New type of overrunning clutch based on curved-plate compression-torsion metamaterial

Overrunning clutches are unidirectional drive mechanisms that are widely used in transmission systems. However, existing overrunning clutches have complex structures, require high preparation accuracy, and fail after a certain degree of wear. To address these issues, we propose a new type of overrunning clutch consisting of a conical structure and novel compression-torsion conversion (CTC) metamaterial with curved plates. Theoretical calculations are employed to guide the material distribution and ensure the deformation coordination of the curved-plate CTC metamaterial for greater ultimate torque. The transmission mechanism of the proposed overrunning clutch is derived to guide the parameter selection of the CTC metamaterial and the conical structure. Experiments and finite element simulations reveal that the curved-plate CTC metamaterial features excellent CTC efficiency, flexibility, and transverse stiffness, which is conducive reducing the resistance of the overrunning state and ensures stability during operation. The unidirectional transmission system constructed with the new overrunning clutch shows reliable performances under working and overrunning states. The constructed overrunning clutch provides an effective one-way transmission method. The clutch with simple construction and self-compensated ability for wear exhibits great potential in miniaturized and lightweight equipment or robots.