A planetary gearbox identifies a gear system in which a number of ‘planet’ gears rotate around a central ‘sun’ gear. Typically, a world carrier is powered by the insight torque which rotates the planets around a fixed outer ring (sometimes referred to as the annulus). This in turn drives sunlight gear which then provides the output torque. However there are types of the other combinations, such as the sun gear being set and the band providing output torque.
The main advantage of planetary gearboxes are their high power transmission efficiencies. 
Typicially this is often around simply 3% per stage. Additional to this, the high effiency is delivered despite the compact style giving a big torque to size/weight ratio. A few of this is because of the load sharing occurring across the multiple planet gears.
A planetary gearbox identifies a gear system in which one or more ‘planet’ gears rotate around a central ‘sun’ gear. Typically, a planet carrier is driven by the input torque which rotates the planets around a set outer ring (sometimes known as the annulus). This in turn drives sunlight gear which then supplies the output torque. However there are types of the additional combinations, like the sun gear being fixed and the ring providing output torque.
The main benefit of planetary gearboxes are their high power transmission efficiencies. Typicially this can be around just 3% per stage. Further to this, the high effiency is definitely delivered regardless of the compact design giving a large torque to size/weight ratio. Some of this is because of the load sharing occurring across the multiple planet gears.
Reliable Small Planetary Gearbox
EP Motor’s small planetary gearbox is available in 7 different sizes with diameters of 16mm, 22mm, 26mm, 28mm, 32mm, 36mm, and 45mm, each consisting with mono and multi-phases, and the gear ratios range from 3.3:1 ~ 1500:1.