A planetary gearbox is a gearbox with the input shaft and the result shaft aligned. A planetary gearbox is used to transfer the biggest torque in the many compact form (known as torque density).

The bicycle’s acceleration hub is a superb example of a planet-wheel mechanism: Have you ever wondered how you can get so much power and capabilities in such a small hub? For a three-velocity hub, a one-stage planetary equipment system can be used, for a five-rate hub a 2-stage. Each planet gear program has a reduction state, a direct coupling and an acceleration setting.

In mathematical terms, the smallest reduction ratio is 3: 1, the biggest is 10: 1. At a ratio of less than 3, the sun gear becomes too large against the earth gears. At a ratio greater than 10 sunlight wheel becomes too little and the torque will drop. The ratios are often absolute i.electronic. an integer number.

Whoever invented the planetary gearbox is not known, but was functionally described by Leonardo da Vinci in 1490 and has been used for centuries.