Hydraulic Impulse-Testing System with Pressure Difference Feedback from a Second-Stage Valve

Abstract

To guarantee the reliability of hydraulic systems, it is of vital importance to do impulse testing for hydraulic components. A hydraulic impulse-testing system with pressure difference feedback from a second-stage valve is studied. A mathematical model of the system is built, and it shows that the inner closed-loop damping ratio of the system is influenced by the pressure difference feedback of the control chambers of the second-stage valve. And by changing the pressure difference feedback gain, various damping ratios can be achieved, which is a key factor affecting the system overshoot. The results of both the simulation and experiment show that with the same square wave input the system overshoot can be freely controlled between 0 and 50% by adjusting the pressure difference feedback gain, which is a new method to obtain both peak wave impulse pressure cycle and square wave impulse pressure cycle utilizing the same system and the same input.