Rotating electric machine

Abstract

To obtain a rotating electric machine with a novel configuration that allows for easy cooling of the coil ends. [Solution] The rotating electric machine comprises a rotor rotatable around a central axis of rotation, a stator core surrounding the rotor, a stator having a plurality of coil ends that protrude from the stator core in the axial direction of the central axis of rotation and are spaced apart in the circumferential direction of the central axis of rotation, and an insulating spacer interposed between two adjacent coil ends in the circumferential direction, the spacer being provided with a first ventilation hole through which gas can pass.

Description

Technical Field

[0001] Embodiments of the present invention relate to a rotating electric machine.

Background Art

[0002] Conventionally, there has been a rotating electric machine in which a spacer is provided between two adjacent coil ends in a stator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of rotating electric machine, for example, since there is a spacer between two adjacent coil ends, it is difficult for gas to flow between the two coil ends, and it is difficult to cool the coil ends.

[0005] An example of the problem to be solved by the present invention is to obtain a rotating electric machine with a novel configuration in which the coil ends are easily cooled.

Means for Solving the Problems

[0006] A rotating electric machine according to an embodiment of the present invention includes a rotor rotatable about a rotation center axis, a stator core surrounding the rotor, a coil having a plurality of coil ends protruding axially from the stator core in the axial direction of the rotation center axis and arranged at intervals in the circumferential direction of the rotation center axis, a stator having the coil, and a spacer having insulation and interposed between two adjacent coil ends in the circumferential direction, wherein the spacer is provided with a first vent hole through which gas can pass.

Effects of the Invention

[0007] According to the present invention, for example, a rotating electric machine with a novel configuration in which the coil ends are easily cooled can be obtained. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic cross-sectional view showing a rotating electric machine according to an embodiment. [Figure 2] Figure 2 is a perspective view showing a portion of the stator of a rotating electric machine according to an embodiment. [Figure 3] Figure 3 is a perspective view showing multiple coil ends and spacer structures in the stator of a rotating electric machine according to an embodiment. [Figure 4] Figure 4 is a cross-sectional view showing a spacer structure according to an embodiment. [Figure 5] Figure 5 shows a spacer according to an embodiment. [Figure 6] Figure 6 shows a spacer for the first modified embodiment. [Figure 7] Figure 7 shows a spacer for a second modified example of the embodiment. [Modes for carrying out the invention]

[0009] Illustrative embodiments of the present invention are disclosed below. The configurations of the embodiments shown below, as well as the functions and effects brought about by such configurations, are examples only. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derived effects) that can be obtained by the configuration.

[0010] Furthermore, the drawings are schematic representations, and the dimensional relationships and proportions of each element may differ from reality. Also, there may be discrepancies in dimensional relationships and proportions between different drawings.

[0011] Figure 1 is a schematic cross-sectional view showing a rotating electric machine 10 according to an embodiment. The rotating electric machine 10 is, for example, a squirrel-cage three-phase induction motor and is used as an electric motor or a generator. Note that the rotating electric machine 10 is not limited to this example.

[0012] The rotating electric machine 10 includes a stator 11, a rotor 12, a housing 13, two bearings 15, and an internal fan 16.

[0013] In this specification, for convenience, axial, radial, and circumferential directions are defined. The axial direction is the direction along the rotational axis Ax. The radial direction is the direction perpendicular to the rotational axis Ax. The circumferential direction is the direction of rotation around the rotational axis Ax.

[0014] The rotational axis Ax is the center of rotation of the rotor 12, and is, for example, a hypothetical straight line passing through the center of the shaft 14 of the rotor 12.

[0015] The stator 11 comprises a stator core 20 and a coil 21. The stator core 20 is formed in a substantially cylindrical shape surrounding the rotational axis Ax. The coil 21 is attached to the stator core 20 by passing through slots provided in the stator core 20.

[0016] The rotor 12 has a rotor core 31 and conductors 32. The rotor core 31 is formed in a substantially cylindrical shape surrounding the rotational axis Ax and is located inside the stator core 20. The conductors 32 are spaced apart from each other in the circumferential direction. The conductors 32 have, for example, conductor bars that penetrate the rotor core 31 in the axial direction and short-circuit rings coupled to the axial ends of all the conductor bars.

[0017] The housing 13 has a frame 41 and two bearing brackets 42. The frame 41 is formed in a substantially cylindrical shape surrounding the rotational axis Ax. The stator 11 and rotor 12 are arranged inside the frame 41. The stator core 20 is fixed to the frame 41.

[0018] The two bearing brackets 42 are connected to both ends of the frame 41 in the axial direction. The bearing brackets 42 block the space inside the frame 41. Each of the bearing brackets 42 supports the corresponding bearing 15. The bearing brackets 42 are also referred to as walls.

[0019] The shaft 14 is formed in a substantially cylindrical shape extending along the rotation center axis Ax. The shaft 14 passes through the bearing brackets 42 and extends across the inside and outside of the housing 13. The shaft 14 is rotatably supported about the rotation center axis Ax by the bearings 15.

[0020] The shaft 14 extends axially through the inside of the stator 11 and the rotor 12. The shaft 14 is coupled to the rotor core 31 of the rotor 12. The rotor 12 and the shaft 14 can rotate integrally about the rotation center axis Ax with respect to the stator 11.

[0021] The two bearings 15 are located on one side and the other side in the axial direction with respect to the rotor 12. That is, the rotor 12 is located between the two bearings 15.

[0022] The inner fan 16 is coupled to the shaft 14 inside the housing 13. The inner fan 16 can rotate integrally about the rotation center axis Ax with the shaft 14. By rotating, the inner fan 16 generates an air flow for cooling the stator 11 and the rotor 12.

[0023] Next, the stator 11 will be described in detail. FIG. 2 is a perspective view showing a part of the stator 11 of the rotating electric machine 10 of the embodiment. FIG. 3 is a perspective view showing a plurality of coil ends 22a and the spacer structure 61 in the stator 11 of the rotating electric machine 10 of the embodiment. FIG. 4 is a cross-sectional view showing the spacer structure 61 of the embodiment. FIG. 5 is a view showing the spacer 62 of the embodiment.

[0024] As shown in Figures 1 and 2, the coil 21 of the stator 11 has a plurality of unit coils 22. The plurality of unit coils 22 are arranged circumferentially with spacing between them and penetrate the stator core 20 axially. The unit coils 22 have coil ends 22a at both axial ends. The coil ends 22a protrude axially from the stator core 20. The plurality of coil ends 22a of the plurality of unit coils 22 are arranged circumferentially with spacing between them.

[0025] As shown in Figure 3, the stator 11 further comprises a plurality of spacer structures 61. The spacer structures 61 are interposed between two circumferentially adjacent coil ends 22a.

[0026] As shown in Figure 4, the spacer structure 61 includes a spacer 62 and a cushioning material 63.

[0027] As shown in Figures 4 and 5, the spacer 62 is formed in a plate-like (rectangular parallelepiped) shape and is interposed between two adjacent coil ends 22a in the circumferential direction. The spacer 62 is made of materials such as polyester glass mat laminate, epoxy glass cloth laminate, silicone glass cloth laminate, or epoxy glass mat laminate, and has insulating properties.

[0028] The spacer 62 has a pair of opposing surfaces 62b, 62c and a pair of end surfaces 62e, 62d. The pair of opposing surfaces 62b, 62c face two coil ends 22a that are adjacent in the circumferential direction. The pair of end surfaces 62e, 62d are provided across the pair of opposing surfaces 62b, 62c and connect the pair of opposing surfaces 62b, 62c.

[0029] As shown in Figures 4 and 5, the spacer 62 is provided with a first vent hole 62a through which gas can pass. The first vent hole 62a penetrates the spacer 62 and opens into a pair of end faces 62e and 62d. The opening shape (cross-sectional shape) of the first vent hole 62a is a square (a rectangle as an example).

[0030] As shown in Figure 4, the cushioning material 63 is interposed between the spacer 62 and the coil end 22a, filling the space between them. The cushioning material 63 is made of felt (nonwoven fabric) and has insulating properties. The felt (nonwoven fabric) is impregnated with a synthetic resin material such as epoxy resin. The cushioning material 63 is elastic. The cushioning material 63 is softer than the spacer 62. The cushioning material 63 is also called a filler member or elastic member.

[0031] In detail, the cushioning material 63 has a pair of wall sections 63a and a connecting wall 63b that connects the pair of wall sections 63a. The pair of wall sections 63a are interposed between a pair of opposing surfaces 62b, 62c of the spacer 62 and two circumferentially adjacent coil ends 22a. The connecting wall 63b is superimposed on the end surface 62d of the spacer 62. The connecting wall 63b is provided with a second ventilation hole 63c that leads to the first ventilation hole 62a.

[0032] Here, as shown in Figure 3, a unit coil 22 is provided for each phase. As an example, in this embodiment, multiple unit coils 22U for the U phase, multiple unit coils 22V for the V phase, and multiple unit coils 22W for the W phase are provided. Also, in this embodiment, the number of spacers 62 between two adjacent coil ends 22a of different phases is greater than the number of spacers 62 between two adjacent coil ends 22a of the same phase. Furthermore, multiple spacers 62 between two adjacent coil ends 22a of different phases are arranged in a continuous manner (in contact with each other). Multiple spacers 62 between two adjacent coil ends 22a of the same phase are arranged spaced apart from each other.

[0033] In the above configuration, the gas (e.g., air) in the housing 13 is circulated inside the housing 13 by an internal fan 16 that rotates integrally with the shaft 14, thereby cooling the inside of the housing 13. At this time, the gas passes through the second vent hole 63c of the buffer material 63 and the first vent hole 62a of the spacer 62. In Figure 4, the direction of gas flow is indicated by arrows. This cools the coil ends 22a. Here, since multiple spacers 62 are arranged in a continuous manner (in contact with each other) between two adjacent coil ends 22a of different phases, if the first vent hole 62a is not provided in the spacer 62, it is difficult for the gas to pass between the two adjacent coil ends 22a of different phases. In contrast, in this embodiment, since the first vent hole 62a is provided in the spacer 62, the gas can pass between the two adjacent coil ends 22a of different phases by passing through the first vent hole 62a. Therefore, two adjacent coil ends 22a of different phases can be cooled. Furthermore, in a configuration in which the housing 13 and the inside of the housing 13 are cooled by an external fan provided on the outside of the housing 13, even if the external fan fails and does not operate, the reduction in the cooling performance of the coil ends 22a can be suppressed by providing the first ventilation holes 62a in the spacer 62.

[0034] As described above, the rotating electric machine 10 of this embodiment comprises a rotor 12, a stator 11, and a spacer 62. The rotor 12 is rotatable around the rotational axis Ax. The stator 11 has a stator core 20 and coils 21. The stator core 20 surrounds the rotor 12. The coils 21 have a plurality of coil ends 22a that protrude from the stator core 20 in the axial direction of the rotational axis Ax and are spaced apart in the circumferential direction of the rotational axis Ax. The spacer 62 is insulating and is interposed between two circumferentially adjacent coil ends 22a. The spacer 62 is provided with a first vent hole 62a through which gas can pass.

[0035] With this configuration, since the spacer 62 is provided with a first ventilation hole 62a through which gas can pass, the coil end 22a is easily cooled. Therefore, deterioration of the coil end 22a due to heat can be suppressed.

[0036] Furthermore, the rotating electric machine 10 includes a cushioning material 63 interposed between the spacer 62 and the coil end 22a.

[0037] With this configuration, the space between the spacer 62 and the coil end 22a can be filled with cushioning material 63, thereby suppressing displacement of the spacer 62.

[0038] Furthermore, the cushioning material 63 is provided with a second ventilation hole 63c that leads to the first ventilation hole 62a.

[0039] With this configuration, there is no need to divide the cushioning material 63 to avoid the first ventilation hole 62a, making it easier to simplify the structure of the rotating electric machine 10.

[0040] Next, a modified example will be described. Figure 6 shows the spacer 62 of the first modified example of the embodiment. Figure 7 shows the spacer 62 of the second modified example of the embodiment.

[0041] The opening shape (cross-sectional shape) of the first ventilation hole 62a in the first modified example shown in Figure 6 is a square (a rectangle as an example), but it is smaller than the first ventilation hole 62a shown in Figure 5.

[0042] In the second modified example shown in Figure 7, the opening shape (cross-sectional shape) of the first ventilation hole 62a is circular. Multiple first ventilation holes 62a are provided in the second modified example. By having a circular opening shape (cross-sectional shape) for the first ventilation hole 62a, stress concentration at the edges of the first ventilation hole 62a is suppressed. The shape of the first ventilation hole 62a can be selected depending on the required strength of the spacer 62.

[0043] Furthermore, the materials of the multiple spacers 62 may vary depending on factors such as the distance between two adjacent coil ends 22a.

[0044] Furthermore, in a configuration where coils are provided on the rotor, spacers 62 and cushioning material 63 may be provided at the coil ends of the rotor coils.

[0045] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of 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]

[0046] 10... Rotating electric machine, 11... Stator, 12... Rotor, 20... Stator core, 21... Coil, 22a... Coil end, 62... Spacer, 62a... First vent, 63... Cushioning material, 63c... Second vent, Ax... Rotational axis.

Claims

1. A rotor that can rotate around its central axis, A stator comprising: a stator core surrounding the rotor; and a coil having a plurality of coil ends that protrude from the stator core in the axial direction of the rotational axis and are spaced apart in the circumferential direction of the rotational axis; A spacer having insulating properties, interposed between two adjacent coil ends in the circumferential direction, Equipped with, The spacer is provided with a first ventilation hole through which gas can pass. Rotating electric machine.

2. A cushioning material is interposed between the spacer and the coil end. The rotating electric machine according to claim 1.

3. The cushioning material is provided with a second ventilation hole that leads to the first ventilation hole. The rotating electric machine according to claim 2.

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