the gearing mechanism inside the Cycloidal reducer.

Cycloidal reducer,The word Cycloid, with its adjective Cycloidal, is derived from Hypocycloid which describes the curve traced by a point on the circumference of a smaller circle rotating inside the circumference of a larger fixed circle.  Just like words such as helical, worm, spur, and bevel, cycloidal is a generic adjective; cycloidal transmission merely describes the gearing mechanism inside the speed reducer.