What are 3-stage Micro Planetary Gear Motors?

The 3-stage micro planetary gear motor is a planetary gear motor which is normally used when high torque is needed in limited spaces. Planetary gearboxes have better reliability and longer service life than spur gearboxes.

The 3-stage micro planetary gear motor is named according to the number of gear stages. A set of planetary gear motors includes the sun gear, planet gear, and ring gear.   

The Reason Why the 3-stage Micro Gear Motor is Invented

When the reduction ratios of 1-stage and 2-stage planetary gears are unable to meet requirements, a 3-stage micro planetary gear motor that meshes with more gear sets can better meet the demands by providing a large gear ratio.

Due to the increase in the number of planetary gear stages, the length of the motor of the 2-stage or 3-stage gearbox increases, and efficiency decreases. There are generally 1-stage, 2-stage, and 3-stage gearboxes on the market, but ZHAOWEI also provides 4-stage planetary gearboxes.  

The Structure of 3-stage Micro Planetary Gear Motor

The transmission structure of the planetary gear motor mainly consists of planet gears, sun gears, and ring gears. Planetary gear transmissions are small, have large loading capacity, and run smoothly. The high-power and high-speed planetary gear transmission structure is relatively complex, and requires high precision.  

The 3-stage planetary gear motor includes a housing, an output device, and an input device which are coaxially and rotationally assembled at the front and rear positions of the housing. The transmission structure of the 3-stage planetary gear set is between the input and output devices inside the housing. The output device is an output shaft - an internal spline sleeve. The transmission structure of the planetary gears at all stages meshes with the ring gear, while the planet gears are assembled between the sun gear and ring gear, connected with the planet gear carrier. The sun gear of the 1-stage gearbox is integrated with the output device. In addition to the overall arrangement of the planet gear carrier and the output device of the 3-stage gearbox, the planet gear carriers in other transmission structures, such as 1-stage and 2-stage planetary gearboxes, are in coaxial transmission coordination with lower-stage sun gear through splines.