Operating characteristics of a passive, bidirectional overrunning clutch for rotary joints of robots

Abstract

For the development of robots the mode of assembly and the effectiveness of their joints are of elementary significance. To enable powerful movements, strong torques are required which, when employing electromechanical actuators, are generated by high-capacity motors in combination with adequate speed transformations. Furthermore, such drive systems have to withstand even very high external loads which can be caused by uncontrolled motions, e.g., by stumbling of a humanoid robot. In particular the gears have therefore to be of robust construction. Likewise, the energy efficiency of the drive systems plays a decisive role for the perseverance of robots. The latter underlies a negative impact especially by frictional losses of highly transforming gears. In the present publication a novel design of a clutch is described. It has been developed with the goal to equally meet the requirements both of high energy efficiency and capacitance of robots. Apart from its configuration, this paper mainly deals with the technical performance of the new clutch, especially in combination with the actuator used.