Steady-State Performance Research on a New Water Hydraulic Servo Valve Using Finite Element Method

摘要

To figure out the steady-state responses of a new water hydraulic servo valve when a specific displacement is inputted from the actuator, an analysis has been conducted on the hydraulic bridge of the servo valve with annular clearance between sleeve and spool land as its first hydraulic resistance. Results show that the pressure difference of spool ends has a nearly linear relationship with the flapper displacement. Through the study of motion characteristics and force status of feedback rod, the steady state force equilibrium equation is established. Considering overall forces and constraint conditions on the components consisting of feedback rod and spool, the steady state finite element model is subsequently established. Steady-state responses of the servo valve with different feedback rods matched can be obtained when the input displacement from the actuator has been given to the software calculation. A suitable feedback rod is selected to meet the design requirements. Finally, a discussion focused on the simplified model which is used in finite element software calculation has been carried out. Results show that the finite element analytic solution equals the software solution well.