Hydraulic circuit analysis for the electro-hydrostatic actuator system

An Electro-Hydrostatic Actuator(EHA) is a kind of a closed loop system using bi-directional hydraulic pump and cylinder assembly, and is used to control the position of the aircraft and the missile. The EHA is also applied to the leisure field such as roof control of an automobile, wing body and power gate control of a special vehicle and tilting system control of a motor boat. In this study, a development research of an arm cylinder of an excavator which has some valves, a bi-directional hydraulic pump, an auxiliary power assister and a generator with a hydraulic motor is conducted, and an arm cylinder is controlled by closed loop method. Also, the possibility of the EHA system for the next generation excavator is discussed and estimated using SimulationX software.