Simulation Of The Flow Field Of Hydrostatic Support Seal For Servo Hydraulic Cylinder Based On Fluent

Servo hydraulic cylinder as the actuator of hydraulic servo system, its performance directlyaffects the control precision, static and dynamic quality of the system. Consequently, in order tomeet the high frequency of overload and lateral load requirements, servo hydraulic cylinderdiffers by the very small friction and excellent oriented capability from the common hydrauliccylinder. So it’s very crucial to choose appropriate seal and piston rod guide type for servohydraulic cylinder. Based on the research of the hydraulic excitation system for dynamicresponse testing of railway subgrade, a two stage servo-hydraulic cylinder with special structureis designed for this excitation system, in order to make it has low friction and outstandingoriented performance, using hydrostatic support seal in piston rod.Firstly, use Pro/e to finish modeling the flow field of the hydrostatic support seal and dividestructured grid of the flow field by Gambit. Secondly, use Fluent to simulate the flow field of thehydrostatic support seal,then analyze the pressure and velocity distribution of the flowfield,study the influences of the velocity and leakage of the flow field caused by motion of thepiston rod. Meanwhile, study the piston rod friction generated by hydrostatic support seal andits connection between the piston rod speed. Finally, do the research about the influence ofpiston rod speed, input flow and piston rod eccentric arm to the lateral bearing capacity ofhydrostatic support seal.The simulation results show that hydrostatic support has very small friction and canprovide lateral bearing capacity when piston rod has lateral load, which can improvethe vibration frequency and positioning accuracy of the servo hydraulic cylinder.