Expandable strut assembly for a wing of an aircraft and method of using the same

Patent metadata

Field	Value
Publication number	US-12286222-B2
Application number	US-202318171345-A
Country	US
Kind code	B2
Filing date	Feb 18, 2023
Priority date	Feb 18, 2023
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

There is provided an expandable strut assembly for a wing of an aircraft, having a strut with a strut cross section with an airfoil shape, and the strut having an outboard end coupled to the wing, an inboard end coupled to a fuselage, and an elongate body, and having at least one shape transition assembly connected to the strut. Each shape transition assembly is configured to transition the strut between a contracted position and an expanded position, and is configured to transition the strut cross section between a contracted airfoil shape and an expanded airfoil shape. Each shape transition assembly has a shape transition mechanism attached to an interior of the strut. The shape transition mechanism includes fixed length structural members, and a drive mechanism of variable length structural member(s), includes an actuation mechanism connected to the shape transition mechanism, and an activation mechanism coupled to the actuation mechanism.

First claim

The invention claimed is:

1. An expandable strut assembly for a wing of an aircraft, the expandable strut assembly comprising:
a strut having a strut cross section with an airfoil shape, and the strut having an outboard end coupled to the wing of the aircraft, an inboard end coupled to a fuselage of the aircraft, and an elongate body defined between the outboard end and the inboard end; and
at least one shape transition assembly connected to an interior of the strut, each shape transition assembly configured to transition the strut between a contracted position and an expanded position, and configured to transition the strut cross section between a contracted airfoil shape and an expanded airfoil shape, each shape transition assembly comprising:
a shape transition mechanism attached to one or more interior portions in the interior of the strut, the shape transition mechanism comprising:
a plurality of fixed length structural members;
a drive mechanism connected to the plurality of fixed length structural members, the drive mechanism comprising one or more variable length structural members;

an actuation mechanism connected to the shape transition mechanism, the actuation mechanism configured to actuate the drive mechanism of the shape transition mechanism; and
an activation mechanism coupled to the actuation mechanism, the activation mechanism configured to activate the actuation mechanism, to initiate a position transition of the strut between the contracted position and the expanded position, and to initiate a shape transition of the strut cross section between the contracted airfoil shape and the expanded airfoil shape.

2. The expandable strut assembly of claim 1 , wherein the expandable strut assembly further comprises:
a jury strut attached between a top portion of the strut and an underside portion of the wing, and forms a jury strut joint location, wherein a first end of the jury strut joins to the top portion of the strut, and further wherein each of the at least one shape transition assemblies has an outboard end attached to the interior of the strut at the jury strut joint location.

3. The expandable strut assembly of claim 1 , wherein:
the strut is in the contracted position and the strut cross section is in the contracted airfoil shape during a cruise flight condition of the aircraft; and
the strut is in the expanded position and the strut cross section is in the expanded airfoil shape, when the strut is under compression during a wing down-bending flight condition of the aircraft.

4. The expandable strut assembly of claim 1 , wherein the strut further comprises a leading edge comprising:
a leading edge skin that is flexible in a chord-wise direction of the strut, the leading edge skin having a constant length, and having a first end, a second end, and an arc length defined therebetween;
a flexible skin portion at a forward-most end of the leading edge; and
a leading edge shape control mechanism attached to the leading edge skin at a plurality of discrete, fixed support locations, and configured to transition the leading edge skin from a first shape having a first curvature profile to a second shape having a second curvature profile different than the first curvature profile without a change in the arc length.

5. The expandable strut assembly of claim 1 , wherein the strut further comprises a trailing edge comprising:
a trailing edge skin having a constant length; and
an aft membrane configured to close off a strut enclosure of the strut.

6. The expandable strut assembly of claim 5 , wherein the aft membrane comprises an accordion aft membrane having an accordion shape profile when the strut is in the expanded position.

7. The expandable strut assembly of claim 1 , wherein the plurality of fixed length structural members comprise one or more of fixed length spars, inner brace members, truss members, bars, and cross-beam members.

8. The expandable strut assembly of claim 1 , wherein the plurality of fixed length structural members form an expandable structure having a cross section profile comprising a rhombus shape.

9. The expandable strut assembly of claim 1 , wherein the plurality of fixed length structural members form an expandable structure having a cross section profile comprising a hexagon shape.

10. The expandable strut assembly of claim 1 , wherein the one or more variable length structural members of the drive mechanism comprise:
one or more compression chains attached to the actuation mechanism, the one or more compression chains oriented in the strut in one of a chord-wise direction or a span-wise direction.

11. The expandable strut assembly of claim 10 , wherein the one or more compression chains are pre-loaded with one or more springs members in the interior of the strut.

12. The expandable strut assembly of claim 10 , wherein the one or more compression chains are connected to a reduction gear system having a plurality of gears.

13. The expandable strut assembly of claim 1 , wherein the one or more variable length structural members of the drive mechanism comprise a plurality of variable length structural members comprising:
a spring assembly attached to one or more of the plurality of fixed length structural members, the spring assembly comprising one or more vertical springs and one or more horizontal springs; and
a plurality of cables attached to the actuation mechanism and to one or more of the plurality of fixed length structural members.

14. The expandable strut assembly of claim 1 , wherein the one or more variable length structural members of the drive mechanism comprise a plurality of variable length structural members comprising:
a cam assembly comprising one or more cam elements; and
a plurality of cables comprising one or more vertical cables, one or more horizontal cables, and one or more shear cables, the plurality of cables attached to one or more of the actuation mechanism and the plurality of fixed length structural members.

15. The expandable strut assembly of claim 1 , wherein the actuation mechanism comprises:
a first spine member having a restrained end attached to the outboard end of the strut and having an unrestrained end, and extending along a length of the strut;
a second spine member having a restrained end attached to a fuselage structure in an interior of the fuselage, and having an unrestrained end, and extending along the length of the strut parallel to the first spine member; and
one or more compression chain attachment points connecting the first spine member and connecting the second spine member to the drive mechanism.

16. The expandable strut assembly of claim 15 , wherein the first spine member and the second spine member are positioned in a parallel position to a load path of the strut.

17. The expandable strut assembly of claim 1 , wherein the actuation mechanism comprises:
an immovable spine member having a restrained end attached to a fuselage structure in an interior of the fuselage, and having an unrestrained end, and extending along a length of the strut; and
one or more compression chain attachment points connecting the immovable spine member to the drive mechanism.

18. The expandable strut assembly of claim 17 , wherein the actuation mechanism further comprises:
a rack-and-pinion system in the interior of the fuselage, the rack-and-pinion system connected to a spring system and connected to the immovable spine member.

19. The expandable strut assembly of claim 1 , wherein the actuation mechanism comprises:
a movable spine membe

Assignees

• Boeing Co

Inventors

• Grip Robert E
• Droney Christopher K
• Vassberg John C
• Roman Dino L
• Brown John J
• Noel Nathaniel J
• Peyton Charles Daniel

Classifications

• B64C3/18 Primary

  Spars; Ribs; Stringers · CPC title

• B64C3/48 Primary

  by relatively-movable parts of wing structures · CPC title