Aircraft shock absorber with double seal arrangement

摘要

An aircraft shock absorber 1 has a top end 2 connected to the fuselage of an aircraft and a bottom end 3 associated with a wheel axis. A first outer tubular component 20 forms an oil filled chamber 4. A second inner tubular component 10 is displaceable within the first component along a common longitudinal axis. The shock absorber has at least two seals 31,32 arranged between the outer surface of the second component and the inner surface of the first component. The two seals are arranged in series in the direc­tion of the common longitudinal axis. At least one bypass line 5 can be closed by means of a switching valve 60. The bypass line connects the fluid-filled chamber 4 and the space 6 between the seals. During normal operation seal 31 has full fluid pressure of chamber 4 acting on it and inner seal 32 is pressure equalised and does not experience any wear. Should the outer seal 31 leak then valve 60 can be closed so that the inner seal 32 completely takes over the sealing function until the primary seal 31 can be replaced.