Cycloidal gearbox Cycloidal gearboxes
Cycloidal gearboxes or reducers contain four simple 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 track of the cycloidal cam lobes engages cam followers in the casing. Cylindrical cam followers act as teeth on the internal gear, and the amount of cam followers exceeds the number of cam lobes. The second 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 result shaft, thus increasing torque and reducing swiftness.
Compound cycloidal gearboxes offer ratios ranging from as low as 10:1 to 300:1 without stacking phases, as in regular planetary gearboxes. The gearbox’s compound reduction and will be calculated using:
where nhsg = the amount of followers or rollers in the fixed housing and nops = the number for followers or rollers in the slower 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 basic design principles but generate cycloidal movement in different ways.
Planetary gearboxes are made of three simple force-transmitting elements: a sun gear, three or more satellite or world gears, and an interior ring gear. In a typical gearbox, the sun gear attaches to the input shaft, which is linked to the servomotor. The sun gear transmits electric motor rotation to the satellites which, subsequently, rotate inside the stationary ring equipment. The ring gear is section of the gearbox casing. Satellite gears rotate on rigid shafts connected to the planet carrier and cause the earth carrier to rotate and, thus, turn the output shaft. The gearbox provides result shaft higher torque and lower rpm.