the same.

[0039] [Core block variation 1] In the example shown in FIG. 13, a plurality of first groove portions 61 are formed in the core block 51 within a range of a predetermined angle (120°), and a plurality of second groove portions 62 are formed in the core block 51 within a range of a predetermined angle (240°), but this is not limited to this. Here, FIG. 22 is a diagram showing a core block 80 of Modification 1. As shown in FIG. 22, a plurality of groove portions 61, 62 corresponding to the above-mentioned slots S1 to S48 are formed in the inner peripheral portion of the core block (plate group) 80. The groove portions 61, 62 formed in the core block 80 include a plurality of first groove portions 61 with a width dimension set to "W1" and a plurality of second groove portions 62 with a width dimension set to "W2" wider than "W1". Furthermore, as shown by ranges α1 and α2, the plurality of first groove portions 61 are The first angle is The second grooves 62 are formed in two ranges across a predetermined angle (60°), and as shown by the ranges β1 and β2, The second angle isThe slots S1 to S48 are formed in two ranges that span a predetermined angle (120°). Even when the first groove portions 61 are formed in multiple ranges and the second groove portions 62 are formed in multiple ranges in this way, the slots S1 to S48 can be formed by the first groove portions 61 and the second groove portions 62 by forming the stator core 24 by rotating the core blocks 80 in the same way as the stator core 24 described above.

[0040] [Core block variation 2] In the example shown in Fig. 13, the width dimension W1 of the first groove portion 61 is constant, but this is not limited thereto, and the width dimension of the first groove portion 61 may be varied depending on the location. Here, Fig. 23 is a diagram showing a core block 90 of Modification 2, Fig. 24 is a diagram showing a first groove portion 91 provided in the core block 90, and Fig. 25 is a diagram showing the first groove portion 91 into which the segment coil 40 is inserted. Note that Figs. 24 and 25 show an enlarged range Xa in Fig. 23.

[0041] As shown in FIG. 23, a plurality of grooves 91, 62 corresponding to the slots S1 to S48 described above are formed in the inner periphery of the core block (plate group) 90. As shown in FIGS. 23 and 24, the grooves 91, 62 formed in the core block 90 include a plurality of first grooves 91, some of which have a width dimension set to "W1," and a plurality of second grooves 62, some of which have a width dimension set to "W2" greater than "W1." Also, as shown in FIG. 24, the first grooves 91 include an inner groove 92 that opens radially inward of the core block 51, and an outer groove 93 that is continuous with the inner groove 92 and extends radially outward of the core block 51. Furthermore, the width dimension of the inner groove 92 is set to "W1," and the width dimension of the outer groove 93 is set to "W2" greater than "W1."

[0042] Furthermore, the width dimension W1 of the inner groove portion 92 and the width dimension W2 of the outer groove portion 93 are the same as the width dimensions W1, W2 shown in FIG. 21 above. That is, the width dimension W1 of the inner groove portion 92 is set smaller than the width dimension Wc of the segment coil 40, and the width dimension W2 of the outer groove portion 93 is set larger than the width dimension Wc of the segment coil 40. As a result, an interference similar to the interference wa described above is provided between the inner groove portion 92 of the first groove portion 91 and the segment coil 40. Note that in the illustrated example, the width dimension W2 of the outer groove portion 93 of the first groove portion 91 and the width dimension W2 of the second groove portion 62 are made to match each other, but this is not limited thereto, and the width dimensions of the outer groove portion 93 and the second groove portion 62 may be made different from each other.

[0043] When the segment coil 40 is inserted into the first groove portion 91, as shown by the arrows in Fig. 25, a compressive stress acts on both the inner groove portion 92 and the segment coil 40, and the interference allows the first groove portion 91 and the segment coil 40 to be firmly fastened together. In this way, by restraining the tips of the teeth T with the segment coil 40, the vibration of the teeth T (arrow V) can be actively suppressed, and variation in the natural frequency of mass-produced stators 20 can be reduced.

[0044] Incidentally, in order to effectively suppress vibration of the teeth T, it is desirable to restrain the tip ends of the teeth T rather than the base ends. Therefore, in the example shown in FIGS. 24 and 25 , the first groove portions 91 are formed by inner groove portions 92 and outer groove portions 93, with the inner groove portions 92 being narrower than the outer groove portions 93. By configuring the first groove portions 91 in this manner, it is possible to reduce the number of segment coils 40 fastened within the first groove portions 91 while suppressing vibration of the teeth T of the stator core 24. This makes it possible to prevent an excessive increase in insertion resistance of the coil group 70 into the stator core 24, reduce the load on the press machine 71 described above, and lower manufacturing equipment costs.

[0045] The present invention is not limited to the above-described embodiment and may be modified in various ways without departing from the spirit and scope of the present invention. In the above description, each phase coil Cu, Cv, Cw is formed by connecting multiple segment coils 40 in series. However, this is not limited to this; each phase coil Cu, Cv, Cw may be formed by connecting multiple segment coils 40 in parallel. In the illustrated example, eight segment coils 40 are inserted into one slot, but this is not limited to this. For example, more than eight segment coils 40 may be inserted into one slot, or fewer than eight segment coils 40 may be inserted into one slot. In the above description, a stator core 24 with 48 slots is used. However, this is not limited to this; a stator core with a different number of slots may also be used.

[0046] In the above description, the width dimension Wc of the segment coil 40 is set to be larger than the width dimension W1 of the first groove portion 61, but this is not limited thereto, and the width dimension Wc of the segment coil 40 may be set to be equal to the width dimension W1 of the first groove portion 61. In other words, even if the width dimension Wc of the segment coil 40 is equal to the width dimension W1 of the first groove portion 61, the gap between the segment coil 40 and the first groove portion 61 is eliminated, so that the segment coil 40 can suppress vibration of the teeth T and reduce variations in the natural frequency of the stator 20. Note that, in a structure in which the segment coil 40 is not covered by the insulating sheet 74, it goes without saying that the width dimension of the coil side 41 of the segment coil 40 may be set to be equal to the width dimension W1 of the first groove portion 61 or may be set to be larger than the width dimension W1 of the first groove portion 61.

[0047] In the example shown in Fig. 14, the stator core 24 is formed using three core blocks 51a, 51b, and 51c. However, this is not a limitation. The stator core 24 may be formed using two core blocks 51, or may be formed using four or more core blocks 51. In the above description, the core blocks 51a, 51b, and 51c are rotated by 120° when the core blocks 51a, 51b, and 51c are rotated. However, this is not a limitation. The core blocks 51a, 51b, and 51c may be rotated by other angles. In the example shown in Fig. 14, the core blocks 51a, 51b, and 51c have the same thickness. However, this is not a limitation. The core blocks 51a, 51b, and 51c may have different thicknesses. That is, the number of core plates 50 constituting each of the core blocks 51a, 51b, 51c may be the same, or the number of core plates 50 constituting each of the core blocks 51a, 51b, 51c may be different.

[0048] In the example shown in FIG. 13 , 16 first grooves 61 and 32 second grooves 62 are formed in the core block 51, but this is not limited thereto. For example, even if the stator core 24 is made up of three core blocks 51 and has 48 slots, 15 or fewer first grooves 61 may be formed in the core block 51, or 17 or more first grooves 61 may be formed in the core block 51. That is, in the above description, all of the slots S1 to S48 are configured using the first grooves 61 and the second grooves 62, but this is not limited thereto. Some of the slots S1 to S48 may be configured using only the first grooves 61, or some of the slots S1 to S48 may be configured using only the second grooves 62. That is, it is sufficient that at least one of the slots S1 to S48 is configured using the first grooves 61 and the second grooves 62. [Explanation of symbols]

[0049] 10 Rotating Electric Machine 20 Stator 24 stator core 40 Segment coil (segment conductor) 50 core plates 51, 51a, 51b, 51c Core block (plate group) 61 First groove 62 Second groove 70 Coil group (conductor group) 80 Core block (plate group) 90 Core block (plate group) 91 First groove 92 Inner groove 93 Outer groove SC stator coil S1~S48 slots wa Interference S100 Plate lamination process (core lamination process) S110 Block rolling process (core lamination process) S130 Coil insertion process

Claims

1. A stator provided in a rotating electric machine, a stator core formed of a plurality of plates that are rotated one over the other and have a plurality of slots; a stator coil including a plurality of segment conductors inserted into the plurality of slots and assembled to the stator core; and Each of the plurality of plate groups includes, as groove portions constituting the plurality of slots, a plurality of first groove portions and a plurality of second groove portions each having a width greater than that of the first groove portions, At least one of the plurality of slots is configured using the first groove portion and the second groove portion that are arranged in the axial direction of the stator core, the first groove portions of the plurality of plate groups do not overlap with each other in the axial direction of the stator core; Stator.

2. 2. The stator according to claim 1, All of the plurality of slots are configured using the first groove portion and the second groove portion that are arranged in the axial direction of the stator core. Stator.

3. 3. The stator according to claim 1, the first groove portion includes an inner groove portion that opens to the radially inner side of the plate group, and an outer groove portion that is continuous with the inner groove portion and extends to the radially outer side of the plate group, The inner groove is narrower than the outer groove. Stator.

4. The stator according to any one of claims 1 to 3, The plurality of core plates constituting the plurality of plate groups have the same shape. Stator.

5. The stator according to any one of claims 1 to 4, an interference is provided between the first groove portion and the segment conductor, There is no interference between the second groove portion and the segment conductor. Stator.

6. The stator according to any one of claims 1 to 5, In each of the plurality of plate groups, The plurality of first groove portions are formed over a first angle in the circumferential direction of the stator core, the plurality of second groove portions are formed over a second angle in the circumferential direction of the stator core, the second angle being greater than the first angle; Stator.

7. A method for manufacturing a stator provided in a rotating electric machine, comprising: a core lamination step of laminating a plurality of core plates to form a stator core made up of a plurality of plate groups that are rotated one on top of the other; a coil insertion step of inserting a conductor group consisting of a plurality of segment conductors into a plurality of slots formed in the stator core; and Each of the plurality of plate groups includes, as groove portions constituting the plurality of slots, a plurality of first groove portions and a plurality of second groove portions each having a width greater than that of the first groove portions, At least one of the plurality of slots is configured using the first groove portion and the second groove portion that are arranged in the axial direction of the stator core, the first groove portions of the plurality of plate groups do not overlap with each other in the axial direction of the stator core; A method for manufacturing a stator.

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