Study On The Lateral Hydraulic Damper Of Semi-active Secondary Suspension System For High-speed Train

This dissertation is derived from the Semi-active Suspension Department, CNR Sifang Rolling Stock Research Institute, "Research on Semi-active Suspension System". With the large_scale increasing speed of the transportation, the career of Chinese railway has been in the high-speed development. But the increased speed will inevitably lead to the increased vibration of the train, especially in the lateral one. Some researches have shown that full active or semi-active lateral suspension system can improve the lateral dynamical characteristic. With the advantages of the simpler structure and the cheaper costs, semi-active suspension is currently the optimum mode of the high-speed train suspension in China. So research on semi-active suspension system has great significance to improve lateral stability and increase ride comfort.This dissertation focuses on the research of the hydraulic damper in the system of semi-active lateral suspension system. In this dissertation, the control strategy of semi-active lateral suspension and the working principle of damper controlled by the electro-hydraulic reverse-proportional relief valve are introduced, together with the damper's design scheme is researched. The mathematical mode of the semi-active damper is deduced, and its steady-state characteristic and the dynamic characteristic is simulated. Last, the engineering design of damper's actor is completed initially.In chapter 1, the exordium, the research on the present development condition of semi-active lateral suspension system in China and other countries are firstly overviewed. The background and the significance of the project are explained, together with the main contents of the dissertation.In chapter 2, the following items are introduced. The basic control strategy of semi-active lateral suspension, the actualizing scheme on train, the working principle and the characteristics of the semi-active damper controlled by the electro-hydraulic reverse-proportional relief valve.In chapter 3 , the structure principle and technical characteristics of some representative dampers are analysed. At the same time. two structure schemes of semi-active damper are put forward . The scheme of the electro-hydraulic reverse-proportional relief valve is researched, and two assistant valves are designed.In chapter 4, the mathematical mode of the semi-active damper is deduced based on hydromechanical knowledge and modeling technique of hydraulic system. The transfer function of the damper are deduced by the linearizing principle and the working principle of the dynamic balance. And its dynamic response characteristic is analyzed theoretically, by which the simulation and the design can be directed.In chapter 5, the following structure parameters are calculated. The actor of the semi-active damper and the electro-hydraulic reverse-proportional relief valve. These parameters have being as basal data in following simulation and engineering design.In chapter 6, the development condition of the simulation on hydraulic system, especially the technical characteristics and operating method of AMESim software are introduced, by which the steady-state characteristic and the dynamic characteristic of the semi-active damper is simulated and a series of performance curves are acquired.In chapter 7, the engineering design of damper's actor is completed, involving the seal structure, the select of joining structure and the technics design and the intensity calculation of other parts.In chapter 8, the research project in this dissertation is summarized, and the prospect of the future research work is also presented.