Design of Bevel Rolling Contact Joint for Transmission Mechanism in Robotics

In robotic grippers, gears used in transmission mechanism of fingers are prone to drift error due to backlash. Replacing gears with Compliant Rolling Contact Joints (CRJs) can prevent backlash and thus contribute to more precise operation of gripper. In addition, CRJs do not require lubrication and thus can operate in a viscous fluid medium even in fully immersed condition. While CRJs’ substitutes exist for spur gears, there is a lack of robust substitutes for bevel gears. Hence, in this work, design of a spatial compliant rolling joint known as compliant bevel rolling contact joint (CBRCJ) for usage in transmission mechanisms in robot grippers is proposed. The complaint element is a circular plate that is deformed into a conical shell, and its design is done in ANSYS Mechanical APDL software. Based on the results of the parametric study, suitable grades of spring steel can be chosen whose yield stress exceeds the maximum von-Mises stress produced in the plate by any arbitrary safety factor.