Rotor span-balance pocket

Patent metadata

Field	Value
Publication number	US-10822075-B2
Application number	US-201715664809-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Jul 31, 2017
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

The present invention includes a span-balance pocket in a surface of a rotor blade, the span-balance pocket including an inboard surface and an outboard surface; and one or more weights disposed in the span-balance pocket to span-balance the rotor blade; and at least one of one or more retention devices to retain the one or more weights against the outboard surface of the span-balance pocket or the span-balance pocket is machined or molded into a tip block of the rotor blade.

First claim

What is claimed is:

1. A rotor-blade span-balancing system, comprising:
a span-balance pocket in a surface of a rotor blade, the span-balance pocket comprising an inboard surface and an outboard surface;
one or more weights disposed against the outboard surface in the span-balance pocket to react the centrifugal force of the one or more weights through the outboard surface; and
one or more retention devices positioned between the one or more weights and the inboard surface of the span-balance pocket to retain the one or more weights against the outboard surface of the span-balance pocket such that there are no shear loads on the one or more retention devices.

2. The system of claim 1 , wherein the rotor blade is a tail rotor blade, main rotor blade, proprotor blade, a propeller blade, or a wind-turbine blade.

3. The system of claim 1 , wherein the span-balance pocket is machined or molded into the surface of the rotor blade.

4. The system of claim 3 , wherein the span-balance pocket is machined or molded into the surface of a tip block of the rotor blade.

5. The system of claim 1 , further comprising a cover covering the span-balance pocket, wherein the cover is substantially flush with the surface of the rotor blade and is attached to the rotor blade.

6. The system of claim 5 , wherein a cover recess to accommodate the cover is machined or molded into the surface of the rotor blade.

7. The system of claim 1 , wherein the one or more retention devices comprise one or more bolts.

8. A rotor-blade span-balancing system, comprising:
a span-balance pocket in a surface of a rotor blade, the span-balance pocket comprising an inboard surface and an outboard surface;
one or more weights disposed against the outboard surface in the span-balance pocket to react the centrifugal force of the one or more weights through the outboard surface; and
wherein the span-balance pocket is machined or molded into a tip block of the rotor blade.

9. The system of claim 8 , wherein the rotor blade is a tail rotor blade, main rotor blade, proprotor blade, a propeller blade, or a wind-turbine blade.

10. The system of claim 8 , further comprising a cover covering the span-balance pocket, wherein the cover is substantially flush with the surface of the rotor blade and is attached to the rotor blade.

11. The system of claim 10 , wherein a cover recess to accommodate the cover is machined or molded into the surface of the rotor blade.

12. The system of claim 8 , further comprising one or more retention devices to retain the one or more weights against the outboard surface of the span-balance pocket.

13. The system of claim 12 , wherein the one or more retention devices comprise one or more bolts.

14. The system of claim 12 , wherein the one or more retention devices are positioned between the one or more weights and the inboard surface of the span-balance pocket.

15. A method of rotor-blade span balancing, comprising:
providing a span-balance pocket in a surface of a rotor blade, the span-balance pocket comprising an inboard surface and an outboard surface;
disposing one or more weights against the outboard surface to react the centrifugal force of the one or more weights through the outboard surface; and
retaining the one or more weights against the outboard surface of the span-balance pocket with one or more retention devices positioned between the one or more weights and the inboard surface of the span-balance pocket such that there are no shear loads on the one or more retention devices.

16. The method of claim 15 , wherein the rotor blade is a tail rotor blade, main rotor blade, proprotor blade, a propeller blade, or a wind-turbine blade.

17. The method of claim 15 , further comprising providing the span-balance pocket in the surface of the rotor blade by machining or molding the span-balance pocket into the surface of the rotor blade.

18. The method of claim 17 , further comprising machining or molding the span-balance pocket into a surface of a tip block of the rotor blade.

19. The method of claim 15 , further comprising providing a cover covering the span-balance pocket, wherein the cover is substantially flush with the surface of the rotor blade and is attached to the rotor blade.

20. The method of claim 19 , further comprising machining or molding a cover recess into a surface of a rotor blade to accommodate the cover.

21. The method of claim 15 , wherein the one or more retention devices comprise one or more bolts.

22. A method of rotor-blade span balancing, comprising:
machining or molding a span-balance pocket into a tip block of a rotor blade, the span-balance pocket comprising an inboard surface and an outboard surface; and
disposing one or more weights against the outboard surface to react the centrifugal force of the one or more weights through the outboard surface.

23. The method of claim 22 , wherein the rotor blade is a tail rotor blade, main rotor blade, proprotor blade, a propeller blade, or a wind-turbine blade.

24. The method of claim 22 , further comprising providing a cover covering the span-balance pocket, wherein the cover is substantially flush with a surface of the tip block of the rotor blade and is attached to the rotor blade.

25. The method of claim 24 , further comprising machining or molding a cover recess into the surface of the tip block of the rotor blade to accommodate the cover.

26. The method of claim 22 , further comprising retaining the one or more weights against the outboard surface of the span-balance pocket.

27. The method of claim 26 , further comprising retaining the one or more weights against the outboard surface of the span-balance pocket with one or more retention devices.

28. The method of claim 27 , wherein the one or more retention devices comprise one or more bolts.

29. The method of claim 27 , further comprising positioning the one or more retention devices between the one or more weights and the inboard surface of the span-balance pocket.

30. A rotorcraft, comprising:
a fuselage;
one or more engines coupled to the fuselage; and
at least one rotor system coupled to the one or more engines, the at least one rotor system comprising a plurality of rotor blades, at least one rotor blade comprising:
a span-balance pocket in a surface of the at least one rotor blade, the span-balance pocket comprising an inboard surface and an outboard surface;
one or more weights disposed against the outboard surface in the span-balance pocket to react the centrifugal force of the one or more weights through the outboard surface; and
one or more retention devices positioned between the one or more weights and the inboard surface of the span-balance pocket to retain the one or more weights against the outboard surface of the span-balance pocket such that there are no shear loads on the one or more retention devices.

31. A rotorcraft, comprising:
a fuselage;
one or more engines coupled to the fuselage; and
at least one rotor system coupled to the one or more engines, the at least one rotor system comprising a plurality of rotor blades, at least one rotor blade comprising:
a span-balance pocket in a surface of the at least one rotor blade; and
one or more weights disposed against the outboard surface in the span-balance pocket to react the centrifugal force of the one or mo

Assignees

• Bell Helicopter Textron Inc

Inventors

• Sherrill Paul
• Ledbetter Tim
• Yates Kelli
• Self Robert
• Green Nathan
• Cole Russell

Classifications

• B64C27/82

  characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft · CPC title

• B64C27/473

  Constructional features · CPC title

• B64C27/463

  Blade tips · CPC title

• B64C27/008 Primary

  Rotors tracking or balancing devices · CPC title

• B64C27/04

  Helicopters · CPC title