Study of self-excited noise and pressure oscillations in a hydraulic jet-pipe servo-valve with magnetic fluids

In order to overcome self-excited high frequency oscillations and noise appearing sometimes during the working of hydraulic jet-pipe servo-valve, application of magnetic fluid (MF) in hydraulic jet-pipe servo-valve is developed in this paper. Large damping can be introduced into the servo-valve if magnetic fluid is filled into the working gaps of hydraulic servo-valve torque motor. Construction of hydraulic jet-pipe servo-valve with magnetic fluid is introduced. The noise signals are tested and recorded when magnetic fluid is applied or not in the servo-valve. Experimental results are compared and analyzed using FFT analysis. It is shown that noise of servo-valve is depressed when magnetic fluid is applied.