Winding structure for rotary electric machine and manufacturing method for the same

Abstract

To provide a winding structure capable of preventing or suppressing circulating current more effectively.SOLUTION: In a rotary electric machine 12, a winding 24 is formed by bundling a plurality of unit windings 25 in the radial direction of a stator 14. A winding structure 10 is formed by winding the winding 24 on a slot 20. One turn is defined as the state in which the winding 24 is wound once around the slot 20. The one turn has a first axial direction portion 34a, which is one of a pair of winding areas extending in the axial direction of the stator 14, and a second axial direction portion 34b, which is the other of the pair of winding areas. The order of a plurality of unit windings 25 in the radial direction is mutually reversed between the first axial direction portion 34a and the second axial direction portion 34b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a winding structure for a rotating electrical machine and a manufacturing method thereof. [Background technology]

[0002] In recent years, research and development into energy efficiency has been conducted in various fields, including the field of rotating electrical machines, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. When circulating currents occur in the stators of rotating electrical machines due to leakage flux (flux linkage), the efficiency of the machines decreases. For this reason, for example, the winding structure of Patent Document 1 attempts to suppress the generation of circulating currents by devising the cross-sectional shape of the windings (strands of wires). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-136300 Summary of the Invention [Problem to be solved by the invention]

[0004] In the winding structure of Patent Document 1, the circulating current increases depending on how the winding is wound. Therefore, it is desired to be able to more effectively prevent or suppress the circulating current.

[0005] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0006] A first aspect of the present disclosure is a winding structure for a rotating electric machine in which a unit winding is formed by bundling a plurality of wires, a winding is formed by bundling a plurality of the unit windings in the radial direction of a stator of the rotating electric machine, and the winding is wound around a slot formed between a plurality of teeth in the stator that are arranged opposite a rotor, wherein one turn of the winding is defined as one circumference of the slot, and the one turn has a first axial portion that is one of a pair of winding areas extending in the axial direction of the stator, and a second axial portion that is the other of the pair of winding areas, and the arrangement order of the plurality of unit windings in the radial direction is reversed in the first axial portion and the second axial portion.

[0007] A third aspect of the present disclosure is a manufacturing method for a winding structure formed by winding a winding around a slot formed between a plurality of teeth arranged opposite a rotor in a stator of a rotating electric machine, the method comprising: a first step of providing a winding formed by bundling a plurality of unit windings, wherein a unit winding is formed by bundling a plurality of the unit windings; and a second step of winding the winding around the slot so that one turn of the winding is defined as one turn wound around the slot, the one turn having a first axial portion that is one of a pair of winding regions extending in the axial direction of the stator and a second axial portion that is the other of the pair of winding regions, and the plurality of unit windings are aligned in the radial direction of the stator, wherein in the second step, the winding is twisted 180 degrees between the first axial portion and the second axial portion, thereby reversing the arrangement order of the plurality of unit windings in the radial direction between the first axial portion and the second axial portion. [Effects of the Invention]

[0008] According to the present invention, the arrangement order of the unit windings is reversed between the first axial portion and the second axial portion, so that the potential difference within one turn of the winding is canceled out, preventing or suppressing the generation of circulating current, thereby contributing to energy efficiency. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a winding structure of a rotating electrical machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a schematic diagram of the winding structure. [Figure 4] FIG. 4 is a circuit diagram of the winding structure. [Figure 5] FIG. 5 is a flowchart of a method for manufacturing a winding structure. DETAILED DESCRIPTION OF THE INVENTION

[0010] In Fig. 1, a plurality of teeth 18 are provided on a stator 14 of a rotating electric machine 12, facing a rotor 16. A plurality of slots 20 are formed between the plurality of teeth 18. A winding structure 10 of the rotating electric machine 12 is formed by winding a winding 24 around the plurality of slots 20. The rotating electric machine 12 may be an electric motor or a generator. The rotating electric machine 12 may be a three-phase AC electric motor or a three-phase AC generator.

[0011] The rotating electric machine 12 includes a rotor 16 and a stator 14. The radial direction of the rotor 16 and the radial direction of the stator 14 are the same direction. For this reason, hereinafter, the radial direction of the rotor 16 and the radial direction of the stator 14 may be simply referred to as the "radial direction" without distinguishing between them. Note that the "radial direction" may also be used to describe each component of the stator 14.

[0012] The rotor 16 is rotatably supported by bearings (not shown). In Fig. 1, the rotor 16 is rotatable inside the stator 14. The rotor 16 is also rotatable outside the stator 14. The rotor 16 has a plurality of permanent magnets. The number of poles of the rotating electric machine 12 corresponds to the number of permanent magnets, and can be, for example, 2, 4, 6, 8, or 10 poles.

[0013] The stator 14 includes a stator core 22 and windings 24. The stator core 22 is made of a magnetic material. The stator core 22 has an annular portion 19 and a plurality of teeth 18. One tooth 18 is representatively shown in FIG. 1. The annular portion 19 forms the outer periphery of the stator core 22. The plurality of teeth 18 protrude radially inward (in the direction R2) from the annular portion 19. That is, the plurality of teeth 18 protrude from the annular portion 19 toward the rotor 16. The plurality of teeth 18 are spaced apart at equal intervals around the circumferential direction of the stator 14. A flange portion 26 protruding on both circumferential sides is provided at the radially inner end of each tooth 18.

[0014] The winding 24 is an electrical conductor. The conductor is a wire (conductor) selected from copper, aluminum, and the like. The winding 24 is wound around the slot 20 (teeth 18) multiple times to form one coil portion 30. The multiple coil portions 30 are spaced apart in the circumferential direction of the stator 14. The stator 14 has multiple coil portions 30 for each of the U, V, and W phases. FIG. 1 shows one coil portion 30 for one of the U, V, and W phases. FIG. 1 illustrates concentrated winding, in which one coil portion 30 is arranged for each slot 20, as an example of how the winding 24 is wound. However, distributed winding, in which one coil portion 30 is arranged across multiple slots 20, may also be used.

[0015] The winding 24 is formed by bundling (overlapping) a plurality of unit windings 25 in the radial direction (R direction) of the stator 14. That is, the plurality of unit windings 25 are arranged along the radial direction of the stator 14. The plurality of unit windings 25 are electrically connected in parallel to one another. In FIG. 1, the winding 24 is divided into five unit windings 25.

[0016] Each unit winding 25 is formed by bundling a plurality of wires 250. The number of wires 250 constituting each of the plurality of unit windings 25 is the same. For example, if one winding 24 is made up of 300 wires 250, the number of wires 250 constituting each unit winding 25 is 60. The number of unit windings 25 (number of sections) constituting the winding 24 is not limited to five, and may be two or more.

[0017] When the number of the plurality of unit windings 25 is n, the plurality of unit windings 25 are arranged in order along the radial direction from the first unit winding 25a which is the first unit winding 25 to the nth unit winding 25 which is the nth unit winding 25. In this embodiment, the number of unit windings 25 is five, so the first unit winding 25a, the second unit winding 25b, the third unit winding 25c, the fourth unit winding 25d, and the fifth unit winding 25e are arranged in order along the radial direction.

[0018] As shown in FIG. 2, one turn of the winding 24 is defined as one full turn of the winding 24 wound around the slot 20. Each coil portion 30 has multiple turns because it is wound multiple times. Each turn has a first circumferential portion 32a, a second circumferential portion 32b, a first axial portion 34a, and a second axial portion 34b. The first circumferential portion 32a and the second circumferential portion 32b extend in the circumferential direction of the stator 14. The first circumferential portion 32a and the second circumferential portion 32b are spaced apart from each other in the axial direction (X direction) of the stator 14.

[0019] The first axial portion 34a and the second axial portion 34b extend in the axial direction of the stator 14. The first axial portion 34a and the second axial portion 34b are spaced apart from each other in the circumferential direction (direction C) of the stator 14. In one turn of the winding 24, the first axial portion 34a is one of a pair of winding regions extending in the axial direction of the stator 14. In one turn of the winding 24, the second axial portion 34b is the other of the pair of winding regions extending in the axial direction of the stator 14.

[0020] One turn is formed by the first circumferential portion 32a, the first axial portion 34a, the second circumferential portion 32b, and the second axial portion 34b being connected in order. The first axial portion 34a belongs to the first half region of one turn. The second axial portion 34b belongs to the second half region of one turn. The second axial portion 34b is connected to the first circumferential portion 32a of the next turn. One coil portion 30 is wound multiple times, and therefore each turn is configured as described above.

[0021] 3, the R1 direction is the radially outward direction of the stator 14, and the R2 direction is the radially inward direction of the stator 14. The arrangement order of the multiple unit windings 25 in the radial direction of the stator 14 is reversed between the first axial portion 34a and the second axial portion 34b. As described above, the stator 14 has multiple coil portions 30 for each of the U, V, and W phases. Therefore, in each of the multiple coil portions 30 for each of the U, V, and W phases, the arrangement order of the multiple unit windings 25 in the radial direction is reversed between the first axial portion 34a and the second axial portion 34b.

[0022] Specifically, in one of the first axial portion 34a and the second axial portion 34b, the first unit winding 25a is located at the radially outermost position among the plurality of unit windings 25. In the other of the first axial portion 34a and the second axial portion 34b, the first unit winding 25a is located at the radially innermost position among the plurality of unit windings 25. In this embodiment, the number of unit windings 25 is five. Therefore, the following will describe the arrangement order of the first to fifth unit windings 25a to 25e in each turn of the winding 24.

[0023] For ease of understanding, in Fig. 3, the first to fifth unit windings 25a to 25e are denoted by symbols A to E, respectively. As shown in Fig. 3, in the first axial portion 34a, the first to fifth unit windings 25a to 25e are arranged in this order toward the radially inward direction (R2). Therefore, in the first axial portion 34a, the first unit winding 25a is located at the radially outermost position among the first to fifth unit windings 25a to 25e. In the first axial portion 34a, the fifth unit winding 25e is located at the radially innermost position among the first to fifth unit windings 25a to 25e.

[0024] Meanwhile, in the second axial portion 34b, the first to fifth unit windings 25a to 25e are arranged in this order radially outward (R1). Therefore, in the second axial portion 34b, the first unit winding 25a is located at the innermost position in the radial direction among the first to fifth unit windings 25a to 25e. In the second axial portion 34b, the fifth unit winding 25e is located at the outermost position in the radial direction among the first to fifth unit windings 25a to 25e.

[0025] 2, the winding 24 is twisted 180° between the first axial portion 34a and the second axial portion 34b. The winding 24 is twisted 180° at approximately the midpoint of one turn (first circumferential portion 32a). Therefore, the first circumferential portion 32a has a twisted portion 36. Next, a method for manufacturing the winding structure 10 having the twisted portion 36 will be described.

[0026] 5, the method for manufacturing the winding structure 10 includes a first step S1 and a second step S2. First step S1 and second step S2 will be described with reference to FIG. 1 or 2. In first step S1, a unit winding 25 is formed by bundling a plurality of wires 250, and a winding 24 is provided by bundling the plurality of unit windings 25. In second step S2, the winding 24 is wound around the slot 20 so that one turn of the winding 24 has a first axial portion 34a that is one of a pair of winding regions extending in the axial direction of the stator 14 and a second axial portion 34b that is the other of the pair of winding regions, and so that the plurality of unit windings 25 are aligned in the radial direction of the stator 14.

[0027] Specifically, in a second step S2, the first axial portion 34a is wound starting from one axial side (X1 side) of the stator 14, and then the first circumferential portion 32a is wound at the other axial side (X2 side) of the stator 14, which is the turn-back position. When winding the first circumferential portion 32a, the winding 24 is twisted 180 degrees to form a twisted portion 36. In the second step S2, the winding 24 is wound multiple times so as to form a twisted portion 36 for each turn, thereby forming a coil portion 30 having multiple turns.

[0028] As a result, the radial arrangement order of the first to fifth unit windings 25a to 25e is reversed between the first axial portion 34a belonging to the first half region of one turn and the second axial portion 34b belonging to the second half region of one turn, as shown in Fig. 3. In this way, by twisting the winding 24 by 180 degrees between the first axial portion 34a and the second axial portion 34b, it is possible to easily realize a structure in which the arrangement order of the unit windings 25 is reversed between the first axial portion 34a and the second axial portion 34b.

[0029] The present embodiment configured as above has the following advantages.

[0030] During operation of the rotating electric machine 12 shown in FIG. 1, leakage magnetic flux occurs inside the rotating electric machine 12. When the leakage magnetic flux acts on the winding 24, an induced electromotive force is induced in each unit winding 25. The induced electromotive force increases as the magnetic flux density increases. The magnetic flux density of the leakage magnetic flux inside the rotating electric machine 12 increases radially inward. Therefore, if the induced electromotive forces that can be generated in the multiple unit windings 25 due to the leakage magnetic flux differ from one another depending on the relative positions of the unit windings 25, a potential difference occurs between the multiple unit windings 25, generating a circulating current.

[0031] Therefore, in the winding structure 10 of the rotating electric machine 12 according to this embodiment, the arrangement order of the plurality of unit windings 25 is reversed between the first axial portion 34a and the second axial portion 34b. Referring to FIG. 4, the magnitude relationship of the potential difference that can be generated by the induced electromotive force due to the leakage magnetic flux is shown for the first to fifth unit windings 25a to 25e in the first axial portion 34a and the second axial portion 34b. The magnitude relationship of the potential difference that can be generated by the induced electromotive force is shown in FIG. 4. <V2<V3<V4<V5である。

[0032] That is, in the first axial portion 34a, the induced electromotive force (potential difference that can be generated by the induced electromotive force) in the first unit winding 25a is the smallest, and the induced electromotive force in the fifth unit winding 25e is the largest. In the second axial portion 34b, the induced electromotive force in the first unit winding 25a is the largest, and the induced electromotive force in the fifth unit winding 25e is the smallest. As a result, the induced electromotive forces in the first to fifth unit windings 25a to 25e are equalized, and the generation of potential differences among the first to fifth unit windings 25a to 25e is prevented or suppressed. This makes it possible to prevent or suppress the generation of circulating current within one turn of the winding 24.

[0033] The following additional notes are further disclosed regarding the above embodiment.

[0034] (Appendix 1) The winding structure (10) of the rotating electric machine (12) of the present disclosure has a unit winding (25) formed by bundling a plurality of wires (250), a winding (24) formed by bundling a plurality of the unit windings in the radial direction of a stator (14) of the rotating electric machine, and the winding is wound around a slot (20) formed between a plurality of teeth (18) of the stator that are arranged opposite a rotor (16), and the winding structure of the rotating electric machine is formed by winding the winding around the slot (20), where one turn of the winding is defined as one circumference of the slot, and the one turn has a first axial portion (34a) that is one of a pair of winding areas extending in the axial direction of the stator, and a second axial portion (34b) that is the other of the pair of winding areas, and the arrangement order of the plurality of unit windings in the radial direction is reversed in the first axial portion and the second axial portion.

[0035] With this configuration, the arrangement order of the unit windings is reversed between the first axial portion and the second axial portion, so that potential differences within one turn of the winding are canceled out, preventing or suppressing the generation of circulating currents, thereby contributing to improved energy efficiency.

[0036] (Appendix 2) In the winding structure of the rotating electric machine described in Supplementary Note 1, the number of the plurality of unit windings may be n, and the plurality of unit windings may be arranged in order along the radial direction from a first unit winding (25a) that is the first unit winding to an nth unit winding that is the nth unit winding, and the first unit winding may be located at the outermost radial position among the plurality of unit windings in one of the first axial portion and the second axial portion, and the first unit winding may be located at the innermost radial position among the plurality of unit windings in the other of the first axial portion and the second axial portion.

[0037] (Appendix 3) In the winding structure of the rotating electric machine described in Supplementary Note 2, the winding may be twisted by 180° between the first axial portion and the second axial portion.

[0038] According to this configuration, it is possible to easily realize a structure in which the arrangement order of the unit windings is reversed between the first axial portion and the second axial portion.

[0039] (Appendix 4) In the winding structure of a rotating electric machine according to any one of Supplementary Notes 1 to 3, the winding may have a plurality of turns by being wound around the slot a plurality of times.

[0040] With this configuration, it is possible to prevent or suppress the generation of circulating current in the coil portion having multiple turns.

[0041] (Appendix 5) In the winding structure of a rotating electric machine described in any one of Supplementary Notes 1 to 4, a plurality of coil sections (30) may be formed by winding the winding in each of the plurality of slots, and in each of the plurality of coil sections, the arrangement order of the plurality of unit windings in the radial direction may be reversed between the first axial section and the second axial section.

[0042] With this configuration, it is possible to effectively prevent or suppress the generation of circulating current in each coil portion of the stator.

[0043] (Appendix 6) The method for manufacturing a winding structure according to the present disclosure is a method for manufacturing a winding structure (10) formed by winding a winding (24) around a slot (20) formed between a plurality of teeth (18) provided opposite to a rotor (16) in a stator (14) of a rotating electric machine (12), the method comprising the steps of: a first step (S1) of providing a winding (25) formed by bundling a plurality of wires (250) together; a second step (S2) of providing a winding formed by bundling a plurality of the unit windings together; and a third step (S3) of providing a winding (25) formed by bundling a plurality of the unit windings together, the first step (S4) of providing a winding (25) formed by bundling a plurality of the unit windings together, the first step (S5) of providing a winding (25) formed by bundling a plurality of the unit windings together, the second step (S6) of providing a winding (25) formed by bundling a plurality of the unit windings together, the second step (S7) of providing a winding (25) formed by bundling a plurality of the unit windings together, the third step (S8) of providing a winding (25) formed by bundling a plurality of the unit windings together, the third step (S9) of providing a winding (25) formed by bundling a plurality of the unit windings together, the third step (S1) of providing a winding (25) formed by bundling a plurality of the unit windings together, the fourth ... a first axial portion (34a) that is one of a pair of winding regions extending in a radial direction of the stator, and a second axial portion (34b) that is the other of the pair of winding regions, and a second step (S2) of winding the windings around the slots so that a plurality of the unit windings are aligned in a radial direction of the stator, wherein in the second step, the windings are twisted by 180° between the first axial portion and the second axial portion, thereby reversing the arrangement order of the plurality of unit windings in the radial direction between the first axial portion and the second axial portion.

[0044] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0045] 10... Winding structure 12... Rotating electric machine 14... Stator 16... Rotor 18...Teeth 20...Slot 22... Stator core 24... Winding 25...Unit winding 30...Coil section

Claims

1. A winding structure for a rotating electric machine, in which a unit winding is formed by bundling a plurality of wires, a winding is formed by bundling a plurality of the unit windings in the radial direction of a stator of the rotating electric machine, and the winding is wound in slots formed between a plurality of teeth of the stator that are provided opposite to a rotor, One turn is defined as one full turn of the winding around the slot. The one turn has a first axial portion which is one of a pair of winding regions extending in the axial direction of the stator, and a second axial portion which is the other of the pair of winding regions, A winding structure for a rotating electric machine, wherein the arrangement order of the plurality of unit windings in the radial direction is reversed between the first axial portion and the second axial portion.

2. 2. The winding structure of a rotating electric machine according to claim 1, the number of the plurality of unit windings is n, the plurality of unit windings are arranged in order along the radial direction from a first unit winding that is the first unit winding to an n-th unit winding that is the n-th unit winding, the first unit winding is located radially outermost among the plurality of unit windings in one of the first axial portion and the second axial portion; a first unit winding positioned radially innermost among the plurality of unit windings in the other of the first axial portion and the second axial portion;

3. 3. The winding structure of a rotating electric machine according to claim 2, A winding structure for a rotating electric machine, wherein the winding is twisted 180 degrees between the first axial portion and the second axial portion.

4. 2. The winding structure of a rotating electric machine according to claim 1, The winding structure of a rotating electric machine, wherein the winding has a plurality of turns by being wound around the slot a plurality of times.

5. The winding structure of a rotating electric machine according to any one of claims 1 to 4, a plurality of coil portions are formed by winding the winding in each of the plurality of slots, A winding structure for a rotating electric machine, wherein in each of the plurality of coil portions, the arrangement order of the plurality of unit windings in the radial direction is reversed between the first axial portion and the second axial portion.

6. A method for manufacturing a winding structure formed by winding a winding around a slot formed between a plurality of teeth of a stator of a rotating electric machine that are provided facing a rotor, the method comprising: a first step of providing a unit winding formed by bundling a plurality of wires, the unit winding being formed by bundling a plurality of the unit windings; a second step of winding the winding around the slot such that one turn of the winding is defined as one circumference of the winding around the slot, the one turn having a first axial portion which is one of a pair of winding regions extending in the axial direction of the stator and a second axial portion which is the other of the pair of winding regions, and a plurality of the unit windings are aligned in the radial direction of the stator; In the second step, the winding is twisted 180 degrees between the first axial portion and the second axial portion, thereby reversing the arrangement order of the plurality of unit windings in the radial direction between the first axial portion and the second axial portion.

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