Abstract:The pressure reducing valve is used as the pressure control valve of the hydraulic servo system of the aircraft, and must maintain the necessary service performance in the vibration environment of the whole machine. A small-sized pressure reducing valve for an aircraft is used as a research object, and the pressure sensing chamber oil is equivalent to a hydraulic spring, which together with the pressure regulating spring and the valve core constitute a typical mass-spring (mechanical spring and Hydraulic spring) - Damping system. The mathematical model of the pressure reducing valve is established when the whole machine is not vibrating and the whole machine is vibrating. The research results show that the stiffness of the pressure-regulating spring is higher when the whole machine is not vibrating, and the valve resonance frequency is higher. The larger the pressure-sensing cavity volume is, the lower the valve resonance frequency is. The vibration environment of the whole machine affects the working performance of the pressure reducing valve, and the parameters such as the diameter of the pressure reducing valve, the spring stiffness, and the pressure sensing chamber size can be properly designed, so that the pressure reducing valve can realize the necessary working characteristics in the vibration environment of the whole machine. The theoretical results are basically consistent with the experimental results. The analysis method and the established mathematical model of the hydraulic valve in the vibration environment provide basic theoretical support for the performance prediction and evaluation of hydraulic components under the vibration environment of the whole machine.