Steady-state analysis of a precision hydraulic flow control servovalve using the finite element method

In the present paper, an attempt has been made to simulate the steady-state operation of the jet pipe Electro-Hydraulic ServoValve (EHSV) using the Finite Element Method (FEM). The jet pipe servovalve has two stages and consists of two main assemblies: first-stage torque motor assembly and second-stage valve assembly. Between the first and second stage there is a mechanical feedback to stabilize the valve operation. Each assembly has various delicate and precise components. The finite element analysis has been carried out on jet pipe and feedback spring assembly. The analysis shows that the stiffness of flexure tube and feedback spring assembly plays the major role in achieving steady-state valve operation. The stiffness of these components is obtained through the FEM and these results are validated with experiment. The commercial ABAQUS finite element code has been used for the simulation. The mathematical model of the jet pipe EHSV has been developed and simulated using MATLAB to study the spool dynamics with the main emphasis on the steady-state valve operation. The required simulation parameters, like moment of inertia, stiffness of the components and lever arm length. are obtained from the FEM.