Technology Of High-speed Reversal With Electrohvdraulic Vibration

Vibration technology is a kind of technology that exciting force generated by exciters is imposed on subjects, making them produce vibration with certain form and size. As a kind of indispensable fundamental technology in both scientific research and engineering application, Vibration technology will directly affect the accuracy of experimental results in scientific research and the product performance in engineering application, reflecting a countries’ scientific research capability and industrial development level. According to the comprehensive analysis of research status and trend about excitation technology at home and abroad, the paper indicates that electrohydraulic vibration is very promising due to its high power density, high thrust, continuous amplitude adjustment, adaptive load and convenient operation. In the engineering application of railway tamper, considering the existed tampers’shortages, such as large impact, easy abrasion, dependent adjustment between frequency and amplitude, new electrohydraulic exciter is designed, mainly consisting of spin valve and micro-displacement cylinder.Supported by the National Natural Science Foundation of China, the project did some meaningful research works, including theoretical model, analysis of dynamic characteristic, system simulation and experimental validation, which not only provide design basis and theoretic guide for future development, but also narrow the gap between home and abroad.The main research works are as follows.1. Working principle and structure of new tamping device with electrohydraulic vibration are introduced. Compared with the existed tamping devices, the new tamping device has the merits of high working efficiency, strong adaptability and low failure rate. In addition, combining the working principle of new tamping device, the working principle of electrohydraulic exciter, which produces vibration motion, is also depicted. In order to realize high working frequency and large flow rate, the spin valve is designed and further optimized, finally owing the advantages of reasonable structure, excellent sealing effect and diverse shapes of grooves.2. The inlet flow field of spin valve is modeled and simulated with CFD software. Then considering the factors, including different shapes of grooves, different opening of grooves, different numbers of grooves, different axial lengths of grooves and different supply pressure, stable simulation results are analysed. On the other hand, simulation results and dynamic simulation results are compared. According to their flow character, the flow are models are founded and analysed respectively under different shapes of grooves.3. The pressure-flow characteristics equation is founded. As important measuring indexes of performance, equivalent diameter and flow pulsation are put forward and analysed. Besides, in the aspects of step response and amplitude-frequency characteristics, dynamic characters of spin valve with different structural parameters are discussed. In order to explore stress mechanism, steady and dynamic flow forces are founded respectively.4. Theoretical model of electrohydraulic exciter is founded and solved through Matlab/Simulink or AMEsim. Considering different different shapes of grooves, different numbers of grooves, different axial lengths of grooves and different supply pressure, different working frequencies and different diameters of damping hole used for internal leakage, dynamic characters of electrohydraulic exciter are discussed.5. Electrohydraulic exciter rig is established and related experimental validations of spin valve and electrohydraulic exciter are conducted.