US Patent 12009703 Rotor-cooling structure of a drive motor

A rotor-cooling structure is for a drive motor including an inner shaft, a rotor shaft surrounding the inner shaft, a rotor connected to the rotor shaft, and a stator disposed to be spaced apart from the rotor. The rotor-cooling structure includes: a first flow passage formed in the inner shaft; a second flow passage formed in the rotor shaft to receive oil through the first flow passage; a third flow passage formed in a plate disposed at an end of a rotor core, constituting the rotor, to be connected to the second flow passage; and a fourth flow passage formed to be connected to the third flow passage and to penetrate the rotor core in the direction in which core plates constituting the rotor core are stacked.