Composite leg for landing gear assembly

• US 8,541,091 B2
• Filed: 03/26/2012
• Issued: 09/24/2013
• Est. Priority Date: 03/31/2005
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Kismarton, Max U.
• Primary Examiner(s): DINH, TIEN QUANG
• Application Number:
  US13/429,630
• Publication Number:
  US 20120234972A1
• Time in Patent Office: 547 Days
• Field of Search: 244/100.R, 244/104.LS, 244/108, 244/104.R, 244/103.R, 244/107, 446/55, 428/123, 428/292.1, 428/293.1, 528/31, 528/41, 528/37
• US Class Current: 428/113
• CPC Class Codes: B64C 2025/325 specially adapted for helicopters
• CPC Class Codes: B64C 25/06 fixed
• CPC Class Codes: Y10T 428/24124 Fibers

Abstract

A composite leg for a landing gear assembly includes a composite compression cap including reinforcing fibers that provide strength in compression, and a tension cap including reinforcing fibers that provide strength in tension. At least some of the fibers are oriented at +α and −α with respect to a longitudinal axis of the leg, where α is between 2 and 8 degrees.

Claims

1. A composite leg for a landing gear assembly, the composite leg comprising:

a composite compression cap including reinforcing fibers that provide strength in compression; and

a composite tension cap including reinforcing fibers that provide strength in tension;

wherein at least some of the fibers are oriented at +α and

−

α

with respect to a longitudinal axis of the leg, where α

is between 2 and 8 degrees.

2. The composite leg of claim 1, further comprising a torque box for providing torsional rigidity of the leg and carrying shear flow between the caps.

3. The composite leg of claim 2, wherein plies of reinforcing fibers in the torque box are interleaved with plies of the fibers in the caps.

4. The composite leg of claim 3, wherein the reinforcing fibers in the torque box have a lower strain of compression than the fibers that provide the strength in compression and a lower strain of tension than the fibers that provide strength in tension.

5. The composite leg of claim 1, wherein the fibers providing the strength in compression include glass fibers and wherein the fibers providing strength in tension include plastic fibers.

6. The composite leg of claim 1, wherein the fibers providing strength in compression and tension both include glass fibers.

7. The composite leg of claim 1, wherein the compression cap is 20-40% thicker than the tension cap.

8. The composite leg of claim 1, wherein the compression cap and the tension cap have the same thickness.

9. The composite leg of claim 1, wherein the leg has holes for receiving attachment members, and wherein the leg further includes thickened pads of carbon fibers are around the holes.

10. A landing gear assembly comprising at least one composite leg of claim 1.

11. An aerospace vehicle comprising:

a fuselage; and

a landing gear assembly coupled to the fuselage, the landing gear assembly including at least one composite leg of claim 1.

12. The composite leg of claim 1, further comprising a torque box for providing torsional rigidity of the leg and carrying shear flow between the caps.

13. The composite leg of claim 12, wherein the torque box includes plies of reinforcing fibers that are interleaved with plies of the fibers in the caps.

14. The composite leg of claim 13, wherein the reinforcing fibers in the torque box have a lower strain of compression than the fibers in the compression cap and a lower strain of tension than the fibers in the tension cap.

15. The composite leg of claim 13, wherein the reinforcing fibers in the torque box include carbon fibers, the fibers in the composite compression cap include glass fibers, and the fibers in the composite tension cap include plastic fibers.

16. A landing gear assembly leg comprising:

a composite compression cap including reinforcing fibers oriented at +α and

−

α

with respect to a longitudinal axis of the leg; and

a composite tension cap including reinforcing fibers oriented at +α and

−

α

with respect to the longitudinal axis of the leg;

where α

is between 2 and 8 degrees.

17. The composite leg of claim 16, wherein the compression cap and the tension cap have the same thickness.

18. The composite leg of claim 16, wherein the leg has holes for receiving attachment members, and wherein the leg further includes thickened pads of carbon fibers are around the holes.

19. A landing gear assembly comprising at least one composite leg of claim 16.

20. An aerospace vehicle comprising:

a fuselage; and

a landing gear assembly coupled to the fuselage, the landing gear assembly including at least one composite leg of claim 16.