The cyclo drive train is a special variant of the planetary drive train, where the planets are gears with a cycloid profile, while rollers are placed on the central gears (wheels). An analysis of the gear ratios of two types of cycloid drive train was performed. The first type is a classic cycloid drive train, while the second is a special variant with stepped planets. The cycloid drive with stepped planets can achieve very large gear ratios, while using central gears with a relatively small number of rollers.
