Abstract
Robustness and force sensitivity are often difficult to achieve using conventional gear train mechanism. Usage of a Series Elastic Actuator (SEA) is a common method to resolve the problem, but it should be said that SEA gives only partial solution to the problem. We have developed fully backdrivable hydraulic actuator called Electro-Hydrostatic Actuator (EHA) to resolve this problem. However, it lacked the energy storage capability that are present in Series Elastic Actuators. In this paper, we propose a hydraulic component to store mechanical energy to realize energy storage capability and enhance efficiency and speed of the actuator in dynamic motion. We call this device a "Differential Accumulator." The mechanical design and evaluation of the prototype are presented.
