Stator, method for manufacturing stator, rotating electrical machine, and method for manufacturing rotating electrical machine

Abstract

A stator according to one embodiment of the present invention includes a stator core and coil blocks. The stator core includes: an annular yoke section centered on the central axis; and a plurality of teeth sections protruding in the axial direction or the radial direction from one surface of the yoke section and arranged in the circumferential direction. The coil blocks are positioned in a plurality of slots arranged in the circumferential direction between teeth sections adjacent to each other in the circumferential direction among the plurality of teeth sections. Each coil block includes: a coil in which a conducting wire is wound in an annular shape; and a resin layer in which resin is integrally molded with the coil. The resin layer is disposed at least on the inner peripheral side of the coil.

Description

Stator, Method of Manufacturing Stator, Rotating Electric Machine, and Method of Manufacturing Rotating Electric Machine

[0001] The disclosed embodiments relate to a stator, a method of manufacturing a stator, a rotating electric machine, and a method of manufacturing a rotating electric machine. This application claims priority based on Japanese Patent Application No. 2025-014963 filed in Japan on January 31, 2025, the content of which is incorporated herein by reference.

[0002] There is a technique for electrically insulating teeth and a coil by disposing a flat insulator between teeth of a stator core and a surface on the inner peripheral side of a coil formed by winding a conducting wire around the teeth (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2016-135023

[0004] However, in a stator of a rotating electric machine in which a flat insulator is disposed between teeth and a surface on the inner peripheral side of a coil, a gap is generated between the insulator and irregularities on the coil surface, so heat tends to be trapped in the gap and the heat dissipation performance deteriorates.

[0005] One aspect of the embodiment is made in view of the above, and an object thereof is to provide a stator capable of improving heat dissipation performance.

[0006] A stator according to one aspect of the embodiment includes a stator core and a coil block. The stator core has an annular yoke portion centered on a central axis, and a plurality of tooth portions protruding axially or radially from one surface of the yoke portion and arranged in the circumferential direction. The coil block is located in a plurality of slots arranged in the circumferential direction between tooth portions adjacent to each other in the circumferential direction among the plurality of tooth portions. The coil block includes a coil in which a conducting wire is wound in a ring shape, and a resin layer integrally formed with the coil. The resin layer is disposed at least on the inner peripheral side of the coil.

[0007] In the stator according to one aspect of the embodiment, no gap is generated between the surface on the inner peripheral side of the coil and the resin layer, and heat is less likely to be trapped, so the heat dissipation property can be improved.

[0008] Figure 1 is a perspective view showing an example of a rotating electric machine according to the embodiment. Figure 2 is an exploded perspective view showing an example of a stator according to the embodiment. Figure 3 is a perspective view showing a coil according to the embodiment. Figure 4 is a perspective view showing a coil block according to the embodiment. Figure 5 is a cross-sectional view of the coil block according to the embodiment, cut by a plane normal to the axial direction. Figure 6 is an enlarged view showing the area within the dashed frame shown in Figure 5. Figure 7 is a plan view showing a mold for molding a resin layer according to the embodiment. Figure 8 is a plan view showing the mold with the coil according to the embodiment arranged in it.

[0009] The following describes in detail, with reference to the drawings, the stator, the method for manufacturing the stator, the rotating electric machine, and embodiments for carrying out the method for manufacturing the rotating electric machine according to this disclosure. Note that this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate. In the following embodiments, components that perform the same function are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations, for example, in manufacturing accuracy or installation accuracy.

[0011] Figure 1 is a perspective view showing an example of a rotating electric machine 2 according to an embodiment. The rotating electric machine 2 shown in Figure 1 is a DSSR (Double Stator Single Rotor) type motor comprising two annular stators 3 and 4 centered on a central axis 20 and one rotor 5. The two stators 3 and 4 are arranged opposite each other in the axial direction of the central axis 20. The rotor 5 is positioned between the two stators 3 and 4 and rotates around the central axis 20. Note that the rotating electric machine according to this embodiment may also be an SSDR (Single Stator Double Rotor) type motor having one stator and two rotors.

[0012] Next, stators 3 and 4 will be described with reference to Figure 2. Stators 3 and 4 have similar configurations. Therefore, stator 3 will be described here, and the redundant explanation for stator 4 will be omitted. Figure 2 is an exploded perspective view showing an example of stator 3 according to the embodiment.

[0013] As shown in Figure 2, the stator 3 includes a stator core 33, a plurality of coil blocks 34, and a plurality of umbrellas 38. The stator core 33 has an annular yoke portion 35 centered on a central axis 20, and a plurality of teeth portions 36 that protrude from one surface of the yoke portion 35 in the axial direction of the central axis 20 and are arranged in the circumferential direction. The plurality of teeth portions 36 may also be configured to protrude radially from the annular yoke portion 35. The stator 3 and the busbars 32 connected to each coil block 34 are arranged inside the housing 31. Each coil block 34 is constructed by integrally molding a coil around which a conductor is wound and a resin layer. The configuration of such coil blocks 34 will be described later with reference to Figures 3 and 4.

[0014] Each coil block 34 is located within a plurality of slots 37 arranged circumferentially between adjacent teeth 36 of the yoke portion 35. Each umbrella 38 is a soft magnetic composite material (SMC material) placed on the side of the stator core 33 facing the yoke portion 35 and the side facing it in each coil block 34.

[0015] Next, the coil block 34 will be described with reference to Figures 3 to 6. Figure 3 is a perspective view showing the coil 41 according to the embodiment. Figure 4 is a perspective view showing the coil block 34 according to the embodiment. Figure 5 is a plan view of the coil block 34 according to the embodiment. Figure 6 is an enlarged view showing the area within the dashed frame shown in Figure 5.

[0016] As shown in Figure 3, the coil block 34 includes a coil 41 in which a conductor is wound in a ring shape. In Figure 3, a flat wire with a rectangular cross-section is used for the conductor, but other shapes such as a round wire with a round cross-section may also be used. Furthermore, as shown in Figure 4, the coil block 34 includes a resin layer 6 integrally molded with the coil 41, which has heat dissipation and insulating properties. The resin layer 6 is disposed at least on the inner surface 42 of the annularly wound coil 41.

[0017] As a result, there is no gap between the inner surface 42 of the coil 41 and the resin layer 6, so heat does not accumulate in the gap between the coil 41 and the insulator resin layer 6, and the heat dissipation performance can be improved by dissipating heat from the coil 41 to the outside through the resin layer 6.

[0018] As shown in Figure 4, the resin layer 6 located at the corners of the annularly wound coil 41 in the coil block 34 has rib marks 45 to 51 formed during the molding of the resin layer 6. These rib marks 45 to 51 will be described later in conjunction with the explanation of the molding process of the resin layer 6.

[0019] Furthermore, the resin layer 6 is also placed on the surface 43 of the coil 41 that faces the yoke portion 35 (see Figure 2). This allows for electrical insulation between the coil 41 and the yoke portion 35.

[0020] Furthermore, at least a portion of the resin layer 6 is in contact with the teeth portion 36. This allows for insulation between the coil 41 and the teeth portion 36 without the need to interpose a flat insulator between the inner surface 42 of the coil 41 and the teeth portion 36.

[0021] Furthermore, the resin layer 6 is positioned on at least a portion of the outer surface 44 of the annularly wound coil 41. This provides insulation between the coil 41 and the adjacent teeth portion 36.

[0022] Furthermore, as shown in Figures 5 and 6, the thickness of the resin layer 6 placed on the inner surface 42 of the coil 41 (see Figures 3 and 4) is greater than the thickness of the resin layer 6 placed on the outer surface 44 of the coil 41 (see Figures 3 and 4). This ensures an insulating distance between the coil 41 and the teeth portion 36, and provides insulation between the coil 41 and adjacent teeth portions 36 (see Figure 2).

[0023] Furthermore, the resin layer 6 is positioned in the gaps between adjacent wires wound around the coil 41. This reduces the gap between the coil 41 and the resin layer 6, and also improves heat dissipation.

[0024] Next, the manufacturing method of the rotating electric machine 2 will be described. Here, we will focus on the manufacturing process of the coil block 34, which is included in the manufacturing process of the stator core 33 of the rotating electric machine 2. In the process of manufacturing the coil block 34, first, as shown in Figure 3, a coil 41 is formed by winding a wire in a ring shape (winding process).

[0025] Subsequently, a mold is prepared for integrally molding the resin layer 6 onto the coil 41. Figure 7 is a plan view showing the mold 7 for molding the resin layer according to the embodiment. Figure 8 is a plan view showing the mold 7 with the coil 41 arranged according to the embodiment.

[0026] As shown in Figure 7, the mold 7 has an annular groove 70 in which the coil 41 is placed, and in a plan view the same shape as the coil 41 in a plan view. Ribs 71 to 78 are provided at the four corners of the groove 70, protruding from the outer surface of the groove 70 toward the inner surface. The mold 7 also has claws 80 to 83 extending from the upper surface of the outer frame toward the four corners of the groove 70. The claws 80 to 83 may be provided on both ends of either of the two opposing sides of the groove 70. Alternatively, the claws 80 to 83 may be provided on the diagonal portions of the groove 70, which is square in shape in a plan view.

[0027] Ribs 71-78 are formed from the bottom surface of the groove 70 to the middle section towards the top surface. Ribs 71-78 function as support parts for the coil 41 placed in the groove 70. The mold 7 also includes a resin injection channel 79 that connects from the outer surface to the groove 70.

[0028] Subsequently, as shown in Figure 8, the coil 41 is placed in the groove 70 of the mold 7. At this time, the four corners of the coil 41 are supported by the ribs 71-78 and the claws 80-83, thereby positioning the coil 41 within the groove 70 (positioning step). This makes it easy to position the coil 41 within the mold 7.

[0029] In the example shown in Figure 7, the mold 7 has ribs 71 to 78 at the four corners of the groove 70, but this is just one example. At least one rib may be provided that protrudes from the outer surface of the groove 70 towards the inner surface. Even with this configuration, it is possible to position the coil 41 within the mold 7. By providing ribs 71 to 78 at the four corners of the inner surface of the mold 7, the coil 41 can be positioned more stably within the mold 7.

[0030] Next, resin is injected from the resin injection channel 79 into the groove 70 inside the mold 7, and the resin is integrally molded onto at least the inner surface 42 of the coil 41 (see Figures 2 and 3) to form a coil block 34 (resin injection step). This allows the inner surface 42 of the coil 41 to be easily covered with the resin layer 6. At this time, rib marks 45 to 51 (see Figure 4) are formed at the corners of the outer surface of the resin layer 6, and rib marks 48 to 51 are formed at the four corners of the upper surface of the resin layer 6.

[0031] Furthermore, in the positioning step for positioning the coil 41 within the groove 70, the ribs 71-78 and claws 80-83, which function as support parts, support at least a portion of the outer surface 44 of the coil 41 and the axial end faces of the central axis 20.

[0032] At this time, the coil 41 is positioned in a state where it is floating above the bottom surface of the mold 7 by the ribs 71 to 78 which function as support parts. This makes it easy to cover the bottom surface 43 of the coil 41, which is the surface facing the yoke portion 35 (see Figure 2), with the resin layer 6.

[0033] Furthermore, in the resin injection process, where resin is injected into the mold 7, the resin is injected into the mold 7 from the outer circumference of the coil 41 through the injection passage 79. This allows for insulation between the coil 41 and the teeth portion 36 without the need to interpose a flat insulator between the coil 41 and the teeth portion 36.

[0034] Subsequently, the coil block 34, in which the resin layer 6 is integrally molded with the coil 41, is removed from the mold 7, and the coil block 34 is placed in the slot 37 of the stator core 33 (see Figure 2). This allows for insulation between the coil 41 and the teeth portion 36 without the need to interpose a flat insulator between the coil 41 and the teeth portion 36.

[0035] The stators 3 and 4 manufactured in this way are assembled with a rotor 5 that faces the stators 3 and 4 in the axial direction and is rotatable around the central axis 20 of the stators 3 and 4 to manufacture a rotating electric machine 2 (see Figure 1). This makes it possible to manufacture a rotating electric machine 2 with improved heat dissipation.

[0036] Furthermore, a rotating electric machine can also be manufactured by assembling a rotatable rotor radially inward of the stators 3 and 4 manufactured as described above. In such a rotating electric machine, the resin layer 6 is integrally molded with respect to the coils 41 of the stators 3 and 4, resulting in improved heat dissipation compared to a rotating electric machine in which a flat insulator is provided between the coils 41 and the teeth 36.

[0037] Furthermore, this technology can take the following configurations: (1) A stator having a stator core having an annular yoke portion centered on a central axis and a plurality of teeth portions that protrude axially or radially from one surface of the yoke portion and are arranged in the circumferential direction, and a coil block located in a plurality of slots arranged in the circumferential direction between adjacent teeth portions in the circumferential direction, wherein the coil block comprises a coil in which a conductor is wound in an annular shape, and a resin layer integrally molded with the coil, wherein the resin layer is disposed at least on the inner circumference side of the coil. (2) The stator according to (1), wherein the resin layer is disposed on the surface of the coil facing the yoke portion. (3) The stator according to (1) or (2), wherein at least a part of the resin layer is in contact with the teeth portion. (4) The stator according to any one of (1) to (3), wherein the resin layer is disposed on at least a part of the outer circumference side of the coil. (5) The stator according to (4), wherein the thickness of the resin layer arranged on the inner circumference side of the coil is greater than the thickness of the resin layer arranged on the outer circumference side of the coil. (6) The stator according to any one of (1) to (5), wherein the resin layer is wound around the coil and arranged in the gap between adjacent conductors. (7) A rotating electric machine comprising: the stator according to any one of (1) to (6); and a rotor facing the stator and rotatable about the central axis of the stator.(8) A method for manufacturing a stator, comprising: a stator core having an annular yoke portion centered on a central axis and a plurality of teeth portions that protrude axially or radially from one surface of the yoke portion and are arranged in the circumferential direction; and a coil block located in a plurality of slots arranged in the circumferential direction between adjacent teeth portions among the plurality of teeth portions, the method comprising: a winding step of winding a wire in an annular shape to form a coil; a positioning step of placing the coil in a mold having a support portion for supporting the coil and positioning the coil with the support portion; and a resin injection step of injecting resin into the inside of the mold and integrally molding the resin with at least the inner circumference of the coil to form the coil block. (9) The method for manufacturing a stator according to (8), wherein in the positioning step, the support portion supports at least a portion of the outer circumference and both end faces of the coil, and the support portion positions the coil while it is floating above the bottom surface of the mold. (10) The method for manufacturing a stator according to (8) or (9), wherein in the resin injection step, resin is injected into the mold from the outer circumference of the coil. (11) The method for manufacturing a stator according to any one of (8) to (10), further comprising a coil block arrangement step of arranging the coil block in the slot. (12) The method for manufacturing a rotating electric machine, further comprising a step of assembling a stator manufactured by the manufacturing method according to any one of (8) to (11) with a rotor that faces the stator in the axial or radial direction and is rotatable about the central axis of the stator.

[0038] Further effects and modifications can be readily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the specific details and representative embodiments expressed and described above. Accordingly, various modifications are possible without departing from the spirit or scope of the overall concept of the invention as defined by the appended claims and their equivalents.

[0039] 2 Rotating electric machine 3,4 Stator 5 Rotor 6 Resin layer 7 Mold 20 Central shaft 31 Housing 32 Busbar 33 Stator core 34 Coil block 35 Yoke section 36 Teeth section 37 Slot 38 Umbrella 41 Coil 71-78 Rib 79 Injection channel

Claims

1. A stator having an annular yoke portion centered on a central axis, and a plurality of teeth portions that protrude axially or radially from one surface of the yoke portion and are arranged circumferentially, and a coil block located in a plurality of slots arranged circumferentially between adjacent teeth portions in the circumferential direction, wherein the coil block comprises a coil in which a conductor is wound in an annular shape, and a resin layer integrally molded with the coil, wherein the resin layer is located at least on the inner circumference side of the coil.

2. The stator according to claim 1, wherein the resin layer is arranged on the surface of the coil facing the yoke portion.

3. The stator according to claim 1, wherein at least a portion of the resin layer is in contact with the teeth portion.

4. The stator according to claim 1, wherein the resin layer is disposed on at least a portion of the outer circumference of the coil.

5. The stator according to claim 4, wherein the thickness of the resin layer disposed on the inner circumference side of the coil is greater than the thickness of the resin layer disposed on the outer circumference side of the coil.

6. The stator according to claim 1, wherein the resin layer is wound in the coil and positioned in the gaps between adjacent conductors.

7. A rotating electric machine comprising: a stator according to any one of claims 1 to 6; and a rotor facing the stator and rotatable about the central axis of the stator.

8. A method for manufacturing a stator having: a stator core having an annular yoke portion centered on a central axis and a plurality of teeth portions that protrude axially or radially from one surface of the yoke portion and are arranged in the circumferential direction; and a coil block located in a plurality of slots arranged in the circumferential direction between adjacent teeth portions among the plurality of teeth portions, the method comprising: a winding step of winding a wire in an annular shape to form a coil; a positioning step of placing the coil in a mold having a support portion for supporting the coil and positioning the coil with the support portion; and a resin injection step of injecting resin into the inside of the mold and integrally molding the resin with at least the inner circumference of the coil to form the coil block.

9. The method for manufacturing a stator according to claim 8, wherein in the positioning step, the support portion supports at least a portion of the outer circumference and both end faces of the coil, and the support portion positions the coil in a state where it is suspended from the bottom surface of the mold.

10. The method for manufacturing a stator according to claim 8, wherein in the resin injection step, resin is injected into the mold from the outer circumference of the coil.

11. A method for manufacturing a stator according to claim 8, comprising a coil block placement step of placing the coil block in the slot.

12. A method for manufacturing a rotating electric machine, further comprising the step of assembling a stator manufactured by the manufacturing method described in any one of claims 8 to 11 with a rotor that faces the stator in the axial or radial direction and is rotatable about the central axis of the stator.

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