Landing gear system for an aircraft
AssigneeAirbus Operations GmbH
InventorPeter SHARPE
Life of this patent
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Abstract
Retraction of a landing gear assembly on an aircraft is actuated by a hydraulic actuator. The actuator includes a piston that travels within a cylinder along a stroke length between a first position corresponding to the landing gear assembly when extended and a second position corresponding to the landing gear assembly when retracted. The movement of the piston along its stroke length is snubbed at one end by a different amount according to the direction of travel, for example by use of an orifice plate that has a discharge coefficient that is greater in one direction than in the opposite direction. Asymmetric snubbing is thus provided, which enables the landing gear to retract faster.
Claims18
A landing gear system for an aircraft, wherein the system includes
- a retractable landing gear assembly, and
- a hydraulic actuator for actuating retraction of at least a part of the landing gear assembly from an extended configuration to a retracted configuration,
- the hydraulic actuator including a piston that travels within a cylinder along a stroke length between a first position corresponding to the extended configuration of said part of the landing gear assembly and a second position corresponding to the retracted configuration of said part of the landing gear assembly, and
- movement of the piston along its stroke length being snubbed for a portion of the stroke length when proximate to, and moving in a direction towards, one of the first position and the second position, and wherein the snubbing, if any, is less when moving in the opposite direction, there thus being provided asymmetric snubbing,
- the asymmetric snubbing being provided by the flow of hydraulic fluid through a passageway, there being more snubbing for fluid flow in one direction than in the opposite direction, as a result of the shape of the passageway.
A method of operating an aircraft landing gear which is movable between a deployed position suitable for supporting a portion of the weight of the aircraft on the ground and a stowed position, the method comprising the steps of
- moving the landing gear from the stowed position to the deployed position, the last 5% of the distance to be travelled by the landing gear as a percentage of the total distance from the stowed position to the deployed position being at an average speed, V1, that is lower than the average speed, V2, for the middle 90% of the distance, and then
- moving the landing gear from the deployed position to the stowed position, the first 5% of the distance to be travelled by the landing gear as a percentage of the total distance from the deployed position to the stowed position being at an average speed, V3, that is greater than V1 by at least 10%.
An aircraft landing gear retraction actuator configured to provide asymmetric snubbing at an end of its stroke length with the use of an orifice plate that has a discharge coefficient that is greater in one direction than in an opposite direction.
Dependencies are inferred from the claim text.