Concept of Rotor-Stator Three Point Contact Interaction in Vibrodrives for Robotic Applications

An original concept of a travelling wave type vibrodrive for the application as an actuator in robots or robotic units preferably as locomotion unit in small size mobile robots is proposed. The essential novelty of the vibrodrive is the structure of its stator which consists of three piezoceramic rings elastically suspended in the unit's frame and symmetrically arranged with 1200 angular displacement one with respect to another. At operation mode, i.e. when traveling waves in the piezoceramic rings are excited as they contact the rotor by their inner surfaces in initially prestrained manner the stability of the frictional contact and thus the performance reliability of the unit is achieved. The analysis of the interaction piezoceramic ring - rotor was performed by FEM using the simplified model consisting of one ring and the rotor. The obtained output characteristics proved the proposed structure vibrodrive to have the sufficient performance characteristics to meat the set objectives.