Airfoil with an integrally stiffened composite cover

Patent metadata

Field	Value
Publication number	US-9957972-B2
Application number	US-201414913709-A
Country	US
Kind code	B2
Filing date	Aug 12, 2014
Priority date	Sep 9, 2013
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An airfoil according to an exemplary aspect of the present disclosure includes, among other things, a main body extending between a leading edge and a trailing edge separated in a chordwise direction and extending between a tip and a root in a spanwise direction. The main body defines a suction side and a pressure side separated in a thickness direction and a plurality of channels extending inwardly from at least one of said suction and pressure sides. A composite cover is attached to the main body. The composite cover includes a plurality of stiffeners each received within one of the channels. A cover skin is adjacent the stiffeners, and an over-wrap surrounds the stiffeners and the cover skin.

First claim

What is claimed is:

1. An airfoil comprising:
a main body extending between a leading edge and a trailing edge in a chordwise direction and extending between a tip and a root in a spanwise direction, said main body defining a suction side and a pressure side separated in a thickness direction and a plurality of channels extending inwardly from at least one of said suction and pressure sides; and
a composite cover attached to said main body, wherein said composite cover includes a plurality of stiffeners each received within one of said channels, a cover skin adjacent said stiffeners, and an over-wrap surrounding said stiffeners and said cover skin.

2. The airfoil of claim 1 , wherein each of said stiffeners is formed from a stiffener wrap surrounding a stiffener body.

3. The airfoil of claim 2 , wherein said stiffener body is removable from said stiffener wrap to define a stiffener shell.

4. The airfoil of claim 2 , wherein said stiffener wrap includes a plurality of braided yarns.

5. The airfoil of claim 2 , wherein said stiffener is made of a first material and said main body is made of a second material different from the first material in density.

6. The airfoil of claim 1 , wherein said cover skin includes a braided fabric.

7. The airfoil of claim 6 , wherein said braided fabric includes a first fiber material extending in a braid axial direction and a second fiber material different from said first fiber material and extending in a braid bias direction.

8. The airfoil of claim 1 , wherein said composite cover is bonded to said channels.

9. The airfoil of claim 1 , wherein said composite cover defines a continuous surface with at least one of said suction and pressure sides.

10. The airfoil of claim 1 , wherein said composite cover includes a plurality of spacers each received between said over-wrap, one of said stiffeners and said cover skin.

11. The airfoil of claim 10 , wherein each of said spacers includes at least one of a plurality of braided yarns and a braided fabric.

12. The airfoil of claim 11 , wherein each of said spacers includes a foam material encapsulated by a spacer over-wrap.

13. A gas turbine engine comprising:
a turbine section; and
a fan section in communication said turbine section, said fan section including a plurality of fan blades, each fan blade including an airfoil and root, said airfoil including a main body and a composite cover attached to said main body;
wherein said main body defines a plurality of channels extending inwardly from at least one of a suction side and a pressure side defined by said main body; and
wherein said composite cover includes a cover skin, a plurality of stiffeners each received within one of said channels and an over-wrap surrounding said stiffeners and said cover skin.

14. The gas turbine engine of claim 13 , wherein the fan section is driven by a geared architecture mechanically coupled to said turbine section.

15. The gas turbine engine of claim 13 , wherein each of said stiffeners is formed from a stiffener wrap surrounding a stiffener body.

16. The gas turbine engine of claim 15 , wherein said stiffener wrap includes a plurality of braided yarns.

17. The gas turbine engine of claim 13 , wherein said cover skin includes at least one ply of a braided fabric.

18. A method of forming a composite cover for an airfoil, comprising:
forming a plurality of channels within at least one of a pressure side and a suction side of a main body;
fabricating a plurality of stiffeners each by braiding a plurality of fiber yarns over a stiffener body;
fabricating a cover skin from at least one ply of a braided fabric;
arranging each of said stiffeners adjacent to said cover skin;
surrounding said stiffeners and said cover skin with an over-wrap;
curing said stiffeners, said cover skin and said over-wrap within a resin to define a composite cover; and
bonding said composite cover to said channels.

19. The method as recited in claim 18 , comprising the step of curing said fiber yarns within a resin to define a stiffener shell prior to the step of encapsulating said stiffeners and said cover skin with said over-wrap.

20. The method as recited in claim 18 , wherein said composite cover defines a continuous surface with at least one of said suction and pressure sides.

Assignees

• United Technologies Corp

Inventors

• Foster Larry

Classifications

• F01D5/282

  Selecting composite materials, e.g. blades with reinforcing filaments · CPC title

• B29D99/0028

  hollow blades · CPC title

• F05D2300/6012

  Woven fabrics · CPC title

• F05D2230/60

  Assembly methods · CPC title

• F05D2250/23

  prismatic · CPC title