Rotating electric machine

Abstract

Provided is a rotating electric machine that facilitates assembly and disassembly of a coil while maintaining reliable fixing of the coil to a stator core during rotational driving, and that makes it possible to reduce the amount of CO2 emitted during manufacture and to recycle resources. This rotating electric machine comprises: a stator including a stator core having a plurality of teeth and a plurality of slots formed between adjacent teeth, and a coil wound around the teeth; and a rotor disposed facing the stator via a predetermined gap and rotatably held. The rotating electric machine is characterized in that: the slots each have an opening at one end in the radial direction of the rotating electric machine; the coil has a first slot insertion portion and a second slot insertion portion that are inserted into the slots, and a winding portion connecting the first slot insertion portion and the second slot insertion portion at an axial end portion of the rotating electric machine; and the first slot insertion portion and the second slot insertion portion are covered with insulation material portions formed in accordance with the shape of the slots, the insulation material portions each having at least one protrusion formed extending in the radial direction.

Description

Rotating electric machines

[0001] The present invention relates to the structure of a rotating electric machine, and more particularly to a technique that is effective when applied to a method of fixing a coil to a stator core.

[0002] Rotating electric machines such as motors and generators are installed in a wide range of products, including automobiles, trucks, buses, construction machinery, railway vehicles, elevators, and home appliances.

[0003] In these rotating electrical machines, when the stator core or coil vibrates during operation, the insulating coating on the coil can be damaged, increasing the risk of a short circuit. For this reason, the stator core and coil have traditionally been fixed together using varnish hardening or resin potting.

[0004] Background art in this technical field includes, for example, a technique such as that disclosed in Patent Document 1. Patent Document 1 discloses a technique in which an adhesive layer, an expansion material made of a foamable resin, and an insulator are sequentially arranged between a stator core and a coil, and the foamable resin is expanded by heating to fix the coil.

[0005] JP 2014-93893 A

[0006] With the recent rapid spread of electric vehicles, the motors that serve as the driving source are required to be evaluated not only for their energy consumption efficiency while in operation, but also for their CO2 emissions over their life cycle. ２ There is a demand for reducing emissions and recycling resources.

[0007] However, the varnish curing and resin potting applied to conventional coils consume a large amount of energy for heating during the manufacturing process, and it is difficult to disassemble the coil in the event of a breakdown such as insulation breakdown. ２ There were issues with not being able to reduce emissions or recycle resources.

[0008] According to the method of Patent Document 1, the stator core and coil are fixed via an adhesive layer, making it relatively easy to disassemble the coil. However, the adhesive layer remains on the stator core after the coil is disassembled, making it difficult to reuse. Furthermore, because a heating process is required, similar to conventional varnish curing and resin potting, it is not possible to significantly reduce energy consumption during manufacturing.

[0009] Therefore, an object of the present invention is to provide a coil that can be easily assembled and disassembled while maintaining a secure fixation of the coil to the stator core during rotational driving, and to reduce CO2 during manufacturing. ２ The present invention provides a rotating electrical machine that can reduce emissions and recycle resources.

[0010] In order to achieve the above-mentioned object, the present invention includes various embodiments, and one example thereof is a rotating electric machine comprising: a stator core having a plurality of teeth and a plurality of slots formed between adjacent teeth; a stator including a coil wound around the teeth; and a rotor arranged opposite the stator across a predetermined gap and held rotatably, wherein the slots are open at one radial end of the rotating electric machine, the coils have first and second slot insertion portions inserted into the slots, and a winding portion connecting the first and second slot insertion portions at axial ends of the rotating electric machine, the first and second slot insertion portions are covered with an insulating material formed to match the shape of the slots, and the insulating material each has at least one protrusion formed extending in the radial direction.

[0011] According to the present invention, the coil can be easily assembled and disassembled while maintaining a secure fixation of the coil to the stator core during rotational driving, and CO2 during manufacturing can be reduced. ２ It is possible to realize a rotating electrical machine that can reduce emissions and recycle resources.

[0012] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments.

[0013] 5A is a cross-sectional view showing a schematic configuration of a rotating electric machine (motor) according to a first embodiment of the present invention. FIG. 6 is a view showing the structure of a coil 200 in FIG. 1. FIG. 7 is a view showing the structure of a slot 13 in FIG. 1. FIG. 8 is a view showing the cross-sectional structure of the coil 200 in FIG. 1. FIG. 9 is a view showing a modified example of FIG. 4A. (Modification 1) is a view showing a modified example of FIG. 4A. (Modification 2) is a perspective view showing the three-dimensional shape of the coil 200 in FIG. 1. FIG. 10 is a view showing a modified example of FIG. 5A. FIG. 11 is a cross-sectional view showing a schematic configuration of a rotating electric machine (motor) according to a second embodiment of the present invention. FIG. 12 is a view showing the structure of a slot 13 in FIG. 13. FIG. 13 is a view showing the structure of coils 201, 202 in FIG. 13. FIG. 14 is a view showing a schematic configuration of a rotating electric machine (motor) according to a third embodiment of the present invention. FIG. 15 is a view showing a manufacturing process for a conventional distributed winding structure. FIG. 16 is a view showing a manufacturing process for a conventional concentrated winding structure. CO during manufacturing of a rotating electric machine according to the present invention. ２ FIG. 1 is a diagram showing the effects of reducing emissions and recycling resources.

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and detailed description of overlapping parts will be omitted.

[0015] Furthermore, although the following description mainly focuses on inner rotor type rotating electric machines, the present invention is not limited to this and can also be applied to outer rotor type rotating electric machines, which will be described later in Example 3.

[0016] First Embodiment A rotating electric machine according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5 and 10A to 10C.

[0017] FIG. 1 is a cross-sectional view showing a schematic configuration of a rotating electric machine (motor) 1 of this embodiment. FIG. 2 is a view showing the structure of a coil 200 in FIG. 1. FIG. 3 is a view showing the structure of a slot 13 in FIG. 1. FIG. 4A is a view showing the cross-sectional structure of the coil 200 in FIG. 1. FIGS. 4B and 4C are both views showing modifications of FIG. 4A. FIG. 5A is a perspective view showing the three-dimensional shape of the coil 200 in FIG. 1. FIG. 5B is a view showing a modification of FIG. 5A. FIG. 10A is a view showing a manufacturing process for a conventional distributed winding structure. FIG. 10B is a view showing a manufacturing process for a conventional concentrated winding structure. FIG. 10C is a view showing a CO ２FIG. 1 is a diagram showing the effects of reducing emissions and recycling resources.

[0018] As shown in Fig. 1, the rotating electric machine (motor) 1 of this embodiment mainly comprises a cylindrical stator 10 and a rotor 20 concentrically disposed inside the stator 10 with a gap 30 therebetween. In the following description, a direction parallel to the central axis of rotation of the rotor 20 of the rotating electric machine 1 will be referred to as the "axial direction," a diameter direction of the rotor 20 perpendicular to the central axis of rotation of the rotor 20 of the rotating electric machine 1 will be referred to as the "radial direction," and a circumferential direction centered on the central axis of rotation of the rotor 20 of the rotating electric machine 1 will be referred to as the "circumferential direction." Fig. 1 is a view of the rotating electric machine 1 as seen from the axial direction.

[0019] The stator 10 is composed of a stator core 11 having a plurality of teeth 12 and a plurality of slots 13 formed between adjacent teeth 12, and coils 200 wound around the teeth 12. In the example of FIG. 1, the number of slots is 12.

[0020] The coil 200 is composed of three phases, U, V, and W, with two coils for each phase. That is, the U phase is composed of coil 200 (U1) and coil 200 (U2), the V phase is composed of coil 200 (V1) and coil 200 (V2), and the W phase is composed of coil 200 (W1) and coil 200 (W2), for a total of six coils for the three phases.

[0021] The rotor 20 is composed of a rotor core 21 in which permanent magnets 22 are embedded. The permanent magnets 22 are arranged in a V-shape and form magnetic poles of north or south poles, with a total of 10 poles.

[0022] As shown in Fig. 2, the coil 200 includes a first slot insertion portion 210, a second slot insertion portion 220, and a winding portion 230 connecting the first and second slot insertion portions 210 and 220 at their axial ends. The first slot insertion portion 210 and the second slot insertion portion 220 are covered with an insulating material 300 (not shown in Fig. 2) formed to fit the shape of the slot 13. The insulating material 300 includes a press-fit holding protrusion 400 formed to extend radially, and in the state shown in Fig. 1, the press-fit holding protrusion 400 comes into contact with the inside of the slot 13 to fix the coil 200.

[0023] The insulating material 300 may be made of an epoxy resin or other insulating material. At least one press-fit holding protrusion 400 may be provided in each of the first slot insertion portion 210 and the second slot insertion portion 220. In FIG. 2, the press-fit holding protrusions 400 are provided in a total of 12 locations on the outside and inside of the coil 200.

[0024] 3, the slot 13 has an open radial end facing the gap 30 (open slot), and during manufacturing, the coil 200 is press-fitted into this opening from the radially inner side toward the radially outer side (coil press-fit direction). Both the first slot insertion portion 210 and the second slot insertion portion 220 are fixed by contact between the press-fit holding protrusion 400 and the inner side of the slot 13.

[0025] However, during the press-fitting operation, the insulating material 300 covering the coil 200 is easily damaged. To avoid this, it is conceivable to place insulating paper or insulating film in the slot 13, but this requires setting work for the insulating paper or insulating film, which increases manufacturing costs, and there are also issues such as the insulating paper or insulating film being damaged when the coil 200 is pressed into place, resulting in defects.

[0026] In contrast, in the present invention, the press-fit holding protrusion 400 comes into contact with the slot 13 during the press-fitting operation, but the insulating material 300 does not come into contact with the slot 13. This makes it possible to avoid damage to the insulating material 300. Note that, although a gap is generated between the coil 200 and the slot 13 due to the presence of the press-fit holding protrusion 400, this gap can be utilized as an oil passage 500, and the coil 200 can be cooled by flowing cooling oil therethrough.

[0027] 2, the press-fit holding protrusion 400 is configured to gradually widen toward the gap 30 (radially inward), which facilitates the positioning and press-fitting of the first slot insertion portion 210 and the second slot insertion portion 220 when inserting the coil 200 into the slot 13.

[0028] Furthermore, the press-fit holding protrusions 400 are arranged in a staggered pattern so that their axial positions differ when viewed from the radial direction between the first slot insertion portion 210 and the second slot insertion portion 220. This allows the stress that the coil 200 receives from the press-fit holding protrusions 400 during press-fitting to be dispersed in the axial direction, thereby preventing deformation of the coil 200 and damage to the insulating material 300.

[0029] Furthermore, the press-fit holding protrusion 400 may be made of a material different from that of the insulating material 300. For example, if the press-fit holding protrusion 400 is made of a material that is softer or more elastic than the insulating material 300, the press-fit holding protrusion 400 will deform during press-fitting, making the press-fitting operation even easier.

[0030] Furthermore, by providing a recess on the surface of the tooth 12 facing the press-fit holding protrusion 400 and configuring it to fit with the press-fit holding protrusion 400, only the press-fit holding protrusion 400 deforms during press-fitting, making the press-fitting operation even easier.

[0031] 4A to 4C, the cross sections of the coil 200 at the first slot insertion portion 210 and the second slot insertion portion 220 can take various forms. Specifically, there are a configuration in which flat, rectangular coil conductors 240 are stacked radially as shown in Fig. 4A, a configuration in which rectangular coil conductors 240 are arranged circumferentially and radially as shown in Fig. 4B, and a configuration in which round coil conductors 240 are arranged circumferentially and radially as shown in Fig. 4C. In any of the configurations, the coil conductors 240 are each covered with an insulating coating (not shown) and are further covered with an insulating material 300 formed to match the shape of the slot 13.

[0032] As shown in FIG. 5A , the coil 200 includes a first slot insertion portion 210, a second slot insertion portion 220, and a winding portion 230 connecting the first and second slot insertion portions 210 and 220 at their axial ends. The first slot insertion portion 210 and the second slot insertion portion 220 are covered with an insulating material 300 (see FIGS. 4A to 4C ) formed to match the shape of the slot 13, and a total of 20 press-fit retaining protrusions 400 are provided on the outer and inner sides of the coil 200. As described above, the number of press-fit retaining protrusions 400 may be increased or decreased depending on the axial length of the coil 200, etc. Furthermore, the press-fit retaining protrusions 400 may be provided on the lower half of the coil 200, or may be provided so as to cover the entire circumference of the coil 200, including the first slot insertion portion 210, the second slot insertion portion 220, and the winding portion 230.

[0033] 5B , an insulating material 300 such as insulating paper or film may be provided with press-fit holding protrusions 400 in advance, and then attached to the coil 200. In FIG. 5B , insulating materials 300a and 300b are attached to the first slot insertion portion 210 and the second slot insertion portion 220, respectively. The insulating material 300 may be fixed to the coil 200 with an adhesive or the like, or may be fixed by another method as long as the insulating material 300 is not peeled off or damaged when the coil 200 is press-fitted into the slot 13. Furthermore, although the insulating materials 300a and 300b are configured with three sides in a roughly U-shape when viewed in the axial direction, they may also be configured with four sides in a roughly square-shape, or may be configured with some overlapping sides.

[0034] As described above, in the present invention, the coil 200 is press-fitted from the opening of the slot 13, and after press-fitting, the coil 200 is fixed by utilizing the frictional force generated by the press-fit holding protrusion 400. This eliminates the need for a heating process and reduces CO2 during manufacturing. ２ Furthermore, because no adhesive is used, the stator core 11 can be easily dismantled by pushing the coil 200 toward the opening of the slot 13, enabling resource recycling. Furthermore, because expensive equipment such as a heating device is not required during manufacturing or dismantling, capital investment and operating costs can be reduced.

[0035] The effects obtained by the present invention are shown in Figure 10C , in comparison with the conventional distributed winding shown in Figure 10A and the conventional concentrated winding shown in Figure 10B . As shown in Figure 10A , the conventional distributed winding requires heating during the welding and varnish curing processes, resulting in a problem of high energy consumption during manufacturing. Furthermore, if a failure such as insulation breakdown occurs during operation, disassembling the varnished coil and reusing the stator core requires many man-hours, which is more expensive than using a new stator core. Therefore, after a failure, there is no practical option other than to discard the stator core without disassembly. These problems are also present in the conventional concentrated winding shown in Figure 10B . On the other hand, as shown in Figure 10C , the configuration of the present invention does not require heating processes such as welding and varnish curing, making it possible to disassemble the coil and reuse the stator core after a failure.

[0036] 3 and 4A to 4C show the most stable fixation of coil 200 to stator core 11 in the present invention. That is, of the three adjacent teeth 12a, 12b, and 12c, coil 200 is wound around center tooth 12b, first slot insertion portion 210 of coil 200 is fixed to teeth 12a and 12b via press-fit retaining protrusions 400, and second slot insertion portion 220 is fixed to teeth 12b and 12c via press-fit retaining protrusions 400.

[0037] Such a coil configuration can be achieved by selecting a pole-slot combination such that the relationship between the number of slots Q, the number of phases m, the number of poles P, and the number of pole slots q per phase of the rotating electric machine 1 is expressed by equation (1) and c in equation (1) is an even number.

[0038] For example, when the number of slots Q is 12, the number of phases m is 3, and the number of poles P is 10 as shown in Fig. 1, a = 0, b = 5, and c = 2 in equation (1). Therefore, a coil configuration such as that shown in Fig. 3 can be obtained.

[0039] Second Embodiment A rotating electrical machine according to a second embodiment of the present invention will be described with reference to FIGS.

[0040] Fig. 6 is a cross-sectional view showing a schematic configuration of a rotating electric machine (motor) 1 of this embodiment. Fig. 7 is a diagram showing the structure of the slot 13 in Fig. 6. Fig. 8 is a diagram showing the structure of the coils 201 and 202 in Fig. 6.

[0041] As shown in Fig. 6, what differs from Example 1 (Fig. 1) is that a concentrated winding configuration is used, with coils 201 and 202 wound around each tooth 12. Specifically, as shown in Fig. 7, a first coil 201 and a second coil 202 are wound around adjacent teeth 12a and 12b, respectively, and the first coil 201 and the second coil 202 are arranged adjacent to each other in the circumferential direction within the same slot 13.

[0042] As shown in Figure 8, on the adjacent surfaces of the first coil 201 and the second coil 202, the first coil 201 and the second coil 202 each have at least one press-fit retaining protrusion 400, and each press-fit retaining protrusion 400 is arranged so that it is positioned differently when viewed radially, i.e., in a staggered pattern.

[0043] Even with such a concentrated winding configuration, in the present invention, the coils 201 and 202 are press-fitted from the opening of the slot 13, and after press-fitting, the coils 201 and 202 are fixed by utilizing the frictional force generated by the press-fit holding protrusion 400, so a heating process is not required and CO ２ Furthermore, because no adhesive is used, the stator core 11 can be easily disassembled by pushing the coils 201, 202 toward the openings of the slots 13, which allows for resource recycling.

[0044] Third Embodiment A rotating electrical machine according to a third embodiment of the present invention will be described with reference to FIG.

[0045] Fig. 9 is a diagram showing a schematic configuration of a rotating electric machine (motor) of this embodiment, and corresponds to Fig. 3 of embodiment 1. In embodiments 1 and 2, the explanation is based on an inner rotor type rotating electric machine, but the present invention can also be applied to an outer rotor type rotating electric machine shown in Fig. 9.

[0046] 9 , the slot 13 has an open end (open slot) in the radial direction facing the gap 30, and during manufacturing, the coil 200 is press-fitted into this opening from the radially outer side toward the radially inner side (coil press-fit direction). Both the first slot insertion portion 210 and the second slot insertion portion 220 are fixed by contact between the press-fit holding protrusion 400 and the inside of the slot 13.

[0047] The outer rotor type rotating electrical machine of this embodiment (FIG. 9) can also provide the same effects as the inner rotor type rotating electrical machine of the first embodiment (FIG. 3).

[0048] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0049] 1: rotating electric machine (motor), 10: stator, 11: stator core, 12, 12a, 12b, 12c: teeth, 13: slot, 20: rotor, 21: rotor core, 22: permanent magnet, 30: gap, 200: coil, 201: first coil, 202: second coil, 210: first slot insertion portion, 220: second slot insertion portion, 230: winding portion, 240: coil conductor, 300, 300a, 300b: insulating material, 400: press-fit retaining protrusion, 500: oil passage

Claims

1. A rotating electric machine comprising: a stator core having a plurality of teeth and a plurality of slots formed between adjacent teeth; a stator including coils wound around the teeth; and a rotor arranged opposite the stator with a predetermined gap between them and held for free rotation, wherein the slots are open at one radial end of the rotating electric machine; the coils have first and second slot insertion portions inserted into the slots, and a winding portion connecting the first and second slot insertion portions at the axial end of the rotating electric machine; the first and second slot insertion portions are covered with an insulating material formed to fit the shape of the slots; and the insulating material each has at least one protrusion formed extending in the radial direction.

2. A rotating electric machine according to claim 1, characterized in that the width of the protrusion gradually increases in the direction of the gap.

3. A rotating electric machine according to claim 1, wherein the protrusion is made of a material different from the insulating material.

4. A rotating electric machine according to claim 1, characterized in that the protrusions are located at different positions in the radial direction between the first slot insertion portion and the second slot insertion portion.

5. A rotating electric machine according to claim 1, characterized in that the relationship between the number of slots Q, the number of phases m, the number of poles P, and the number of slots per pole per phase q is expressed by equation (1), and c in equation (1) is an even number.

6. A rotating electric machine according to claim 1, characterized in that the first slot insertion portion and the second slot insertion portion are distributed windings inserted into adjacent slots, respectively.

7. A rotating electric machine according to claim 1, characterized in that the first slot insertion portion and the second slot insertion portion are concentrated windings inserted into the same slot.

8. A rotating electric machine as claimed in claim 7, wherein the coil comprises a first coil and a second coil wound around each tooth, the first coil and the second coil are arranged adjacent to each other in the circumferential direction within the same slot, and the first coil and the second coil each have at least one protrusion on the adjacent surface between the first coil and the second coil.

9. A rotating electric machine according to claim 8, characterized in that the protrusions on the adjacent surfaces of the first coil and the second coil in the same slot are positioned at different positions when viewed in the radial direction.

10. A rotating electric machine according to claim 1, characterized in that it is either an inner rotor type or an outer rotor type.

11. A rotating electric machine according to claim 1, wherein the insulating material is an insulating paper or film material having the protrusions.

12. A rotating electric machine according to claim 1, characterized in that the surfaces of the teeth facing the protrusions have recesses, and the protrusions and the recesses fit together.

Images