A planetary gearbox is a gearbox with the insight shaft and the output shaft aligned. A planetary gearbox is utilized to transfer the biggest torque in the the majority of compact form (referred to as torque density).
The bicycle’s acceleration hub is a superb exemplory case of a planet-wheel mechanism: Perhaps you have ever wondered ways to get so much power and features in such a small hub? For a three-acceleration hub, a one-stage planetary gear 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 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 usually absolute i.e. an integer number.
Whoever invented the planetary gearbox isn’t known, but was functionally described simply by Leonardo da Vinci in 1490 and has been used for years and years.