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US 11,939,044 B2Granted
Landing gear system for an aircraft
AssigneeAirbus Operations GmbH
InventorPeter Sharpe
Life of this patent
Estimating the term…
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.
Claims19
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 during both directions of travel of the piston through a passageway connected to a first hydraulic supply line and including a cross-sectional shape which tapers in one direction such that there is more snubbing for fluid flow in one direction than in the opposite direction, as a result of the shape of the passageway, and
- wherein the passageway has a discharge coefficient of 0.9 or more in a flow direction corresponding to the snubbing, if any, when the piston is moving in said opposite direction.
3 more elements
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,
- 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 during both directions of travel of the piston through a passageway connected to a first hydraulic supply line and including a cross-sectional shape which tapers in one direction such that there is more snubbing for fluid flow in one direction than in the opposite direction, as a result of the shape of the passageway, and
- wherein a portion of the passageway comprises a structure with a plurality of perforations through which the hydraulic fluid flows.
3 more elements
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,
- 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 during both directions of travel of the piston through a passageway connected to a first hydraulic supply line and including a cross-sectional shape which tapers in one direction such that there is more snubbing for fluid flow in one direction than in the opposite direction, as a result of the shape of the, and
- wherein the passageway has a discharge coefficient of 0.7 or less in a flow direction corresponding to the greater snubbing of the piston.
3 more elements
Dependencies are inferred from the claim text.