Planetary gears are at the heart of modern engineering and are used in gearboxes that power everything from basic plant machinery to cutting-edge electric vehicles. The simple configuration of a central drive and orbiting gears was developed thousands of years ago to model the movements of the planets. Today, engineers use planetary gears in applications that demand high torque density, operational efficiency and durability. In this article, we explore the principles of operation, how planetary gears work, and where you might find them.
A simple planetary gear set is made up of three main components:
1. The sun gear that sits in the centre (central gear).
2. Multiple planet gears.
3. The ring gear (outer gear).
The three components make up a stage within a planetary gearbox. For higher ratios we can offer double or triple stages.
Planetary gearboxes can be powered by either electric motors, hydraulic motors or petrol or diesel combustion engines.
The load from the sun gear is distributed to several planetary gears which can either be used to drive an outer ring or a shaft or spindle. The central sun gear takes a high-speed, low-torque input. It drives several rotating external gears which increases the torque.
The simple design is a highly efficient and effective way of transferring power from a motor to an output. Approximately 97% of the energy input is delivered as an output.