Scientific Bulletin of the The 6th International Conference on Politehnica University of Timisoara Hydraulic Machinery and Hydrodynamics Transactions on Mechanics Special issue Timisoara, Romania, October 21 - 22, 2004 THEORETICAL SIMULATION OF STATIC AND DYNAMIC BEHAVIOR OF ELECTRO-HYDRAULIC SERVO VALVES Victor BALASOIU, Prof.* Mircea Octavian POPOVICIU, Prof. Department of Hydraulic Machinery Department of Hydraulic Machinery “Politehnica” University of Timisoara “Politehnica” University of Timisoara Ilare BORDEASU, Assoc. Prof. Department of Hydraulic Machinery “Politehnica” University of Timisoara *: Bv Mihai Viteazu 1, 300222, Timisoara, Romania, Tel.: (+40) 256 403681, Fax: (+40) 256 403700, (+) 256 4030682, Email:
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[email protected] ABSTRACT The electro-hydraulic servo-valves (EHSV) as in- range Yoi and the clearance J over the linearity degree terface in automatic hydraulic systems are in essence and the magnitude of the adjusted flow. hydroelectric directional control valves with cylindrical The model of the dynamic equilibrium of the spool spool, with integral reaction. The output quantity valve is defined starting with the computation of forces (flow rate, pressure) is modified proportional with acting on the spool. Introducing the concept of interac- the control signal (voltage, current) together link tion between the aggregate components nozzle-spool- (electrical, hydraulic or mechanical). Both the manner distributor it was defined the mathematical model for in which the reaction signal is produced and the the directional spool valve as a whole. position of the information circuit where it is applied, After defining the transfer function, both analyze characterises the type but also static and dynamic and syntheses of performances were possible for the behavior of the servo valve.