Stator for rotary electric machine, method for manufacturing stator for rotary electric machine, and apparatus for manufacturing stator for rotary electric machine

Abstract

To provide a stator for a rotary electric machine capable of increasing the occupancy of a coil in a slot without impairing insulation.SOLUTION: A stator for a rotary electric machine includes a stator core 20 provided with a plurality of slots 22 in a circumferential direction, a conductor segment 210 arranged in the slot 22, and a resin part for fixing the conductor segment 210 to the stator core 20. The resin portion includes a slot resin portion 31 provided in the slot, and an end surface resin portion 32,33 connected to the slot resin portion 31 and provided on an axial end surface of the stator core 20. The end surface resin portions 32,33 are a plurality of end surface resin portions in the circumferential direction provided to be separated from each other corresponding to the plurality of slots 22 in the circumferential direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, a stator for a rotating electric machine has been known in which a bobbin is fitted into a slot in the stator core to insulate the stator core from the coil, a coil made of rectangular wire is inserted into the bobbin, and the stator core, coil, and bobbin are fixed together via resin (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-57947 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when bobbins are fitted into the slots of the stator core from the viewpoint of improving insulation, as in the stator for a rotating electrical machine described in Patent Document 1, the occupancy rate of the coils in the slots becomes small. [Means for solving the problem]

[0005] A stator for a rotating electric machine according to one aspect of the present invention includes a stator core provided with a plurality of circumferential slots extending substantially parallel to the axis, segment coils arranged in the slots, and resin portions that fix the segment coils to the stator core with axial ends of the segment coils protruding from the axial end face of the stator core. The resin portions have slot resin portions provided within the slots and end face resin portions that are continuous with the slot resin portions and are provided on the axial end face of the stator core, and the end face resin portions are a plurality of circumferential end face resin portions that are provided separately from one another and correspond to the plurality of circumferential slots.

[0006] Another aspect of the present invention is a method for manufacturing a stator for a rotating electric machine, which manufactures the above-mentioned stator for a rotating electric machine, wherein the segment coil has a pair of legs inserted into a different pair of slots among a plurality of circumferential slots, and a connecting portion connecting the pair of legs. The method for manufacturing a stator for a rotating electric machine includes the steps of: placing a stator core in a lower mold having recesses facing the lower end faces of the slots; inserting the legs of the segment coil into the slots from above the stator core; inserting a plurality of upper molds in the circumferential direction, each having recesses facing the upper end faces of the slots, from the radial outside along the upper end face of the stator core, to form a space through the slots from the recesses of the lower mold to the recesses of the upper mold; and supplying resin into the space to form a resin portion.

[0007] In yet another aspect of the present invention, there is provided a manufacturing apparatus for a stator for a rotating electric machine, which manufactures the above-described stator for a rotating electric machine, and the manufacturing apparatus includes a lower die arranged opposite the lower end surface of the stator core, an upper die arranged opposite the upper end surface of the stator core, and a guide inserted from below through the lower die into a plurality of circumferential slots. The guide has a coil accommodating portion that forms a space into which the segment coils are inserted. [Effects of the Invention]

[0008] According to the present invention, the occupancy rate of the coil in the slot can be increased without impairing the insulation properties. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing a configuration of a main part of a rotating electric machine including a stator for a rotating electric machine according to an embodiment of the present invention; [Figure 2] FIG. 2 is an enlarged view of a main part of the stator core of FIG. 1. [Figure 3] 3 is a perspective view showing an example of a process of inserting conductor segments included in the stator for a rotating electric machine of FIG. 1; FIG. [Figure 4] 1 is a perspective view showing the overall configuration of a stator for a rotating electric machine according to an embodiment of the present invention; [Figure 5] FIG. 5 is a cross-sectional view schematically showing the configuration of a main part of the stator shown in FIG. 4. [Figure 6A] 5 is a perspective view of a main part of the stator, showing the configuration of an end face resin portion provided on the upper end face of the stator core of FIG. 4. [Figure 6B] 5 is a perspective view of a main part of the stator, illustrating the configuration of an end face resin portion provided on the lower end face of the stator core in FIG. 4. [Figure 7] 6B is a plan view of a main part of the stator, in which the upper end surface of the stator core in FIG. 6A is viewed from above. [Figure 8A] FIG. 8 is a diagram showing a comparative example of FIG. 7. [Figure 8B] FIG. 8 is a diagram showing another comparative example of FIG. 7. [Figure 9] 5A to 5C are diagrams illustrating the effects of the stator for a rotating electric machine according to the embodiment of the present invention; [Figure 10] 3 is a flowchart showing an example of a procedure for a method of manufacturing a stator for a rotating electric machine according to an embodiment of the present invention. [Figure 11] FIG. 11 is a diagram for explaining the process of step S1 in FIG. 10. [Figure 12] FIG. 11 is a diagram for explaining the process of step S3 in FIG. 10. [Figure 13] FIG. 10 is a cross-sectional view schematically showing the configuration of the slot after the guide plate is inserted. [Figure 14] FIG. 10 is a perspective view of the upper mold alone, as viewed obliquely from above. [Figure 15] FIG. 11 is a diagram for explaining the process of step S6 in FIG. 10. [Figure 16A] FIG. 11 is a diagram for explaining the process of step S8 in FIG. 10. [Figure 16B] FIG. 11 is a diagram for explaining the process of step S9 in FIG. 10. [Figure 17] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 17. Fig. 1 is a cross-sectional view showing a schematic configuration of a rotating electric machine 100 including a rotating electric machine stator according to an embodiment of the present invention. The rotating electric machine 100 is mounted on a hybrid vehicle or an electric vehicle and can be used as an electric motor for driving the vehicle, and can also be used as a generator. Note that the rotating electric machine 100 can also be mounted on a vehicle and used for various purposes.

[0011] As shown in Fig. 1, a rotating electric machine 100 includes a rotor 1 that rotates about an axis line CL0, and a stator 2 that is provided outside the rotor 1 so as to surround an outer peripheral surface 1a of the rotor 1. A case 3 is disposed around the stator 2, and the stator 2 is fixed to the case 3. For convenience, the case 3 is shown in Fig. 1 as having a substantially cylindrical shape. Below, the direction in which the axis line CL0 extends is defined as the axial direction, the direction extending radially from the axis line CL0 is defined as the radial direction, and the direction along the circumference of a circle centered on the axis line CL0 is defined as the circumferential direction.

[0012] The rotating electric machine 100 is configured as, for example, an interior magnet synchronous motor. Therefore, the rotor 1 has a rotor core 10 having a substantially annular shape centered on an axis CL0, and a plurality of magnetic pole portions (not shown) formed in the rotor core 10 in the circumferential direction. Permanent magnets are embedded in the magnetic pole portions. A rotor shaft (not shown), which constitutes, for example, the output shaft of the rotating electric machine 100, is fitted into the inner peripheral surface 10a of the rotor core 10, and the rotor 1 rotates integrally with the rotor shaft. The rotor core 10 is formed by stacking a plurality of (for example, several tens of) magnetic metal electromagnetic steel plates in the axial direction.

[0013] The stator 2 has a substantially annular stator core 20 centered on an axis CL0 and having an inner circumferential surface 2a disposed at a predetermined radial distance from the outer circumferential surface 1a of the rotor 1. The stator core 20 is formed by stacking multiple magnetic steel plates made of metal in the axial direction.

[0014] Fig. 2 is an enlarged view of a main portion of the stator core 20 of Fig. 1. As shown in Fig. 2, the stator core 20 has a plurality of circumferential teeth 23 that protrude radially inward from a substantially annular yoke 24 at equal intervals in the circumferential direction. A plurality of circumferential slots 22 are provided between adjacent circumferential teeth 23, extending radially outward from the inner circumferential surface 2a. Note that the slots 22 are provided around the entire periphery of the inner circumferential surface 2a, but for convenience, Fig. 1 shows only the slots 22 near the top of the stator core 20.

[0015] The stator 2 has a plurality of coils 21 arranged in each slot 22. The coils 21 are segment coils formed by conductor segments having a substantially rectangular cross section. The coils 21 may also be formed by conductor segments having a circular cross section. The coils 21 include, for example, a U-phase coil, a V-phase coil, and a W-phase coil, and are formed as a three-phase coil. Instead of forming the motor as a three-phase motor, the motor may also be formed as a motor other than a three-phase motor (for example, a two-phase motor).

[0016] 1, when the rotating electric machine 100 is used as an electric motor, AC power is supplied to each coil 21 from a power converter (not shown). This generates a magnetic field in the stator 2, and this magnetic field interacts with the magnetic field generated by the permanent magnets in the magnetic pole portions of the rotor 1, causing the rotor 1 to rotate. As a result, a driving force is generated, causing the vehicle to travel. When the rotating electric machine 100 is used as a generator, AC power generated by driving the rotating electric machine 100 is supplied to the power converter or the like.

[0017] As shown in FIG. 2 , the slot 22 has an opening 221 provided in the inner circumferential surface 2a of the stator core 20 and an accommodating portion 222 provided radially outward of the opening 221. The accommodating portion 222 has a pair of side surfaces 222a, 222b extending radially and facing each other, and a bottom surface 222c on the radially outer side connecting the pair of side surfaces 222a, 222b. The width of the accommodating portion 222, i.e., the distance (circumferential length) between the pair of side surfaces 222a, 222b, is constant along the radial direction, and the accommodating portion 222 is formed in a generally rectangular shape elongated in the radial direction. The tooth 23 has protrusions 231 protruding from the radially inner tip portion on both circumferential sides, and the opening 221 is provided between the pair of protrusions 231. The width (circumferential length) of the accommodating portion 222 is greater than the width of the opening 221.

[0018] In the accommodation portion 222, for example, eight conductor segments 210 forming the coil 21 are arranged side by side in the radial direction. The number of conductor segments 210 in the accommodation portion 222 may be more or less than eight. For example, the number of conductor segments 210 in the accommodation portion 222 may be four. The conductor segments 210 in the slots 22 are surrounded by insulating resin 31, and the conductor segments 210 are fixed to the stator core 20 via the resin 31. For convenience, the resin 31 in such slots 22 is referred to as a slot resin portion.

[0019] The conductor segments 210 are inserted into the slots 22 from one axial end face of the stator core 20. Fig. 3 is a perspective view showing an example of the insertion process of the conductor segments 210. As shown in Fig. 3, the conductor segment 210 has a pair of legs 211, 211 extending parallel to each other, and a top portion 213 that is bent at bent portions 212, 212 and connects the ends of the pair of legs 211, 211, and has a generally U-shape as a whole. The pair of legs 211, 211 are inserted into different slots 22 in the circumferential direction.

[0020] The pair of legs 211, 211 each include straight portions 214, 214 continuing to a top portion 213, inclined portions 215, 215 that are bent as shown by dotted lines after insertion into the slot 22, and joint portions 216, 216 at the tips of the inclined portions 215, 215. The conductor segment 210 is formed from a rectangular wire made of a conductive material such as copper, and is covered with an insulating coating except for the pair of joint portions 216, 216.

[0021] The straight portion 214 is longer than the length from one axial end face (upper end face in FIG. 4) 200a to the other axial end face (lower end face in FIG. 4) 200b of the stator core 20, i.e., the axial length of the slot 22. Therefore, when the conductor segment 210 is inserted into the slot 22, the apex 213 protrudes from the one axial end face 200a of the stator core 20, and the inclined portion 215 protrudes from the other axial end face 200b of the stator core 20. One end side (apex side) of the conductor segment 210 protruding from the stator core 20 becomes a closed-side coil end, and the other end side (tip side) becomes an open-side coil end.

[0022] After the conductor segment 210 is inserted into the slot 22, the joint 216 at the tip of the conductor segment 210 is electrically and physically connected to the joint 216 at the tip of another conductor segment 210 that constitutes the same phase (see FIG. 5). By connecting multiple conductor segments 210 in this manner, a coil 21 is formed that winds around multiple teeth 23 in the circumferential direction. Note that the conductor segment 210 may also be simply referred to as the coil 21.

[0023] FIG. 4 is a perspective view showing the overall configuration of the stator 2. In the following, the direction along the axis CL0 as shown in FIG. 4 is defined as the up-down direction, and the configuration of each part of the stator 2 will be described in accordance with this definition. The up-down direction corresponds to the direction in which the stator 2 is manufactured. In FIG. 4, unlike FIG. 3, a flange portion 200c for fixing the stator 2 to the case 3 is provided on the outer peripheral surface of the stator core 20. Conductor segments 210 protrude from the upper end surface 200a and the lower end surface 200b of the stator core 20, and protrusions 21a are provided, but detailed illustration of the protrusions 21a of the coils 21 is omitted in FIG. 4, with some exceptions.

[0024] FIG. 5 is a cross-sectional view of the stator 2 taken along a conductor segment 210, schematically illustrating the configuration of the main parts of the stator 2. FIG. 5 shows a single conductor segment 210 with a pair of legs 211 inserted into a pair of slots 22. The pair of slots 22 in FIG. 5 is inserted into a pair of slots 22, 22, straddling a predetermined number of slots 22 in the circumferential direction. Therefore, although not shown, there are a predetermined number of slots 22 between the pair of slots 22 in FIG. 5.

[0025] 4 and 5, an insulating resin 32 is provided on the upper end surface 200a of the stator core 20, and the upper ends of the conductor segments 210 (more specifically, the upper ends of the straight portions 214) are fixed to the stator core 20 via the resin 32. As shown in Fig. 5, an insulating resin 33 is provided on the lower end surface 200b of the stator core 20, and the lower ends of the conductor segments 210 (more specifically, the lower ends of the straight portions 214) are fixed to the stator core 20 via the resin 33. For convenience, the resin along the upper end surface 200a and the lower end surface 200b of the stator core 20 in this manner is referred to as an end surface resin portion.

[0026] The end surface resin portions 32, 33 on the upper end surface 200a and the lower end surface 200b of the stator core 20 have the same configuration (shape as viewed in the axial direction and shape as viewed in the radial direction). The end surface resin portions 32, 33 are formed using a mold, which will be described later. The upper surface of the end surface resin portion 32 is flat, and the height (length in the vertical direction) H1 of the end surface resin portion 32 is equal to or less than the length H2 from the upper end surface 200a of the stator core 20 to the upper end (bent portion 212) of the straight portion 214 of the conductor segment 210. The lower surface of the end surface resin portion 33 is flat, and the height H3 of the end surface resin portion 33 is equal to or less than the length H4 from the lower end surface 200b of the stator core 20 to the lower end of the straight portion 214 of the conductor segment 210. The end surface resin portion 32 and the end surface resin portion 33 are connected via the slot resin portion 31, and these resin portions 31 to 33 are provided integrally.

[0027] A recess 210a is provided on the surface of the straight portion 214 of the conductor segment 210, for example, in the center in the up-down direction, facing the slot resin portion 31. This increases the contact area between the conductor segment 210 and the slot resin portion 31, making it possible to reduce stress (for example, stress due to thermal contraction) when a relative force in the axial or radial direction acts on the conductor segment 210 with respect to the slot resin portion 31.

[0028] 6A is a perspective view showing the configuration of end surface resin portion 32 provided on upper end surface 200a of stator core 20, and is a perspective view of a main portion of stator 2 viewed obliquely from above upper end surface 200a. Fig. 6A shows a state in which coil 21 is cut along horizontal plane PL1 indicated by the two-dot chain line in Fig. 5, i.e., horizontal plane PL1 passing through the upper end portion (bent portion 212) of straight portion 214, and top portions 213 of conductor segments 210 are not shown.

[0029] 6A, a plurality of end surface resin portions 32 are provided in the circumferential direction in correspondence with the slots 22 so as to individually cover the entire upper end faces of the plurality of slots 22. That is, the same number of end surface resin portions 32 as the number of slots 22 are provided. Circumferentially adjacent end surface resin portions 32, 32 are separated from each other by a gap CL1 of a predetermined width. The end surface resin portions 32 have rectangular resin portions 321 that are substantially rectangular in plan view from above and trapezoidal resin portions 322 that are substantially trapezoidal, arranged alternately in the circumferential direction.

[0030] More specifically, rectangular resin portion 321 has a pair of side surfaces 321a extending radially, and a substantially arc-shaped inner circumferential surface 321b and outer circumferential surface 321c connecting the inner diameter end and outer diameter end of pair of side surfaces 321a, 321a, respectively. The width (circumferential length) of rectangular resin portion 321, i.e., the distance between pair of side surfaces 321a, 321a, is longer than the width of slot 22 (the distance between pair of side surfaces 222a, 222b in FIG. 2) and is constant in the radial direction.

[0031] The trapezoidal resin portion 322 has a pair of side surfaces 322a, 322a extending in the radial direction, and a generally arcuate inner circumferential surface 322b and outer circumferential surface 322c connecting the inner diameter end and outer diameter end of the pair of side surfaces 322a, 322a, respectively. The width of the trapezoidal resin portion 322, i.e., the distance between the pair of side surfaces 322a, 322a, gradually increases from the inner diameter side to the outer diameter side. The width of the inner circumferential surface 322b is greater than the width of the slot 22 and is, for example, the same as or nearly the same as the width of the inner circumferential surface 321b of the rectangular resin portion 321. The side surfaces 321a of the rectangular resin portion 321 and the side surfaces 322a of the trapezoidal resin portion 322 that are adjacent in the circumferential direction are generally parallel, and a gap CL1 between the rectangular resin portion 321 and the trapezoidal resin portion 322 has a constant width in the radial direction.

[0032] Inner peripheral surface 321b of rectangular resin portion 321 and inner peripheral surface 322b of trapezoidal resin portion 322 are located on the same cylindrical surface centered on axis CL0, as is inner peripheral surface 2a of stator core 20. Inner peripheral surface 31a of slot resin portion 31 (the surface along opening 221 of slot 22 in FIG. 2) is also located on the same cylindrical surface as inner peripheral surface 2a of stator core 20. Outer peripheral surface 321c of rectangular resin portion 321 and outer peripheral surface 322c of trapezoidal resin portion 322 are located on the same cylindrical surface centered on axis CL0.

[0033] 6B is a perspective view showing the configuration of end face resin portion 33 provided on lower end face 200b of stator core 20, and is a perspective view of a main portion of stator 2 viewed obliquely from below lower end face 200b. Fig. 6B shows a state in which coil 21 is cut along horizontal plane PL2 indicated by the two-dot chain line in Fig. 5, i.e., horizontal plane PL2 passing through the lower end of straight portion 214, and does not show inclined portion 215 of conductor segment 210.

[0034] 6B, a plurality of end surface resin portions 33 are provided in the circumferential direction corresponding to the slots 22 so as to individually cover the entire lower end surfaces of the plurality of slots 22. That is, the same number of end surface resin portions 33 as the number of slots 22 are provided. Circumferentially adjacent end surface resin portions 33, 33 are separated from each other by a gap CL1 of a predetermined width. The end surface resin portions 33 have rectangular resin portions 331 that are substantially rectangular in plan view from below and trapezoidal resin portions 332 that are substantially trapezoidal, arranged alternately in the circumferential direction.

[0035] The lower rectangular resin portion 331 and trapezoidal resin portion 332 are configured to have the same shapes as the upper rectangular resin portion 321 and trapezoidal resin portion 322. A single rectangular resin portion 331 is provided below the single rectangular resin portion 321, and a single trapezoidal resin portion 332 is provided below the single trapezoidal resin portion 322. Therefore, the rectangular resin portion 321 and the rectangular resin portion 331 are connected via the slot resin portion 31, and the trapezoidal resin portion 322 and the trapezoidal resin portion 332 are connected via the slot resin portion 31. Note that a single trapezoidal resin portion 332 may be provided below the single rectangular resin portion 321, and a single rectangular resin portion 331 may be provided below the single trapezoidal resin portion 322.

[0036] Fig. 7 is a plan view showing the configuration of a main part of stator 2 when upper end surface 200a of stator core 20 in Fig. 6A is viewed from above. In Fig. 7, a line passing through the center of slot 22 covered by rectangular resin portion 321 and extending radially outward from axis CL0 is defined as reference line L1, and a line passing through the center of slot 22 covered by trapezoidal resin portion 322 and extending radially outward from axis CL0 is defined as reference line L2.

[0037] In this embodiment, the end face resin portion 32 is molded in each of a plurality of circumferential regions AR1 extending from the reference line L1 to the reference lines L2, L2 on both sides of the reference line L1 in the circumferential direction. Therefore, a plurality of molds (upper molds) 50 are used in the circumferential direction to form the end face resin portion 32, and a single upper mold 50 simultaneously molds the entire rectangular resin portion 321 in the region AR1 and a pair of regions 322d of the trapezoidal resin portion 322 located circumferentially inward (on the reference line L1 side) of the reference line L2, as shown by hatching in FIG. 7 . In other words, a plurality of end face resin portions 32 are molded using a single upper mold 50. Therefore, the number of upper molds 50 (the number of regions AR1) is smaller than the number of end face resin portions 32 (the number of slots 22), specifically, half the number of end face resin portions 32.

[0038] The side surface 321a of the rectangular resin portion 321 and the side surface 322a of the trapezoidal resin portion 322 that are adjacent in the circumferential direction extend parallel to the reference line L1. Therefore, after the end surface resin portion 32 is molded by the upper mold 50, the upper mold 50 can be easily removed by moving the upper mold 50 radially outward parallel to the reference line L1, while providing a gap CL between the side surface 321a and the side surface 322a.

[0039] 8A, which is a comparative example of FIG. 7, if the end surface resin portion 32 is entirely made up of rectangular resin portions 321, that is, if the rectangular resin portions 321 are configured around not only the reference line L1 but also the reference line L2, the side surface 321a of the rectangular resin portion 321 facing the gap CL1 cannot be made parallel to the reference line L1. As a result, the upper mold 50 cannot be moved radially outward along the reference line L1.

[0040] 8B, which is a comparative example of FIG. 7, if the end surface resin portion 32 is entirely made up of trapezoidal resin portions 322, that is, if the trapezoidal resin portions 322 are configured around the reference line L1 as well as the reference line L2, the side surfaces 322a of the trapezoidal resin portions 322 will not be parallel to the reference line L1. For this reason, the upper mold 50 cannot be moved radially outward along the reference line L1.

[0041] 9 is a diagram illustrating the effects of the stator 2 for a rotating electric machine according to this embodiment. As shown in FIG. 9, in this embodiment, end surface resin portions 32, 33 are provided along the upper end surface 200a and the lower end surface 200b of the stator core 20, respectively, and the upper end surface 200a and the lower end surface 200b of the stator core 20 are covered with the insulating end surface resin portions 32, 33. This makes it possible to lengthen the distance L11, i.e., the creepage distance, from the surface of the coil 21 that is not covered with the insulating material (for example, a portion where the insulating coating on the surface is damaged) to the portion of the stator core 20 that is not covered with the insulating material, thereby achieving good insulation performance of the stator 2.

[0042] In contrast, if the end surface resin portions 32, 33 are not provided, the creepage distance L12 between the coil 21 and the stator core 20 becomes shorter. Therefore, in order to ensure sufficient insulation performance of the stator 2, it is necessary to insert an additional insulating member between the slot 22 and the coil 21. As a result, the occupancy rate of the coil 21 in the slot decreases and costs increase.

[0043] In this regard, in the present embodiment, since there is no need to insert an insulating member into the slot, the occupancy rate of the coil 21 within the slot can be increased. This improves the performance of the rotating electric machine 100, and allows heat from the coil 21 to be efficiently dissipated to the outside via the stator core 20. Also, in the present embodiment, the upper and lower end face resin portions 32, 33 are connected via the slot resin portion 31, so axial displacement of the resin portions 31 to 33 can be prevented. Furthermore, in the present embodiment, the end face resin portions 32, 33 are provided separately for each slot, so stress during thermal contraction can be reduced. It is also possible to shorten the molding time for each slot 22.

[0044] A method for manufacturing the stator 2 for a rotating electric machine configured as described above will now be described. The stator 2 is manufactured using various manufacturing devices. FIG. 10 is a flowchart showing an example of the steps of the method for manufacturing the stator 2 for a rotating electric machine. As shown in FIG. 10, first, in step S1, the stator core 20 is set in a lower mold. FIG. 11 is a diagram illustrating the process of step S1. As shown in FIG. 11, the lower mold 55 has, on its upper surface 55a, a substantially ring-shaped core installation portion 56 that bulges upward from the upper surface 55a.

[0045] The core mounting portion 56 has a plurality of circumferential through-holes 57 formed therein, each having the same shape as the slots 22 that penetrate the lower mold 55 in the up-down direction. Furthermore, the core mounting portion 56 has recesses 58 formed around the through-holes 57, each of which corresponds to the rectangular resin portion 331 and the trapezoidal resin portion 332 in FIG. 6B. The stator core 20 is mounted on the upper surface of the core mounting portion 56 so that the slots 22 are aligned with the through-holes 57. At this time, the recesses 58 of the core mounting portion 56 are covered by the lower end surface 200b of the stator core 20.

[0046] Next, in step S2 of Fig. 10, with stator core 20 set in lower die 55, stator core 20 and lower die 55 are placed in a preheating furnace and heated to a predetermined temperature. That is, stator core 20 is preheated. After preheating is complete, stator core 20 is removed from the preheating furnace and placed together with lower die 55 into a molding facility. Steps from step S3 onwards are performed within the molding facility.

[0047] In step S3, guide plates are inserted into the slots 22 of the stator core 20. FIG. 12 is a diagram illustrating step S3. As shown in FIG. 12, guide plates 60 protrude upward from a plate-shaped base 61. The guide plates 60 are provided at equal intervals in the circumferential direction, corresponding to the plurality of slots 22 in the circumferential direction. As shown in the enlarged view of part A in FIG. 12, the guide plate 60 has a pair of side walls 62, 62 facing a pair of side surfaces 222a, 222b (FIG. 2) of the slots 22, and a connecting wall 63 connecting the radially outer ends of the pair of side walls 62, 62. The guide plate 60 has a substantially U-shape in plan view, and a space SP3 is formed inside the guide plate 60. The guide plate 60 is inserted into the slots 22 from below the lower mold 55 through the through-hole 57.

[0048] Next, in step S4 of Fig. 10, the conductor segments 210 are inserted into the slots 22 from above the stator core 20. At this time, the lower ends of the conductor segments 210 pass through the through holes 57 of the lower mold 55 and protrude downward from the lower mold 55. Fig. 13 is a cross-sectional view that schematically shows the configuration of the slots 22 after the guide plates 60 have been inserted. As shown in Fig. 13, when the guide plates 60 are inserted into the slots 22, the upper end of the guide plate 60 is located above the upper end surface 200a of the stator core 20, and the lower end of the guide plate 60 is located below the lower end surface 200b of the stator core 20.

[0049] Therefore, as shown by the arrow in Figure 13, the conductor segments 210 can be inserted into the space SP3 inside the guide plate 60 without coming into contact with the side surfaces of the slots 22. Because the stator core 20 is a laminate of multiple electromagnetic steel sheets, the side surfaces of the slots 22 are uneven. Therefore, if the conductor segments 210 come into contact with the side surfaces of the slots 22, the surfaces (insulating coatings) of the conductor segments 210 may be damaged. In this regard, by inserting the conductor segments 210 with the guide plate 60 interposed therebetween, damage to the surfaces of the conductor segments 210 can be prevented.

[0050] 10, the guide plate 60 is moved downward relative to the lower mold 55, and the guide plate 60 is removed from the slot 22. For example, the guide plate 60 is moved downward, or the lower mold 55 is moved upward, and the guide plate 60 is removed.

[0051] Next, in step S6, the upper die 50 (FIG. 7) is set on the upper end surface 200a of the stator core 20. FIG. 14 is a perspective view of the upper die 50 alone, as viewed from diagonally above, and FIG. 15 is a diagram illustrating the process of step S6. FIG. 15 is a perspective view of multiple upper dies 50, as viewed from diagonally below, after and during the insertion of the upper die 50 from the radially outer side between circumferentially adjacent coils 21, 21. Note that, for convenience, in FIG. 15, the conductor segments 210 are indicated by two-dot chain lines, and the stator core 20 is not shown.

[0052] 14 and 15, the upper mold 50 has a base 51 extending in the circumferential direction and a pair of leg portions 52 extending radially inward from the base 51. The upper mold 50 is configured symmetrically about an axis CL2 (FIG. 14) that passes through the center of the base 51 and extends radially. More specifically, the base 51 has an upper surface 511 and a lower surface 512, a pair of end faces 513 and 514 on the outer side in the circumferential direction, and inner and outer circumferential surfaces 515 and 516 on the inner and outer sides in the radial direction. The leg portions 52 have an upper surface 521 and a lower surface 522, a pair of side surfaces 523 and 524 on the outer and inner sides in the circumferential direction, and an inner circumferential surface 525 on the inner side in the radial direction.

[0053] An upper surface 511 of the base 51 and an upper surface 521 of the leg 52 are located on the same plane, and a lower surface 512 of the base 51 and a lower surface 522 of the leg 52 are located on the same plane. Therefore, the height from the lower surface 512 of the base 51 to the upper surface 511 is equal to the height from the lower surface 522 of the leg 52 to the upper surface 521. As shown in Fig. 14, the leg 52 extends radially from an inner circumferential surface 515 of the base 51, circumferentially outward from the axis CL2 and circumferentially inward from the end surface 514. Therefore, the inner circumferential surface 515 of the base 51 has an inner circumferential surface 515a at the circumferential center and a pair of inner circumferential surfaces 515b, 515b on the circumferential outer sides.

[0054] An inner space SP1 is formed inside the pair of leg portions 52, 52 and is surrounded by the pair of side surfaces 524, 524 and the inner circumferential surface 515a. As shown in FIG. 15 , the inner space SP1 accommodates a conductor segment 210. When the upper mold 50 is set, the end faces 514, 514 of circumferentially adjacent upper molds 50, 50 abut against each other. At this time, an end space SP2 is formed and is surrounded by the side surface 523 and inner circumferential surface 515b of the leg portion 52 of one upper mold 50 and the side surface 523 and inner circumferential surface 515b of the leg portion 52 of the other upper mold 50, and the conductor segment 210 is accommodated in the end space SP2. The inner space SP1 and the end space SP2 have the same shape.

[0055] A recess 53 of a predetermined depth is provided on the lower surface of the upper mold 50. The recess 53 has an inner recess 531 provided around the inner space SP1 and a pair of end recesses 532, 532 provided around the end space SP2. More specifically, the inner recess 531 has a pair of side surfaces 531a, 531a and an outer peripheral surface 531c corresponding to the pair of side surfaces 321a, 321a and the outer peripheral surface 321c of the rectangular resin portion 321 in FIG. 6A, and has a generally rectangular shape corresponding to the rectangular resin portion 321. The end recess 532 has a side surface 532a and an outer peripheral surface 532c corresponding to the side surface 322a and the outer peripheral surface 322c of the trapezoidal resin portion 322 in FIG. 6A. The end recesses 532, 532 of a pair of circumferentially adjacent upper molds 50, 50 have a generally trapezoidal shape corresponding to the trapezoidal resin portion 322.

[0056] A pair of partition walls 54, 54 extending in the radial direction are provided between the inner recess 531 and the end recess 532 of the upper mold 50. The pair of partition walls 54, 54 extend substantially parallel to the axis CL2 in Figure 14, and the partition walls 54, 54 form a gap CL1 in Figure 6A.

[0057] In step S6, the upper die 50 is inserted from the radially outer side of the stator core 20 while sliding the lower surfaces 512, 522 of the upper die 50 along the upper end surface 200a of the stator core 20, with the axis CL2 aligned with the reference line L1 in FIG. 7 . More specifically, the legs 52 of the upper die 50 are inserted between the circumferentially adjacent conductor segments 210, 210. The height of the legs 52 is the same or nearly the same as the height from the upper end surface 200a of the stator core 20 to the bent portions 212 of the conductor segments 210. As shown in FIG. 14 , an arc-shaped curved surface portion 526 is provided at the intersection between the upper surface 521 and the side surface 523 of the leg 52. The curvature of the curved surface portion 526 and the bent portion 212 are the same or nearly the same, and when the leg 52 is inserted, the curved surface portion 526 is in close contact with the bent portion 212.

[0058] 10, a substantially cylindrical inner diameter die centered on the axis CL0 is set along the inner circumferential surface 2a of the stator core 20. The inner diameter die is provided to define the inner circumferential surface 31a of the slot resin portion 31, the inner circumferential surfaces 321b, 331b of the upper and lower rectangular resin portions 321, 331, and the inner circumferential surfaces 322b, 332b of the upper and lower trapezoidal resin portions 322, 332. For this reason, although not shown in the drawings, the upper end of the inner diameter die protrudes above the upper end surface 200a of the stator core 20, and the lower end protrudes below the lower end surface 200b of the stator core 20.

[0059] The inner diameter die is configured to be expandable and contractible in the radial direction. This allows the outer peripheral surface of the inner diameter die to easily come into close contact with the inner peripheral surface 2a of the stator core 20. When the inner diameter die is set, the inner peripheral surfaces 525 of the legs 52 of the upper die 50 abut against the outer peripheral surface of the inner diameter die. This forms a space SP0 (FIG. 16A) for supplying resin, which extends from the recess 58 of the lower die to the recess 53 of the upper die 50 via the slot 22.

[0060] 10, a resin material that will form the base of the resin portions (slot resin portion 31, end face resin portions 32, 33) is set in lower mold 55. FIG. 16A is a diagram illustrating the process of step S8, and shows the main parts of lower mold 55 in a simplified manner, along with multiple conductor segments 210 and stator core 20. As shown in FIG. 16A, a recess 59 is provided in the lower surface of lower mold 55, and resin material 70 is placed in recess 59.

[0061] FIG. 17 is a bottom view of the lower mold 55 as viewed from below. As shown in FIG. 17, a plurality of recesses 59 are provided in the circumferential direction on the radially outer side of the core installation portion 56. The recesses 59 have, for example, a substantially cylindrical shape, and a resin material 70 having, for example, a substantially cylindrical shape is placed in each of the plurality of recesses 59. As shown in the enlarged view of portion A in FIG. 17, one end of a runner portion 591, which is a flow path for the molten resin material 70, is connected to the recesses 59. The other end of the runner portion 591 passes through the lower mold 55 and is connected to the upper recess 58. As a result, the recesses 59 and the recess 58 are in communication with each other via the runner portion 591.

[0062] Next, as shown in step S9 of Fig. 10, the resin material 70 is pressurized to form resin portions (slot resin portion 31, end surface resin portions 32, 33). Fig. 16B is a diagram illustrating the process of step S9, and similarly to Fig. 16A, the main portions of the lower mold 55 are shown in a simplified manner. As shown in Fig. 16B, a pressurizing device 71 (e.g., a cylinder) is installed below the recess 59. The resin material 70 is pressurized upward by the pressurizing device 71.

[0063] This causes the molten resin material 70 to flow upward through the recesses 58 and slots 22 and reach the recesses 53 on the lower side of the upper mold 50. As a result, the space SP0 (FIG. 16A) from the recesses 58 to the recesses 53 is filled with resin, and the slot resin portion 31 and the end face resin portions 32, 33 can be molded. In this case, since multiple recesses 59 for placing the resin material 70 are provided around the core installation portion 56 (FIG. 17), the length of the runner portion 591 can be shortened. This improves the yield of resin.

[0064] Although not shown in Figure 10, after the resin portions 31-33 are molded, the pressure device 71 is lowered, and then the lower mold 55 is lowered and removed from the stator 2. Next, the lower ends of the conductor segments 210 are bent to form the inclined portions 215 (Figure 2), and the multiple conductor segments are welded together via the joints 216 at the tips of the inclined portions 215. This completes the manufacture of the stator 2.

[0065] According to this embodiment, the following effects can be achieved. (1) A stator 2 for a rotating electric machine includes a stator core 20 having a plurality of circumferential slots 22 extending substantially parallel to an axis CL0, coils 21, more specifically conductor segments (segment coils) 210, arranged in the slots 22, and a resin portion that fixes the coils 21 to the stator core 20 with axial ends of the coils 21 protruding from axial end faces 200a, 200b of the stator core 20 ( FIGS. 1, 2, and 5 ). The resin portion includes slot resin portions 31 arranged in the slots and end face resin portions 32, 33 that are continuous with the slot resin portions 31 and are arranged on the axial end faces 200a, 200b of the stator core 20 ( FIG. 5 ). The end face resin portions 32 are a plurality of circumferential end face resin portions 32 that are separated from one another and correspond to the plurality of circumferential slots 22 ( FIGS. 4 and 6A ).

[0066] By providing the end face resin portions 32, 33 on the end faces 200a, 200b of the stator core 20 so as to cover the slots 22 in this manner, it is possible to increase the creepage distance L11 (FIG. 9) from the coils 21 to the stator core 20. This allows the occupancy rate of the coils 21 in the slots to be increased without impairing the insulation of the coils 21. As a result, it is possible to improve the performance of the rotating electric machine 100 and also improve the cooling performance of the coils 21. Furthermore, since the end face resin portions 32, 33 are provided on both axial sides of the resin portions 31-33, it is possible to prevent the slot resin portion 31 from shifting in the axial direction. Furthermore, since resin molding can be performed for each slot 22, it is possible to shorten the molding time.

[0067] (2) The multiple end surface resin portions 32 in the circumferential direction include trapezoidal resin portions 322 that are generally trapezoidal in shape when viewed from the axial direction and rectangular resin portions 321 that are generally rectangular in shape when viewed from the axial direction ( FIG. 6A ). The trapezoidal resin portions 322 and rectangular resin portions 321 are alternately arranged in the circumferential direction with a predetermined gap CL1 between them ( FIG. 6A ). This allows the upper mold 50 to be removed radially outward along a reference line L1 that passes through the center of the rectangular resin portion 321 after the end surface resin portion 32 below the top portion 213 of the conductor segment 210 has been molded ( FIG. 7 ). This facilitates molding of the end surface resin portions 32.

[0068] (3) The conductor segment 210 has a straight portion 214 that protrudes a predetermined length (predetermined heights H2, H4) from the axial end faces 200a, 200b of the stator core 20, and a bent portion 212 and an inclined portion 215 that bend from the end of the straight portion 214 (FIG. 5). The axial heights H1, H3 of the multiple circumferential end face resin portions 32, 33 are equal to or less than the predetermined heights H2, H4, respectively (FIG. 5). Because the shape of the bent portions (such as the bent portion 212) of the coil 21 varies greatly, if the resin reaches the bent portion, the resin is likely to leak from the mold during resin molding. In this regard, providing the end face resin portions 32, 33 within the range of the straight portion 214 can prevent resin leakage.

[0069] (4) The straight portion 214 has a recess 210a on its outer circumferential surface facing the slot resin portion 31 (FIG. 5). This increases the contact area between the coil 21 and the resin, suppressing axial displacement of the coil 21 and reducing stress during thermal contraction.

[0070] (5) The conductor segment 210 has a pair of legs 211, 211 inserted into a pair of different slots 22, 22 among the plurality of slots 22 in the circumferential direction, and an apex 213 connecting the pair of legs 211, 211 (FIG. 3). A manufacturing method for the stator 2 for a rotating electric machine described above includes the steps of placing the stator core 20 in a lower mold 55 having recesses 58 facing the lower end faces 200b of the slots 22, inserting the legs 211 of the conductor segments 210 into the slots 22 from above the stator core 20, inserting a plurality of upper molds 50 in the circumferential direction, each having recesses 53 facing the upper end faces 200a of the slots 22, from the radially outer side along the upper end faces 200a of the stator core 20, to form spaces SP0 through the slots 22 from the recesses 58 of the lower mold 55 to the recesses 53 of the upper mold, and supplying resin material 70 into the spaces SP0 to form the resin portions 31-33 (FIG. 10). This configuration allows the resin portions 31-33 to be molded while the stator core 20 remains placed in the lower mold 55, facilitating the manufacturing of the stator 2.

[0071] (6) The manufacturing method of the stator 2 for a rotating electric machine further includes a step of inserting a guide plate 60 (guide) into the slot 22 from below the lower mold 55 (FIG. 10). In the step of inserting the conductor segment 210, the legs 211 of the conductor segment 210 are inserted along the guide plate 60, and after the legs 211 are inserted, the guide plate 60 is removed from below (FIGS. 12 and 13). This prevents damage to the conductor segment 210 that may occur when the conductor segment 210 comes into contact with the peripheral surface of the slot 22 during insertion.

[0072] (7) The manufacturing apparatus for the stator 2 for a rotating electric machine includes a lower die 55 arranged to face the lower end surface 200b of the stator core 20, an upper die 50 arranged to face the upper end surface 200a of the stator core 20, and a guide plate 60 that penetrates the lower die 55 and is inserted from below into a plurality of circumferential slots 22 (FIGS. 11 to 15). The guide plate 60 has a pair of side walls 62, 62 and a connecting wall 63 that form a space SP3 into which the conductor segment 210 is inserted (FIG. 12). This prevents the conductor segment 210 from contacting the circumferential surface of the slot 22 during insertion, thereby protecting the surface of the conductor segment 210.

[0073] (8) The upper mold 50 is inserted from the radially outer side along the upper end surface 200a of the stator core 20, and is a plurality of upper molds having recesses 53 facing the slots 22 (FIGS. 7 and 15). As a result, even if the top 213 exists above the stator core 200 and the upper mold cannot be removed from above the stator core 20, the upper mold 50 can be easily removed, and the slot resin portion 31 and the upper and lower end face resin portions 32, 33 can be molded simultaneously.

[0074] (9) The lower mold 55 has a recess 58 facing the slot 22, and is configured to form a space SP0 that passes through the slot 22 from the recess 58 to the recess 53 of the upper mold 50 (FIG. 16A). The lower mold 55 has a recess 59 in which a resin material 70 that is a base material for the resin supplied to the space SP0 is placed, and a runner portion 591 that connects the recess 58 of the lower mold 55 to the recess 59 (FIG. 17). This allows the runner portion 591 to be shortened, improving the yield of resin.

[0075] This embodiment can be modified in various ways. Some modifications will be described below. In the above embodiment, the trapezoidal resin portions 322, 332 (first end face resin portions) and the rectangular resin portions 321, 331 (second end face resin portions) are provided alternately in the circumferential direction on the axial end faces 200a, 200b of the stator core 20, but the configuration of the multiple end face resin portions in the circumferential direction is not limited to the above. End face resin portions of the same shape may be provided in the circumferential direction. In the above embodiment, the recesses 210a are provided on the outer peripheral surface of the straight portion 214 of the coil 21 facing the slot resin portion 31, but multiple recesses 210a may be provided on the outer peripheral surface of the straight portion 214, and the shape and number of the recesses 210a are not limited to the above.

[0076] In the above embodiment, the conductor segment 210 has a pair of legs 211 (leg portions) and a top portion 213 (connection portion) connecting the pair of legs 211, and is configured to have a generally U-shape overall, but the configuration of the segment coil is not limited to that described above. In the above embodiment, the guide plate 60 (guide) is inserted into the slot 22 from below the lower mold 55, and the conductor segment 210 is inserted into the space SP3 formed by the pair of side walls 62, 62 and the connection wall 63, but the configuration of the coil accommodating portion that forms the space SP3 is not limited to that described above.

[0077] In the above embodiment, resin material 70 was placed in recess 59 on the lower surface of lower mold 55 as a base material for resin supplied to space SP0 extending from recess 58 of lower mold 55 to recess 53 of upper mold 50, but a resin placement section may be provided on the upper surface of the lower mold. A resin placement section may also be provided on the upper mold. In the above embodiment, runner section 591 was provided that penetrates lower mold 55 in the vertical direction and connects recesses 58 and 59 of lower mold 55 that form end face resin section 33, but the configuration of the communication section that connects the recess of the lower mold and resin placement section is not limited to that described above.

[0078] In the above embodiment, the stator 2 for a rotating electric machine is applied to a vehicle, but the stator for a rotating electric machine of the present invention can also be applied to things other than vehicles.

[0079] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0080] 2 stator, 20 stator core, 21 coil, 22 slot, 31 slot resin portion, 32, 33 end face resin portion, 50 upper mold, 53 recess, 55 lower mold, 58 recess, 59 recess, 60 guide plate, 62 side wall, 63 connecting wall, 70 resin material, 200a upper end surface, 200b lower end surface, 210 conductor segment, 210a recess, 211 leg, 212 bent portion, 213 top portion, 214 straight portion, 215 inclined portion, 321 rectangular resin portion, 322 trapezoidal resin portion, 591 runner portion, SP0, SP3 space

Claims

1. a stator core provided with a plurality of circumferential slots extending substantially parallel to the axis; A segment coil disposed in the slot; a resin portion that fixes the segment coil to the stator core in a state in which the axial end portion of the segment coil protrudes from the axial end face of the stator core, the resin portion includes a slot resin portion provided in the slot, and an end face resin portion connected to the slot resin portion and provided on the axial end face of the stator core, a stator for a rotating electric machine, wherein the end surface resin portion comprises a plurality of end surface resin portions provided in a circumferential direction and separated from one another in correspondence with the plurality of circumferential slots;

2. 2. The stator for a rotating electric machine according to claim 1, the plurality of circumferential end surface resin portions include a first end surface resin portion that is substantially trapezoidal when viewed from the axial direction and a second end surface resin portion that is substantially rectangular when viewed from the axial direction, The stator for a rotating electric machine, wherein the first end surface resin portion and the second end surface resin portion are provided alternately in a circumferential direction with a predetermined gap therebetween.

3. 2. The stator for a rotating electric machine according to claim 1, The segment coil has a straight portion protruding by a predetermined length from the axial end face of the stator core and a bent portion bent from an end of the straight portion, a stator for a rotating electric machine, wherein the axial height of each of the plurality of circumferential end surface resin portions is equal to or less than the predetermined length;

4. 4. The stator for a rotating electric machine according to claim 3, The linear portion has a recess on its outer circumferential surface facing the slot resin portion.

5. A method for manufacturing a stator for a rotating electric machine according to any one of claims 1 to 4, comprising the steps of: The segment coil has a pair of legs inserted into a pair of different slots among the plurality of circumferential slots, and a connection portion connecting the pair of legs, a step of placing the stator core in a lower mold having a recess facing a lower end surface of the slot; Inserting the leg portions of the segment coils into the slots from above the stator core; a step of inserting a plurality of upper dies in a circumferential direction, each having a recess facing the upper end surface of the slot, along the upper end surface of the stator core from the radially outer side, and forming a space passing through the slot from the recess of the lower die to the recess of the upper die; and a step of supplying a resin into the space to form the resin portion.

6. 6. The method for manufacturing a stator for a rotating electric machine according to claim 5, The method further includes inserting a guide into the slot from below the lower die; A method for manufacturing a stator for a rotating electric machine, characterized in that in the process of inserting the segment coil, the legs of the segment coil are inserted along the guide, and after the legs are inserted, the guide is removed from below.

7. A manufacturing apparatus for a stator for a rotating electric machine for manufacturing the stator for a rotating electric machine according to any one of claims 1 to 4, a lower die disposed opposite to a lower end surface of the stator core; an upper die disposed opposite to an upper end surface of the stator core; a guide that penetrates the lower die and is inserted from below into the plurality of circumferential slots, The manufacturing device for a stator for a rotating electric machine is characterized in that the guide has a coil accommodating portion that forms a space into which the segment coil is inserted.

8. 8. The manufacturing apparatus for a stator for a rotating electric machine according to claim 7, A manufacturing device for a stator for a rotating electric machine, characterized in that the upper mold is a plurality of upper molds that are inserted from the radial outside along the upper end surface of the stator core and have recesses facing the slots.

9. 9. The manufacturing apparatus for a stator for a rotating electric machine according to claim 8, the lower mold has a recess facing the slot, and is configured to form a space passing through the slot from the recess to the recess of the upper mold; A manufacturing device for a stator for a rotating electric machine, characterized in that the lower mold has a resin placement section in which a base material of resin to be supplied to the space is placed, and a communication section that connects the recess of the lower mold with the resin placement section.

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