Stator and motor

Abstract

A stator (11) comprises: a stator core (20) having a plurality of teeth (22) in the circumferential direction; coils (40) respectively wound around the plurality of teeth in a concentrated manner; a plurality of slots (S) that are spaces respectively formed between the teeth adjacent to each other in the circumferential direction among the plurality of teeth and through which parts of the coils respectively pass; and an insulating member (50) provided between the coils adjacent to each other in the circumferential direction in at least one of the plurality of slots. The insulating member is provided partially with respect to the radial length of the coils and is provided between the coils at a location (40X) where the coils adjacent to each other in the circumferential direction are closest to each other.

Description

Stator and motor CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-59135, filed on April 1, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a stator and a motor.

[0003] Conventionally, some motor stators include an insulating sheet interposed between coils in slots, which are spaces formed between circumferentially adjacent teeth (see, for example, Patent Document 1). In the stator of Patent Document 1, the radial dimension of the insulating sheet is set to be equal to or larger than the radial dimension of the coil. This allows the insulating sheet to face the entire radial dimension of the coil in the circumferential direction.

[0004] Japanese Patent Application Laid-Open No. 2019-30158

[0005] The stator described above has a problem in that the heat dissipation performance of the coil is reduced by the insulating sheet. An object of the present disclosure is to provide a stator and a motor that can suppress the reduction in heat dissipation performance.

[0006] In a first aspect of the present disclosure, a stator includes a stator core having a plurality of teeth in the circumferential direction, a coil wound in a concentrated manner on each of the plurality of teeth, a plurality of slots which are spaces formed between circumferentially adjacent teeth among the plurality of teeth and through which a portion of the coil passes, and an insulating member provided between circumferentially adjacent coils in at least one of the plurality of slots, wherein the insulating member is provided partially relative to the radial length of the coil and is provided between the coils at the point where circumferentially adjacent coils are closest to each other.

[0007] In a second aspect of the present disclosure, a motor includes a stator and a rotor facing the stator, wherein the stator includes a stator core having a plurality of teeth in the circumferential direction, coils wound in a concentrated manner on each of the plurality of teeth, a plurality of slots which are spaces formed between circumferentially adjacent teeth among the plurality of teeth and through which a portion of the coil passes, and an insulating member provided between circumferentially adjacent coils in at least one of the plurality of slots, wherein the insulating member is provided partially relative to the radial length of the coils and is provided between the coils at the point where circumferentially adjacent coils are closest to each other.

[0008] According to the above configuration, the insulating member is interposed at the point where the circumferentially adjacent coils are closest to each other, thereby ensuring the insulation distance between the coils at that point. Furthermore, since the insulating member is provided partially along the radial length of the coil, it is possible to prevent the insulating member from reducing the heat dissipation performance of the coil.

[0009] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic diagram of a motor according to one embodiment, Fig. 2 is a perspective view showing a portion of a stator according to the same embodiment, and Fig. 3 is a partial cross-sectional view of the stator according to the same embodiment.

[0010] An embodiment of a stator and a motor will be described below. (Configuration of Motor 10) As shown in Fig. 1, the motor 10 includes a stator 11 and a rotor 12 facing the stator 11. The stator 11 has an annular shape. The rotor 12 is disposed inside the stator 11. That is, the rotor 12 faces the stator 11 in the radial direction. The stator 11 is housed in a cylindrical housing 13. The stator 11 is housed in the housing 13 by, for example, shrink fitting.

[0011] (Configuration of Stator 11) The stator 11 includes a stator core 20, an insulator 30, a coil 40, an insulating member 50, and a molded resin 60. Note that Fig. 1 shows a schematic cross section of the insulator 30 and the coil 40.

[0012] The stator core 20 is formed of a conductor such as metal. The stator core 20 includes a plurality of split cores 20a that are divided in the circumferential direction. In this embodiment, the stator core 20 is made up of 12 split cores 20a. The stator core 20 has an annular portion 21 having an annular shape and a plurality of teeth 22 that extend radially inward from the annular portion 21 in the circumferential direction. One tooth 22 is provided for each split core 20a. That is, the stator core 20 of this embodiment has 12 teeth 22.

[0013] Slots S, which are spaces formed between circumferentially adjacent teeth 22, are formed in the stator 11. The number of slots S is the same as the number of teeth 22, that is, 12 in this embodiment.

[0014] The insulators 30 are made of an insulating material such as synthetic resin. The insulators 30 are attached to each of the split cores 20a. The coils 40 are wound around the teeth 22 via the insulators 30 in a concentrated winding manner. A portion of each coil 40 passes through each slot S in the axial direction.

[0015] Three-phase AC currents, for example, with a phase difference of 120 degrees, are supplied to each coil 40. Currents of different phases are supplied to coils 40 adjacent to each other in the circumferential direction in each slot S. When power is supplied to each coil 40, a rotating magnetic field for rotating the rotor 12 is generated in the stator 11.

[0016] Fig. 2 shows a part of the stator 11. As shown in Fig. 2 and Fig. 3 , the insulator 30 includes a first covering portion 31 that covers the inner circumferential surface of the annular portion 21 of the stator core 20, and a second covering portion 32 that covers the teeth 22. The second covering portion 32 covers both axial end faces and both circumferential end faces of the teeth 22.

[0017] (Configuration of Coil 40) As shown in Fig. 2, the coil 40 is formed by winding one conductor wire 41 around the outer periphery of the second covering portion 32 of the insulator 30. The conductor wire 41 forming the coil 40 includes a winding start wire 42, which is the winding start portion, and a winding end wire 43, which is the winding end portion. The winding start wire 42 is one of the conductor wires 41 located in the innermost layer of the coil 40 and is drawn out in the axial direction from the coil 40. The winding end wire 43 is one of the conductor wires 41 located in the outermost layer of the coil 40 and is drawn out in the axial direction from the coil 40. The winding start wire 42 and the winding end wire 43 are connected to, for example, a bus bar (not shown) that is arranged axially laterally of the stator core 20.

[0018] 3, the coil 40 has a conductor group 40A located in the outermost layer. The conductor group 40A includes a winding end wire 43 and an adjacent conductor wire 44 that is radially adjacent to the winding end wire 43. Note that in this embodiment, the conductor group 40A is composed of only two wires: the winding end wire 43 and the adjacent conductor wire 44.

[0019] (Configuration of insulating members 50) As shown in Fig. 1 , the insulating members 50 are disposed in each slot S. For example, one insulating member 50 is provided in each slot S. That is, the stator 11 of this embodiment includes twelve insulating members 50. Furthermore, each insulating member 50 is fixed to a corresponding coil 40.

[0020] The insulating member 50 is made of an insulating material such as synthetic resin. Examples of synthetic resins that form the insulating member 50 include PPS (polyphenylene sulfide) resin. The insulating member 50 is made of a material that has lower thermal conductivity than the molded resin 60 (described later) and is more elastic than the molded resin 60.

[0021] 3, the insulating member 50 has a base 51 and a pair of clamping portions 52 extending in the same direction from the base 51. The insulating member 50 has a shape in which an opening is formed between the tips of the pair of clamping portions 52. The insulating member 50 is disposed in the slot S with the pair of clamping portions 52 facing each other in the radial direction.

[0022] The insulating member 50 is fixed to, for example, the outermost conductor wire 41 of the coil 40. More specifically, the insulating member 50 is fixed to the coil 40 by clamping together the multiple conductor wires included in the outermost conductor wire group 40A between a pair of clamping portions 52. The insulating member 50 of this embodiment also holds all of the conductor wires included in the conductor wire group 40A, i.e., the winding end wire 43 and the adjacent conductor wire 44, together. This fixes the winding end wire 43 to the adjacent conductor wire 44. The insulating member 50 is fixed to the winding end wire 43 and the adjacent conductor wire 44 by snap fitting.

[0023] For example, an insertion portion 53 is formed to protrude from the tip of each clamping portion 52. The insertion portion 53 of one clamping portion 52 is inserted between the end-of-winding wire 43 and the adjacent conductor wire 41 on the inner layer side relative to the end-of-winding wire 43. The insertion portion 53 of the other clamping portion 52 is inserted between the adjacent conductor wire 44 and the adjacent conductor wire 41 on the inner layer side relative to the adjacent conductor wire 44. Each insertion portion 53 more firmly fixes the insulating member 50 to the coil 40.

[0024] 2 , the insulating member 50 is provided partially relative to the radial length of the coil 40. The radial dimension of the insulating member 50 is set smaller than the radial dimension of the coil 40. The insulating member 50 is provided, for example, at a position closer to the radial outer side in the slot S, i.e., at a position close to the first covering portion 31 of the insulator 30.

[0025] Furthermore, the insulating member 50 is provided partially relative to the axial length of the coil 40. The axial dimension of the insulating member 50 is set to be smaller than the axial dimension of the slot S. The insulating member 50 is provided at a location immediately before the end of the winding wire 43 is pulled out from the coil 40. In other words, the insulating member 50 is provided at one axial end of the portion of the coil 40 that passes through the slot S along the axial direction.

[0026] 1 , the insulating member 50 is provided between the coils 40 at the location (closest location 40X) where circumferentially adjacent coils 40 are closest to each other in each slot S. The closest location 40X is set, for example, at a position closer to the radial outside in the slot S. By providing the insulating member 50 between the coils 40 at the closest location 40X, it is possible to ensure an insulation distance between the coils 40 at the closest location 40X.

[0027] (Configuration of molded resin 60) The molded resin 60 is provided as a heat dissipation filler in the stator 11. The molded resin 60 is formed of, for example, an epoxy-based resin material containing alumina. Note that it is preferable to select a material for forming the molded resin 60 that has a linear expansion coefficient close to that of the material of the insulating member 50.

[0028] The molded resin 60 is formed using a mold (not shown). That is, the molded resin 60 is formed by pouring molten resin into a mold fixed to the stator core 20 and allowing the molten resin to harden. The molded resin 60 is formed so as to collectively cover each coil 40 and the insulator 30. That is, the winding start wire 42 and winding end wire 43 of the coil 40 and the insulating member 50 are embedded inside the molded resin 60. Note that, for ease of explanation, the molded resin 60 is not shown in FIG. 3.

[0029] The molded resin 60 includes axial covering portions 61 that cover both axial ends of the stator core 20, and intra-slot portions 62 that fit between circumferentially adjacent coils 40 in each slot S. The axial covering portion 61 is formed, for example, in an annular shape along the circumferential direction of the stator 11. The axial covering portion 61 seals the portions of the coils 40 that protrude from the axial ends of the stator core 20. The bus bars are embedded in the axial covering portions 61. The intra-slot portions 62 in each slot S are connected to a pair of axial covering portions 61 on both axial sides.

[0030] (Operation of this embodiment) The operation of this embodiment will be described below. When molding the molded resin 60, the resin flows into the slot S from a position closer to the radial inside. In contrast, the insulating member 50 is provided in a position closer to the radial outside within the slot S. In other words, the insulating member 50 is provided in a position that minimizes the obstruction to the flow of the resin that forms the molded resin 60.

[0031] Furthermore, when molding the molded resin 60, the winding end wire 43 included in the outermost conductor group 40A of the coil 40 is subjected to the pressure of the flowing resin. Here, the winding end wire 43 is fixed to the adjacent conductor wires 44 by the insulating member 50. In other words, the movement of the winding end wire 43 is restricted by the insulating member 50. Therefore, when molding the molded resin 60, the winding end wire 43 is prevented from approaching the adjacent coil 40 due to the pressure of the resin. Note that, since a greater winding tension is applied to the wires of the coil 40 other than the winding end wire 43 (wires including the adjacent conductor wire 44) than to the winding end wire 43, the adjacent conductor wire 44 is less likely to loosen than the winding end wire 43.

[0032] (Effects of this embodiment) The effects of this embodiment will be described below. (1) The insulating member 50 is provided partially along the radial length of the coil 40, and is provided between the coils 40 at the locations (closest locations 40X) where circumferentially adjacent coils 40 are closest to each other. With this configuration, the insulating member 50 is interposed at the closest locations 40X where circumferentially adjacent coils 40 are closest to each other, thereby ensuring an insulation distance between the coils 40 at the closest locations 40X. Furthermore, because the insulating member 50 is provided partially along the radial length of the coil 40, it is possible to prevent the insulating member 50 from reducing the heat dissipation performance of the coil 40.

[0033] (2) The insulating member 50 is provided partially along the axial length of the coil 40. With this configuration, it is possible to further prevent the insulating member 50 from reducing the heat dissipation performance of the coil 40.

[0034] (3) One insulating member 50 is provided for each of the plurality of slots S. With this configuration, in each slot S, an insulating distance between the coils 40 at the closest point 40X can be ensured.

[0035] (4) The coil 40 has a winding end wire 43. The insulating member 50 is provided at a position corresponding to the winding end wire 43. According to this configuration, the insulating member 50 can restrict the movement of the winding end wire 43, thereby preventing the winding end wire 43 from approaching an adjacent coil 40.

[0036] (5) The coil 40 has an outermost conductor group 40A including the winding end wire 43. The insulating member 50 collectively holds multiple conductors (the winding end wire 43 and the adjacent conductor wires 44) including the winding end wire 43 in the conductor group 40A. This configuration allows the insulating member 50 to fix the winding end wire 43. This allows the insulating member 50 to more effectively restrict movement of the winding end wire 43.

[0037] (6) The insulating member 50 has a base 51 and a pair of clamping portions 52 extending from the base 51. The pair of clamping portions 52 clamp a plurality of conductors (the winding end wire 43 and the adjacent conductor wires 44) including the winding end wire 43 of the conductor group 40A. With this configuration, the pair of clamping portions 52 of the insulating member 50 can fix the winding end wire 43.

[0038] (7) The stator 11 includes a molded resin 60 formed to collectively cover each coil 40. The molded resin 60 includes an intra-slot region 62 that fits between circumferentially adjacent coils 40 within the slot S. Because the insulating member 50 is provided partially along the radial length of the coil 40, it is possible to ensure a large contact area between the coil 40 and the intra-slot region 62 within the slot S. This makes it possible to ensure a heat dissipation path that transfers heat from the coil 40 to the intra-slot region 62.

[0039] (8) The mold resin 60 is set to have a higher thermal conductivity than the insulating member 50, which makes it possible to improve the heat dissipation of the coil 40. (Other Embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0040] In the above embodiment, the outermost layer conductor group 40A of the coil 40 is composed of only two conductors, the winding end wire 43 and the adjacent conductor wire 44. However, this is not limited to this, and the outermost layer conductor group 40A may include three or more conductors including the winding end wire 43. In this case, the insulating member 50 may collectively hold all of the conductors included in the outermost layer conductor group 40A.

[0041] The configuration of the insulating member 50, such as its shape, is not limited to the above embodiment and can be changed as appropriate depending on the configuration of the stator 11. The insulating member 50 may be provided at a radially inner position within the slot S or at a radially intermediate position within the slot S.

[0042] In the above embodiment, the insulating member 50 is provided at one axial end of the portion of the coil 40 that passes through the slot S along the axial direction, but this is not particularly limited to this. For example, the insulating member 50 may be provided at an axial middle position of the portion of the coil 40 that passes through the slot S along the axial direction.

[0043] The axial dimension of the insulating member 50 may be set to be equal to the axial dimension of the slot S. The insulating member 50 may be fixed to a portion of the coil 40 that does not include the end winding wire 43.

[0044] In the above embodiment, the insulating member 50 can be fixed to the coil 40 by snap-fitting. However, the insulating member 50 may be fixed to the coil 40 by other methods, such as adhesive.

[0045] In the above embodiment, the insulating member 50 is fixed to the coil 40. However, the present invention is not limited to this. For example, the insulating member 50 may be fixed to the first covering portion 31 of the insulator 30 by adhesive or the like.

[0046] The insulating member 50 may be provided in only some of the slots S among the plurality of slots S. The material of the insulating member 50 is not limited to that in the above embodiment, and may be changed as appropriate depending on the configuration of the stator 11.

[0047] The material of the molded resin 60 is not limited to that in the above embodiment and can be changed as appropriate depending on the configuration of the stator 11. In the stator 11 of the above embodiment, the molded resin 60 may be omitted. If the molded resin 60 is omitted, cooling oil may be applied to the surface of the coil 40. Even in this case, by providing the insulating member 50 partially with respect to the radial length of the coil 40, the cooling oil can easily adhere to the surface of the coil 40, which can be said to be an advantageous configuration in terms of improving the heat dissipation performance of the coil 40.

[0048] In the above embodiment, the stator core 20 is made up of a plurality of split cores 20a. However, the present invention is not limited to this. That is, the stator core 20 may have an annular portion 21 that is connected around the entire circumference.

[0049] In the above embodiment, the stator 11 has twelve teeth 22. However, the present invention is not limited to this. For example, the stator 11 may have another number of teeth 22, such as twenty-four.

[0050] In the above embodiment, the stator 11 and the housing 13 are fixed by shrink fitting, but this is not limited to this and other fixing configurations may also be used. While the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to these examples or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. Additionally, various combinations and configurations, including only one element, more than one element, or fewer elements, are also within the scope and spirit of the present disclosure.

[0051] (Additional Notes) Features of the present disclosure are as follows: [1] A stator (11) including a stator core (20) having a plurality of teeth (22) in the circumferential direction, coils (40) wound in a concentrated manner around each of the plurality of teeth, a plurality of slots (S) that are spaces formed between circumferentially adjacent teeth of the plurality of teeth and through which portions of the coils pass, and an insulating member (50) provided between circumferentially adjacent coils in at least one of the plurality of slots, wherein the insulating member is provided partially with respect to the radial length of the coils and is provided between the coils at a location (40X) where the circumferentially adjacent coils are closest to each other.

[0052] [2] The stator according to the above [1], wherein the insulating member is provided partially with respect to the axial length of the coil. [3] The stator according to the above [1] or [2], wherein the insulating member is provided one for each of the plurality of slots.

[0053] [4] A stator according to any one of [1] to [3] above, wherein the coil has a winding end wire (43), and the insulating member is provided at a position corresponding to the winding end wire.

[0054] [5] The stator described in [4] above, wherein the coil has an outermost layer of a group of conductors (40A) including the winding end wire, and the insulating member holds together multiple conductors (43, 44) including the winding end wire from the group of conductors.

[0055] [6] The stator described in [5] above, wherein the insulating member has a base (51) and a pair of clamping portions (52) extending from the base, and the pair of clamping portions clamp the plurality of conductors of the group of conductors.

[0056] [7] A stator described in any one of [1] to [6] above, further comprising a molded resin (60) formed to cover each of the coils collectively, the molded resin including an inner slot portion (62) that fits between circumferentially adjacent coils in each of the plurality of slots.

[0057] [8] The stator according to [7], wherein the molded resin has a thermal conductivity set higher than that of the insulating member. [9] A motor (10) including a stator (11) and a rotor (12) facing the stator, wherein the stator includes a stator core (20) having a plurality of teeth (22) arranged in a circumferential direction, coils (40) wound concentrically around each of the plurality of teeth, a plurality of slots (S) each formed as spaces between adjacent ones of the plurality of teeth in the circumferential direction, and through which a portion of the coil passes, and an insulating member (50) provided between adjacent ones of the coils in the circumferential direction in at least one of the plurality of slots, wherein the insulating member is provided partially along the radial length of the coils and is provided between the coils at a position (40X) where adjacent ones of the coils are closest to each other in the circumferential direction.

Claims

1. A stator (11) comprising: a stator core (20) having a plurality of teeth (22) in the circumferential direction; coils (40) wound in a concentrated manner around each of the plurality of teeth; a plurality of slots (S) which are spaces formed between circumferentially adjacent teeth among the plurality of teeth and through which a portion of the coil passes; and an insulating member (50) provided between circumferentially adjacent coils in at least one of the plurality of slots, wherein the insulating member is provided partially relative to the radial length of the coils and is provided between the coils at a point (40X) where circumferentially adjacent coils are closest to each other.

2. The stator according to claim 1, wherein the insulating member is provided over a portion of the axial length of the coil.

3. The stator according to claim 1, wherein the insulating member is provided for each of the plurality of slots.

4. A stator according to claim 1, wherein the coil has a winding end wire (43), and the insulating member is provided at a position corresponding to the winding end wire.

5. A stator as set forth in claim 4, wherein the coil has an outermost layer of conductor wires (40A) including the winding end wire, and the insulating member collectively holds a plurality of conductor wires (43, 44) including the winding end wire among the conductor wires.

6. A stator according to claim 5, wherein the insulating member has a base (51) and a pair of clamping portions (52) extending from the base, the pair of clamping portions clamping the plurality of conductors of the group of conductors.

7. A stator as set forth in claim 1, further comprising a molding resin (60) formed to cover each of the coils collectively, the molding resin including an intra-slot portion (62) that fits between circumferentially adjacent coils in each of the plurality of slots.

8. The stator according to claim 7, wherein the molding resin is set to have a higher thermal conductivity than the insulating member.

9. A motor (10) comprising a stator (11) and a rotor (12) facing the stator, wherein the stator comprises: a stator core (20) having a plurality of teeth (22) in the circumferential direction; coils (40) wound in a concentrated manner around each of the plurality of teeth; a plurality of slots (S) which are spaces formed between circumferentially adjacent teeth of the plurality of teeth and through which a portion of the coil passes; and an insulating member (50) provided between circumferentially adjacent coils in at least one of the plurality of slots, wherein the insulating member is provided partially along the radial length of the coils and is provided between the coils at a point (40X) where the circumferentially adjacent coils are closest to each other.

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