Method for manufacturing a stator, and stator

Abstract

To suppress variations of natural frequency of a stator.SOLUTION: A manufacturing method of a stator includes a coil insertion step of inserting a cylinder conductor group obtained by combining a plurality of segment conductors to a plurality of slots formed in a stator core. As a plurality of segment conductors constructing the conductor group, there is a plurality of inner segment conductors constructing an inner peripheral portion of the conductor group. At least one of the inner segment conductors is a fastening segment conductor comprising: a first pressurization portion inserted into any one of the plurality of slots; a second pressurization portion inserted into the other one of the plurality of slots; and a connection portion connecting the first pressurization portion and the second pressurization portion each other. At least a part of an interval between the first pressurization portion and the second pressurization portion is narrower than that of each of slots into which the first pressurization portion is inserted and the second pressurization portion is inserted, respectively.SELECTED DRAWING: Figure 18

Description

Technical Field

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

Background Art

[0002] A rotating electrical machine such as an electric motor or a generator has a stator composed of a stator core and a stator coil, and a rotor accommodated inside a cylindrical stator. As a stator coil wound around the stator core, a stator coil composed of a plurality of segment coils has been proposed (see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the segment coils constituting the stator coil are accommodated in a plurality of slots formed in the stator core. Further, varnish is filled in the gap between the slot and the segment coil, and the segment coil is fixed to the slot by curing this varnish. However, fixing the segment coil with varnish has been a factor causing variations in the natural value of the stator, that is, the natural frequency. That is, it is difficult to fill varnish over the entire area in the slot, and since the fixing positions of the segment coils by the varnish are not uniformly determined, variations occur in the natural frequency of each manufactured stator. Therefore, it is required to suppress variations in the natural frequency of the stator.

[0005] The objective of this invention is to suppress variations in the natural frequency of the stator. [Means for solving the problem]

[0006] A method for manufacturing a stator according to one embodiment is a method for manufacturing a stator provided in a rotating electric machine, and comprises a coil insertion step of inserting a group of cylindrical conductors, which are made up of multiple segment conductors, into a plurality of slots formed in a stator core. do. The plurality of segment conductors constituting the conductor group include a plurality of inner segment conductors constituting the inner circumference of the conductor group, a plurality of outer segment conductors constituting the outer circumference of the conductor group, and a plurality of intermediate segment conductors other than the inner segment conductors and the outer segment conductors. ru. The inner segment conductor all This is a clamping segment conductor comprising a first pressing portion inserted into one of the plurality of slots, a second pressing portion inserted into any other of the plurality of slots, and a connecting portion that connects the first pressing portion and the second pressing portion to each other. ru. At least a portion of the distance between the first pressing portion and the second pressing portion is narrower than the distance between the slot into which the first pressing portion is inserted and the slot into which the second pressing portion is inserted. i. All of the outer segment conductors are normal segment conductors comprising a first insertion portion inserted into any of the plurality of slots, a second insertion portion inserted into any other of the plurality of slots, and a connecting portion connecting the first insertion portion and the second insertion portion to each other. The distance between the first insertion portion and the second insertion portion is the same as the distance between the slot into which the first insertion portion is inserted and the slot into which the second insertion portion is inserted.

[0007] A stator in one embodiment is a stator provided in a rotating electric machine, comprising a stator core having a plurality of slots formed therein, and a group of cylindrical conductors made up of a plurality of segment conductors, with stator windings attached to the plurality of slots. do. The plurality of segment conductors constituting the conductor group include a plurality of inner segment conductors constituting the inner circumference of the conductor group, a plurality of outer segment conductors constituting the outer circumference of the conductor group, and a plurality of intermediate segment conductors other than the inner segment conductors and the outer segment conductors. ru. The inner segment conductor allThis is a clamping segment conductor comprising a first pressing portion inserted into one of the plurality of slots, a second pressing portion inserted into any other of the plurality of slots, and a connecting portion that connects the first pressing portion and the second pressing portion to each other. ru. The first pressing portion pushes the inner wall of the slot into which the first pressing portion is inserted in one direction in the circumferential direction of the stator core, and the second pressing portion pushes the inner wall of the slot into which the second pressing portion is inserted in the other direction in the circumferential direction of the stator core. All of the outer segment conductors are standard segment conductors comprising a first insertion portion inserted into one of the plurality of slots, a second insertion portion inserted into any other of the plurality of slots, and a connecting portion connecting the first insertion portion and the second insertion portion to each other. The distance between the first insertion portion and the second insertion portion is the same as the distance between the slot into which the first insertion portion is inserted and the slot into which the second insertion portion is inserted. [Effects of the Invention]

[0008] According to the present invention, vibrations of the stator core can be suppressed by the clamping segment conductor, and variations in the natural frequency of the stator can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram shows a vehicle equipped with a rotating electric motor. [Figure 2] This is a cross-sectional view showing an example of the configuration of a rotating electric machine. [Figure 3] This is a cross-sectional view showing the stator core along line AA in Figure 2. [Figure 4] This is a cross-sectional view showing the stator along line AA in Figure 2. [Figure 5] This is a cross-sectional view showing a stator core equipped with a U-phase coil. [Figure 6] This is a perspective view showing an example of a segment coil. [Figure 7] This is a perspective view showing the status. [Figure 8] This figure shows an example of a segment coil connection structure. [Figure 9] This figure shows an example of the stator coil wiring configuration. [Figure 10] This figure shows an example of the coil structure of a U-phase coil. [Figure 11] This diagram shows the placement of the segment coils that make up the U-phase coil relative to the slots. [Figure 12]It is a diagram showing the accommodation position of the segment coil constituting the U-phase coil with respect to the slot. [Figure 13] It is a diagram showing an example of a method for manufacturing a stator. [Figure 14] It is a diagram showing an example of a coil group assembled to a stator core. [Figure 15] It is a diagram showing an example of a normal segment coil and a clamping segment coil. [Figure 16] It is a diagram simply showing the coil insertion process. [Figure 17] It is a diagram showing the insertion state of a normal segment coil. [Figure 18] It is a diagram showing the insertion state of a clamping segment coil. [Figure 19] It is a diagram showing a part of the U-phase coil attached to the stator core. [Figure 20] It is a diagram showing the slot and its vicinity. [Figure 21] It is a graph showing the relationship between the mounting position of the clamping segment coil and the increase rate of the natural vibration frequency of the stator core. [Figure 22] It is a graph showing the relationship between the mounting position of the clamping segment coil and the increase rate of the natural vibration frequency of the stator core. [Figure 23] It is a diagram showing the clamping segment coils of Modifications 1 and 2. [Figure 24] It is a diagram showing another example of the accommodation position of the segment coil with respect to the slot. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In the following description, the same or substantially the same configurations and elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0011] [Examples of Use of Rotating Electrical Machines] Figure 1 shows a vehicle 11 on which a rotating electric machine 10 is mounted. As shown in Figure 1, the vehicle 11 is equipped with an electric axle 14 consisting of a rotating electric machine 10 housed in an axle case 12 and a differential mechanism 13, etc. The rotating electric machine 10 and the differential mechanism 13 are connected via a gear train (not shown), and the wheels 16 are connected to the differential mechanism 13 via an axle 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. Although the rotating electric machine 10 incorporated into the electric axle 14 is shown as an example of a rotating electric machine, it is not limited to this, and it may be a rotating electric machine incorporated into a transmission, or a rotating electric machine incorporated into a device other than a vehicle.

[0012] [Rotating Electrical Machine Structure] Figure 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 Figure 2 is provided with a stator 20, which is one embodiment. As shown in Figure 2, the rotating electric machine 10 has a motor case 21 which constitutes part of the axle case 12. The motor case 21 comprises a bottomed cylindrical case body 22 and an end cover 23 which closes the open end of the case body 22. The stator 20 fixed inside the case body 22 has a cylindrical stator core 24 made of a plurality of silicon steel plates or the like, and a three-phase stator coil SC wound around the stator core 24.

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

[0014] Furthermore, a cylindrical rotor 32 is rotatably housed in the center of the stator core 24. This rotor 32 has a cylindrical rotor core 33 made of multiple silicon steel plates or the like, multiple permanent magnets 34 provided on 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 on the case body 22, and the other end of the rotor shaft 35 is supported by a bearing 37 provided on the end cover 23.

[0015] [Stator structure] Figure 3 is a cross-sectional view showing the stator core 24 along line AA in Figure 2, and Figure 4 is a cross-sectional view showing the stator 20 along line AA in Figure 2. Figure 5 is a cross-sectional view showing the stator core 24 equipped with a U-phase winding (hereinafter referred to as U-phase coil Cu), and Figure 6 is a perspective view showing an example of a segment coil 40. As will be described later, the stator coil SC is composed of a U-phase coil Cu, 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). Furthermore, the U-phase coil Cu, V-phase coil Cv, and W-phase coil Cw shown have the same coil structure and are assembled to the stator core 24 with a phase difference of 120° from each other.

[0016] As shown in Figure 3, multiple teeth T1 to T48 are formed on the inner circumference of the cylindrical stator core 24 at predetermined intervals in the circumferential direction. In other words, multiple slots S1 to S48 are formed on the inner circumference of the cylindrical stator core 24 at predetermined intervals in the circumferential direction. As shown in Figure 4, a segment coil (segment conductor) 40 is housed in each slot S1 to S48, and a stator coil SC is formed by connecting multiple segment coils 40 to each other. As shown in Figures 4 and 5, the segment coils 40 constituting the U-phase coil Cu are housed in slots S1, S2, S7, S8, etc., the segment coils 40 constituting the V-phase coil Cv are housed in slots S3, S4, S9, S10, etc., and the segment coils 40 constituting the W-phase coil Cw are housed in slots S5, S6, S11, S12, etc.

[0017] As shown in Figure 6, the segment coil 40, which is bent into a roughly U-shape, has a coil side 41 that is housed in one of the slots (for example, slot S7) and a coil side 42 that is housed in another slot (for example, slot S13) at a predetermined coil pitch. The segment coil 40 also has an end portion 43 that connects the pair of coil sides 41 and 42 to each other, and joint ends 44 and 45 that extend from each of the pair of coil sides 41 and 42. The segment coil 40 is made of a flat rectangular wire made of a conductive material such as copper, and an insulating coating such as enamel or resin coating is provided on the segment coil 40 except for the tips of the joint ends 44 and 45. Furthermore, the shape of the end portion 43 that constitutes the segment coil 40 is not limited to the shape shown, and can be bent into various shapes depending on the assembly position on the stator core 24.

[0018] Here, Figure 7 is a perspective view showing the stator 20, and Figure 8 is a diagram showing an example of the connection structure of the segment coils 40. As shown in Figures 4 and 7, multiple segment coils 40 are assembled in each slot S1 to S48 of the stator core 24. Also, as shown in Figures 7 and 8, when the segment coils 40 are assembled to the stator core 24, the connecting ends 44 and 45 of the segment coils 40 are positioned to protrude from one end face 50 of the stator core 24 toward the power line side, and the end portion 43 of the segment coils 40 is positioned to protrude from the other end face 51 of the stator core 24 toward the opposite power line side.

[0019] As shown in Figure 8, the joint ends 44 and 45 protruding from one end face 50 of the stator core 24 are bent to contact the joint ends 44 and 45 of other segment coils 40, forming a conductor joint 52. Then, by welding the individual conductor joints 52 by TIG welding or the like, the multiple segment coils 40 are connected to each other via the conductor joints 52. In other words, the multiple segment coils 40 constitute a U-phase coil Cu, the multiple segment coils 40 constitute a V-phase coil Cv, and the multiple segment coils 40 constitute a W-phase coil Cw. The welded conductor joints 52 are then subjected to an insulating treatment, such as forming a resin coating to cover the conductors.

[0020] [Stator coil structure] Figure 9 shows an example of the wiring configuration of the stator coil SC. In the previous explanation, the segment coils were denoted with the symbol "40," but in the following explanation, to distinguish between individual segment coils, the segment coils will be denoted with the symbols "u1~u64, v1~v64, w1~w64."

[0021] As shown in Figure 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 u1 to u64 connected in series with each other. One end of this U-phase coil Cu is the power point Pu, and the other end is the neutral point Nu. The V-phase coil Cv is composed of multiple segment coils v1 to v64 connected in series with each other. One end of this V-phase coil Cv is the power point Pv, and the other end is the neutral point Nv. Furthermore, the W-phase coil Cw is composed of multiple segment coils w1 to w64 connected in series with each other. One end of this W-phase coil Cw is the power point Pw, and the other end is the neutral point Nw. Furthermore, the neutral points Nu of the U-phase coil Cu, Nv of the V-phase coil Cv, and Nw of the W-phase coil Cw are connected to each other, and the stator coil SC is composed of each phase coil Cu, Cv, and Cw.

[0022] [U-phase coil structure] The structure of the U-phase coil Cu will be described in detail. Figure 10 shows an example of the coil structure of the U-phase coil Cu, and the slot numbers indicated in Figure 10 indicate the slots in which the segment coils u1 to u64 are housed. Figures 11 and 12 show the housing positions of the segment coils u1 to u64 that constitute the U-phase coil Cu in relation to slots S1, S2, S7, S8, etc. Figure 11 shows the housing positions of segment coils u1 to u32, and Figure 12 shows the housing positions of segment coils u33 to u64.

[0023] In Figures 11 and 12, the "power line side" refers to the side where the joint ends 44 and 45 of the segment coil 40 are located, as shown in Figures 2 and 7, i.e., the side where the busbar unit 25 is located. In Figures 11 and 12, the "opposite power line side" refers to the side opposite to the power line side, i.e., the side where the end portion 43 of the segment coil 40 is located, as shown in Figures 2 and 7. In Figures 11 and 12, the "inside" refers to the radially inner side of the stator core 24, as shown in Figure 4, and the "outside" refers to the radially outer side of the stator core 24. Furthermore, the hatched areas in Figures 11 and 12 are the welded locations of the segment coils u1 to u64.

[0024] As shown in Figure 10, the U-phase coil Cu has a coil structure that repeats the connection pattern of eight segment coils (e.g., u1~u8, u9~u16, u17~u24, ...). Here, the connection pattern of segment coils u1~u8, indicated by the symbol X1 in Figure 10, will be described.

[0025] As indicated by the symbol X1 in Figure 11, segment coil u1 is housed in the 8th position (outer position) of slot S1, S43, segment coil u2 is housed in the 7th position of slot S1 and the 6th position of slot S43. Segment coil u3 is housed in the 5th position of slot S1 and the 4th position of slot S43, segment coil u4 is housed in the 3rd position of slot S1 and the 2nd position of slot S43, segment coil u5 is housed in the 1st position of slot S1, S43. Furthermore, segment coil u6 is housed in the 2nd position of slot S37 and the 3rd position of slot S43, segment coil u7 is housed in the 4th position of slot S37 and the 5th position of slot S43, and segment coil u8 is housed in the 6th position of slot S37 and the 7th position of slot S43.

[0026] Then, between slots S1 and S43 on the power line side, segment coil u1 from slot S43 and segment coil u2 from slot S1 are welded to each other, and segment coil u2 from slot S43 and segment coil u3 from slot S1 are welded to each other. Also, segment coil u3 from slot S43 and segment coil u4 from slot S1 are welded to each other, and segment coil u4 from slot S43 and segment coil u5 from slot S1 are welded to each other. Furthermore, between slots S37 and S43 on the power line side, segment coil u5 from slot S43 and segment coil u6 from slot S37 are welded to each other, segment coil u6 from slot S43 and segment coil u7 from slot S37 are welded to each other, and segment coil u7 from slot S43 and segment coil u8 from slot S37 are welded to each other.

[0027] By repeating this connection pattern to connect the segment coils u1 to u64, the U-phase coil Cu is formed by the segment coils u1 to u64, as shown in Figures 10 to 12. As shown in Figures 11 and 12, the power point Pu of the U-phase coil Cu extends from the 8th position of slot S1, and the neutral point Nu of the U-phase coil Cu extends from the 7th position of slot S8.

[0028] [Method for manufacturing stators] Next, a method for manufacturing the stator 20, which is one embodiment, will be described. Figure 13 shows an example of a method for manufacturing the stator 20, and Figure 14 shows an example of a coil group 60 assembled to the stator core 24. In the following description, segment coils will be denoted with the symbol "40," but the aforementioned symbols "u1 to u64" will be used to describe the segment coils as needed. Similarly, slots will be denoted with the symbol "SL," but the aforementioned symbols "S1 to S48" will be used to describe the slots as needed.

[0029] <Coil Assembly Process> As shown in Figure 13, the manufacturing process of the stator 20 includes a coil assembly process S100 in which a coil group 60 is formed by combining multiple segment coils 40. As shown in Figure 14, in the coil assembly process S100, a cylindrical coil group (conductor group) 60 is formed by combining multiple segment coils 40. The multiple segment coils 40 that make up this coil group 60 include multiple inner segment coils (inner segment conductors) 40i that make up the inner circumference 60i of the coil group 60, and multiple outer segment coils (outer segment conductors) 40o that make up the outer circumference 60o of the coil group 60. In addition, the multiple segment coils 40 that make up the coil group 60 include intermediate segment coils (intermediate segment conductors) 40m, which are segment coils other than the inner segment coils 40i and outer segment coils 40o. In other words, the multiple segment coils 40 that make up the coil group 60 include multiple intermediate segment coils 40m that make up the intermediate part 60m of the coil group 60 other than the inner circumference 60i and outer circumference 60o.

[0030] For example, in the configurations shown in Figures 11 and 12, segment coils u5, u12, u21, u29, u37, u45, u53, and u61 correspond to the inner segment coils 40i that constitute the inner circumference 60i of the coil group 60. Also, segment coils u1, u9, u17, u25, u33, u41, u49, and u57 correspond to the outer segment coils 40o that constitute the outer circumference 60o of the coil group 60. Furthermore, segment coils u2 to u4, u6 to u8, etc. correspond to the intermediate segment coils 40m other than the segment coils 40i and 40o. In this way, the multiple segment coils 40 (u1 to u64, v1 to v64, w1 to w64) that constitute the coil group 60 are divided into inner segment coils 40i, outer segment coils 40o, and intermediate segment coils 40m. Furthermore, the multiple segment coils 40 constituting the coil group 60 are classified into ordinary segment coils 70 and clamping segment coils 80, as described later, based on their structural and functional aspects.

[0031] <Standard segment coils, clamping segment coils> A standard segment coil (standard segment conductor) 70 and a clamping segment coil (clamping segment conductor) 80 will be described. Figure 15 shows an example of a standard segment coil 70 and a clamping segment coil 80. In Figure 15, a segment coil u25 is shown as a standard segment coil 70, and a segment coil u29 is shown as a clamping segment coil 80.

[0032] As shown in Figure 15, the structure of a typical segment coil 70 will be explained using segment coil u25 as an example. A typical segment coil 70 has a coil side (first insertion part) 71 that is inserted into slot S7 and a coil side (second insertion part) 72 that is inserted into another slot S13. A typical segment coil 70 also has an end part (connecting part) 73 that connects the pair of coil sides 71 and 72 to each other, and joining ends 74 and 75 that extend from each of the pair of coil sides 71 and 72. Furthermore, the distance Cp1 between coil side 71 and coil side 72 is set to be the same as the distance SP between slot S7 into which coil side 71 is inserted and slot S13 into which coil side 72 is inserted. Note that coil sides 71 and 72 extend parallel to each other and also parallel to slot SL. Such a typical segment coil 70 is used as an outer segment coil 40o such as segment coil u25, and as an intermediate segment coil 40m such as segment coils u26 to u28.

[0033] Furthermore, as shown in Figure 15, the structure of the clamping segment coil 80 will be explained using the segment coil u29 as an example. The clamping segment coil 80 has a coil side (first pressing portion) 81 that is inserted into the slot S7 and a coil side (second pressing portion) 82 that is inserted into the other slot S13. The clamping segment coil 80 also has an end portion (connecting portion) 83 that connects the pair of coil sides 81 and 82 to each other, and joining ends 84 and 85 that extend from the pair of coil sides 81 and 82, respectively. In addition, the coil side 81 has a straight portion 81a that is connected to the joining end 84 and an inclined portion that is inclined with respect to the straight portion 81a and connected to the end portion 83. (1st slope part) 81b and, similarly, the coil side 82 has a straight portion 82a connected to the joint end 85 and an inclined portion that is inclined with respect to the straight portion 82a and connected to the end portion 83. (Second slope part) It is equipped with 82b.

[0034] Furthermore, the distance Cp1 between the straight portion 81a of coil side 81 and the straight portion 82a of coil side 82 is set to be the same as the distance SP between the slot S7 into which coil side 81 is inserted and the slot S13 into which coil side 82 is inserted. Also, the distance Cp2 between the inclined portion 81b of coil side 81 and the inclined portion 82b of coil side 82 is set to be narrower than the distance SP between the slot S7 into which coil side 81 is inserted and the slot S13 into which coil side 82 is inserted. In other words, at least a portion of the distance between coil side 81 and coil side 82 is set to be narrower than the distance SP between the slot S7 into which coil side 81 is inserted and the slot S13 into which coil side 82 is inserted. Such a clamping segment coil 80 is used as an inner segment coil 40i of a segment coil u29 or the like.

[0035] As shown in Figure 5, the spacing SP between the slots (e.g., S7, S13) into which each segment coil 40 is inserted varies depending on the radial position of the stator core 24. In other words, the slot pitch, or slot spacing SP, becomes narrower the further radially inward the stator core 24 is, and the slot pitch, or slot spacing SP, becomes wider the further radially outward the stator core 24 is. Thus, since the slot spacing SP differs depending on the part of the stator core 24, the spacings Cp1 and Cp2 are usually set appropriately according to the mounting position relative to the slot SL in the segment coils 70 and clamping segment coils 80.

[0036] <Coil insertion process> As shown in Figure 13, the manufacturing process of the stator 20 includes a coil insertion step S110 in which a coil group 60 is inserted into the slot SL of the stator core 24. Here, Figure 16 is a simplified diagram of the coil insertion step S110. Figure 17 shows the insertion status of the normal segment coil 70, and Figure 18 shows the insertion status of the tightening segment coil 80. In Figure 17, the segment coil u25 is shown as the normal segment coil 70, and in Figure 18, the segment coil u29 is shown as the tightening segment coil 80.

[0037] As shown in Figure 16, in the coil insertion process S110, a coil group 60 consisting of multiple segment coils 40 is inserted into the slot SL of the stator core 24. The stator core 24 is placed on the bed 91 of the press machine 90, and the joint ends 44 and 45 of the coil group 60 are inserted into the slot SL of the stator core 24. Then, by lowering the slide 92 of the press machine 90 and pushing the coil group 60 in the direction of arrow P, the coil sides 41 and 42 of the coil group 60 are inserted into the slot SL of the stator core 24. As shown in the enlarged portion of Figure 16, an insulating sheet 93, such as aramid paper, also called an insulator, is provided between the slot SL and the segment coil 40.

[0038] As shown in Figure 17, in the coil insertion process S110, the segment coil u29, which is normally a segment coil 70, is pushed in the direction of arrow P by the slide 92 of the press machine 90. As mentioned above, the distance Cp1 between the coil side 71 and the coil side 72 is set to be the same as the distance SP between the slots S7 and S13 into which the coil sides 71 and 72 are inserted. Therefore, as shown in the enlarged portion of Figure 17, even when the coil sides 71 and 72 are inserted to a predetermined completion position, the coil sides 71 and 72 do not strongly interfere with the slots S7 and S13.

[0039] As shown in Figure 18, in the coil insertion process S110, the segment coil u29, which is the tightening segment coil 80, is pushed in the direction of arrow P by the slide 92 of the press machine 90. As mentioned above, the distance Cp2 between coil side 81 and coil side 82 is set to be narrower than the distance SP between the slots S7 and S13 into which the coil sides 81 and 82 are inserted. Therefore, as shown in the enlarged portion of Figure 18, once the coil sides 81 and 82 are inserted to a predetermined completion position, the inclined portions 81b and 82b of the coil sides 81 and 82 deform along the inner walls S7a and S13a of the slots S7 and S13, pushing the inner walls S7a and S13a in the directions of arrows α1 and α2. In other words, the coil side (first pressing part) 81 pushes the inner wall S7a of slot S7 in one direction (direction of arrow α1) of the stator core 24, and the coil side (second pressing part) 82 pushes the inner wall S13a of slot S13 in the other direction (direction of arrow α2) of the stator core 24.

[0040] <Coil bending process, coil welding process, varnish impregnation process> As shown in Figure 13, the manufacturing process of the stator 20 includes a coil insertion process S110, followed by a coil bending process S120, a coil welding process S130, and a varnish impregnation process S140. As shown in Figure 8 above, in the coil bending process S120, the joint ends 44 and 45 of the segment coils 40 protruding from one end face 50 of the stator core 24 are bent, and multiple conductor joints 52 are formed by the joint ends 44 and 45 of the segment coils 40. In the coil welding process S130, the multiple segment coils 40 constituting the coil group 60 are joined by welding the conductor joints 52 by TIG welding or the like, completing the stator coil SC. Furthermore, in the varnish impregnation process S140, the stator coil SC is firmly fixed to the stator core 24 by impregnating the gap between the stator core 24 and the stator coil SC with varnish made of resin or organic solvent and hardening it.

[0041] <Pressing condition by tightening segment coil: U-phase coil> As mentioned above, in the coil insertion process S110, the inner walls of each slot S1 to S48 are pushed in the direction of arrow α1 and arrow α2 by the tightening segment coil 80, which is positioned as an inner segment coil 40i in the coil group 60, that is, the tightening segment coil 80 that constitutes the inner circumference 60i of the coil group 60. In other words, each tooth T1 to T48 is pushed in the direction of arrow α1 and arrow α2 by the tightening segment coil 80 that constitutes the inner circumference 60i of the coil group 60. In this way, by pushing each tooth T1 to T48 in the circumferential direction with the tightening segment coil 80, it is possible to suppress variations in the eigenvalues, i.e., natural frequencies, of the mass-produced stator core 24, as will be described later.

[0042] Here, Figure 19 shows a part of the U-phase coil Cu attached to the stator core 24, and Figure 20 shows slots S7, S8 and their vicinity. As shown in Figure 19, the teeth T7 of the stator core 24 are pushed in the direction of arrow α1 by the clamping segment coil 80 (hereinafter referred to as the clamping segment coil u29), which is a segment coil u29. Here, as shown in Figure 20, since the teeth T7 are pushed in the direction of arrow α1 by the clamping segment coil u29, the vicinity of the tip of the teeth T7 is restrained by the clamping segment coil u29. As a result, the vibration of the teeth T7 (arrow β) can be suppressed by the clamping segment coil u29, and variations in the natural frequency of mass-produced stator cores 24 can be suppressed. Furthermore, because the vibration of the teeth T7 is suppressed by the clamping segment coil u29, the natural frequency of the stator core 24 can be increased. This allows the natural frequency of the stator core 24 to be raised and separated from the natural frequency of the motor case 21 etc. that houses the rotating electric machine 10, thereby suppressing resonance in the electric axle 14 etc. into which the rotating electric machine 10 is incorporated.

[0043] In the example shown in Figure 20, the vibration of tooth T7 is suppressed by the clamping segment coil u29, but the vibration of the other teeth T1-T6 and T8-T48 is also suppressed by the other inner segment coils 40i, which are also clamping segment coils 80. In other words, as shown in Figure 19, the clamping segment coil u29, which is part of the clamping segment coil 80, pushes teeth T7 and T12 in the directions of arrows α1 and α2. Also, the inner segment coils u61, which is part of the clamping segment coil 80, push teeth T8 and T13 in the directions of arrows α1 and α2. Furthermore, the inner segment coils u5, u21, u37, and u53, which are part of the clamping segment coil 80, push teeth T1, T19, T20, and T48 in the directions of arrows α1 and α2.

[0044] Furthermore, since the inner segment coils 40i constituting the U-phase coil, as well as the inner segment coils 40i constituting the V-phase and W-phase coils, are also composed of the aforementioned tightening segment coils 80, each tooth T1 to T48 is pushed in the direction of arrows α1 and α2. In this way, the tightening segment coils 80 constituting the inner circumference 60i of the coil group 60 can suppress vibrations of each tooth T1 to T48, thereby suppressing variations in the natural frequencies of mass-produced stator cores 24.

[0045] Incidentally, as shown in Figure 18, when inserting the clamping segment coil 80 into the stator core 24, the coil sides 81 and 82 of the clamping segment coil 80 deform. Therefore, incorporating many clamping segment coils 80 into the coil group 60 would increase the load on the press machine 90. For this reason, ordinary segment coils 70 with low insertion resistance are used for the intermediate segment coil 40m that constitutes the middle part 60m of the coil group 60, and for the outer segment coil 40o that constitutes the outer periphery 60o of the coil group 60. This reduces the insertion resistance of the coil group 60 into the stator core 24, thereby reducing the load on the press machine 90 and lowering manufacturing equipment costs. Furthermore, as shown in Figure 15, ordinary segment coils 70 have fewer bends than clamping segment coils 80, making it easier to lower the manufacturing cost of ordinary segment coils 70 than that of clamping segment coils 80. From this point of view as well, reducing the number of clamping segment coils 80 that constitute the coil group 60 can lower the manufacturing cost of the stator coil SC and, consequently, the stator 20.

[0046] <Increase rate of natural frequency of stator core> Figures 21 and 22 are graphs showing the relationship between the mounting position of the clamping segment coil 80 and the rate of increase in the natural frequency of the stator core 24. In Figures 21 and 22, the natural frequency of the stator core 24 using only the normal segment coil 70 as the stator coil SC is used as a reference, and the rate of increase in the natural frequency from this reference value is shown for each mounting position of the clamping segment coil 80. Note that the graphs in Figures 21 and 22 are the results of vibration testing of the stator core 24 in a predetermined vibration mode, with the inner wall portion of each slot SL corresponding to the mounting position of the clamping segment coil 80 restrained.

[0047] In Figure 21, "Turn 1" means that the tightening segment coil 80 is installed in the first position (inner position) of each slot SL, and "Turn 2" means that the tightening segment coil 80 is installed in the second position of each slot SL. Similarly, in Figure 21, "Turn 3," "Turn 5," and "Turn 8" mean that the tightening segment coil 80 is installed in the third, fifth, and eighth positions of each slot SL, respectively. Also, in Figure 22, "Turn 1" means that the tightening segment coil 80 is installed in the first position (inner position) of each slot SL. Furthermore, in Figure 22, "Turns 1-2" means that the tightening segment coil 80 is installed in the first and second positions of each slot SL. Similarly, in Figure 22, "Turns 1-3" means that the tightening segment coil 80 is installed in the first, second, and third positions of each slot SL.

[0048] As shown in Figure 21, the closer the clamping segment coil 80 is attached to the first turn, that is, the closer it is attached to the inner circumference of the stator core 24, the higher the natural frequency increase rate of the stator core 24 can be. In other words, in order to effectively suppress the vibration of each tooth T1 to T48, it is desirable to restrain the tip of each tooth T1 to T48 rather than the base. Also, as shown in Figure 22, the natural frequency increase rate of the stator core 24 can be increased by attaching the clamping segment coil 80 to the "1st-2nd turn" or "1st-3rd turn" rather than attaching it only to the first turn. However, as shown in Figure 22, even if the clamping segment coil 80 is added to the second turn or later, it is difficult to dramatically increase the natural frequency increase rate.

[0049] Therefore, in one embodiment of the stator 20, the clamping segment coil 80 is used only for the inner segment coil 40i that constitute the inner circumference 60i of the coil group 60, while the intermediate segment coil 40m and outer segment coil 40o use normal segment coils 70. This increases the natural frequency of the stator 20 by using the clamping segment coil 80 placed in the inner circumference 60i of the coil group 60, and reduces the manufacturing cost of the stator 20 by reducing the number of clamping segment coils 80.

[0050] In the above explanation, all of the inner segment coils 40 are fitted with clamping segment coils 80, and all of the intermediate segment coils 40 and outer segment coils 40 are fitted with normal segment coils 70, but this is not limited to this. That is, it is sufficient that at least one of the inner segment coils 40i is fitted with a clamping segment coil 80. For example, some of the inner segment coils 40i may be fitted with normal segment coils 70, some of the intermediate segment coils 40m may be fitted with clamping segment coils 80, and some of the outer segment coils 40o may be fitted with clamping segment coils 80. Alternatively, all of the inner segment coils 40i, intermediate segment coils 40m, and outer segment coils 40o may be fitted with clamping segment coils 80.

[0051] [Modified examples of clamping segment coils] In the example shown in Figure 15, the spacing Cp2 between the coil sides 81 and 82 is narrowed by forming inclined portions 81b and 82b on the clamping segment coil 80, but this is not the only method. Here, Figure 23 shows the clamping segment coils 100 and 110 of modified examples 1 and 2.

[0052] As shown in Figure 23 as Modification 1, the segment coil u29 will be used as an example to explain the clamping segment coil 100. The segment coil u29, or clamping segment coil 100, has a coil side (first pressing portion) 101 that is inserted into the slot S7 and a coil side (second pressing portion) 102 that is inserted into the other slot S13. The clamping segment coil 100 also has an end portion (connecting portion) 103 that connects the pair of coil sides 101 and 102 to each other, and joining ends 104 and 105 that extend from the pair of coil sides 101 and 102, respectively. Furthermore, the coil side 101 has a first side portion 101a that is connected to the joining end portion 104 and a second side portion 101b that is connected to the end portion 103. Similarly, the coil side 102 includes a first side portion 102a connected to the joint end portion 105 and a second side portion 102b connected to the end portion 103.

[0053] Furthermore, the distance Cp1 between the first side portion 101a of coil side 101 and the first side portion 102a of coil side 102 is set to be the same as the distance SP between the slot S7 into which coil side 101 is inserted and the slot S13 into which coil side 102 is inserted. Also, the distance Cp2 between the second side portion 101b of coil side 101 and the second side portion 102b of coil side 102 is set to be narrower than the distance SP between the slot S7 into which coil side 101 is inserted and the slot S13 into which coil side 102 is inserted. In other words, at least a portion of the distance between coil side 101 and coil side 102 is set to be narrower than the distance SP between the slot S7 into which coil side 101 is inserted and the slot S13 into which coil side 102 is inserted.

[0054] Even when using such a clamping segment coil 100, it can function in the same way as the clamping segment coil 100 shown in Figure 15. That is, when the coil sides 101 and 102 are inserted into the slots, the second side portions 101b and 102b of the coil sides 101 and 102 deform along the inner walls S7a and S13a of the slots S7 and S13, pushing the inner walls S7a and S13a in the circumferential direction of the stator core 24. This suppresses vibrations of the teeth T1 to T48 and increases the natural frequency of the stator 20.

[0055] As shown in Figure 23 as Modification 2, the segment coil u29 will be used as an example to explain the tightening segment coil 110. The segment coil u29, or tightening segment coil 110, has a coil side (first pressing portion) 111 that is inserted into the slot S7 and a coil side (second pressing portion) 112 that is inserted into the slot S13. The tightening segment coil 110 also has an end portion (connecting portion) 113 that connects the pair of coil sides 111 and 112 to each other, and joining ends 114 and 115 that extend from the pair of coil sides 111 and 112, respectively.

[0056] Furthermore, the distance Cp2 between coil side 111 and coil side 112 is set to be narrower than the distance SP between slot S7 into which coil side 111 is inserted and slot S13 into which coil side 112 is inserted. In other words, the entire distance between coil side 111 and coil side 112 is set to be narrower than the distance SP between slot S7 into which coil side 111 is inserted and slot S13 into which coil side 112 is inserted.

[0057] Even when using such a clamping segment coil 110, it can function in the same way as the clamping segment coil 110 shown in Figure 15. That is, when the coil sides 111 and 112 are inserted into the slots, the coil sides 111 and 112 of the clamping segment coil 110 deform along the inner walls S7a and S13a of the slots S7 and S13, pushing the inner walls S7a and S13a in the circumferential direction of the stator core 24. This suppresses vibrations of teeth T1 to T48 and increases the natural frequency of the stator 20.

[0058] [Variations of inner and outer segment coils] Figure 24 shows another example of the housing position of the segment coil 40 for slots S1, S7, etc. Note that Figure 24 also shows a portion of the U-phase coil Cu on the counter-power line side.

[0059] In the examples shown in Figures 11 and 12 above, segment coils u5, u12, u21, u29, u37, u45, u53, and u61 are given as inner segment coils 40i that constitute the inner circumference 60i of the coil group 60. These segment coils u5, u12, etc. are structured so that both coil sides 41 and 42 are inserted into the first position of slot SL, but the structure is not limited to this.

[0060] In other words, as shown in Figure 24, segment coils c1 to c8 can be used as inner segment coils 40i that constitute the inner circumference 60i of the coil group 60. For example, in segment coil c1, one of the coil sides 41 and 42 is inserted into the first position (innermost position) of slot S1, and the other of the coil sides 41 and 42 is inserted into the second position of slot S43. Thus, any segment coil 40 in which one of the coil sides 41 and 42 is inserted into the first position of slot SL can be used as an inner segment coil 40i that constitutes the inner circumference 60i of the coil group 60.

[0061] In the examples shown in Figures 11 and 12 above, the outer segment coils 40o constituting the outer periphery 60o of the coil group 60 are given as segment coils u1, u9, u17, u25, u33, u41, u49, and u57. These segment coils u1, u9, etc., are structured so that both coil sides 41 and 42 are inserted into the 8th position (outermost position) of the slot SL, but the structure is not limited to this.

[0062] In other words, as shown in Figure 24, segment coils c9 to c16 can be used as outer segment coils 40o that constitute the outer periphery 60o of the coil group 60. For example, in segment coil c9, one of the coil sides 41 and 42 is inserted into the 8th position of slot S1, and the other of the coil sides 41 and 42 is inserted into the 7th position of slot S43. Thus, any segment coil 40 in which one of the coil sides 41 and 42 is inserted into the 8th position of slot SL can be used as an outer segment coil 40o that constitutes the outer periphery 60o of the coil group 60.

[0063] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention. In the above description, each phase coil Cu, Cv, and Cw is configured by connecting a plurality of segment coils 40 in series, but the invention is not limited to this, and each phase coil Cu, Cv, and Cw may be configured by connecting a plurality of segment coils 40 in parallel. Also, in the illustrated example, eight segment coils 40 are inserted into one slot SL, but the invention is not limited to this. For example, more than eight segment coils 40 may be inserted into one slot SL, or fewer than eight segment coils 40 may be inserted into one slot SL. Furthermore, in the above description, a stator core 24 with 48 slots is used, but the invention is not limited to this, and a stator core 24 with a different number of slots may be used. [Explanation of symbols]

[0064] 10 Rotating Electric Machines 20 stata 24 Stator core 40 Segment coil (segment conductor) 40i Inner Segment Coil (Inner Segment Conductor) 40° Outer segment coil (outer segment conductor) 40m Intermediate Segment Coil (Intermediate Segment Conductor) 60 coil group 70. Standard segment coil (standard segment conductor) 71 Coil side (first insertion section) 72 Coil side (second insertion section) 73 End section (connecting section) 80. Clamping Segment Coil (Clamping Segment Conductor) 81 Coil side (first pressing part) 82 Coil side (second pressing area) 83 End section (connecting section) 100 Tightening Segment Coil (Tightening Segment Conductor) 101 Coil side (first pressing part) 102 Coil side (second pressing section) 103 End section (connecting section) 110 Clamping Segment Coil (Clamping Segment Conductor) 111 Coil side (first pressing part) 112 Coil side (second pressing section) 113 End section (connecting section) SC stator coil (stator winding) u1~u64, v1~v64, w1~w64 Segment coil (segment conductor) SL Slot S1~S48 Slots S7a,S13a Inner wall T1~T48 Teeth SP interval Cp1 interval Cp2 interval S110 Coil insertion process

Claims

1. A method for manufacturing a stator installed in a rotating electric machine, The process includes inserting a coil insertion step into multiple slots formed in the stator core, in which a cylindrical group of conductors, composed of multiple segment conductors, is inserted. The plurality of segment conductors constituting the conductor group include a plurality of inner segment conductors constituting the inner circumference of the conductor group, a plurality of outer segment conductors constituting the outer circumference of the conductor group, and a plurality of intermediate segment conductors other than the inner segment conductors and the outer segment conductors. All of the aforementioned inner segment conductors are tightening segment conductors comprising a first pressing portion inserted into one of the plurality of slots, a second pressing portion inserted into any other of the plurality of slots, and a connecting portion that connects the first pressing portion and the second pressing portion to each other. At least a portion of the distance between the first pressing portion and the second pressing portion is narrower than the distance between the slot into which the first pressing portion is inserted and the slot into which the second pressing portion is inserted. All of the aforementioned outer segment conductors are standard segment conductors comprising a first insertion portion inserted into one of the plurality of slots, a second insertion portion inserted into any other of the plurality of slots, and a connecting portion that connects the first insertion portion and the second insertion portion to each other. The distance between the first insertion portion and the second insertion portion is the same as the distance between the slot into which the first insertion portion is inserted and the slot into which the second insertion portion is inserted. A method for manufacturing a stator.

2. In the method for manufacturing a stator according to Claim 1, The first pressing portion has a first inclined portion connected to the connecting portion, The second pressing portion has a second inclined portion connected to the connecting portion, The distance between the first inclined portion and the second inclined portion narrows as it approaches the connecting portion. A method for manufacturing a stator.

3. In the method for manufacturing a stator according to claim 1 or 2, At least one of the intermediate segment conductors is the normal segment conductor. A method for manufacturing a stator.

4. In the method for manufacturing a stator according to claim 3, All of the aforementioned intermediate segment conductors are the aforementioned ordinary segment conductors. A method for manufacturing a stator.

5. A stator installed in a rotating electric machine, A stator core in which multiple slots are formed, It consists of a cylindrical conductor group made up of multiple segment conductors, and a stator winding attached to the multiple slots, It has, The plurality of segment conductors constituting the conductor group include a plurality of inner segment conductors constituting the inner circumference of the conductor group, a plurality of outer segment conductors constituting the outer circumference of the conductor group, and a plurality of intermediate segment conductors other than the inner segment conductors and the outer segment conductors. All of the aforementioned inner segment conductors are tightening segment conductors comprising a first pressing portion inserted into one of the plurality of slots, a second pressing portion inserted into any other of the plurality of slots, and a connecting portion that connects the first pressing portion and the second pressing portion to each other. The first pressing portion presses the inner wall of the slot into which the first pressing portion is inserted in one direction in the circumferential direction of the stator core. The second pressing portion presses the inner wall of the slot into which the second pressing portion is inserted toward the other side in the circumferential direction of the stator core. All of the aforementioned outer segment conductors are standard segment conductors comprising a first insertion portion inserted into one of the plurality of slots, a second insertion portion inserted into any other of the plurality of slots, and a connecting portion that connects the first insertion portion and the second insertion portion to each other. The distance between the first insertion portion and the second insertion portion is the same as the distance between the slot into which the first insertion portion is inserted and the slot into which the second insertion portion is inserted. stata.

6. In the stator described in Claim 5, The first pressing portion has a first inclined portion connected to the connecting portion, The second pressing portion has a second inclined portion connected to the connecting portion, The distance between the first inclined portion and the second inclined portion narrows as it approaches the connecting portion. stata.

Images