Simulation Analysis Of Sealing Performance And Study On Wear Rule Of Aircraft Landing Gear Hydraulic Reciprocating Mechanism

The role of sealing ring in the mechanical system is irreplaceable,it can prevent the working medium inside the mechanical system from leaking to the outside and prevent it from causing pollution to the natural environment;It can also prevent outside contaminants from entering the mechanical system,preventing it from damaging the mechanical system.The hydraulic reciprocating mechanism seal of the aircraft landing gear studied in this paper is a typical reciprocating seal,and the sealing ring used is generally a rubber and plastic combination seal ring with simple structure and excellent performance,which is an important part of ensuring the safe takeoff and landing of the aircraft.In this thesis,VL-type sealing ring(cross-sectional shape is "VL" type)applied to the hydraulic reciprocating sealing system of aircraft landing gear is taken as the research object,and the sealing performance of VL-type sealing ring under high pressure is explored by combining theoretical analysis and experimental measurement.Firstly,the contour and material of VL-type sealing ring are experimentally tested,and the AB AQUS finite element model is established according to the experimental data and simulated analysis,and the stress-strain cloud diagram of VL-type sealing ring under different working conditions is obtained,and the parts of VL-type sealing ring that are prone to failure under high pressure are explored.At the same time,the contact pressure distribution of V-ring sealing surface under different working conditions was extracted to provide basic data for the numerical calculation in Chapter 3.Based on the sealing mechanism of reciprocating sealing,the solid mechanics analysis is carried out firstly,and the contact pressure distribution of the sealing surface is obtained through finite element simulation.Secondly,the hydrodynamic analysis is carried out,and the oil film thickness distribution of the internal and external strokes of the reciprocating system and the liquid flow through the sealing interface are calculated by solving the Reynolds equation in reverse.Then,the contact mechanics analysis is carried out,and the rough peak contact pressure calculation formula is established through the G-W model.Finally,the fluid-structure interaction analysis is carried out by the stiffness matrix method,and the numerical model of reciprocating seal mixed lubrication is established.Through numerical calculation,the change law of sealing parameters such as reverse pump return rate and friction under different working conditions is obtained,and the numerical calculation results are verified by using the reciprocating sealing test bench.Based on the classical wear theory,through the friction and wear experiment of PTFE materials,the wear depth fitting formula of PTFE materials was established,the evolution law of VL sealing ring performance was explored,and the change law of reverse pump return rate,friction and other parameters with wear time was predicted.Finally,the sealing ring structure is optimized by orthogonal test to achieve the optimization goal of reducing friction and increasing the reverse pump return rate.