Development of Decentralized Actuators

1The development of quiet, high-reliability linear and rotary electromechanical actuators to operate independent of a central hydraulic plant is proposed. It is shown that the combination in an integral package of brushless DC motors and certain speed reducers, especially compudrive's patented orbidrive, affords the ideal solution to the requirement. Orbidrive is a gearless, concentric speed reducer which utilizes the cycloidal motion of a dual-faced, multi-lobed cam nutating on an eccentric shaft to effect desired speed reduction. The eccentric input shaft forces the cam to engage respective sets of rollers, each of which contains one more roller than the number of mating cam lobes, such that the cam is advanced exactly one lobe per input shaft rotation while the output shaft is retarded exactly one lobe per cam rotation. Torque transmission is thus accomplished via a rolling motion in contrast to the noisy sliding of mated gear teeth of conventional gear boxes. Phase I objectives of comprehensive analysis of the proposed approach and preliminary design of a linear and a rotary actuator are detailed. Phase II objectives of optimization, construction and testing of the linear and rotary actuators are outlined.