Rotary electric machine and stator thereof

Abstract

The purpose of the present invention is to provide: a rotary electric machine comprising a refrigerant flow path that is effective in suppressing a decrease in a space factor; and a stator of the rotary electric machine. The stator of the rotary electric machine comprises: a stator core 21 having a slot 23; a plurality of coils 25 inserted into the slot 23 and arranged side by side in the radial direction of the stator core 21; a first insulation member 26 disposed between the plurality of coils 25 and an inner surface 23a of the slot 23; and second insulation members 27 disposed between the plurality of coils 25. The second insulating members 27 have protrusion parts 27 that are provided on one or both of radial surfaces 25-1d and 25-2c facing each other on two adjacent coils 25-1 and 25-2, the protrusion parts 27 being in contact with the other coil. The protrusion parts 27 are disposed in the circumferential direction on one coil 25, and form an inside refrigerant flow path 28a that causes the refrigerant to flow in the axial direction between the plurality of protrusion parts 27a, 27b disposed in the circumferential direction.

Description

Rotating Electric Machine and Its Stator

[0001] The present invention relates to a rotating electric machine and its stator.

[0002] In the summary of Patent Document 1 and FIG. 11, a conductor segment including a conductor, an outer peripheral insulating member, and a convex portion is described. The conductor segment includes a slot accommodating portion 111f accommodated in a slot of a stator core. The convex portion is provided linearly continuously on the outer peripheral surface of the outer peripheral insulating member in the slot accommodating portion and at a predetermined angle other than 0 degrees with respect to the axial direction of the conductor. Thereby, varnish can be retained in the slot, and the fixing force of the conductor can be improved. Further, in paragraphs 0064 and FIGS. 20 to 22 of Patent Document 1, a configuration is described in which the convex portion is provided on the outer peripheral surface of the outer peripheral insulating member facing the outer peripheral surface of the outer peripheral insulating member of another slot accommodating portion. Further, in paragraphs 0067 and FIGS. 23 to 25, a configuration is described in which the convex portion is provided on the outer peripheral surface of the outer peripheral insulating member at the corner portion of the conductor as viewed from the axial direction of the conductor.

[0003] Japanese Unexamined Patent Application Publication No. 2017-34883

[0004] In Patent Document 1, the purpose is to improve the fixing force of the conductor while suppressing a decrease in the filling factor, and there is no consideration for forming a refrigerant flow path around the conductor, and a configuration of a refrigerant flow path effective for suppressing a decrease in the filling factor is not disclosed.

[0005] An object of the present invention is to provide a rotating electric machine provided with a refrigerant flow path effective for suppressing a decrease in the filling factor and its stator.

[0006] To achieve the above objective, the stator of the rotating electric machine of the present invention comprises: a stator core having slots; a plurality of coils inserted into the slots and arranged radially in line with the stator core; a first insulating member disposed between the plurality of coils and the inner surface of the slots; and a second insulating member disposed between the plurality of coils, wherein each coil has a conductor and an insulating coating that covers the outer circumference of the conductor to provide electrical insulation; the second insulating member has projections provided on either or both of the radial surfaces of two adjacent coils that face each other and that contact the other coil; a plurality of these projections are arranged circumferentially in one coil, forming an inner refrigerant flow path between the circumferentially arranged projections that allows refrigerant to flow axially.

[0007] According to the present invention, it is possible to provide a rotating electric machine and its stator equipped with a refrigerant flow path that is effective in suppressing a decrease in the space factor.

[0008] Other issues, configurations, and effects not mentioned above will be clarified by the following description of embodiments for carrying out the invention.

[0009] This is a cross-sectional view showing a rotating electric machine according to one embodiment of the present invention. This is an enlarged cross-sectional view showing the vicinity of one slot in the cross-sectional view of Figure 1. This is a cross-sectional view showing the III-III section of Figure 2. This is a cross-sectional view showing the cross-section of one coil in Figure 2. This is a perspective view showing a coil according to one embodiment of the present invention. This is a perspective view showing a modification example 1 of the coil according to one embodiment of the present invention. This is a perspective view showing a modification example 2 of the coil according to one embodiment of the present invention. This is a perspective view showing a modification example 3 of the coil according to one embodiment of the present invention. This is a diagram showing a method for assembling a coil according to one embodiment of the present invention.

[0010] In the following explanation, similar components in each figure will be denoted by the same reference numeral to avoid repetition of similar explanations. Furthermore, if there are differences among components denoted by the same reference numeral, those differences will be explained.

[0011] A rotating electric machine 1 according to one embodiment of the present invention will be described using Figures 1 and 2. Figure 1 is a cross-sectional view showing a rotating electric machine 1 according to one embodiment of the present invention. Figure 2 is an enlarged cross-sectional view showing the vicinity of one slot 23 in the cross-sectional view of Figure 1. The cross-section shown in Figure 1 is a cross-section perpendicular to the central axis (axis) of the rotating shaft 38. In the following description, the direction along the central axis of the rotating shaft 38 will be referred to as the "axial direction". Unless otherwise specified, "circumferential direction" and "radial direction" refer to the "circumferential direction" and "radial direction" of the rotating electric machine (stator core, rotor core).

[0012] As shown in Figure 1, the rotating electric machine 1 has a stator 2 and a rotor 3. In this embodiment, an internal rotation type rotating electric machine 1 is described in which the rotor 3 is arranged on the inner circumference side of the stator 2. The rotating electric machine to which the present invention can be applied is not limited to the internal rotation type rotating electric machine 1, but can also be applied to an external rotation type rotating electric machine.

[0013] The stator 2 has a stator core 21. The stator core 21 has a plurality of teeth 22 arranged at intervals in the circumferential direction, a plurality of slots 23 formed between adjacent teeth 22, and a yoke 24 connecting the plurality of teeth 22. The yoke 24 constitutes the outer periphery of the stator core 21, and the teeth 22 are provided to protrude inward from the yoke 24.

[0014] The stator core 21 is housed in a housing (not shown) and supported by the housing. The stator 2 is positioned such that its inner circumferential surface (the tip surface of the teeth 22) faces the outer circumferential surface of the rotor core 31. A gap G is provided between the inner circumferential surface of the stator core 21 and the outer circumferential surface of the rotor core 31.

[0015] Coils 25 are wound around the slots 23 of adjacent stator cores 21. A portion of the coil 25 is inserted into the slot 23, and the portion exposed outside the slot 23 forms the coil end. The segment coil 25 will be described simply as a "coil".

[0016] The rotor 3 comprises a rotor core 31, a plurality of magnets (permanent magnets) 32 that constitute the magnetic poles, and a rotating shaft 38. In this embodiment, an example is shown in which one magnetic pole is composed of two magnets 32, but the configuration of the magnets is not limited to the configuration of this embodiment, and other configurations may be adopted.

[0017] As shown in Figure 2, the stator 2 of the rotating electric machine 1 has a stator core 21. The stator core 21 has slots 23. Multiple slots 23 are arranged on the inner circumference side of the stator core 21, spaced apart in the circumferential direction. Teeth 22 are formed between the multiple slots 23. A yoke 21a is provided on the outer circumference side of the stator core 21. The teeth 22 are configured to protrude inward from the yoke 21a. The tip surface 22a of the teeth 22 faces the outer circumference surface of the rotor core 31 (see Figure 1) of the rotor 3, with a small gap G between them.

[0018] Multiple coils 25 are inserted through slot 23. The multiple coils 25 are arranged in a line along the radial direction D1 of the stator core 21. Figure 2 shows an example in which four coils 25 are arranged in one slot 23, but the number of coils 25 is not limited to four. In addition, the four coils 25 are distinguished by assigning the symbols "25-1" to "25-4" from the innermost diameter side to the outermost diameter side.

[0019] A first insulating member 26 is placed between the multiple coils 25 and the inner surface 23a of the slot 23. The first insulating member 26 is a sheet-like material that surrounds the four coils 25 arranged in the radial direction D1 and is positioned to be interposed between the four coils 25 and the inner surface 23a of the slot 23. By using foamed insulating paper for the first insulating member 26, the coils 25 can be fixed to the inner circumferential surface of the slot 23.

[0020] The coils 25 arranged in the slots 23 of the stator core 21 will be described using Figures 3 and 4 in conjunction with Figure 2. Figure 3 is a cross-sectional view showing the section taken along line III-III in Figure 2. Figure 4 is a cross-sectional view showing the section of one coil 25 in Figure 2. As shown in Figure 2, a second insulating member 27 is arranged between two adjacent coils 25 in a plurality of coils 25. The second insulating member 27 is provided on the coil 25 so as to be integrated with the coil 25. By forming the second insulating member 27 to be integrated with the coil 15, it becomes possible to insert it into the slot 23 in the same process as a conventional coil without the second insulating member 27.

[0021] The second insulating member 27 is composed of protrusions. For this reason, in this embodiment, "second insulating member" and "protrusions" are used as synonyms. The second insulating member (protrusions) 27 may be made of resin. In this embodiment, the second insulating member 27 has a circular cross-section when viewed from the radial direction D1 and is composed of granular protrusions.

[0022] The second insulating member 27 forms gaps (spaces) 28a and 28b between two adjacent coils 25. These gaps 28a and 28b serve as refrigerant flow paths. For this reason, reference numerals 28a and 28b are also used for refrigerant flow paths.

[0023] The coil 25 has circumferential surfaces 25e and 25f (see Figure 4) that face the inner surface 23a of the slot 23 in the circumferential direction D2, and these surfaces face the inner surface 23a without the second insulating member 27 in between. In this case, the first insulating member 26 is interposed between the circumferential surfaces 25e and 25f of the coil 25 and the inner surface 23a.

[0024] In this embodiment, two second insulating members 27 are provided spaced apart in the circumferential direction D2 of the stator core 21. Between the two second insulating members 27a and 27b, a central refrigerant flow path 28a is formed, located in the center of the slot 23 in the circumferential direction D2. Between one of the two second insulating members 27a and the adjacent inner surface 23a, a side refrigerant flow path 28b is formed, located on the side of the slot 23 in the circumferential direction D2. Furthermore, between the other second insulating member 27b and the adjacent inner surface 23a, a side refrigerant flow path 28c is formed, located on the side of the slot 23 in the circumferential direction D2. In other words, the projection 27 forms gaps 28a, 28b (or 28a, 28c) on both sides of the projection 27 in the circumferential direction D2 between two adjacent coils 25, allowing refrigerant to flow. The central refrigerant flow path 28a and the side refrigerant flow paths 28b and 28c do not need to be separated within the slot 23; by shaping them as described later, they can be configured to communicate with each other within the slot 23.

[0025] As shown in Figure 3, the second insulating member 27 is composed of a plurality of protrusions arranged along the axial direction D3. The plurality of protrusions 27 are spaced apart in the axial direction D3. By arranging the protrusions 27 along the axial direction D3, it becomes possible to uniformly form the gap (refrigerant flow path) 28 between adjacent coils 25 in the slot 23 along the axial direction D3, thereby making the cooling performance uniform.

[0026] Since the second insulating member 27 is a member that forms the refrigerant flow path 28, in this embodiment, the second insulating member 27 is provided in coils 25-1, 25-2, and 25-3, but not in coil 25-4. It is also possible to provide the second insulating member 27 in coils 25-2, 25-3, and 25-4, but not in coil 25-1. The second insulating member 27 is not limited to these configurations, and may be placed between adjacent coils 25.

[0027] As shown in Figure 4, the coil 25 is composed of a segment coil having an insulating coating such as enamel. The coil 25 has an electrical conductor (hereinafter referred to as "conductor") 25a and an insulating coating 25b that covers the outer circumference of the conductor 25a to provide electrical insulation. The second insulating members 27a and 27b can also be considered as part of the coil 25.

[0028] In this embodiment, the second insulating member 27 is provided on one of the two radial surfaces 25c and 25d of the coil 25, specifically on one of the radial surfaces 25d. The radial surfaces 25c and 25d are surfaces facing the radial direction D1, and in this embodiment, they are surfaces perpendicular to the radial direction D1. One of the radial surfaces 25d faces the outer diameter side.

[0029] The second insulating member 27 may be provided on the other radial surface 25c. Alternatively, the second insulating member 27 may be provided on both of the two radial surfaces 25c and 25d.

[0030] Returning to Figure 2, the second insulating member 27 will be described. In this embodiment, the second insulating member 27 is provided on one of the radial surfaces 25-1d and 25-2c of two adjacent coils 25, for example coils 25-1 and 25-2, and contacts the radial surface 25-2c of the other coil 25-2. In other words, in this embodiment, the second insulating member (projection) 27 is provided on coil 25-1 and contacts coil 25-2.

[0031] As described above, the second insulating member 27 may be provided on the radial surface 25-2c of the coil 25-2. Alternatively, the second insulating member 27 may be provided on both the mutually opposing radial surfaces 25-1d and 25-2c of the coil 25-1 and the coil 25-2. In this case, the second insulating member 27 provided on one of the mutually opposing radial surfaces 25-1d and 25-2 of the coils 25-1 and 25-2 may be configured to contact the second insulating member 27 provided on the other coil 25-2. In this case, the second insulating member (projection) 27 provided on the coil 25-1 contacts the coil 25-2 by contacting the second insulating member 27 provided on the coil 25-2.

[0032] As described above, the second insulating member 27 of this embodiment has projections provided on one or both of the mutually opposing radial surfaces 25-1d and 25-2c of two adjacent coils 25, for example, coils 25-1 and 25-2, that contact the other coil. Multiple projections 27 are arranged circumferentially in one coil 25, and an inner refrigerant flow path 28a is formed between the multiple circumferentially arranged projections 27 that allow refrigerant to flow axially. In this case, the second insulating member 27 is composed of projections provided on one of the two adjacent coils 25-1 and 25-2, and the projections 27 contact both radial surfaces 25-1d and 25-2c of the two adjacent coils 25.

[0033] In this embodiment, a refrigerant such as oil is flowed through the refrigerant passage 28 to cool the coil. According to this embodiment, by directly providing the second insulating member 27 to the coil 25, the stator 2 can be assembled in the same process as in the conventional method, and the refrigerant passage 28 can be formed while suppressing an increase in cycle time. Since the second insulating member 27 follows the deformation of the coil 25, it is easy to insert into the slot 23, the same dimensional setting as in the conventional method is possible, and a decrease in the coil's packing ratio can be suppressed. In addition, since the second insulating member 27 is directly molded to the coil 25, the insulating coating 25b of the coil 25 is not damaged when inserting the coil.

[0034] By adding the second insulating member 27 to the conventional structure, a refrigerant flow path 28 can be formed, thereby suppressing an increase in direct material costs and a decrease in the space utilization ratio. For this reason, the cooling structure realized by the second insulating member (projection) 27 of this embodiment is superior to conventional cooling structures in terms of productivity and cost, and losses can be reduced by improving the space utilization ratio of the coil.

[0035] The second insulating member 27 will be described in more detail, including modified examples, using Figures 5 to 8. Figure 5 is a perspective view showing a coil 25 according to one embodiment of the present invention. In this embodiment, the second insulating member 27 is configured as granular protrusions and is provided on the radial surface 25d of the coil 25. That is, the protruding (granular) second insulating member 27 is directly provided on the radial surface 25d of the coil 25.

[0036] Figure 6 is a perspective view showing a modified example 1 of the coil 25 according to one embodiment of the present invention. The second insulating member 27 in this example has a base portion 271 provided on the radial surface 25d of the coil 25. In this case, the second insulating member 27, which is a projection, protrudes in a direction away from the radial surface 25d. In this case, the base portion 271 has a plurality of projections 27.

[0037] For example, the second insulating member (projection) 27 is provided on a sheet (film) shaped base 271, and the back surface of the base 271 is an adhesive surface. The second insulating member (projection) 27 is provided on the coil 25 by attaching the base 271 to the radial surface 25d of the coil 25. In other words, the base 271 of the second insulating member 27 in this example is made of a film-like material, and the base 271 is attached to the radial surface 25d of the coil 25.

[0038] In this example as well, similar to the previously described embodiment, the stator 2 can be assembled using the same process as in the conventional method, and the refrigerant flow path 28 can be formed while suppressing an increase in cycle time. Furthermore, by forming a protrusion on the base 271 in advance with a resin member, it is no longer necessary to wait for the resin member to harden during the assembly process, and the cycle time can be further shortened.

[0039] Furthermore, in this example, since the base portion 271 is made of a film-like material having an adhesive surface, the projection portion 27 can be integrated with the coil 25 simply by attaching the base portion 271 to the surface of the coil 25, making it easy to integrate the second insulating member (projection portion) 27 and the coil 25 during the assembly process.

[0040] Figure 7 is a perspective view showing a modified example 2 of the coil 25 according to one embodiment of the present invention. The second insulating member 27 in this example is composed of a projection formed linearly along the axial direction D3 (see Figure 3).

[0041] In this example as well, the same effects as in the previously described embodiment can be obtained. Furthermore, since the projection 27 is formed along the axial direction D3, it becomes possible to uniformly form the gap (refrigerant flow path) 28 between adjacent coils 25 in the slot 23 along the axial direction D3, thereby making the cooling performance uniform.

[0042] FIG. 8 is a perspective view showing a modification 3 of the coil 25 according to an embodiment of the present invention. The second insulating member (protrusion) 27 in this example has the same shape as that in the modification 2 and has a sheet-like base portion 271 similar to that in the modification 1. Also in this example, the same effects as those described in the above-described embodiment, modification 1, and modification 2 can be obtained.

[0043] The method of assembling the coil 25 will be described with reference to FIG. 9. FIG. 9 is a diagram showing a method of assembling the coil 25 according to an embodiment of the present invention. Conventionally, a method of assembling a coil in which a bobbin is disposed in a slot and the coil is inserted into the bobbin is known. In this case, spacers (protrusions) are formed on the bobbin, and the coil cannot be chucked together and inserted into the bobbin, that is, the slot. As a result, conventionally, it has been necessary to insert the coils one by one into the slot, and there has been a problem that the tact time increases.

[0044] In addition, in order to ensure the insertability of the coil, there have been problems such as an increase in tact time and a decrease in occupation ratio, such as a need for high dimensional accuracy (straightness) of the coil or a need for a dimension setting with a margin in the bobbin.

[0045] Further, since the bobbin is harder than the insulating paper, there is a possibility that the coil film may be damaged and the insulation performance may be reduced when the coil and the bobbin come into contact with each other during coil insertion.

[0046] In this example, with the second insulating member (protrusion) 27 attached to the coil 25, the coils 25 corresponding to the number to be inserted into the slot 23 are chucked together and inserted into the slot 23. A refrigerant flow path 28 is secured by the second insulating member (protrusion) 27 between the plurality of coils 25 inserted into the slot 23. The first insulating member 26 is previously placed in the slot 23. By such a method of assembling the coil 25, the above-described problems are solved.

[0047] The stator 2 of the rotating electrical machine 1 in the above-described embodiment has the following characteristics. (1) A stator core 21 having slots 23, a plurality of coils 25 inserted through the slots 23 and arranged side by side in the radial direction of the stator core 21, a first insulating member 26 disposed between the plurality of coils 25 and the inner surface 23a of the slots 23, and a second insulating member 27 disposed between the plurality of coils 25. The coil 25 has a conductor 25a and an insulating coating 25b that covers the outer periphery of the conductor 25a and electrically insulates it. The second insulating member 27 has protrusions 27 provided on either one or both of the radially facing surfaces 25-1d and 25-2c of two adjacent coils 25-1 and 25-2 and contacting the other coil. The protrusions 27 are arranged in plurality in the circumferential direction in one coil 25, and an inner refrigerant flow path 28a for flowing refrigerant along the axial direction is formed between the plurality of protrusions 27a and 27b arranged in the circumferential direction.

[0048] (2) The protrusions 27a and 27b form gaps 28b and 26c through which the refrigerant flows on both sides in the circumferential direction D2 with respect to the protrusions 27a and 27b between two adjacent coils 25-1 and 25-2.

[0049] (3) The circumferential surfaces 25e and 25f of the coil 25 that face the inner surface 23a of the slot 23 in the circumferential direction D2 face the inner surface 23a without passing through the protrusions 27.

[0050] (4) The second insulating member 27 has a base portion 271 provided on the radial surface 25d of the coil 25.

[0051] (5) The second insulating member 27 is composed of protrusions 27 provided on one of two adjacent coils 25-1 and 25-2, and the protrusions 27 contact both of the radially facing surfaces 25-1d and 25-2c of two adjacent coils 25-1 and 25-2.

[0052] (6) The protrusions 27 are arranged in plurality along the axial direction D3.

[0053] (7) The plurality of protrusions 27 are arranged at intervals in the axial direction D3.

[0054] (8) The second insulating member 27 is composed of a projection that is formed linearly along the axial direction D3.

[0055] (9) The second insulating member 27 is provided on the coil 25 so as to be integrated with the coil 25.

[0056] (10) The base portion 271 of the second insulating member 27 is made of a film-like material, and the base portion 271 is attached to the radial surface 25d of the coil 25.

[0057] (11) The rotating electric machine 1 comprises a stator 2 of the rotating electric machine 1 described in (1) to (10), and a rotor 3 facing the stator 2 with a predetermined air gap G between them.

[0058] It should be noted that the present invention is not limited to the embodiments and modifications described above, and includes various modifications. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all of the above configurations. Furthermore, it is possible to add, delete, or replace some of the configurations in the embodiments and modifications with other configurations.

[0059] 1...rotating electric machine, 2...stator, 3...rotor, 21...stator core, 23...slot, 23a...inner surface of slot 23, 25, 25-1, 25-2...coil, 25a...conductor of coil 25, 25b...insulating coating of coil 25, 25d, 25-1d, 25-2c...radial surface of coil 25, 25e, 25f...circumferential surface of coil 25, 26 first insulating member, 27, 27a, 27b...second insulating member (projection), 28a...inner refrigerant flow path, 28b, 26c...gap for refrigerant flow (outer refrigerant flow path), 271...base of second insulating member, D2...circumferential direction, D3...axial direction, G...air gap.

Claims

A stator core having slots, A plurality of coils inserted into the slot and arranged radially in line with the stator core, A first insulating member is disposed between the plurality of coils and the inner surface of the slot, A second insulating member is disposed between the plurality of coils, Equipped with, The coil comprises a conductor and an insulating coating that covers the outer circumference of the conductor to provide electrical insulation. The second insulating member has projections provided on either or both of the radial surfaces of two adjacent coils that face each other, and which contact the other coil. The aforementioned projections are arranged in multiple circumferential directions on a single coil, forming an inner refrigerant flow path between the multiple circumferentially arranged projections that allows refrigerant to flow axially, in the stator of a rotating electric machine. 　 A stator for a rotating electric machine according to claim 1, The aforementioned projection is a stator of a rotating electric machine that forms a gap between two adjacent coils, allowing refrigerant to flow on both sides of the projection in the circumferential direction. 　 A stator for a rotating electric machine according to claim 1, The coil is a stator for a rotating electric machine in which the circumferential surface facing the inner surface of the slot in the circumferential direction faces the inner surface without the projection. 　 A stator for a rotating electric machine according to claim 1, The second insulating member is a stator of a rotating electric machine having a base provided on the radial surface of the coil. 　 A stator for a rotating electric machine according to claim 1, The second insulating member is composed of the projection provided on one of the two adjacent coils, The aforementioned projection is a stator of a rotating electric machine that contacts the radial surfaces of both of the two adjacent coils. 　 A stator for a rotating electric machine according to claim 1, The aforementioned protrusions are stators of a rotating electric machine, with multiple protrusions arranged along the axial direction. 　 A stator for a rotating electric machine according to claim 6, The multiple protrusions are arranged at axial distances from each other in the stator of a rotating electric machine. 　 A stator for a rotating electric machine according to claim 1, The second insulating member is a stator of a rotating electric machine, comprising projections formed linearly along the axial direction. 　 A stator for a rotating electric machine according to claim 1, The second insulating member is a stator of a rotating electric machine, provided on the coil so as to be integrated with the coil. 　 A stator for a rotating electric machine according to claim 4, The base of the second insulating member is made of a film-like material. The base is a stator of a rotating electric machine attached to the radial surface of the coil. 　 A rotating electric machine comprising a stator as described in claim 1, and a rotor facing the stator with a predetermined air gap between them.

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