Abstract: The dynamic performance of the nozzle baffle servo valve is related to the control precision and the response speed of the electro-hydraulic speed control system.According to the geometric relationship among the baffle components and the main valve,the functional relation between the baffle and the control valve and dynamic equilibrium equation of the servo valve were constructed.The dynamic model of the nozzle baffle servo valve is established by AMESim with relevant parameters of a certain type of servo valve.The results showed that servo valve has an ultra fast response,high sensitivity,good oil pressure stability and stable dynamic following performance;it is proved that under the step response of the system,the gap between the flapper and the nozzle can return to the initial state both quickly and accurately,which will help ensure the stability of the initial setting speed.The sensitivity characteristics of the internal state variables of the servo valve are analyzed,so this modeling method provides a theoretical basis for the optimal design and dynamic analysis of servo valves.

Key words: AMESim, flapper-nozzle servo valve, dynamic characteristics, simulation analysis