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JP-2026075268-A - Rotor

JP2026075268AJP 2026075268 AJP2026075268 AJP 2026075268AJP-2026075268-A

Abstract

[Problem] To provide a technology for efficiently cooling a rotor with a simple configuration. [Solution] The rotor 10 comprises a rotor shaft 12 and a rotor core 20 attached to the rotor shaft and configured to rotate together with the rotor shaft. The rotor core has a plurality of holes 30 that penetrate from its surface to the rotor shaft. Each hole 30 penetrates from the surface 20a of the rotor core 20 to the rotor shaft 12. [Selection Diagram] Figure 2

Inventors

  • 下河辺 友貴

Assignees

  • トヨタ自動車株式会社

Dates

Publication Date
20260508
Application Date
20241022

Claims (5)

  1. A rotor for a motor, Rotor shaft and The rotor core is attached to the rotor shaft and configured to be rotatable together with the rotor shaft, The rotor core has a plurality of holes that penetrate from its surface to the rotor shaft. Rotor.
  2. The rotor according to claim 1, wherein the plurality of holes are inclined with respect to the radial direction of the rotor when viewed along the axial direction of the rotor.
  3. The rotor according to claim 1 or 2, wherein each of the plurality of holes is located at a different position in the circumferential direction of the rotor.
  4. The rotor according to claim 3, wherein adjacent holes in the circumferential direction of the rotor are positioned differently in the axial direction of the rotor.
  5. A rotor for a motor, Rotor shaft and The rotor core is attached to the rotor shaft and configured to be rotatable together with the rotor shaft, The surface of the rotor core is provided with grooves that extend spirally from one end to the other in the axial direction of the rotor. The groove is configured such that its cross-sectional area decreases from one end to the other end. Rotor.

Description

The technology disclosed herein relates to rotors, and more particularly to rotors for motors. Patent Document 1 discloses a rotor in which cooling oil passages are formed in the yoke portion along the axial direction. In the rotor of Patent Document 1, the rotor is cooled by supplying lubricating oil to the cooling oil passages via a supply passage using an oil pump. Japanese Patent Publication No. 2001-190047 A cross-sectional view of a motor 2 equipped with a rotor 10 according to Embodiment 1.A perspective view of the rotor 10 according to Example 1.Cross-sectional view along the line III-III in Figure 2.A cross-sectional view of the rotor 100 according to Example 2, corresponding to Figure 3.A perspective view of the rotor 200 according to Example 3. (Example 1) Referring to the drawings, the rotor 10 of Embodiment 1 and the motor 2 equipped with the rotor 10 will be described. Although not particularly limited, the motor 2 can be used in an electric vehicle as a prime mover to drive the wheels. Electric vehicles include, for example, battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles. As shown in Figure 1, the motor 2 comprises a stator 4 and a rotor 10. The stator 4 comprises a stator core 6 and coils 8. The stator core 6 is constructed using a soft magnetic material. In this embodiment, the stator core 6 has a structure in which multiple electromagnetic steel sheets (not shown) are laminated. The stator core 6 has a cylindrical shape extending along the axial direction (the direction along the rotation axis A). The stator core 6 is positioned on the outer circumference of the rotor core 20 at a predetermined distance from the rotor core 20. The coils 8 are made of conductors with an insulating coating and are wound around the stator core 6. The coils 8 have coil ends 8a and 8b that protrude outward from each axial end face of the stator core 6. The rotor 10 is located inside the stator 4. The rotor 10 is positioned at a distance from the stator 4. The rotor 10 comprises a rotor shaft 12 and a rotor core 20. The rotor shaft 12 is rotatably supported about the rotation axis A by bearings attached to the housing (not shown) of the motor 2. The rotor core 20 is fixed to the rotor shaft 12 and is configured to rotate together with the rotor shaft 12 around the rotation axis A. The rotor core 20 is constructed using a soft magnetic material. In this embodiment, the rotor core 20 has a structure in which multiple electromagnetic steel sheets are stacked in the axial direction. Multiple permanent magnets (not shown) are provided on the rotor core 20 along the circumferential direction of the rotor 10. As shown in Figures 2 and 3, the rotor core 20 has a plurality of holes 30. As shown in Figure 3, each hole 30 penetrates from the surface 20a of the rotor core 20 to the rotor shaft 12. The number of holes 30 is not particularly limited, but in this embodiment, eight holes 30 are provided in the rotor core 20. Each hole 30 extends linearly along the radial direction of the rotor 10. Each hole 30 is provided at a different position in the circumferential direction of the rotor 10. Each hole 30 is arranged at equal intervals along the circumferential direction. Also, as shown in Figure 2, two adjacent holes 30 in the circumferential direction of the rotor 10 are at different positions in the axial direction. In this embodiment, each hole 30 is arranged spirally along the axial direction. The cross-sectional shape of each hole 30 is not particularly limited, but can be rectangular, circular, etc. Each hole 30 can be formed, for example, by punching after laminating electromagnetic steel sheets. Please note that the stator 4 is not shown in Figures 2, 3, and Figures 4-6 (described later). Next, the method for cooling the rotor 10 will be described. When the rotor 10 rotates, the peripheral speed on the inner diameter side of the rotor 10 (i.e., the rotor shaft 12 side) is faster than the peripheral speed on the outer diameter side of the rotor 10 (i.e., the surface 20a side). Therefore, inside each hole 30, due to the difference in peripheral speed between the inner and outer diameter sides of the rotor 10, the air pressure on the inner diameter side of the rotor 10 becomes lower than the air pressure on the outer diameter side. This pressure difference causes air to flow into each hole 30 as the rotor 10 rotates, drawing air from the outer diameter side to the inner diameter side. This allows for air cooling of the inside of the rotor core 20. Therefore, in the rotor 10 of Embodiment 1, the rotor 10 can be efficiently cooled with a simple configuration. Furthermore, in the rotor 10 of Example 1, the circumferential positions of each hole 30 are different, and the axial positions of adjacent holes 30 in the circumferential direction are also different. Therefore, each hole 30 is balanced along the circumferential and axial directions of the rotor