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Abstract

This technology provides a simpler configuration for more efficient cooling of the stator. [Solution] The stator comprises a stator core extending cylindrically along the axial direction and stator coils provided on the stator coils. Inside the stator core, a refrigerant flow path is provided extending along the axial direction, and the refrigerant flow path is configured such that the cross-sectional area near the refrigerant outlet is smaller than the cross-sectional area of ​​other parts.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a stator. In particular, it relates to a stator for a motor.

Background Art

[0002] Patent Document 1 discloses a stator of a motor. This stator includes a stator core that extends cylindrically along the axial direction, and a stator coil provided on the stator core. Inside the stator core, a plurality of refrigerant flow paths that extend along the axial direction are arranged along the circumferential direction. The refrigerant flowing through the refrigerant flow path is supplied to a coil end (the end portion in the axial direction of the stator coil) that protrudes from the end face of the stator core. Thereby, the inside of the stator core is cooled by the refrigerant, and the coil end can be cooled.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, in order to efficiently cool the stator, it is effective to cool both the inside of the stator core and the coil end. In this specification, a technology for more efficiently cooling the stator with a simple configuration is provided.

Means for Solving the Problems

[0005] The stator disclosed herein comprises a stator core extending cylindrically along the axial direction, and stator coils provided on the stator core. Inside the stator core, a refrigerant flow path is provided extending along the axial direction, and the refrigerant flow path is configured such that the cross-sectional area near the refrigerant outlet is smaller than the cross-sectional area of ​​other parts.

[0006] In the above configuration, the refrigerant flow path is configured such that the cross-sectional area near the refrigerant outlet is smaller than the cross-sectional area of ​​other parts. Therefore, the refrigerant flow velocity is higher near the outlet compared to other parts, and the refrigerant is discharged from the outlet of the refrigerant flow path at a high speed. As a result, even a relatively small amount of refrigerant can be efficiently supplied to the coil end. In addition, since the cross-sectional area of ​​the refrigerant flow path is large in parts other than near the refrigerant outlet, a sufficient contact area of ​​the refrigerant with the stator core can be secured, and the stator core can be efficiently cooled. [Brief explanation of the drawing]

[0007] [Figure 1] Cross-sectional view of motor 2 according to the embodiment. [Figure 2] Cross-sectional view along line II-II in Figure 1. [Figure 3] A partial cross-sectional view showing the configuration of the refrigerant flow path 30. [Modes for carrying out the invention]

[0008] (Examples) Referring to the drawings, the stator 10 of the embodiment and the motor 2 equipped with the stator 10 will be described. Although not particularly limited, the motor 2 can be used in an electric vehicle as a prime mover for driving the wheels. Electric vehicles include, for example, battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles.

[0009] As shown in Figures 1 and 2, the motor 2 comprises a rotor 4 and a stator 10. The rotor 4 is located inside the stator 10 and is rotatably supported about a central axis C. The rotor 4 comprises a shaft 6 and a rotor core 8 fixed to the shaft 6. The rotor core 8 is made of a soft magnetic material. In this embodiment, the rotor core 8 has a structure in which electromagnetic steel sheets are laminated. In addition, the rotor core 8 is provided with a plurality of permanent magnets (not shown) along the circumferential direction R.

[0010] The stator 10 comprises a stator core 12, a stator coil 18, and a casing 20. The stator core 12 is made of a soft magnetic material. In this embodiment, the stator core 12 has a structure in which multiple electromagnetic steel sheets (not shown) are laminated. The stator core 12 has a core back 14 that extends cylindrically along the axial direction (direction along the central axis C), and multiple teeth 16 provided on the inner circumferential surface 14a of the core back 14. As shown in Figure 2, the multiple teeth 16 are arranged at equal intervals along the circumferential direction R. Each tooth 16 protrudes from the inner circumferential surface 14a of the core back 14 toward the central axis C. The casing 20 is arranged to surround the outer circumferential surface 14b of the core back 14.

[0011] The stator coil 18 is provided on multiple teeth 16. The stator coil 18 is composed of multiple coils, each coil arranged to surround one or more corresponding teeth 16. As shown in Figure 1, in the axial direction, both ends 18a and 18b of the stator coil 18 protrude from the stator core 12.

[0012] Multiple refrigerant passages 30 are provided inside the core bag 14. As shown in Figure 2, the multiple refrigerant passages 30 are arranged along the circumferential direction R at positions close to the outer circumferential surface 14b of the core bag 14. The multiple refrigerant passages 30 may be provided around the entire circumference of the core bag 14, or they may be provided only in a portion of the circumferential direction R of the core bag 14. In this embodiment, a refrigerant passage 30 is provided between each of two adjacent teeth 16 in the circumferential direction R. Each refrigerant passage 30 extends along the axial direction and reaches the first end face 14c and the second end face 14d of the core bag 14 in the axial direction. The specific configuration of each refrigerant passage 30 is not particularly limited. For example, the cross-sectional shape of each refrigerant passage 30 may be rectangular, circular, or any other shape. Also, each refrigerant passage 30 may be arranged in two or more rows along the circumferential direction R. Each refrigerant passage 30 is a passage for circulating refrigerant. The refrigerant may be any heat transfer medium intended for cooling, such as liquid oil. Hereinafter, the end of the refrigerant flow path 30 on the second end face 14d side will be referred to as the inlet 30a, and the end of the refrigerant flow path 30 on the first end face 14c side will be referred to as the outlet 30b.

[0013] In the stator 10 of this embodiment, refrigerant is supplied to the refrigerant flow path 30 provided in the stator core 12 (core back 14) from an inlet 30a located on the second end face 14d side. The refrigerant supplied into the refrigerant flow path 30 flows toward the first end face 14c of the core back 14 and is discharged from an outlet 30b located on the first end face 14c side of the refrigerant flow path 30.

[0014] Next, the detailed configuration of the refrigerant flow path 30 will be described. As shown in Figure 3, the refrigerant flow path 30 is configured such that the cross-sectional area of ​​portion 50A near the outlet 30b is smaller than the cross-sectional area of ​​the other portion 50B (i.e., the range of the refrigerant flow path 30 from the inlet 30a to portion 50A). The ratio of portion 50A to portion 50B is not particularly limited, but for example, portion 50B extends beyond the intermediate position in the axial direction of the refrigerant flow path 30 towards the outlet 30b. The cross-sectional area of ​​portion 50A only needs to be smaller than the cross-sectional area of ​​portion 50B, and may be constant along the axial direction, or it may gradually decrease from the second end face 14d side to the first end face 14c side. The cross-sectional area of ​​portion 50B only needs to be larger than that of portion 50A, and may have a constant cross-sectional area along the axial direction, or it may have partially different cross-sectional areas.

[0015] As described above, in the stator 10 of this embodiment, the cross-sectional area of ​​the portion 50A of the refrigerant flow path 30 near the refrigerant outlet 30b is smaller than the cross-sectional area of ​​the other portion 50B. Therefore, in portion 50A, the flow velocity of the refrigerant flowing through the refrigerant flow path 30 is greater than in the other portion 50B, and the refrigerant is discharged at a faster speed from the outlet 30b of the refrigerant flow path 30. For this reason, even with a relatively small amount of refrigerant, it is possible to efficiently supply the refrigerant to one end 18a (coil end) of the stator coil 18. In addition, in portion 50B excluding the vicinity of the refrigerant outlet 30b, the cross-sectional area of ​​the refrigerant flow path 30 is large, so a contact area of ​​the refrigerant with the stator core 12 (core back 14) can be secured, and the stator core 12 can be efficiently cooled. [Explanation of Symbols]

[0016] 2: Motor, 4: Rotor, 6: Shaft, 8: Rotor core, 10: Stator, 12: Stator core, 14: Core back, 14a: Inner surface, 14b: Outer surface, 14c: First end face, 14d: Second end face, 16: Teeth, 18: Stator coil, 20: Casing, 30: Coolant flow path, 30a: Inlet, 30b: Outlet

Claims

[Claim 1] A stator for a motor, A stator core extending cylindrically along the axial direction, The stator coil provided on the stator core, Equipped with, The stator core is provided with a refrigerant flow path that extends along the axial direction. The refrigerant flow path is configured such that the cross-sectional area near the refrigerant outlet is smaller than the cross-sectional area of ​​other parts. stata.

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