U.P.B. Sci. Bull., Series D, Vol. 79, Iss. 4, 2017 ISSN 1454-2358 DYNAMICS OF THE ELECTROHYDRAULIC SERVOPUMPS FOR INDUSTRIAL OPEN CIRCUITS Georgiana Claudia VASILIU 1 , Daniela VASILIU 2 , Marius Daniel BONTOȘ 3 The paper presents the modelling, simulation, and experimental validation of the mathematical model created for a high performance electrohydraulic servopump. The validation test was performed by the authors in the Electrohydraulic Amplifier Performance Certification Laboratory associated to the Romanian Accreditation Association - RENAR. The experimental results were found in good agreement with the theoretical ones. The simulation model was included in the AMESIM super components library developed by the authors in the frame of some PhD thesis. Keywords: modeling, simulation, experimental identification, servopumps, open fluid power systems. 1. Introduction The modern servopumps are controlled by hydro mechanic or electrohydraulic servo systems, according to the application performance demands. Special applications like military ones require hybrid systems, including electric control devices and mechanical feedback, rigid or elastic ones. Another structural matter regards the pressure supply of the control system. The classic servo systems are powered through auxiliary pumps with gears, put into motion by the controlled pumps, and are protected against overpressure by piloted valves. In the case of an open circuit, powering the servo system through the controlled pump is possible, if the minimum back-pressure of the latter is greater than the minimum pressure necessary for control. A typical example for this principle is the PV Plus servopump family (Figs. 1 and 2). The tilting angle of the swash plate is controlled by a three- way flow valve (Fig. 3), with a small overlap, actuated by a proportional force solenoid which has a nominal force of about 90 N. The spool control edges have different geometry: one edge is very sharp and is controlling the displacement increase. The other control edge has a small chamber, increasing the displacement recovery time. The position control loop feedback from the hydraulic cylinder rod 1 PhD, Hydraulics Department, University POLITEHNICA of Bucharest, email: georgiana.claudia.v@gmail.com 2 Prof., Hydraulics Department, University POLITEHNICA of Bucharest, Romania, email: vasiliu1958@gmail.com 3 PhD, Hydraulics Department, University POLITEHNICA of Bucharest, Romania, email: bontosmarius@gmail.com