Patent attributes
A motor includes a rotor to rotate about a motor axis, and a stator radially outside of the rotor. The rotor includes a shaft extending along the motor axis, and a rotor core surrounding the shaft from radially outside. The shaft includes a hollow portion including an inner circumferential surface extending along an axial direction, and a communicating hole extending in a radial direction to bring a space outside of the shaft and the hollow portion into communication with each other, the hollow portion being structured to allow oil to be fed thereinto. The inner circumferential surface of the hollow portion includes a recessed groove extending along a circumferential direction. The communicating hole opens into the hollow portion at the recessed groove.
