Cycloidal gearboxes
Cycloidal gearboxes or Cycloidal gearbox reducers consist of four fundamental components: a high-speed input shaft, an individual or compound cycloidal cam, cam followers or rollers, and a slow-speed output shaft. The input shaft attaches to an eccentric drive member that induces eccentric rotation of the cycloidal cam. In compound reducers, the first tabs on the cycloidal cam lobes engages cam supporters in the casing. Cylindrical cam followers act as teeth on the internal gear, and the amount of cam fans exceeds the number of cam lobes. The next track of compound cam lobes engages with cam followers on the output shaft and transforms the cam’s eccentric rotation into concentric rotation of the output shaft, thus increasing torque and reducing velocity.
Compound cycloidal gearboxes offer ratios ranging from only 10:1 to 300:1 without stacking levels, as in regular planetary gearboxes. The gearbox’s compound reduction and can be calculated using:
where nhsg = the amount of followers or rollers in the fixed housing and nops = the quantity for followers or rollers in the sluggish acceleration output shaft (flange).
There are several commercial variations of cycloidal reducers. And unlike planetary gearboxes where 
variations derive from gear geometry, heat treatment, and finishing processes, cycloidal variations share fundamental design concepts but generate cycloidal motion in different ways.
Planetary gearboxes
Planetary gearboxes are made up of three basic force-transmitting elements: a sun gear, three or even more satellite or planet gears, and an internal ring gear. In a typical gearbox, the sun gear attaches to the insight shaft, which is linked to the servomotor. Sunlight gear transmits electric motor rotation to the satellites which, subsequently, rotate in the stationary ring equipment. The ring equipment is section of the gearbox casing. Satellite gears rotate on rigid shafts linked to the earth carrier and trigger the earth carrier to rotate and, thus, turn the result shaft. The gearbox gives the result shaft higher torque and lower rpm.