A planetary gearbox is a gearbox with the insight shaft and the output shaft aligned. A planetary gearbox is used to transfer the largest torque in the the majority of compact form (known as torque density).

The bicycle’s acceleration hub is an excellent exemplory case of a planet-wheel mechanism: Have you ever wondered ways to get so much power and features in such a small hub? For a three-rate hub, a one-stage planetary equipment system can be used, for a five-rate hub a 2-stage. Each planet gear program includes a reduction state, a primary coupling and an acceleration mode.

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

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