Thermal Coupling Simulation of Electro-Hydrostatic Actuator Subjected to Critical Temperature Conditions

Electro-hydrostatic actuators (EHAs) are emerging transmission techniques originated from aerospace industry and being introduced to various application fields, such as ships, robots, construction machines, and machine tools. Despite the advantages of high efficiency, easy maintenance, electrified power, etc., EHAs are usually self-contained integrated devices, resulting in low heat dissipation ability. Therefore, thermal coupling models are necessary for the evaluation of each design option during the EHA development. In this paper, a thermal coupling model was established for EHA thermal characteristic analysis during the detail design stage. The disciplines of electrics, mechanics, system level hydraulics, losses, and control are implemented by lumped parameter modeling while the disciplines of thermodynamics and fluid dynamics are simulated by computational fluid dynamics (CFD). Subsequently, a simulation analysis focusing on the critical temperature conditions was conducted, and the dynamic thermal and power responses were achieved. The simulation results are applicable to gain confidence for EHA detail design work as well as proved the functions of the proposed model as a practical development tool.