Patent ID: 9714689
Date: 2017-07-25
CPC Classifications: B64C,F16F

Claim:
1. A redundant seal assembly for an aircraft shock absorber having an inner member and an outer member that slidably receives the inner member to form a fluid chamber therebetween, the redundant seal assembly comprising: a first dynamic seal provided between the inner member and the outer member, the first dynamic seal functioning as a primary seal to seal the fluid chamber in an initial operation of the shock absorber; a second dynamic seal provided between the inner member and the outer member, the second dynamic seal functioning as a backup seal while the first dynamic seal functions as the primary seal; and a changeover unit comprising: wherein the shock absorber further has a bearing provided on an inner surface of the outer member to allow slidable movement of the inner member along the inner surface of the outer member, and the first dynamic seal and the second dynamic seal are provided on an inner surface of the bearing facing an outer surface of the inner member; wherein the first dynamic seal is provided in a first groove formed on the inner surface of the bearing, and the second dynamic seal is provided in a second groove formed on the inner surface of the bearing, wherein the first groove is located farther from the fluid chamber than the second groove; and wherein the changeover unit is provided on a wall of the outer member where two holes are formed through the wall, and the fluid passage is formed to extend from the fluid chamber, along an outer surface of the bearing, through one of the holes of the wall of the outer member, through the second spool, through the changeover housing, through the first spool, through the other one of the holes of the wall of the outer member, through a hole formed in the bearing, along the inner surface of the bearing, and to the first dynamic seal.