Compact and Impact-resilient Robot Actuators via Lightweight Overload Clutch with Wedged Rollers

Robots avoid collisions as these can lead to hardware damage. To deploy robots in less structured environments, robust hardware is required. Traditional approaches that improve impact-resilience result in bulky actuators, increased backlash or decreased torque density. A lightweight and compact clutch principle based on wedged rollers is presented as well as an experimental proof-of-concept. A use case involving the design of clutched planetary gearbox actuators tailored to humanoid robot legs shows a reduction in axial length of 25% up to 40% depending on the maximum expected overload.