Design and Testing of a High Pumping Frequency Piezoelectric-Hydraulic Hybrid Actuator

摘要

This paper describes the design and testing of a piezoelectric hydraulic hybrid actuator operating at a high pumping frequency. The actuator is envisaged as a potential actuator for a trailing edge flap of a full scale smart rotor system. Recent research efforts on piezoelectric hydraulic hybrid actuators have investigated devices based on large piezoelectric stacks operating at a relatively low pumping frequency. The present work focuses on the behavior of such an actuator operating at a high pumping frequency and low volumetric displacement. Challenges to achieving high pumping frequencies were identified and solutions were implemented. The actuator was driven by two piezostacks, of a total length of 36 mm and cross-sectional area 10 mm~2. The actuator was tested up to a pumping frequency of 1 kHz, developing a maximum no-load velocity of 1.2 in/sec and a blocked force of 35 1bs in the uni-directional output mode. Bi-directional output performance was also measured, by incorporating a 4-way valve in the hydraulic circuit. At a frequency of 5 Hz, a no-load output displacement with an amplitude 32 mils was measured.