FOLDABLE ROTOR BLADE ASSEMBLY

• US 20180229830A1
• Filed: 02/13/2017
• Published: 08/16/2018
• Est. Priority Date: 02/13/2017
• Status: Active Grant

• Current Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Foskey, Christopher E., Burnett, Michael C.
• Granted Patent: US 10,618,632 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 11/28 Collapsible or foldable blades
• CPC Class Codes: B64C 27/50 Blades foldable to facilitate stowage of aircraft
• CPC Class Codes: B64C 29/0033 the propellers being tiltable relative to the fuselage

Abstract

An adapter for a rotor blade assembly including a support member having an outboard surface and an inboard surface; an outboard feature extending laterally from the outboard surface of the support member and including a first lug and a second lug; an inboard feature extending laterally from the inboard surface of the support member and including a first arm and a second arm. The outboard feature and the inboard feature are configured such that a plane defined by an attachment surface of at least one of the first lug and the second lug is non-parallel to a plane defined by an attachment surface of at least one of the first arm and the second arm.

Claims

1. An adapter for a rotor blade assembly comprising:

a support member having an outboard surface and an inboard surface;

an outboard feature extending laterally from the outboard surface of the support member and including;

a first lug extending laterally from the outboard surface of the support member and having an attachment surface configured to couple to an outboard portion of a rotor blade assembly; and

a second lug extending laterally from the outboard surface of the support member and having an attachment surface configured to couple to an outboard portion of a rotor blade assembly;

an inboard feature extending laterally from the inboard surface of the support member and including;

a first arm extending laterally from the inboard surface of the support member and having an attachment surface; and

a second arm extending laterally from the inboard surface of the support member and having an attachment surface;

wherein the outboard feature and the inboard feature are configured such that a plane defined by the attachment surfaces of at least one of the first lug and the second lug is non-parallel to a plane defined by the attachment surfaces of at least one of the first arm and the second arm.

2. The adapter of claim 1, wherein the first lug, the second lug, the first arm, and the second arm are integral with the support member.

3. The adapter of claim 1, wherein the attachment surfaces of the first arm and the second arm and the attachment surfaces of the first lug and the second lug are substantially perpendicular.

4. The adapter of claim 1, wherein the attachment surfaces of the first lug and the second lug are configured to be coupled to a spar having an inboard end, an outboard end, and a spar axis extending between the inboard end and the outboard end, and a plane defined by at least one of the attachment surfaces of the first lug and the second lug is substantially parallel to the spar axis.

5. The adapter of claim 1, wherein the attachment surfaces of the first arm and second arm are configured to be coupled to one of a portion of a rotor blade assembly and a hub such that rotation of the adapter is permitted about a fold axis, and a plane defined by at least one of the attachment surfaces of the first and second lugs is substantially parallel to the fold axis.

6. The adapter of claim 5, wherein a plane defined by at least one of the attachment surfaces of the first and second arms is substantially perpendicular to the fold axis.

7. The adapter of claim 1, wherein the adapter is made from one of forged titanium, filament windings, or composite fibers.

8. A rotor assembly comprising:

a hub;

a spar comprising;

an inboard end;

an outboard end;

a first spar cap; and

a second spar cap spaced apart from the first spar cap and coupled to the first spar cap by a first curvilinear portion and a second curvilinear portion; and

an adapter comprising;

a support member having an outboard surface and an inboard surface;

an outboard feature extending laterally from the outboard surface of the support member and including;

a first lug extending laterally from the outboard surface of the support member and having an attachment surface coupled to the first spar cap; and

a second lug extending laterally from the outboard surface of the support member and having an attachment surface coupled to the second spar cap;

an inboard feature extending laterally from the inboard surface of the support member and including;

a first arm having an attachment surface coupled a rotor blade assembly; and

a second arm having an attachment surface coupled to an inboard portion of a rotor blade assembly;

wherein the attachment surfaces of the first and second arms are configured to permit rotation of the adapter about a fold axis;

wherein a plane defined by at least one of the attachment surfaces of the first and second arms of the adapter is substantially perpendicular to the fold axis; and

wherein a plane defined by at least one of the attachment surfaces of the first and second lugs of the adapter is non-perpendicular to the fold axis.

9. The assembly of claim 8, further comprising:

load-bearing material positioned within the first spar cap and the second spar cap, where at least 80 percent of the load-bearing material in the spar is positioned within the first spar cap and the second spar cap.

10. The assembly of claim 8, wherein the assembly is configured such that the first spar cap and the second spar cap are non-parallel to a plane defined by at least one of the attachment surfaces of the first and second arms of the adapter.

11. The assembly of claim 8, wherein the assembly is configured such that a load on a rotor blade assembly travels in a first direction through the outboard feature of the adapter and travels in a second direction through the inboard feature of the adapter, and the first direction and the second direction are substantially perpendicular.

12. The assembly of claim 8, further comprising:

an actuator coupled to the adapter and configured to rotate the adapter about the fold axis.

13. The assembly of claim 8, wherein the hub includes a hub axis about which rotor blade assemblies are configured to rotate, and where the hub axis and the fold axis are substantially parallel.

14. The assembly of claim 8, wherein the assembly is configured to be coupled to a tiltrotor aircraft.

15. The assembly of claim 8, wherein the assembly is configured to enable the adapter to rotate about the fold axis by at least 90 degrees in either direction.

16. A tiltrotor aircraft rotor assembly comprising:

a hub having a hub axis about which rotor blade assemblies rotate;

a plurality of rotor blade assemblies; and

a hinge between the hub and at least one of the plurality of rotor blade assemblies, the hinge having a fold axis about which at least a portion of the at least one of the plurality of rotor blade assemblies is permitted to fold;

wherein the hub axis and the fold axis are substantially parallel.

17. The assembly of claim 16, wherein at least a portion of the at least one of the plurality of rotor blade assemblies can rotate about the fold axis by equal to or greater than 90 degrees in either direction.

18. The assembly of claim 16, wherein each rotor blade assembly includes an inboard end and an outboard end, the assembly further comprising:

load-bearing material positioned within at least one of the plurality of rotor blade assemblies such that at least 80 percent of the load-bearing material is substantially parallel to the fold axis, and such that at least 80 percent of the load-bearing material is substantially perpendicular to a direction of rotation of the rotor blade assembly.

19. The assembly of claim 16, further comprising:

an adapter comprising;

a support member having an outboard surface and an inboard surface;

an outboard feature extending laterally from the outboard surface of the support member and coupled to the rotor blade assembly, the outboard feature having at least one lug having at least one attachment surface adjacent to the rotor blade assembly; and

an inboard feature extending laterally from the outboard surface of the support member and coupled to an inboard portion of a rotor blade assembly to form the hinge, the inboard feature having at least one arm having at least one attachment surface adjacent to the inboard portion of a rotor blade assembly that is substantially perpendicular to the fold axis;

wherein a plane defined by the at least one attachment surface of the at least one lug is non-parallel to a plane defined by the at least one attachment surface of the at least one arm.

20. The assembly of claim 19, wherein a plane defined by the at least one attachment surface of the at least one lug intersects a plane defined by the at least one attachment surface of the at least one arm to define an angle of at least 15 degrees.

21. The assembly of claim 19, wherein each of the rotor blade assemblies includes:

a spar comprising;

an inboard end;

an outboard end;

a first spar cap; and

a second spar cap spaced apart from the first spar cap and coupled to the first spar cap by a first curvilinear portion and a second curvilinear portion;

where the at least one lug is coupled to the first spar cap and the second spar cap.

22. The assembly of claim 19, wherein the assembly is configured such that a load on each rotor blade assembly travels in a first direction through the outboard feature of the adapter and travels in a second direction through the inboard feature of the adapter, and the first direction and the second direction are non-parallel.