It is undesirable for an airplane to bounce on landing—it could lead shock absorber design pdf a loss of control. The landing gear should not add to this tendency.
A steel coil spring stores impact energy from landing and then releases it. An oleo strut absorbs this energy, reducing bounce. As the strut compresses, the spring rate increases dramatically, because the air is being compressed, while the viscosity of the oil dampens the rebound movement. The largest cargo airplanes in the world, such as the Antonov An-124 Ruslan, use oleo struts to allow for rough-field landing capacity with a payload of up to 150 tons. This design also cushions the airframe from the impacts of taxiing.
Cleveland Pneumatic Tool Company designed and introduced the first oleo-pneumatic shock-absorbing strut for airplanes, later called “Aerol” struts in 1926. Oleo struts have been in use for many decades. Pneumatic systems like the oleo strut generally have long operating lives, and the construction is not unusually complex for maintenance purposes. When the aircraft is stationary on the ground, its weight is supported by the compressed gas in the cylinder. During landing, or when the aircraft taxis over bumps, the piston slides up and down. It compresses the gas, which acts as a spring, and forces oil through the orifice, which acts as a damper.
Nitrogen is usually used as the gas instead of air, since it is less likely to cause corrosion. The various parts of the strut are sealed with O-rings or similar elastomeric seals, and a scraper ring is used to keep dust and grit adhering to the piston from entering the strut. In this application, an engine driven pump is used to pressurize the hydraulic fluid. The Quadro range of motor scooters use the oleo strut to allow for low speed lean. Welch, John F, Bjork, Lewis and Bjork, Linda, Van Sickle’s modern airmanship.
Webinars – ALC_Content – FAA – FAASTeam”. Welcome to the P28B Web Site”. Woodhouse, Mary and Gifford, Scott “How to make your airplane last forever,” Tab Books, 1996, Page 75. Cleveland: The Making of a City, p.
Patent US2959410 – Double stage oleo-pneumatic shock absorber – Google Patents”. 2015 Quadro 4 Pushes Leaning and Stability to Extremes at EICMA 2014″. This page was last edited on 21 November 2017, at 11:11. Look up shock in Wiktionary, the free dictionary. This disambiguation page lists articles associated with the title Shock. If an internal link led you here, you may wish to change the link to point directly to the intended article.