Hydraulic actuator for semi levered landing gear

Patent metadata

Field	Value
Publication number	US-9481452-B2
Application number	US-95186110-A
Country	US
Kind code	B2
Filing date	Nov 22, 2010
Priority date	Nov 22, 2010
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A device including a first hydraulic piston, a second hydraulic piston disposed within the first hydraulic piston, and a third hydraulic piston disposed within both the first hydraulic piston and the second hydraulic piston. The first, second, and third hydraulic pistons are contained within a common outer wall. A manifold is connected to the first, second, and third hydraulic pistons. The manifold is disposed relative to the first, second, and third hydraulic pistons such that a fluid moving in the manifold can control positions of the first, second, and third hydraulic pistons.

First claim

What is claimed is:

1. A device comprising:
a first hydraulic piston;
a second hydraulic piston disposed within the first hydraulic piston; and
a third hydraulic piston disposed within both the first hydraulic piston and the second hydraulic piston, the third hydraulic piston comprising a floating piston, and wherein the first, second, and third hydraulic pistons are contained within a common outer wall; and
a manifold connected to the first, second, and third hydraulic pistons, the manifold disposed relative to the first, second, and third hydraulic pistons such that a fluid moving through the manifold can control positions of the first, second, and third hydraulic pistons.

2. The device of claim 1 , wherein the common outer wall includes a guide tube configured to separate fluid volumes within chambers of the device.

3. The device of claim 2 , wherein the common outer wall includes a guide tube configured to separate fluid volumes within chambers of the device and wherein the floating piston is configured within the guide tube such that a landing gear connected to the floating piston may extend rapidly relative to a mechanical device for repositioning a landing gear for retraction into a wheel well, that does not contain the floating piston and the guide tube.

4. The device of claim 3 further comprising:
an aircraft connected to the landing gear.

5. The device of claim 4 further comprising:
a multi-mode relief valve connected to the manifold, wherein the multi-mode relief valve is configured to reduce a pressure of fluid in one or more of the first, second, and third hydraulic pistons while the aircraft is on the ground.

6. The device of claim 4 further comprising:
an accumulator disposed with respect to the manifold such that the accumulator absorbs pressure spikes during touchdown of the aircraft.

7. The device of claim 4 further comprising:
a pressure sensor connected to the manifold, wherein the pressure sensor is configured to monitor the health of the device.

8. The device of claim 1 , wherein at least two of the first, second, and third hydraulic pistons share a common fluidic source.

9. The device of claim 1 , wherein the first, and second, hydraulic pistons are configured to be actuated telescopically such that, in a fully extended position, the second hydraulic piston extends past the top of the first hydraulic piston, and the first hydraulic piston extends past the common outer wall of the actuator.

10. The device of claim 1 , wherein the third hydraulic piston in conjunction with the guide tube creates a smaller chamber common to the second piston.

11. The device of claim 1 , wherein the third hydraulic piston moves independently of the first and second hydraulic pistons.

12. The device of claim 1 , wherein the first hydraulic piston can be extended or retracted within the common outer wall by force of different fluid pressures applied to either end of the first hydraulic piston.

13. The device of claim 4 further comprising:
a multi-mode pressure reducer valve connected to the manifold, wherein the multi-mode reducer valve is configured to reduce a pressure of fluid acting on one or more of the first, second, and third hydraulic pistons to provide either full system pressure for lock-up for takeoff or reduced pressure for enhanced air-ground sensing.

14. The device of claim 1 , wherein the first hydraulic piston is configured to resist applied forces tending to extend or compress the first hydraulic piston.

15. The device of claim 1 , wherein fluid pressure can be varied to provide for air-ground sensing during touchdown of the aircraft.

16. The device of claim 1 , wherein the device is further configured such that fluid in the second hydraulic piston can move to the first hydraulic piston upon command, and such that fluid in the first hydraulic piston can move to the second hydraulic piston upon command.

17. The device of claim 1 , wherein the device is further configured such that fluid in the first, second, and or third hydraulic piston can move out of the device automatically, wherein fluid moving out of the device reduces a load in the device.

18. The device of claim 1 , wherein the device is part of a landing gear assembly of an aircraft.

19. A vehicle comprising:
a fuselage;
a wing connected to the fuselage;
a landing gear assembly connected to at least one of the fuselage and the wing; and
a hydraulic actuator connected to the landing gear assembly, wherein the hydraulic actuator comprises:
a first hydraulic piston;
a second hydraulic piston disposed within the first hydraulic piston; and
a third hydraulic piston disposed within both the first hydraulic piston and the second hydraulic piston, the third hydraulic piston comprising a floating piston, and wherein the first, second, and third hydraulic pistons are contained within a common outer wall, the common outer wall including a guide tube configured to separate fluid volumes within chambers of the device; and

a manifold connected to the first, second, and third hydraulic pistons, the manifold disposed relative to the first, second, and third hydraulic pistons such that a fluid moving in the manifold can control positions of the first, second, and third hydraulic pistons.

Assignees

• Lindahl Gary M
• Mellor Mitchell Loren Ray
• Boeing Co

Inventors

• Lindahl Gary M
• Mellor Mitchell Loren Ray

Classifications

• B64C25/36

  Arrangements or adaptations of wheels, tyres or axles in general · CPC title

• B64C25/60 Primary

  Oleo legs · CPC title

• B64C25/22 Primary

  fluid · CPC title

• B64C25/34

  wheeled type, e.g. multi-wheeled bogies · CPC title

• F15B15/16

  of the telescopic type · CPC title