ADJUSTABLE LANDING GEAR SYSTEM

• US 20090321560A1
• Filed: 06/24/2009
• Published: 12/31/2009
• Est. Priority Date: 06/25/2008
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Wilson, Phillip K., Davis, Jonathon R., Luce, William E.
• Granted Patent: US 8,186,620 B2
• Time in Patent Office: Days
• US Class Current: 244/102.00R
• CPC Class Codes: B64C 2025/008 Comprising means for modifying their length, e.g. for kneeling, for jumping, or for leveling the aircraft
• CPC Class Codes: B64C 25/14 fore-and-aft

Abstract

A landing gear system includes a shock strut assembly and a linkage member coupled to an aircraft. Preferably, the shock strut assembly and linkage member are oriented or angled relative to one another in a non-parallel relationship. Actuation of the linkage member moves the shock strut from a de-hiked to a hiked configuration or vice-versa. In addition, the orientation of the linkage member relative to the shock strut assembly permits it to automatically move the shock strut assembly to the de-hiked position during retraction of the landing gear system and prevents the shock strut assembly from exceeding a desired length during retraction. The linkage member may take the form of a hydraulic actuator having a lower end portion coupled to an inner cylinder of the shock strut assembly and an upper end portion coupled to the aircraft aft of where the shock strut assembly is coupled to the aircraft.

Claims

1. A landing gear system for an aircraft, the landing gear system comprising:

a shock strut assembly having a housing, a cylinder and a piston, wherein the piston is movably receivable with respect to the cylinder and the housing is sized to telescopically receive at least a portion of the cylinder, the housing pivotally coupled to the aircraft at a first longitudinal distance from an aircraft center of gravity; and

a linkage member having a first portion moveable relative to a second portion, the first portion pivotally coupled to the aircraft at a second longitudinal distance from the aircraft center of gravity, the second longitudinal distance aft of the first longitudinal distance by a desired amount, the second portion pivotally coupled to the cylinder, the linkage member actuatable from a first length to a second length to change a pre-flight angle of attack of the aircraft when the landing gear system is in a deployed configuration.

2. The landing gear system of claim 1, wherein the piston is telescopically movable with respect to the cylinder.

3. The landing gear system of claim 1, wherein the first portion of the linkage member is an actuator cylinder and the second portion of the linkage member is an actuator piston.

4. The landing gear system of claim 1, wherein the linkage member is hydraulically lockable in the deployed configuration.

5. The landing gear system of claim 1, wherein the linkage member is a hydraulic actuator.

6. The landing gear system of claim 1, wherein the second length is longer than the first length to increase the angle of attack of the aircraft.

7. The landing gear system of claim 1, wherein the desired longitudinal distance is selected to permit the linkage member to urge the shock strut assembly into a stowed configuration upon retraction of the landing gear system into a stowage compartment.

8. The landing gear system of claim 1, wherein the linkage member is kinematically oriented relative to the shock strut assembly to permit the linkage member to decrease a length of the shock strut assembly from the deployed configuration to a stowed configuration upon retraction of the landing gear system into a stowage compartment.

9. A landing gear system for an aircraft, the landing gear system comprising:

a shock strut assembly having a housing, a cylinder and a piston, wherein the piston is movably receivable by the cylinder and the housing is sized to telescopically receive at least a portion of the cylinder, the housing pivotally coupled to the aircraft at a first distance from an aircraft center of gravity; and

a linkage member having a first portion moveable relative to a second portion along a linkage member longitudinal axis, the first portion pivotally coupled to the aircraft at a second distance from the aircraft center of gravity, the second portion pivotally coupled to the cylinder, wherein based on an orientation of the linkage member longitudinal axis relative to a shock strut longitudinal axis the linkage member is configured to urge the shock strut assembly into a stowed configuration upon retraction of the landing gear system.

10. The landing gear system of claim 9, further comprising a lockable brace having a first end portion coupled to the shock strut assembly and a second end portion coupled to the aircraft, wherein the second end portion is located forward of the first longitudinal location.

11. The landing gear system of claim 9, wherein the linkage member longitudinal axis is substantially parallel to the shock strut longitudinal axis.

12. The landing gear system of claim 9, wherein the linkage member longitudinal axis is oriented at an angle relative to the shock strut longitudinal axis

13. The landing gear system of claim 12, wherein the angle is in a range of about 5 degrees to about 45 degrees relative to the shock strut longitudinal axis.

14. The landing gear system of claim 9, wherein the second distance is spaced apart from and located aft of the first distance.

15. The landing gear system of claim 9, wherein the linkage member is actuatable to extend from a first length to a second length while increasing a pre-flight angle of attack of the aircraft.

16. The landing gear system of claim 9, wherein the linkage member is actuatable to move the shock strut assembly from a de-hiked configuration to a hiked configuration while the aircraft is static.

17. A method of operating a landing gear system of an aircraft, the landing gear system having at least one shock strut, the method comprising:

moving the landing gear system to a deployed configuration with the shock strut in a de-hiked configuration relative to the aircraft;

actuating a linkage member to urge the shock strut from the de-hiked configuration to a hiked configuration while the aircraft is static, the linkage member having a first end portion coupled to a telescoping cylinder of the shock strut and a second end portion coupled to the aircraft in a location aft of where the shock strut is coupled to the aircraft; and

while retracting the landing gear system from the deployed configuration to a stowed configuration, shortening the shock strut through operation of a kinematic relationship between the linkage member and the shock strut.

18. The method of claim 17, wherein actuating a linkage member includes pressurizing hydraulic fluid within the linkage member

19. The method of claim 17, wherein retracting the landing gear system to the stowed position includes moving the landing gear system into a landing gear bay of the aircraft.

20. The method of claim 17, wherein shortening the shock strut includes extending the linkage member to a maximum length when the shock strut is stowed from the de-hiked configuration.

21. The method of claim 17, wherein shortening the shock strut includes maintaining the linkage member at a maximum length when the shock strut is stowed from the hiked configuration.

22. The method of claim 17, further comprising locking the linkage member in one of at least the hiked or de-hiked configuration.