Design and Working Principle
The heart of the planetary gearbox is the reduction group composed by the sun pinion (1) and three or more satellites (2) mounted on pins (4) which are supported by the satellite carrier (5). The sun pinion transmits it's motion to the satellites. The satellites then turn inside the ring gear (3) which is static. As consequence the satellite carrier rotates. The motion of the carrier can be transmitted to an output shaft or to another reduction group. The reduction obtained is determined by the relation between the number of teeth on the sun pinion (Z1) and the number of teeth on the ring gear (Z2).

The ratio can be calculated using the shown formula [i=Z2/Z1+1]

Advantages
The planetary gear box offers a set of advantages which makes it an interesting altemative to traditional gear types such as helical and parallel shafts gear boxes. Especially in applications requiring: high reduction ratios, high torque transmission, high radial on output shaft in the following we shall explain why.

High Reduction Ratios
Given the same number of teeth Z1 and Z2 the planetary gear offers a higher ratio than the parallel shaft gear. This makes it possible to obtain:

We are manufacturers, and exporters of Planetary Gear Boxes. For larger reduction in compact space owing to more planets sharing the load, Planetary Gearbox are available in ratio from 3.15 to 450 in models BP-160, 250 & 315 in one or two stages, transmitting from 1 kw to 50 kw power have been added to family of quality products from BEW.