Planetary Gears
Planetary Gearheads, are also called epicyclic gear. In the middle of the planetary gear is the sun wheel, next to it are a hallow wheel and several planetary gears. The sun wheel is driven by the motor and transmits its motion to the rotating planet gears. The rotating planetary gears orbit the central sun wheelr in the transmission, as the planets orbit the sun.
Planetary gears are used in high-precision applications of the drive technology where a high torque to volume ratio and a reduced gear clearance are required.