Flow characteristics of integrated motor-pump assembly with phosphate ester medium for aerospace electro-hydrostatic actuators

Motor-pump assembly is the core component of the Aerospace Electro-hydrostatic Actuator (EHA). Thus, the design of the motor pump can be very challenging under conditions of high speed and wide pressure range, especially in particular working mediums. Our ultimate goal is to pursue better flow characteristics under a wide range of working conditions. In this paper, we built a sub-model of the main friction interfaces and a model of single-shaft coaxial motor-pump assembly adopting the method of hierarchical modeling. The experimental investigation of the output characteristics was mainly carried out in a phosphate ester medium environment. Then, the flow characteristics were compared and analyzed with the simulation results. Results indicated that the flow characteristics of the motor-pump assembly could be accurately simulated by the model and quite severe in a low speed and high-pressure environment.