We are going to brief some information regarding the A320 Landing Gear (Shock Absorber). Below you will find a cross section photo for the shock absorber which will be good to follow while reading the description.
Note: The photo is taken from A320 AMM - Aircraft Maint. Manual- /It's here for studying purposes only. It's not allowed to use it for trading purpose without prior notice from AIRBUS.
1) Compression:
During the compression, the sliding tube goes into the barrel of the main fitting. The capacity of the shock absorber reduces, which compresses the gas. The fluid goes through the damping head and lifts the compression-orifice plate off its seat, to let the fluid flow fully.
Initially, the fluid also flows from the compression chamber to the 1st stage gas chamber, through the first-stage orifices of the damping tube. While the shock absorber compresses, the damping tube and the first-stage orifices go through the damping head. The flow through the first-stage orifices stops, and the flow limits to that through the compression-orifice plate. This produces a two-stage damping effect. The gas compression in the 2nd stage chamber, pushes on the floating piston to help the damping. It also helps to make the damping effect and the compression effect of the oleo smooth.
At the same time, the fluid goes from the 1st stage gas chamber into the recoil chamber, through the openings in the upper bearing. This flow of fluid moves the recoil-orifice plate against the flange of a retaining ring, to let the fluid flow fully. The gas compression and the fluid transfer absorb the shock-loads from the MLG.
(2) Recoil :
The energy in the gas, which is in the 1st stage and the 2nd stage gas chambers, starts the recoil travel. The fluid goes through the recoil-orifice and the compression-orifice plates. The flow of fluid moves these plates to their almost closed position, so that the fluid movement is slow. This decreases the speed of the recoil travel.
A flow of fluid through the first-stage orifices in the damping tube only occurs if the recoil-orifice and the compression-orifice plates go into the compression chamber again. The gas in the 2nd stage chamber helps to make the extension effect of the shock absorber smooth.
(3) Compression and Recoil - 2nd Stage Gas Chamber:
The compression and the expansion of the gas in the 2nd stage gas chamber helps to make the effect of the shock absorber smooth. This is transmitted through the floating piston to the oil and then to the remaining parts of the shock absorber assembly. This procedure helps to make a smooth landing.
I hope the information above is helpful to understand hints of the A320 Shock ABsorber.
B.Regards
Ayman Shak'ah
Licensed Aircraft Maint. Engineer
