Oleo-pneumatic Mixed Shock Absorber Landing Pressure Analysis of Landing Gear

Abstract

The landing gear of an aircraft bears a large impact load during landing, which causes the internal shock absorber to withstand high oil pressure and air pressure, and the buffer performance is greatly influenced. Firstly, based on the axial load of the buffer, the pressure formula of each cavity of the buffer is deduced. Then, the differential equation of the landing motion of landing gear is established by using the two mass system. Finally, the landing gear buffer pressure simulation model is built by using MATLAB/Simulink, which is used to analyze the variation of the pressure of each chamber with time and buffer stroke at different landing speeds, and the influence of oil chamber pressure on the cushioning performance with different oil return areas. The results show that, at different landing speeds, the pressure of each cavity presents a certain regularity at a specific moment of the landing process; the positive stroke oil return hole should not be too small, ensuring that the oil fills the oil return cavity, and the reverse stroke oil return hole cannot be too large to ensure that the oil fills the main oil chamber; the oil pressure in the buffer during landing process affects the stability of the plunger.

Keywords

• landing gear
• shock absorber
• landing
• pressure
• main chamber
• recoil chamber
• pneumatic chamber