Stator

Abstract

This stator (10) comprises: a stator core (24) having a plurality of tooth parts (22) that extend radially; a resin insulator (16) mounted to the stator core; and a wire winding part (18) wound around the plurality of tooth parts with the insulator therebetween. The stator core has mounting surfaces (20A, 22A) to which the insulator is mounted, grooves (36, 38) positioned on the opposite side of the insulator to the wire winding part are formed on the mounting surfaces, and gas layers (40, 42) are formed between the stator core and the insulator by the grooves.

Description

Stator CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on and claims the benefit of priority from Japanese Patent Application No. 2023-199407, filed on November 24, 2023, the entire contents of which are incorporated herein by reference.

[0002] The technology of the present disclosure relates to a stator.

[0003] Conventionally, there is a stator including a stator core having a plurality of radially extending teeth, a resin insulator attached to the stator core, and a winding portion wound around the plurality of teeth via the insulator. Some stators of this type have an insulating film provided between the teeth and the winding portion (see, for example, JP 2018-198515 A).

[0004] As a result of detailed investigations by the inventors, the following problem was discovered: In the above-mentioned conventional technology, when a high voltage is applied to the winding portion, there is a risk of dielectric breakdown in the insulating film. To withstand the high voltage, it is conceivable to increase the thickness of the resin portion of the insulator provided between the teeth and the winding portion, but doing so would result in a risk of the stator becoming larger.

[0005] The technology of the present disclosure aims to provide a stator that can ensure insulation from the winding winding portion while suppressing an increase in size of the stator.

[0006] The stator according to the disclosed technology comprises a stator core having a plurality of radially extending tooth portions, a resin insulator attached to the stator core, and a winding portion wound around the plurality of tooth portions via the insulator, wherein the stator core has a mounting surface on which the insulator is attached, and a groove is formed on the mounting surface located on the opposite side of the insulator from the winding portion, and a gas layer is formed between the stator core and the insulator by the groove.

[0007] According to the stator according to the technique of the present disclosure, it is possible to ensure insulation for the winding winding portion while suppressing an increase in size of the stator.

[0008] Fig. 1 is a plan view of a stator according to a first embodiment; Fig. 2 is a plan cross-sectional view of a stator component according to the first embodiment; Fig. 3 is a plan cross-sectional view of a stator component according to a second embodiment; Fig. 4 is a plan cross-sectional view of a stator component according to a third embodiment; Fig. 5 is a plan cross-sectional view of a stator component according to a fourth embodiment; Fig. 6 is a plan cross-sectional view of a stator component according to a fifth embodiment;

[0009] First Embodiment First, a first embodiment of the technology of the present disclosure will be described.

[0010] As shown in FIG. 1 , a stator 10 according to the first embodiment includes a plurality of stator components 12. The stator 10 is configured by combining a plurality of stator components 12 in an annular shape. FIG. 1 shows the configuration of half of the stator 10. The stator 10 is applied to a brushless motor. Brushless motors may be used for any purpose. Examples of brushless motors include fan motors, pump drive motors, and compressor motors.

[0011] In each figure, the X direction indicates the tangential direction of the stator 10, the Y direction indicates the radial direction of the stator 10, and the Z direction indicates the axial direction of the stator 10. In the following description, the circumferential direction of the stator 10 refers to the direction around the central axis of the stator 10. The tangential direction, radial direction, axial direction, and circumferential direction of the stator core 24, which will be described later, are the same directions as the tangential direction, radial direction, axial direction, and circumferential direction of the stator 10, respectively.

[0012] 2 , each stator component 12 includes a core member 14, an insulator 16, and a winding winding portion 18. The core member 14 has a core back portion 20 and teeth portions 22. The core back portion 20 extends in the circumferential direction of the stator core 24, and the teeth portions 22 extend inward in the Y direction from the center of the core back portion 20. The tip portions of the teeth portions 22 are free ends, and the base ends of the teeth portions 22 are connected to the core back portion 20.

[0013] A stator core 24 (see FIG. 1) is formed by combining a plurality of core members 14 in an annular shape. When the stator core 24 is formed, the plurality of core back portions 20 form an annular portion 26 (see FIG. 1), and the plurality of tooth portions 22 extend radially from the center of the stator core 24. Slots 28 are formed between the plurality of tooth portions 22.

[0014] Note that the configuration of each stator component 12, including its details, is not strictly symmetrical in the X direction when viewed from the Z direction. However, for the sake of convenience, the following description will assume that the main configuration of each stator component 12 is symmetrical in the X direction when viewed from the Z direction, and will explain the configuration of one side of each stator component 12.

[0015] An inner surface 20A is formed in the core back portion 20, and a side surface 22A is formed in the tooth portion 22. The inner surface 20A extends in the X direction and the Z direction and faces inward in the Y direction. The side surface 22A extends in the Y direction and the Z direction and faces the X direction. The inner surface 20A and the side surface 22A are in contact with the slot 28.

[0016] The insulator 16 is attached to the core member 14. The insulator 16 is made of resin. Examples of resins that can be used to form the insulator 16 include polyimide, polyamide, polyphenylene sulfide (PPS), and polybutylene terephthalate (PBT). Any resin can be used to form the insulator 16. The insulator 16 has an inner wall portion 30 and a side wall portion 32. The inner wall portion 30 is attached to the inner surface 20A and covers the inner surface 20A. The side wall portion 32 is attached to the side surface 22A and covers the side surface 22A. The inner wall portion 30 and the side wall portion 32 are disposed in the slot 28.

[0017] The inner surface 20A and the side surface 22A are examples of "mounting surfaces" according to the technology of the present disclosure. The inner surface 20A is an example of a "first mounting surface" according to the technology of the present disclosure, and the side surface 22A is an example of a "second mounting surface" according to the technology of the present disclosure.

[0018] The winding portion 18 is wound around the tooth portion 22 via the insulator 16. The winding portion 18 is formed by winding the wire around the tooth portion 22 in the Y direction. The winding forming the winding portion 18 may have only one winding portion 18 or may have several winding portions 18.

[0019] The winding portion 18 has an axial portion 34 extending in the Z direction. The axial portion 34 is inserted into the slot 28. The axial portion 34 has a side surface 34A and an end surface 34B. The side surface 34A is a surface of the axial portion 34 formed on the tooth portion 22 side (i.e., the inner side surface), and the end surface 34B is a surface of the axial portion 34 formed on the core back portion 20 side. A side wall portion 32 is interposed between the side surface 34A of the axial portion 34 and the side surface 22A of the tooth portion 22, and an inner wall portion 30 is interposed between the end surface 34B of the axial portion 34 and the inner surface 20A of the core back portion 20.

[0020] A first groove 36 is formed in the inner surface 20A, and a second groove 38 is formed in the side surface 22A. The first groove 36 is located on the opposite side of the inner wall 30 from the winding winding portion 18 in the Y direction, and the second groove 38 is located on the opposite side of the side wall 32 from the winding winding portion 18 in the X direction. The position of the first groove 36 in the X direction and the width of the first groove 36 in the X direction are set so that the range of the width of the winding winding portion 18 in the X direction falls within the range of the width of the first groove 36 in the X direction. Similarly, the position of the second groove 38 in the Y direction and the width of the second groove 38 in the Y direction are set so that the range of the width of the winding winding portion 18 in the Y direction falls within the range of the width of the second groove 38 in the Y direction.

[0021] A first gas layer 40 is formed by the first groove 36 between the core back portion 20 and the inner wall portion 30, and a second gas layer 42 is formed by the second groove 38 between the teeth portion 22 and the side wall portion 32. The first groove 36 and the second groove 38 are formed to penetrate in the Z direction.

[0022] The first groove 36 and the second groove 38 are an example of a "groove" according to the technology of the present disclosure. The first gas layer 40 and the second gas layer 42 are an example of a "gas layer" according to the technology of the present disclosure.

[0023] Next, the operation and effects of the first embodiment of the technique of the present disclosure will be described.

[0024] As described above in detail, in the first embodiment, the first gas layer 40 is formed between the core back portion 20 and the inner wall portion 30 by the first groove 36, and the second gas layer 42 is formed between the tooth portion 22 and the side wall portion 32 by the second groove 38. Therefore, an insulating layer formed by adding the first gas layer 40 to the inner wall portion 30 is formed between the core back portion 20 and the winding portion 18, thereby ensuring insulation from the winding portion 18. Furthermore, an insulating layer formed by adding the second gas layer 42 to the side wall portion 32 is formed between the tooth portion 22 and the winding portion 18, thereby ensuring insulation from the winding portion 18.

[0025] Furthermore, by forming the first gas layer 40 between the core back portion 20 and the inner wall portion 30 by the first groove 36, the thickness of the inner wall portion 30 can be made thinner than when the core back portion 20 and the winding portion 18 are insulated only by the inner wall portion 30. Similarly, by forming the second gas layer 42 between the tooth portion 22 and the side wall portion 32 by the second groove 38, the thickness of the side wall portion 32 can be made thinner than when the tooth portion 22 and the winding portion 18 are insulated only by the side wall portion 32. This allows the cross-sectional area of ​​the slot 28 to be increased, which in turn allows the number of turns of the winding portion 18 to be increased, thereby preventing the stator 10 from becoming larger. In other words, it is possible to prevent the stator 10 from becoming larger in size in order to increase the cross-sectional area of ​​the slot 28.

[0026] Second Embodiment Next, a second embodiment of the technique of the present disclosure will be described.

[0027] In the second embodiment, the configuration of the stator 10 is modified as follows compared to the first embodiment. That is, as shown in FIG. 3 , a convex portion 44 that protrudes toward the side wall portion 32 is formed on the bottom surface of the second groove 38, and the convex portion 44 contacts and supports the side wall portion 32. Meanwhile, a concave portion 46 is formed on the surface of the side wall portion 32 opposite the surface that contacts the convex portion 44, and a gas layer 48 is formed by the concave portion 46 between the winding winding portion 18 and the side wall portion 32. The concave portion 46 is formed at the same position as the convex portion 44 in the Y direction. The concave portion 46 is formed to penetrate in the Z direction.

[0028] With this configuration, the side wall portion 32 is supported by the protrusions 44, thereby improving the rigidity of the side wall portion 32. Furthermore, even if the protrusions 44 are formed on the bottom surface of the second groove 38, the gas layer 48 is formed by the recesses 46, so insulation can be ensured.

[0029] 3, one protrusion 44 is formed on the bottom surface of the second groove 38, but multiple protrusions 44 may be formed. Also, corresponding to the multiple protrusions 44, multiple recesses 46 may be formed on the surface of the side wall portion 32 opposite to the contact surface with the protrusion 44.

[0030] 3 , the protrusions 44 may be formed on the bottom surface of the first groove 36, protrude toward the inner wall 30, and support the inner wall 30. The recesses 46 may be formed on the surface of the inner wall 30 opposite the surface that comes into contact with the protrusions 44, and form a gas layer 48 between the winding 18 and the inner wall 30.

[0031] With this configuration, the inner wall portion 30 is supported by the protrusions 44, thereby improving the rigidity of the inner wall portion 30. Furthermore, even if the protrusions 44 are formed on the bottom surface of the first groove 36, the gas layer 48 is formed by the recesses 46, so insulation can be ensured.

[0032] Third Embodiment Next, a third embodiment of the technique of the present disclosure will be described.

[0033] In the third embodiment, the configuration of the stator 10 is modified as follows compared to the first embodiment. That is, as shown in Fig. 4, a continuous groove 50 is formed in the core member 14 from the inner surface 20A to the side surface 22A. The insulator 16 has a dividing portion 54 provided in an R-shaped portion 52 that is a connection portion between the inner surface 20A and the side surface 22A. By being provided in the R-shaped portion 52, the dividing portion 54 divides the groove 50 into a first groove 36 and a second groove 38.

[0034] With this configuration, the grooves 50 can be formed continuously from the inner surface 20A to the side surface 22A, and therefore the processing for forming the grooves 50 can be easily carried out.

[0035] Furthermore, the insulator 16 has a dividing portion 54 provided in the R-shaped portion 52, which is the connection portion between the inner surface 20A and the side surface 22A, and therefore the dividing portion 54 can support the inner wall portion 30 and the side wall portion 32. This ensures the rigidity of the inner wall portion 30 and the side wall portion 32 even if the groove 50 is formed continuously from the inner surface 20A to the side surface 22A.

[0036] Fourth Embodiment Next, a fourth embodiment of the technique of the present disclosure will be described.

[0037] In the fourth embodiment, the configuration of the stator 10 is modified from that of the first embodiment as follows. That is, in the first embodiment, the inner surface 20A extends in the X direction when viewed from the Z direction, but in the fourth embodiment, as shown in Fig. 5, the inner surface 20A extends in a direction that is inclined inward in the Y direction with respect to the X direction when viewed from the Z direction. Similar to the first embodiment, a first gas layer 40 is formed by the first grooves 36 between the core back portion 20 and the inner wall portion 30, and a second gas layer 42 is formed by the second grooves 38 between the tooth portions 22 and the side wall portions 32.

[0038] Even with this configuration, the same effects as in the first embodiment can be achieved.

[0039] Fifth Embodiment Next, a fifth embodiment of the technique of the present disclosure will be described.

[0040] In the fifth embodiment, the configuration of the stator 10 is modified as follows from the third embodiment. That is, in the third embodiment, the inner surface 20A extends in the X direction as viewed from the Z direction, but in the fifth embodiment, as shown in Fig. 6, the inner surface 20A extends in a direction inclined inward in the Y direction with respect to the X direction as viewed from the Z direction. Similar to the third embodiment, a continuous groove 50 is formed in the core member 14 from the inner surface 20A to the side surface 22A, and the insulator 16 has a dividing portion 54 provided in an R-shaped portion 52 that is a connection portion between the inner surface 20A and the side surface 22A.

[0041] Even with this configuration, the same effects as those of the third embodiment can be achieved.

[0042] In the above-described embodiments, the stator core 24 is divided into a plurality of core members 14. However, the plurality of core members 14 may be integrated. Furthermore, the insulators 16 attached to the core members 14 may also be integrated.

[0043] Furthermore, among the configurations described in the above embodiments, configurations that can be combined may be combined as appropriate.

[0044] The above describes one embodiment of the technology of the present disclosure, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modifications within the scope of the gist of the present disclosure.

[0045] The following are supplementary notes regarding the technology of the present disclosure. (Supplementary Note 1) A stator (10) comprising: a stator core (24) having a plurality of radially extending teeth (22), a resin insulator (16) attached to the stator core, and a winding (18) wound around the plurality of teeth with the insulator interposed therebetween, the stator core having a mounting surface (20A, 22A) on which the insulator is attached, grooves (36, 38, 50) formed on the mounting surface on the opposite side of the insulator from the winding, and a gas layer (40, 42) formed by the grooves between the stator core and the insulator. (Supplementary Note 2) The stator according to Supplementary Note 1, wherein the stator core has a core back portion (20) extending in the circumferential direction of the stator core and connected to base ends of the tooth portions, the mounting surface has a first mounting surface (20A) formed on the core back portion and a second mounting surface (22A) formed on the tooth portions, and the grooves (36, 38) have a first groove (36) formed on the first mounting surface and a second groove (38) formed on the second mounting surface. (Supplementary Note 3) The stator according to Supplementary Note 2, wherein the groove (50) is continuous from the first mounting surface to the second mounting surface, and the insulator has a dividing portion (54) provided at a connecting portion (52) between the first mounting surface and the second mounting surface and dividing the groove into the first groove and the second groove. (Supplementary Note 4) The stator according to any one of Supplementary Note 1 to Supplementary Note 3, wherein a convex portion (44) that protrudes toward the insulator and supports the insulator is formed on the bottom surface of the groove, and a concave portion (46) that forms a gas layer (48) between the winding winding portion and the insulator is formed on the surface of the insulator opposite to the contact surface with the convex portion.

Claims

1. A stator (10) comprising: a stator core (24) having a plurality of radially extending tooth portions (22); a resin insulator (16) attached to the stator core; and a winding winding portion (18) wound around the plurality of teeth portions via the insulator, wherein the stator core has a mounting surface (20A, 22A) to which the insulator is attached, and grooves (36, 38, 50) are formed on the mounting surface, the grooves being located on the opposite side of the insulator to the winding winding portion, and a gas layer (40, 42) is formed between the stator core and the insulator by the grooves.

2. A stator as described in claim 1, wherein the stator core has a core back portion (20) extending circumferentially of the stator core and connected to the base ends of the teeth portion, the mounting surface has a first mounting surface (20A) formed on the core back portion and a second mounting surface (22A) formed on the teeth portion, and the grooves (36, 38) have a first groove (36) formed on the first mounting surface and a second groove (38) formed on the second mounting surface.

3. A stator as set forth in claim 2, wherein the groove (50) is continuous from the first mounting surface to the second mounting surface, and the insulator has a dividing portion (54) provided at a connection portion (52) between the first mounting surface and the second mounting surface, dividing the groove into the first groove and the second groove.

4. A stator as claimed in any one of claims 1 to 3, wherein a convex portion (44) that protrudes towards the insulator and supports the insulator is formed on the bottom surface of the groove, and a concave portion (46) that forms a gas layer (48) between the winding winding portion and the insulator is formed on the surface of the insulator opposite to the contact surface with the convex portion.

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