Piezoelectric hydroelectric servo-valve structured by baffle-nozzle valve

摘要

A new type o f hydroelectric servo valve is developed, which uses piezoelectric stack with big stroke as the electric to mechanics converter and builds the baffle-nozzle valve with piezoelectric and nozzle. The static characteristics and dynamics characteristics of servo-valve are measured and the effect of opening-loop and closing-loop on hysteresis are compared. The tests results show that in the condition of closing-loop, flux hysteresis of the servo-valve is less than 0.15% , and the resolution is less than 0.03%. The width of frequency is 900Hz. The factors influencing the characteristics of the servo-valve are analyzed in light of these results. An improved approach is put forward. This servo-valve is characterized by simple structure, quick response, high resolution as well as extraordinary dirtresistance and so on.