A planetary gearbox identifies a gear system where one or more ‘planet’ gears rotate around a central ‘sun’ equipment. Typically, a planet carrier is powered 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. Nevertheless there are examples of the other 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 could be around just 3% per stage. Further to the, the high effiency is certainly delivered regardless of the compact style giving a large torque to size/weight ratio. Some of this is thanks to the load sharing 
occurring over the multiple planet gears.
A planetary gearbox identifies a gear system where a number of ‘planet’ gears rotate around a central ‘sun’ gear. Typically, a world carrier is driven by the input torque which rotates the planets around a fixed outer ring (sometimes known as the annulus). Therefore drives sunlight gear which then supplies the output torque. However there are examples 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 could be around simply 3% per stage. Further to the, the high effiency is certainly delivered despite the compact style giving a large torque to size/weight ratio. A few of this is because of the load sharing that occurs 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-stages, and the gear ratios range between 3.3:1 ~ 1500:1.