small planetary gearbox

A planetary gearbox refers to a gear system where one or more ‘world’ gears rotate around a central ‘sun’ equipment. Typically, a world carrier is driven by the insight torque which rotates the planets around a fixed outer ring (sometimes referred to as the annulus). Therefore drives the sun gear which then provides the output torque. Nevertheless there are examples of the additional combinations, such as the sun gear being fixed and the band providing output torque.

The main advantage of planetary gearboxes are their high power transmission efficiencies. Typicially this is often around just 3% per stage. Additional to the, the high effiency is usually delivered regardless of the compact design giving a sizable torque to size/weight ratio. A few of this is thanks to the load sharing that occurs over the multiple planet gears.