Number of stages: the number of sets of planetary gears. Since a set of planetary gears cannot meet a large transmission ratio, sometimes two or three sets are required to meet the requirements of a larger gear ratio. Due to the increase in the number of planetary gears, level 2 Or the length of the 3-stage reducer will increase, and the efficiency will decrease.
Return gap: The output end is fixed, the input end rotates clockwise and counterclockwise, so that the input end produces a rated torque +-2% torque, the input end of the reducer has a slight angular displacement, this angular displacement is the return clearance. It is a 'minute', which is one-sixtieth of a degree. Some people call it backlash.