Research On Characteristic Of Rotary Spool Electro-Hydraulic Servo Valve

Vibration exciter is a device that forces an object or itself to vibrate.Among the existing excitation modes,electro-hydraulic excitation technology has the advantages of high power density,high thrust and self-adaptive load.It has been widely used in rock fragmentation,road and bridge,aerospace and other fields.Compared with the traditional servo valve,the rotary spool electro-hydraulic servo valve designed in this paper has the advantages of simple structure,low price and higher frequency.In this study,the theoretical analysis,numerical simulation analysis and experimental study are combined to complete the following work.Taking a new type of valve core rotary electro-hydraulic servo valve as the research object,the flow field model of the rotary valve is established based on CFD.At the same time,the working process of rotary valve is analyzed by visual simulation.The static and dynamic characteristics of the rotary valve and the working characteristics of the rotary spool electro-hydraulic vibration exciter are studied.A preliminary experiment is carried out to provide a theoretical basis for the optimization of the structure and performance of the valve core rotary electro-hydraulic servo valve.The main results of this paper are as follows:(1)According to the dynamic model of the hydraulic excitation system,the main control parameters affecting the hydraulic excitation system are obtained.A valve core rotary electrohydraulic servo valve is designed on the basis of high power,heavy load and low frequency of electro-hydraulic excitation required for vibration crushing.(2)The internal flow field of the rotary spool electro-hydraulic servo valve is modeled and analyzed by Fluent,and the distribution characteristics of the pressure,velocity and hydrodynamic force of the rotary valve under different spool speed and different pressure of oil supply are obtained.From the point of view of multiphase flow,the conditions and regional variation law of cavitation phenomenon at valve outlet are studied.(3)By studying the static and dynamic characteristics of the rotary valve,it is found that the flow rate of the rotary valve has a nonlinear positive correlation with the opening of the rotary valve and the pressure of the oil supply.The response characteristics of the rotary valve can be improved by increasing the damping ratio and decreasing the moment of inertia.(4)From the point of view of valve-controlled cylinder,the mathematical model of the rotary spool electro-hydraulic vibration exciter is solved by using Matlab/Simulink and AMESim.The results show that the excitation displacement decreases with the increase of working frequency and load quality,and increases with the increase of oil supply pressure.The optimal working characteristics can be obtained by reasonable matching of the working parameters.(5)The static and dynamic characteristics of the rotary spool electro-hydraulic servo valve are tested and compared with the theoretical results.The results show that the theoretical model and the simulation model have good reliability.Through the above research,it is show that this study will have certain scientific research value and practical significance to the development of rotary valve type hydraulic excitation technology.