Series Elastic Actuator Unit Prolonging High Torque by Flywheel with Speed-Up Gear

Abstract

Series elastic actuator (SEA) is a combination of an actuator, a spring, and a load in series, and improves shock resistance and motion performance such as maximum torque and maximum speed compared to an actuator alone. In SEA, the spring accumulates the kinetic energy of the motor or the load. The natural frequency can be lowered by increasing the moment of inertia by speed-up gear. By lowering the natural frequency, the time that large torque lasts in one direction increases. In this study, we examine the differences in performance due to the disposition of the motor and speed-up gear between the spring and inertia. We propose and evaluate an SEA with a flywheel with a speed-up gear. We develop the SEA unit that increases the time during which large torque lasts in one direction by the inertia with the speed-up gear.