Stator and rotating electric machine

Abstract

Consistent quality can be ensured. [Solution] The stator comprises a plurality of phase coils and a bobbin around which the coils are wound. The bobbin has a plurality of grooves spaced apart from each other along its circumferential surface, each capable of accommodating a coil of each phase such that gaps are formed between adjacent coils of different phases in the radial direction. The plurality of grooves have different radial dimensions, and the outermost layer of the coil is a fusion layer.

Description

Technical Field

[0001] Embodiments of the present invention relate to a stator and a rotating electrical machine.

Background Art

[0002] Patent Document 1 discloses a bobbin in which the radial dimensions of a plurality of groove portions capable of accommodating coils of each phase are formed to be different. By providing steps in the plurality of groove portions, interference in the circumferential direction between the coils of each phase accommodated in the plurality of groove portions is suppressed, and the forming work of the coil ends is made unnecessary.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the conventional configuration, phase insulation paper is provided in the gap between the coils of different phases in order to ensure the insulation between the coils of different phases. Depending on, for example, the type of coil, it may be difficult to uniformly secure the gap between the coils of different phases, and it may be necessary to apply an external force to the coil in the operation of providing the phase insulation paper. In this case, there is a risk that the coil may be damaged, and there is room for improvement in ensuring stable quality.

[0005] Therefore, embodiments of the present invention provide a stator and a rotating electrical machine capable of ensuring stable quality.

Means for Solving the Problems

[0006] The stator of the embodiment comprises a plurality of phase coils and a bobbin around which the coils are wound, wherein the bobbin has a plurality of grooves spaced apart from each other along the circumferential surface of the bobbin, each capable of accommodating the coils of each phase such that gaps are formed between the radially adjacent coils of different phases, the plurality of grooves each having different radial dimensions, and the outermost layer of the coil is a fusion layer. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic front view showing an example of a rotating electric machine according to one embodiment. [Figure 2] A perspective view showing an example of a stator according to one embodiment, with the coil wound around the bobbin. [Figure 3] A cross-sectional view showing an example of the coil structure for a stator according to one embodiment. [Figure 4] A front view showing an example of a stator according to one embodiment, in which the coils of each phase are housed in each groove. [Figure 5] A cross-sectional view showing an enlarged view of the periphery of each groove in a stator according to one embodiment. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings. In each drawing, for the sake of explanation, the dimensions of each component may be enlarged as needed, and the dimensional ratios of each component may not be the same as in reality. The rotating electric machine 1 of the embodiment shown in Figure 1 is composed of, for example, a coreless type rotating electric machine. As shown in Figure 1, the rotating electric machine 1 is composed of a frame 10, a rotor 20, and a stator 30. In the following description, the direction parallel to the rotation center axis O of the rotor 20 will be referred to as the axial direction. When the rotor 20 is rotated around the rotation center axis O, the direction in which the outer surface of the rotor 20 rotates will be referred to as the circumferential direction. The direction perpendicular to the rotation center axis O will be referred to as the radial direction.

[0009] The frame 10 constitutes the outer shell of the rotating electric machine 1. The frame 10 is formed, for example, in a cylindrical shape. The frame 10 has, for example, a plurality of fins (not shown) for heat dissipation. The plurality of fins are formed to protrude radially from the outer circumferential surface of the frame 10. The rotor 20 is arranged inside the frame 10. The rotor 20 as a whole is formed, for example, in a cylindrical shape centered on the rotation axis O. The rotor 20 is provided, for example, inside the stator 30 and is rotatably mounted relative to the stator 30 with a gap between them. The rotating electric machine 1 is configured, for example, as an inner rotor type rotating electric machine.

[0010] The rotor 20 has permanent magnets (not shown). Multiple permanent magnets are arranged circumferentially along the outer surface of the rotor 20 at intervals. The rotor 20 is configured to rotate integrally with the shaft 21 around the rotational axis O. The rotational axis of the shaft 21 coincides with the rotational axis O of the rotor 20.

[0011] The stator 30 is fixed inside the frame 10. The stator 30 is formed in a generally cylindrical shape, for example. The inner diameter of the stator 30 is set to be slightly larger than the outer diameter of the rotor 20. The stator 30 has a bobbin 40, a coil 50, and a back yoke 60. The bobbin 40 is made of, for example, an insulating synthetic resin and is formed in a cylindrical shape. Multiple phase coils 50 are wound around the outer circumference of the bobbin 40. Alternatively, the coils 50 may be wound around the inner circumference of the bobbin 40.

[0012] In this embodiment, the coil 50 is constructed using a so-called wave winding method, as shown in Figure 2, where the wires are arranged in a wave-like pattern on the bobbin 40. The winding method of the coil 50 is not limited to wave winding; other winding methods such as concentric winding or overlapping winding may also be used. The coil 50 is constructed using a winding 51 made of, for example, round wire. The type of winding 51 is not limited to round wire; other shapes such as flat wire or Litz wire may also be used.

[0013] In this embodiment, the winding 51 is made of self-fusing wire. As shown in Figure 3, the winding 51 includes a conductor 511, an insulating layer 512, and a fusion layer 513. The conductor 511 is made of a conductive metal such as copper or a copper alloy, and is formed by twisting together, for example, one strand or multiple strands. The insulating layer 512 covers the conductor 511. The insulating layer 512 is made of a resin such as polyurethane or polyamide, and is formed by baking it onto the outer circumference of the conductor 511, for example.

[0014] The fusion layer 513 covers the insulating layer 512 and constitutes the outermost layer of the windings 51, i.e., the coil 50. The fusion layer 513 is intended to bond adjacent windings 51 together. The fusion layer 513 melts, for example, by heating and then solidifies by cooling. In this embodiment, the coil 50, which has been formed into a predetermined shape using multiple windings 51, is heated and then cooled to firmly fix the multiple windings 51 together. In this way, the coil 50 becomes self-supporting, without being affected by the weight or winding kinks of the windings 51. Note that the fusion layer 513 is not limited to a configuration that melts by heating; other fusion methods such as solvent fusion, which dissolves with a solvent, may also be applied.

[0015] The coil 50 is composed of, for example, coils for each of the three phases, namely the U-phase coil 501 as the first coil, the V-phase coil 502 as the second coil, and the W-phase coil 503 as the third coil. The outer diameters of the coils 501, 502, and 503 for each phase are set to be approximately the same. In this embodiment, the coils 501, 502, and 503 for each phase are composed of the same number of windings, and each is composed of multiple windings, for example, five windings 51 as one set. In addition, the coils 501, 502, and 503 for each phase are connected to connection terminals.

[0016] The coils 501, 502, and 503 of each phase are wound in a single layer around the bobbin 40, for example. In this case, the W-phase coil 503 is wound around the entire circumference of the bobbin 40 first, and then the V-phase coil 502 and U-phase coil 501 are wound sequentially around the entire circumference of the bobbin 40, thereby forming a cylindrical coil 50 overall. The winding order of the coils 501, 502, and 503 of each phase on the bobbin 40 can be set arbitrarily.

[0017] The back yoke 60 is made of a magnetic material such as electrical steel sheet and is formed in a cylindrical shape. A bobbin 40, around which the coil 50 is wound, is fitted and fixed to the inner surface of the back yoke 60. The back yoke 60, which is integrated with the bobbin 40, is then fixed to the frame 10.

[0018] As shown in Figures 4 and 5, the bobbin 40 has a main body portion 41 and groove portions 42. The main body portion 41 is formed in a cylindrical shape and constitutes the main body of the bobbin 40. The groove portions 42 are provided at intervals from each other along the circumferential surface of the main body portion 41. When the coil 50 is wound on the inner circumference of the bobbin 40, the groove portions 42 are provided at intervals from each other along the inner circumferential surface of the main body portion 41. The spacing between the groove portions 42 is set to be, for example, equal. The spacing between the groove portions 42 may be unequal.

[0019] Multiple grooves 42 are provided to accommodate the coils 501, 502, and 503 of each phase. In this case, the groove 42 has a U-phase groove 42a as a first groove for accommodating the U-phase coil 501, a V-phase groove 42b as a second groove for accommodating the V-phase coil 502, and a W-phase groove 42c as a third groove for accommodating the W-phase coil 503. The coils 501, 502, and 503 have improved moldability due to the fusion layer 513, and can form an outer shape corresponding to the shape of the groove 42. As a result, the stator 30 can improve the conductor space factor. Note that in Figure 4 and other figures, only some of the reference numerals for each groove 42a, 42b, and 42c are given to make the drawings easier to read, and the reference numerals for the other grooves 42a, 42b, and 42c are omitted.

[0020] The radial dimensions of the respective groove portions 42a, 42b, 42c corresponding to the coils 501, 502, 503 of each phase, that is, the dimensions from the peripheral surface of the bobbin 40 to the bottom surfaces of the respective groove portions 42a, 42b, 42c, are different from each other. Therefore, steps can be provided in the plurality of groove portions 42a, 42b, 42c. Thus, interference in the circumferential direction between the coils 501, 502, 503 of each phase accommodated in the plurality of groove portions 42a, 42b, 42c can be suppressed, so that the forming operation of the coil ends can be made unnecessary. As a result, the quality of the coil 50 can be improved and the workability can be improved.

[0021] As shown in FIG. 5, the relationship among the groove depth H1 of the groove portion 42a, the groove depth H2 of the groove portion 42b, and the groove depth H3 of the groove portion 42c is such that the relationship H3 > H2 > H1 holds. The maximum dimension H3 of the groove depth of each of the groove portions 42a, 42b, 42c is set to be larger than three times the outer diameter of the coil 50. In the present embodiment, the dimensional difference ΔH of the groove depth H between the adjacent groove portions 42a, 42b, 42c is set to be larger than the outer diameter dimension of the coil 50. Therefore, the coils 501, 502, 503 of each phase are accommodated in the respective groove portions 42a, 42b, 42c so as not to overlap in the circumferential direction of the bobbin 40. And, as shown in FIG. 4, a gap 50d is formed between the coils 501, 502, 503 of each adjacent phase in the radial direction of the stator 30. The gap 504 is formed over the entire circumference along the circumferential direction of the bobbin 40.

[0022] The gap 504 includes an outer gap 504a and an inner gap 504b. The outer gap 504a is located between the U-phase coil 501 and the V-phase coil 502. The inner gap 504b is located between the V-phase coil 502 and the W-phase coil 503. The outer gap 504a is located radially outside the inner gap 504b. In other words, the inner gap 504b is located radially inside the outer gap 504a. The radial dimensions of the outer gap 504a and the inner gap 504b are set to be substantially the same. The radial dimensions of the outer gap 504a and the inner gap 504b are not limited to being substantially the same and may be different.

[0023] In this embodiment, the coils 501, 502, and 503 of each phase can be placed on the bobbin 40 while maintaining their molded state due to the adhesive effect of the fusion layer 513. As a result, the outer gap 504a and the inner gap 504b are kept at approximately the same dimensions as the design values. Therefore, a space is reliably secured between the coils 501, 502, and 503 of each phase in the radial direction, and stable insulation can be obtained without requiring, for example, interphase insulating paper or varnish.

[0024] According to the embodiment described above, the stator 30 comprises coils 501, 502, and 503 of multiple phases, and a bobbin 40 around which the coils 501, 502, and 503 are wound. The bobbin 40 has multiple grooves 42a, 42b, and 42c. The multiple grooves 42a, 42b, and 42c are provided spaced apart from each other along the circumferential surface of the bobbin 40, and are capable of accommodating the coils 501, 502, and 503 of each phase such that a gap 504 is formed between the radially adjacent coils 501, 502, and 503 of different phases. The multiple grooves 42a, 42b, and 42c each have different radial dimensions. The outermost layer of the coils 501, 502, and 503 is a fusion layer 513.

[0025] According to this, since coils 501, 502, and 503 have a fusion layer 513, coils 501, 502, and 503 can be easily formed into the desired shape and stand upright. This ensures that space is provided between each coil 501, 502, and 503 placed on the bobbin 40. As a result, insulation can be ensured without, for example, the provision of interphase insulating paper, eliminating the need for coil forming, thus eliminating the risk of damage to the coil 50 and ensuring stable quality. Furthermore, costs can be reduced by eliminating the need for interphase insulating paper and varnish. In addition, since, for example, the insertion of interphase insulating paper can be omitted, it becomes easier to automate coil production.

[0026] The coils 501, 502, and 503 of each phase are housed in the grooves 42a, 42b, and 42c such that they do not overlap in the circumferential direction of the bobbin 40. This prevents interference between the coils 501, 502, and 503 of different phases in the circumferential direction of the bobbin 40, thereby improving the quality of the coils 50.

[0027] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0028] In the drawing, 1 represents the rotating electric machine, 20 the rotor, 30 the stator, 40 the bobbin, 42a, 42b, and 42c the grooves, 501, 502, and 503 the coils, 504 the gaps, and 513 the fusion layer.

Claims

1. Multiple phase coils, The system comprises a bobbin around which the coil is wound, The bobbin has a plurality of grooves provided at intervals along the circumferential surface of the bobbin, each capable of accommodating the coils of each phase such that gaps are formed between the coils of different phases that are adjacent to each other in the radial direction. The multiple grooves have different radial dimensions. The coil has a fusion layer as its outermost layer. stator.

2. The coils of each phase are housed in the respective grooves of the bobbin so as not to overlap in the circumferential direction. The stator according to claim 1.

3. A stator according to claim 1 or 2, The system comprises a rotor rotatably mounted to the stator with a gap between them, Rotating electric machine.

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