Analysis and Design Method of High Speed Hydraulic Servomechanism

Abstract

As reported by some papers, the piping in the hydraulic servo of which length is unneglible compared to the propagation wave length of the hydraulic fluid plays the opposing roll at the high frequency range of the high speed electro-hydraulic servomechanisms. In this paper, the author considers the following parameters and proposes an approximate calculating method of the frequency response of the by draulic servo incorporating the piping with definite length; giving consideration to mass, rigidity, length, and the viscous resistance of the piping, and mass, bulk modulus and viscosity of the hydraulic fluid.
As the result of the calculation and some experiments, rather distinct peaks take place at the high frequency range of the frequency response of such a hydraulic servo.
These peaks give the abrupt chauge of the impedance seen from the servovalve side. The author also trys to explane squealing phenomena which occur sometimes in the high pressure hydraulic servo utilizing the theory presented here. These results will be shown in the continued papers some other time.