ELECTRIC MOTOR SHAFT, ELECTRIC MOTOR AND ELECTRIC VEHICLE

This application provides a motor shaft, a motor, and an electric vehicle. The motor shaft includes a shaft body and an insulation coating. The shaft body includes a first mounting portion and a second mounting portion that are fastenedly connected. A positioning step surface is disposed at an end that is of the first mounting portion and that is close to the second mounting portion. The first mounting portion is configured to mount a rotor. The second mounting portion is covered with the insulation coating, and the second mounting portion is configured to mount a bearing. A resistivity of the insulation coating is not less than 10 Q m. In this way, a possibility that a shaft current is generated when a shaft voltage discharges and breaks down a lubricating oil film in the bearing to form a path can be effectively reduced. To be specific, the insulation coating can effectively block circulation of the shaft current between the motor shaft and the bearing, to reduce a possibility of abnormal operating noise of the motor due to electrical corrosion of the bearing, and effectively prolong a service life of the motor.