Stitched composite fan blade

• US 6,431,837 B1
• Filed: 05/16/2000
• Issued: 08/13/2002
• Est. Priority Date: 06/01/1999
• Status: Expired due to Term

• Current Assignee: Alexander Velicki
• Original Assignee: Alexander Velicki
• Inventors: Velicki, Alexander
• Primary Examiner(s): Kwon, John
• Application Number:
  US09/571,227
• Time in Patent Office: 819 Days
• Field of Search: 416/229.R, 416/230
• US Class Current: 416/223.00R
• CPC Class Codes: F01D 5/282 Selecting composite materials, e.g. blades with reinforcing filaments
• CPC Class Codes: F01D 5/3053 by means of pins
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F04D 29/388 characterised by construction
• CPC Class Codes: F05D 2240/303 related to the leading edge of a rotor blade
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A hollow core fan blade for a gas turbine engine, having stitched composite skins and substructure, is fabricated using a resin transfer molding approach which results in a damage tolerant and cost-efficient structure. The fan blade is comprised of a stitched composite cover that is in-turn stitched to a spar and rib-like substructure made of similar carbon fiber materials. A titanium leading edge, root section, and tip closeout member are added to the stitched carbon fibers and placed inside a forming die. Resin is infused, after which the blade assembly, having predetermined design characteristics, is cured by heating the forming die and pressurizing the part internally with a set of inflatable bladders which ultimately yields a rigid fan blade component.

Claims

1. A stitched composite fan blade comprising:

a fiber reinforced substructure;

a fiber reinforced cover, attached to said substructure, having a leading edge region, a tip region, and a root region;

penetration thread stitched through at least a portion of the thickness of said cover and through the thickness of said substructure;

and a root fitting attached at said root region.

2. The fan blade as recited in claim 1, further comprising locking thread over which said penetration thread is stitched.

3. The fan blade as recited in claim 1, wherein said substructure is comprised of individual stacks of carbon fiber material.

4. The fan blade as recited in claim 1, wherein said cover is comprised of individual stacks of carbon fiber material.

5. The fan blade as recited in claim 1, wherein the suction and pressure sides of said cover is comprised of at least one stack of carbon fiber material.

6. The fan blade as recited in claim 1, wherein said substructure and said cover are comprised of individual stacks of carbon fiber material.

7. The cover as recited in claim 4, wherein a portion of said individual stacks of carbon fiber material of said cover are continuous around at least a portion of said root fitting.

8. The fan blade as recited in claim 6, wherein said individual stacks of carbon fiber material of said substructure have interior cutouts creating hollow regions enclosed by said cover.

9. The fan blade as recited in claim 8, wherein said penetration thread is stitched through at least a portion of the thickness of said cover in said hollow regions.

10. The fan blade as recited in claim 9 further comprising locking thread over which said penetration thread is stitched.

11. The fan blade as recited in claim 8, further comprising rib and spar structures between hollow regions of said substructure.

12. The fan blade as recited in claim 8, wherein said substructure has at least one passageway located within at least one said rib structure to provide access for internal bladder apparatus insertion and removal.

13. The fan blade as recited in claim 1, further comprising a leading edge detail attached at said leading edge region.

14. The fan blade as recited in claim 1, further comprising a tip closeout detail attached at said tip region.

15. The fan blade as recited in claim 1, further comprising a leading edge detail attached at said leading edge region and a tip closeout detail attached at said tip region.

16. The fan blade as recited in claim 15, wherein said leading edge detail, said tip closeout detail, and said root fitting are fabricated from titanium-alloy materials.

17. The fan blade as recited in claim 1, wherein said root fitting contains at least one passageway to provide access for internal bladder apparatus insertion and removal.

18. The fan blade as recited in claim 14, wherein said tip closeout detail contains at least one passageway to provide access for internal bladder apparatus insertion and removal.

19. The fan blade as recited in claim 1, wherein said root fitting contains at least one locator hole.