Design and experimental study of two-dimensional(2D) electro-hydraulic proportional directional valve

A new kind of roller thrust-torsion coupling was designed in this paper, with low friction and simple structure, linear movement of proportional solenoid can be changed into rotation of the spool movement, at the same time, proportional solenoid´s thrust is amplified. With large flow and simple structure, 2D Electro-hydraulic Proportional Directional Valve (EPDV) which is position feedback mainly consists of roller thrust-torsion coupling and proportional solenoid. Based on the principle of roller thrust-torsion coupling, 2D EPDV had been studied through its mathematical model which was simulated with software MATLAB. Direct-acting and pilot-operated experiment results show: with good input and output characteristics, high pressure and large flow control can be achieved by this valve, no-load hysteresis is 1%, flow hysteresis is under 5% when system pressure is at 21 MPa, its linearity and repeating characteristic are all good.