Planetary Gear Reducer

A planetary gear reducer is a critical component within a slewing unit, responsible for converting high-speed, low-torque input from a motor into low-speed, high-torque output to drive the slewing motion. It consists of a central sun gear, multiple planet gears that rotate around it, and an outer ring gear, all housed within a carrier. This configuration provides high power density, excellent torque transmission, and compact design essential for the precise and heavy-duty rotational movement of slewing applications in machinery like cranes, excavators, and wind turbines.

Power is input to the sun gear. This drives the surrounding planet gears, which mesh simultaneously with both the sun gear and the stationary (or rotating) internal ring gear. The planet gears orbit the sun gear while rotating on their own axes. The planet carrier, which holds the planet gears, becomes the output, providing reduced speed and multiplied torque. The specific gear ratio is determined by the number of teeth on the sun, planet, and ring gears.