The drive motor of electric vehicle usually requires frequent start/stop, acceleration/deceleration, high torque at low speed or climbing, low torque at high speed, and wide speed range. Electric vehicle motors can be divided into two categories: brushless motor and brushless motor according to the power on form of motor; According to the mechanical structure of the motor assembly, it is generally divided into two categories: "toothed" (the motor has high speed and needs to be decelerated through gears) and "toothless" (the motor torque output does not undergo any deceleration).