A cycloidal reducer is a type of gear reducer. The essential operation is that an insight shaft connects to and drives an eccentric bearing. This bearing additional drives a cycloidal disk (sometimes referred to as a cam) that connects to an result shaft.
cycloidal reducer
Normal cycloidal speed reducers, such as for example these Dojen series reducers from Onvio, offer zero backlash by combining a substance reduction cam with preloaded, complete compliment needle bearing cam followers.
The cycloidal disk (or cam) has lobes or teeth that build relationships some type of cam follower, typically a pin or needle bearings. The eccentric rotation of the cam is transformed into rotation of an result shaft at a reduced speed and an increase in torque.
The main advantage of cycloidal reducers is their house of zero or near-zero backlash, which results in high precision and high accuracy. That is especially in demand where highly exact and accurate positioning is necessary, for example in robotic applications, 
machine equipment, and Screw Air Compressor similar applications. Cycloidal reducers also feature rolling instead of sliding contact, hence experiencing less overall wear.