Simulation Analysis Of Structural Deformation And Contamination Stuck Of Aviation Hydraulic Spool Valve

Hydraulic control valves,especially hydraulic spool valves,are widely used in hydraulic systems.Whether the control function of the spool valve is ideal is directly related to the stability and safety of the hydraulic system,so the stuck problem of the spool valve has always been a research hotspot in the field of hydraulic transmission and control technology.In the medium and high pressure system,when the oil medium flows through the valve port of the spool,the viscous temperature rise effect causes the temperature of the local structure of the spool to rise,and the valve core and bushing are unevenly deformed,resulting in a decrease in the matching clearance,which will cause the spool to be stuck.In addition,solid particles are trapped in the mating gap,resulting in wear of the mating pair composed of the valve core and bushing,which will also cause the spool to be stuck.In this paper,aiming at the seizure phenomenon of spool valve due to thermal reasons and pollution reasons,this paper takes a certain type of aviation hydraulic spool valve as the research object,and studies the thermodynamic coupling deformation and internal particle motion characteristics based on the ANSYS Workbench simulation platform,and improves the mating pair and spool structure of the hydraulic spool valve to avoid the phenomenon of spool seizure.According to the working characteristics of the spool valve,the reasons for the temperature rise of oil in the valve cavity of the spool valve were analyzed.The internal heat transfer mode of the spool valve is discussed,the coupling heat transfer is determined as the main heat transfer method inside the spool valve,and the numerical solution of coupled heat transfer is given.The heat-fluid-structure interaction method is comparatively selected,and the thermal fluid-structure interaction model is established in the simulation platform.Aiming at the seizure phenomenon of spool valve due to thermal reasons,based on the ANSYS Workbench simulation platform,the thermal fluid-structure interaction numerical analysis of the hydraulic spool valve was carried out,and the flow field and structural field in the spool valve were numerically calculated,and the velocity,pressure and temperature distribution of the flow field in the spool valve were obtained,and the influence of inlet pressure on the temperature distribution and thermal deformation characteristics of the spool and bushing were analyzed.The thermal deformation characteristics of the spool and bushing mating surface were studied from the circumferential and axial directions,and the mating pair of the spool valve was improved to avoid the thermal seizure of the spool valve.Aiming at the jamming phenomenon of the spool valve due to pollution,a two-dimensional solid-liquid two-phase flow calculation model of the valve cavity of the hydraulic spool valve was established,the movement trajectory of the polluted particles in the valve cavity was numerically calculated,and the effects of particle diameter and valve port opening on the movement trajectory of the particles were analyzed.According to the movement mode of pollution particles invading the gap,an improved scheme of the spool structure of the spool valve is proposed,which effectively reduces the particle volume fraction in the gap and avoids the pollution jamming phenomenon of the spool valve.