Development of a compact piezoelectric-hydraulic hybrid actuator

This paper describes the development of a compact hybrid hydraulic actuation system as a potentially high-authority compact actuator for various applications including actuation of the trailing edge flap of a smart rotor system. The actuation system is divided into two parts, a pump driven by piezostack actuators and an output hydraulic actuator. The present work focuses on the design, analysis and testing of the pump. Analytical models are developed for various elements of the system. Operating the piezostacks at a frequency of up to 250 Hz over a period of five minutes, the pump generated a maximum pressure rise of 180 psi, displacing approximately 100 ml of hydraulic fluid in the process. A maximum temperature of 55 degree(s)C was measured on the piezostack.