液压作动器的密封磨粒磨损及寿命预测若干问题分析-analysis on some problems of seal abrasive wear and life prediction of hydraulic actuator.docxVIP

AbstractHydraulic actuator is an important component of aircraft hydraulic aviation control system. The reliability of hydraulic actuator affects the sensibility and accuracy of the flight attitude. Continuously working in high temperature and pressure in the long term, the function of the actuator relies on the sealing performance. The failure of the sealing can decrease the work efficiency of the hydraulic system, even jeopardizes the security of the whole flight. While the actuator is working, the solid particles inevitably float in the air, and the wear debris form in the sliding pairs. These wear debris will cause wear in the shifting pair between the sealing ring and the piston rod, which can not be ignored. In this paper, the sealing property and life prediction are studied, which focus on the sliding pair between the sealing ring and the piston rod of certain flight hydraulic actuator.Firstly, using the Hertz contact theory as the theoretical basis, the wear model for the sealing structure is established, that is the transition from three-body abrasive wear to two-body abrasive wear, involving two wear stages and models. Based on the oblique-impact theory and Hertz damping contact theory, a three-body abrasive wear model is established. Then based on the plowing abrasive wear theory, a two-body abrasive wear model is established. Considering the contact surface quality, a t oil slick abrasive wear model is established.Secondly, considering the characteristics of the rubber material, a FEM model of the abrasive wear between the sealing ring and the piston rod is established using ANSYS. Then the two stages of the actuator sealing structure abrasive wear are analyzed by FEM, to investigate the factors that influence the abrasive wear. The FEM results turn out that the abrasive diameter have negative correlation and the impacting speed positive correlation to the three-body abrasive wear. The critical condition of three-body abrasive wear is obtained, by which