Research On Temperature Characteristics And Cooling Structure Of Electro-pneumatic Servo Valve Driven By Voice Coil Motor

Electro-pneumatic servo valve is the core control component of pneumatic servo system,which is widely used in military,aerospace and civil equipment.In some special occasions,the installation position of the electro-pneumatic servo valve is narrow,which requires reducing the volume of the electro-pneumatic servo valve and increasing its power density.The temperature rise caused by the increase in power density has disadvantages to the response performance of the electric actuator,the sealing performance of the sealing ring and the precise fit of the valve core and valve sleeve.Excessive temperature rise will even damage the electro-pneumatic servo valve,seriously affecting the reliability and life of the electro-pneumatic servo valve.Therefore,studying the temperature characteristics of the electro-pneumatic servo valve and designing the cooling structure are of great significance for improving the comprehensive performance of the electro-pneumatic servo valve.In order to improve the power density of the electro-pneumatic servo valve,this paper studies the temperature characteristics of the electro-pneumatic servo valve,the computational fluid dynamics methods was used to establish the temperature field-flow field coupling model of the electro-pneumatic servo valve,and the influence of working pressure and motor current on the temperature characteristics of electro-pneumatic servo valve is studied,and on this basis,a heat dissipation device is designed for high-power density electro-pneumatic servo valve.The research content of this paper is as follows:First,the research background and progress of the temperature characteristics and cooling structure design of the electro-pneumatic servo valve are introduced.The main research methods and advantages and disadvantages currently used in the temperature characteristics are analyzed,and the computational fluid dynamics method is selected for research.The temperature characteristics of the electro-pneumatic servo valve are introduced,involving heat transfer and flow field related theories.The forced convection air cooling method is selected to cool the electro-pneumatic servo valve.Secondly,taking the existing electro-pneumatic servo valve as the research object,the electromagnetic-thermal-flow multi-field coupling mathematical model and experimental device of the electro-pneumatic servo valve are built.The temperature characteristics and electromagnetic drive characteristics of the electro-pneumatic servo valve are studied under different working pressures,different currents and fixed valve openings.Finally,a high-power-density electro-pneumatic servo valve with a shroud for heat dissipation driven by a small motor was designed,and the shroud for active heat dissipation of the voice coil motor was simulated and experimentally studied.The influence of the highpressure air inlet position,inlet aperture,number of inlets and annular gap on the heat dissipation capacity of the shroud is studied.The results show that the heat dissipation capacity is the best when the high-pressure air inlet of the shroud is in the middle,the inlet aperture is 4mm,the inlet is 4 holes,and the annular gap is 1mm.The designed high-powerdensity electro-pneumatic servo valve was subjected to sinusoidal tracking response experiments.The results show that the amplitude ratio and phase difference of the sinusoidal response meet the requirements of use.On the basis of not reducing the response performance of the electro-pneumatic servo valve,the rated thrust of the small motor is increased and the steady state temperature is reduced,and the power density of the electro-pneumatic servo valve is improved.This article provides theoretical support for the optimization research of electro-pneumatic servo valve.