motor

Abstract

This invention provides a technology for improving the insulation performance at the connection points of segment coils. [Solution] The motor comprises a stator core having a plurality of slots, a stator coil formed by connecting a plurality of segment coils arranged in the plurality of slots, and an insulating material made of an insulating foam material that covers each connection point of the plurality of segment coils. Each connection point of the plurality of segment coils has a structure in which the ends of the conductor portions of two segment coils, which are exposed, are inserted from both ends into a cylindrical fitting member, and at least one through hole is formed in the side wall of the cylindrical fitting member, and the insulating material extends from the inside to the outside of the fitting member through at least one through hole.

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a motor.

[0002] Patent Document 1 discloses a motor. This motor includes a stator core having a plurality of slots, and a stator coil disposed in the plurality of slots and formed by connecting a plurality of segment coils. The connection points of the plurality of segment coils have a structure in which the exposed ends of the conductor portions of two segment coils are inserted into a fitting member having a cylindrical shape from both ends. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-126153 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] In each slot, several segment coils are running parallel, and two or more connection points are installed adjacent to each other. At each connection point, the conductor portion of the segment coil is exposed, so it is necessary to ensure insulation between adjacent connection points.

[0005] In view of the above, this specification provides a technology for improving the insulation at the connection points of segment coils. [Means for Solving the Problems]

[0006] The technology disclosed herein is embodied in a motor. This motor comprises a stator core having a plurality of slots, a stator coil formed by connecting a plurality of segment coils arranged in the plurality of slots, and an insulating material made of an insulating foam material that covers each connection point of the plurality of segment coils. Each connection point of the plurality of segment coils has a structure in which the ends of the conductive portions of two segment coils, each exposed, are inserted from both ends into a cylindrical fitting member. At least one through hole is formed in the side wall of the cylindrical fitting member. The insulating material extends from the inside to the outside of the fitting member through at least one through hole.

[0007] In the above configuration, each connection point of the multiple segment coils is covered with an insulating material, thereby ensuring insulation between adjacent connection points. Furthermore, with the above configuration, it can be easily realized by connecting the ends of two segment coils via a fitting member, and then heating (i.e., foaming) the foaming material raw material placed inside the fitting member.

[0008] In one embodiment of this technology, at least one through-hole may include a pair of through-holes that open in opposite directions. This configuration allows the insulating material to extend symmetrically with respect to the fitting member at the connection point of the segment coil.

[0009] In the above embodiment, the pair of through holes opening in opposite directions may face each other in a direction perpendicular to the axial direction of the cylindrical fitting member. This configuration allows the insulating material to extend more symmetrically with respect to the fitting member at the connection point of the segment coil.

[0010] In one embodiment of this technology, the insulating material may be made of a thermosetting resin.

[0011] According to the above configuration, the shape of the insulating material is maintained even when the insulating material is reheated. In other words, the insulating properties of the insulating material are maintained.

[0012] The technology disclosed herein is also embodied in a motor manufacturing method. This manufacturing method comprises the steps of: placing a raw material for an insulating foam material inside a cylindrical fitting member; performing a step after the placement step and connecting the ends of two segment coils, where the conductor portions are exposed within the slots of the stator core, via the fitting member; and performing a step after the connecting step and heating the raw material for the foam material located inside the fitting member to cause it to foam. At least one through hole is formed in the side wall of the cylindrical fitting member. In the foaming step, the foam material expands from the inside to the outside of the fitting member through at least one through hole, thereby forming an insulating material that covers the connection point of the two segment coils. According to this manufacturing method, the motor described above can be easily manufactured. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing the configuration of the motor 2 in this embodiment. [Figure 2] This is an enlarged view of part II in Figure 1. [Figure 3] A diagram showing one step in the manufacturing process of motor 2, which involves placing the raw material for foaming material inside a fitting member. [Figure 4] A diagram showing one step in the manufacturing process of motor 2, in which the ends of two segment coils are connected via a fitting member. [Figure 5] A diagram showing one step in the manufacturing process of motor 2, which involves heating the raw material of the foaming material located inside the fitting member to cause it to foam. [Modes for carrying out the invention]

[0014] (Examples) Motor 2 of this embodiment will be described with reference to the drawings. Motor 2 of this embodiment can be used, for example, as a drive source to drive the wheels of a battery electric vehicle (BEV). Furthermore, the configuration of motor 2 described in this embodiment is not limited to a three-phase AC motor, but can be similarly applied to other types of electric motors.

[0015] As shown in Figure 1, the motor 2 of this embodiment comprises a rotor 3 and a stator 8. The rotor 3 consists of a shaft 4 extending along the axial direction, a rotor core 5 provided on the outer surface of the shaft 4, and magnets 6 installed inside the rotor core 5. The rotor core 5 is made of a soft magnetic material, such as electromagnetic steel.

[0016] The stator 8 comprises a stator core 10, a plurality of slots 12 provided in the stator core 10, and a stator coil 14. The stator core 10 is made of a soft magnetic material, such as electrical steel. The stator core 10 has a cylindrical shape and extends axially between a first end face 10a and a second end face 10b. A plurality of slots 12 are formed on the inner circumferential surface of the stator core 10. The plurality of slots 12 are arranged along the circumferential direction. Each of the plurality of slots 12 extends axially.

[0017] The stator coil 14 is composed of multiple segment coils 15 connected together. Each segment coil 15 is inserted into the slot 12 from the first end face 10a or the second end face 10b of the stator core 10. Each segment coil 15 is then connected to other segment coils 15 within the slot 12. That is, multiple connection points 20 are formed within the slot 12 of the stator core 10, and at each connection point 20, a pair of segment coils 15 are connected to each other.

[0018] As shown in FIG. 2, a fitting member 16 is provided at the connection portion 20 of the pair of segment coils 15. The fitting member 16 has a cylindrical shape and is made of a metal such as copper, for example. Each end portion 15a of the pair of segment coils 15 is press-fitted into the fitting member 16 from both sides. At each end portion 15a of the segment coil 15, the conductor portion of the segment coil 15 is exposed. Thereby, the pair of segment coils 15 are connected to each other mechanically and electrically via the fitting member 16.

[0019] Two through holes 16a and 16b are formed in the side wall of the fitting member 16 having a cylindrical shape. The two through holes 16a and 16b open in opposite directions to each other. Although not particularly limited, the two through holes 16a and 16b are provided at the same position with respect to the axial direction of the fitting member 16 (the vertical direction in FIG. 2). That is, the two through holes 16a and 16b face each other in a direction orthogonal to the axial direction of the fitting member 16. As another embodiment, the two through holes 16a and 16b may be offset from each other with respect to the axial direction of the fitting member 16 (the vertical direction in FIG. 2).

[0020] In the motor 2 of this embodiment, an insulating material 18 is provided in the slot 12 of the stator core 10. The insulating material 18 is provided so as to cover the connection portions 20 of the plurality of segment coils 15. That is, each end portion 15a where the conductor portion of the segment coil 15 is exposed and the fitting member 16 connecting them are covered with the insulating material 18. The insulating material 18 extends from the inside to the outside of the fitting member 16 through the two through holes 16a and 16b. By covering not only the fitting member 16 with the insulating material 18 but also the conductor portion of the segment coil 15, sufficient insulation can be ensured between two adjacent connection portions 20.

[0021] The insulating material 18 of this embodiment is composed of a foamed material having insulating properties. The foamed material referred to here broadly means a material having a porous structure, and its manufacturing method is not particularly limited. The material constituting the insulating material 18 may be a polymer material such as a thermosetting resin. However, the insulating material 18 may be composed of a material other than the thermosetting resin.

[0022] The stator coil 14 of this embodiment includes a U-phase coil, a V-phase coil, and a W-phase coil. The U-phase coil, the V-phase coil, and the W-phase coil have different circumferential positions in the stator core 10, but other configurations are common to each other. The specific configurations of the rotor 3 and the stator 8 are not particularly limited.

[0023] (Manufacturing method) Referring to FIGS. 3, 4, and 5, the manufacturing method of the motor 2 of this embodiment will be described. The manufacturing method of the motor 2 includes a step of connecting a plurality of segment coils 15 to form the stator coil 14. First, as shown in FIG. 3, a fitting member 16 is press-fitted into an end portion 15a of one of the pair of segment coils 15 to be connected. Then, from the side opposite to the direction in which the end portion 15a of the segment coil 15 is press-fitted, the raw material 19 of the foamed material is disposed inside the fitting member 16. Although not particularly limited, the raw material 19 of the foamed material may be a thermoplastic resin containing a foaming agent. The foaming agent generates gas when heated, changing the raw material 19 into a foamed material. Thereafter, the segment coil 15 to which the fitting member 16 is attached is inserted into the slot 12 from the first end face 10a side of the stator core 10.

[0024] Subsequently, the other segment coil 15 of the pair of segment coils 15 is inserted into the slot 12 from the second end face 10b side. Then, as shown in Figure 4, the end 15a of the segment coil 15 is press-fitted into the fitting member 16 inside the slot 12. Through the above process, a connection point 20 of the pair of segment coils 15 is formed. At the connection point 20, the foam material raw material 19 is located inside the fitting member 16 between the respective ends 15a of the pair of segment coils 15.

[0025] Next, the stator core 10 is heated. When the stator core 10 is heated, the temperature of the foam material raw material 19 placed inside the fitting member 16 rises. As mentioned above, the foam material raw material 19 contains a foaming agent. Therefore, the foam material raw material 19 placed inside the fitting member 16 foams up and overflows from the inside to the outside of the fitting member 16 through the through holes 16a and 16b provided on the side surface of the fitting member 16. After that, as shown in Figure 5, the foam material covers each connection point 20 of the multiple segment coils 15 inside the slot 12. This forms an insulating material 18 that ensures insulation between two adjacent connection points 20 of the segment coils 15. With the above manufacturing method, a motor 2 with improved insulation at each connection point 20 of the multiple segment coils 15 according to this embodiment can be easily manufactured.

[0026] The specific examples of the technology disclosed in this specification have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples described above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of Symbols]

[0027] 2: Motor 3: Rotor 4: Shaft 5: Rotor core 6: Magnets 8: Status 10: Stator core 10a: 1st end surface 10b: Second end surface 12: Slot 14: Stator coil 15: Segment coil 15a: End 16: Fitting member 16a, 16b: Through hole 18: Insulating material 19: Raw materials for foaming materials 20: Connection point

Claims

1. A stator core having multiple slots, A stator coil is formed by arranging multiple slots and connecting multiple segment coils, An insulating material made of an insulating foam material, which covers each connection point of the plurality of segment coils, Equipped with, Each connection point of the plurality of segment coils has a structure in which the exposed ends of the conductor portions of two segment coils are inserted from both ends into a cylindrical fitting member. At least one through hole is formed in the side wall of the cylindrical fitting member. The insulating material extends from the inside to the outside of the fitting member through at least one through hole. Motor.

2. The at least one through hole includes a pair of through holes that open in opposite directions. The motor according to claim 1.

3. The pair of through holes that open in opposite directions are opposite each other in a direction perpendicular to the axial direction of the cylindrical fitting member. The motor according to claim 2.

4. The aforementioned insulating material is It is made of thermosetting resin. The motor according to claim 1.

5. A method for manufacturing a motor, A step of placing an insulating foam material inside a tubular fitting member, This step is performed after the aforementioned arrangement step, and involves connecting the ends of the two segment coils, where the conductor portions are exposed within the slots of the stator core, via the fitting member. A step performed after the aforementioned connecting step, and which involves heating and foaming the raw material of the foaming material located inside the fitting member, Equipped with, At least one through hole is formed in the side wall of the cylindrical fitting member. In the foaming process, the foamed material expands from the inside to the outside of the fitting member through at least one through hole, thereby forming an insulating material that covers the connection point of the two segment coils. Manufacturing method.

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