Externally verifiable thermal compensation of cowl opening actuator
AssigneeParker-Hannifin Corporation
InventorDavid J. Bouman
Life of this patent
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Abstract
A cowl door actuator is arranged between a head end and a rod end connected to a cowl door in an aircraft. The cowl door has a closed position and an open position, and the cowl door actuator includes a piston rod that is axially moveable between the head end and the rod end. The piston rod has an extended position in which the piston rod contacts the rod end to move the cowl door to the open position, and a retracted position in which the piston rod is axially spaced from the rod end. When the cowl door is in the closed position, the gap between the piston rod and the rod end enables an axial displacement of the piston rod toward the extended position during thermal expansion of fluid remaining in the actuator, such that the cowl door is maintained in the closed position.
Claims20
A cowl door actuator arranged between a head end and a rod end that is connected to a cowl door, the cowl door being moveable between a closed position and an open position, the cowl door actuator comprising a piston rod axially moveable between the head end and the rod end, the piston rod having an extended position in which the piston rod contacts the rod end to move the cowl door to the open position, and a retracted position in which the piston rod is axially spaced from the rod end by a gap, wherein when the cowl door is in the closed position, the gap between the piston rod and the rod end enables an axial displacement of the piston rod toward the extended position during thermal expansion of fluid remaining in the actuator, whereby the cowl door is maintained in the closed position when the piston rod is axially displaced.
A method of opening and closing a cowl door in an aircraft, the method comprising:
- opening the cowl door by moving a piston rod of an actuator to an extended position in which the piston rod contacts a rod end of the actuator that is connected to the cowl door;
- closing the cowl door by displacing fluid out of the actuator;
- moving the piston rod to a retracted position when the cowl door is in a closed position, whereby a gap is formed between the piston rod and the rod end;
- and
- maintaining the cowl door in the closed position using the gap to accommodate for axial displacement of the piston rod during thermal expansion of fluid remaining in the actuator.
Dependencies are inferred from the claim text.