Rotor Blade and Method of Making Same

• US 20100266416A1
• Filed: 12/18/2007
• Published: 10/21/2010
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Textron Innovations Incorporated (Textron Inc)
• Inventors: Hiros, Tricia, Baskin, Bryan K., Marshall, Bryan, Oldroyd, Paul K., Sherrill, Paul
• Granted Patent: US 8,632,310 B2
• Time in Patent Office: Days
• US Class Current: 416/226
• CPC Class Codes: B64C 2027/4736 from composite materials
• CPC Class Codes: B64C 27/473 Constructional features
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing

Abstract

A helicopter rotor blade includes a structural composite skin defining a cavity therein; a composite spar disposed within the cavity and adhesively bonded to the skin, a portion of the spar exhibiting a C-shape in cross section; and a foam core disposed within the cavity and adhesively bonded to the skin. The structural composite skin forms an external, closed box structure configured to transmit mechanical loads encountered by the rotor blade.

Claims

1. A helicopter rotor blade, comprising:

a structural composite skin defining a cavity therein;

a composite spar disposed within the cavity and adhesively bonded to the skin, a portion of the spar exhibiting a C-shape in cross section; and

a foam core disposed within the cavity and adhesively bonded to the skin;

wherein the structural composite skin forms an external, closed box structure configured to transmit mechanical loads encountered by the rotor blade.

2. The helicopter rotor blade, according to claim 1, further comprising:

a composite tube disposed within the cavity and extending between the spar and the foam core, the composite tube being adhesively bonded to the spar, the core, and the skin.

3. The helicopter rotor blade, according to claim 1, wherein at least a portion of the spar is fabricated using an automated fiber placement process.

4. The helicopter rotor blade, according to claim 1, wherein the skin comprises:

an upper skin and a lower skin.

5. The helicopter rotor blade, according to claim 1, wherein the spar comprises:

an upper portion and a lower portion.

6. The helicopter rotor blade, according to claim 1, wherein the foam core comprises:

a closed-cell foam material.

7. The helicopter rotor blade, according to claim 1, having a root and a longitudinal axis, the root defining openings that are generally aligned with the longitudinal axis for connecting the helicopter rotor blade to a helicopter rotor.

8. A method for making a helicopter rotor blade, comprising:

providing a closed mold having an internal surface defining an outer surface of the helicopter rotor blade;

providing a foam core;

providing a cured composite upper skin;

providing a cured composite lower skin;

laying up an upper portion of a spar onto an inner surface of the upper skin;

laying up a lower portion of the spar onto an inner surface of the lower skin;

providing an elastomeric bladder and a mandrel disposed within the bladder;

laying up a plurality of composite plies about the elastomeric bladder;

assembling the upper skin, the lower skin, the upper portion of the spar, the lower portion of the spar, the elastomeric bladder with the mandrel disposed therein and the plurality of composite plies laid up on the elastomeric bladder, the foam core, and adhesive into the closed mold; and

heating the assembled upper skin, the lower skin, the upper portion of the spar, the lower portion of the spar, the elastomeric bladder with the mandrel disposed therein and the plurality of composite plies laid up on the elastomeric bladder, the foam core, and adhesive; and

inflating the elastomeric bladder to urge the plurality of composite plies against the upper portion of the spar, the lower portion of the spar, the upper skin, the lower skin, and the core.

9. The method, according to claim 8, wherein laying up the upper portion of the spar onto the inner surface of the upper skin is accomplished, at least in part, by an automated fiber placement process.

10. The method, according to claim 9, wherein laying up the upper portion of the spar onto the inner surface of the upper skin is accomplished by laying up part of the upper portion of the spar onto the inner surface of the upper skin using a manual method.

11. The method, according to claim 8, wherein laying up the lower portion of the spar onto the inner surface of the lower skin is accomplished, at least in part, by an automated fiber placement process.

12. The method, according to claim 11, wherein laying up the lower portion of the spar onto the inner surface of the lower skin is accomplished by laying up part of the lower portion of the spar onto the inner surface of the lower skin using a manual method.

13. The method, according to claim 8, further comprising:

generating openings in a root of the helicopter rotor blade generally aligned along a longitudinal axis of the helicopter rotor blade for attaching the helicopter rotor blade to a helicopter rotor.