Oleo strut

[7] It had been derived from the recuperative gear design of the Vickers gun, controlling recoil by forcing oil through precisely sized orifices.

[7][8] Oleo-pneumatic technology was subsequently reused by the manufacturer to produce several other products, including hydraulic railway buffers and industrial shock absorbers.

[3] By the twenty-first century, a wide range of different shock-absorbing struts were in use, but typically employ common principles, despite considerable variations in size, weight, and other characteristics.

[4] The oleo strut has seen much use on the largest cargo airplanes in the world, such as the Antonov An-124 Ruslan; it reportedly provides for a rough-field landing capacity while carrying payloads of up to 150 tons.

[21] In non-aircraft use, the Quadro range of motor scooters use the oleo strut, which is claimed to give favourable low speed lean characteristics.

The cavity within the strut and piston is filled with gas (usually nitrogen, sometimes air—especially on light aircraft) and oil (usually hydraulic fluid), and is divided into two chambers that are connected by a small orifice of a precise, calculated size.

A tapered rod is used on some designs to change the size of the orifice as the piston moves, providing greater resistance as compression of the strut increases.

[4] Pneumatic systems like the oleo strut generally have long operating lives, and the construction is not unusually complex for maintenance purposes.