Cycloidal gearboxes
Cycloidal gearboxes or 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 insight shaft attaches to an Cycloidal gearbox eccentric drive member that induces eccentric rotation of the cycloidal cam. In compound reducers, the first tabs on the cycloidal cam lobes engages cam fans in the housing. Cylindrical cam followers act as teeth on the internal gear, and the number of cam fans exceeds the amount of cam lobes. The second track of compound cam lobes engages with cam fans on the output shaft and transforms the cam’s eccentric rotation into concentric rotation of the output shaft, thus increasing torque and reducing swiftness.
Compound cycloidal gearboxes provide ratios ranging from as low as 10:1 to 300:1 without stacking phases, as in regular planetary gearboxes. The gearbox’s compound decrease and will be calculated using:
where nhsg = the number of followers or rollers in the fixed housing and nops = the number for followers or rollers in the slow rate output shaft (flange).
There are many commercial variations of cycloidal reducers. And unlike planetary gearboxes where variations derive from gear geometry, heat therapy, and finishing processes, cycloidal variations share basic design principles but generate cycloidal motion in different ways.
Planetary gearboxes
Planetary gearboxes are made up of 
three simple force-transmitting elements: a sun gear, three or even more satellite or planet gears, and an interior ring gear. In an average gearbox, the sun equipment attaches to the input shaft, which is connected to the servomotor. The sun gear transmits motor rotation to the satellites which, subsequently, rotate in the stationary ring equipment. The ring gear is part of the gearbox housing. Satellite gears rotate on rigid shafts linked to the planet carrier and cause the planet carrier to rotate and, thus, turn the output shaft. The gearbox gives the output shaft higher torque and lower rpm.