Design of a Variable Stiffness Series Mechanism

The elastic joint actuator with outstanding performance in safety, environmental adaptability and energy utilization, has a good application prospect. This paper presents a design of variable stiffness series elastic mechanism based on nonlinear stretching of a linear spring, by adjusting the initial position of the roller on the curved surface, the average output stiffness of the structure is changed. Variable stiffness characteristics are added while retaining the advantage of SEA's ability to calculate output torque. The principle and mechanical realization of variable stiffness structure are presented firstly, and then the design principle of curved surface is given, and SolidWorks simulation data are provided. Finally, a simple joint prototype is built without changing the structure of any core module.