Composite blade manufacture

• US 5,222,297 A
• Filed: 10/18/1991
• Issued: 06/29/1993
• Est. Priority Date: 10/18/1991
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Violette, John A., Graff, John M.
• Primary Examiner(s): ROSENBAUM, IRENE CUDA
• Application Number:
  US07/780,696
• Time in Patent Office: 620 Days
• Field of Search: 29/889.71, 29/889.7, 416/224, 416/230, 416/241 A, 416/241 R, 416/226, 264/103, 264/46.4, 264/46.7, 264/45.1, 264/279.1
• US Class Current: 29/889.71
• CPC Class Codes: B29C 70/865 completely encapsulated
• CPC Class Codes: B29D 99/0025 Producing blades or the like, e.g. blades for turbines, propellers, or wings
• CPC Class Codes: B64C 11/26 Fabricated blades
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 29/49336 Blade making
• CPC Class Codes: Y10T 29/49337 Composite blade

Abstract

A method of manufacturing a lightweight composite propulsor blade of spar and shell construction comprises forming a composite spar (30) having an elongated foam body (20) bonded to a short metal retention tulip (10) and overlayed with a dry braided wrap of angular structural fibers and substantially unidirectional spanwisely aligned structural fiber plies disposed between the braided layers; adding a leading edge foam body (42) and a trailing edge foam body (44) to the spar assembly to form a blade subassembly (50); providing a dry braided fabric wrap over the blade assembly; disposing the fabric covered blade subassembly into a shell molding die and simultaneously impregnating the dry spar fabric wrap and the dry shell fabric wrap with a curable resin material; and curing the impregnated blade subassembly.

Claims

1. A method of manufacturing a lightweight composite propulsor blade having an axially extending load bearing spar disposed within a fiber reinforced shell comprising the steps of:

a. forming a spar subassembly having a short metal retention member and a core of lightweight cellular material extending axially outwardly from the retention member;

b. repeatedly braiding fibers of a structural fiber over the length of the spar subassembly to provide a dry wrap about the spar subassembly formed of a plurality of layers of angularly woven structural fibers;

c. during said spar braiding step, laying up spanwisely extending plies of substantially unidirectional structural fibers between successive angularly woven layers;

d. forming a first filler body of lightweight cellular material on a leading edge of the braided spar assembly and a second filler body of lightweight cellular material on a trailing edge of the braided spar assembly to form a blade subassembly;

e. forming a dry shell warp of braided angularly woven fabric about the blade subassembly; and

f. simultaneously impregnating the dry braided fiber wrap of the braided spar assembly and the dry braided fabric shell wrap about the blade subassembly with a curable resin material whereby upon subsequent curing of the resin material a blade assembly having a composite fiber reinforced load bearing spar and composite fiber reinforced shell is formed.

2. A method as recited in claim 1 wherein the step of forming a dry shell wrap of braided angularly woven fabric about the blade subassembly comprises fitting at least one dry preformed braided fabric sock over the blade subassembly.

3. A method as recited in claim 2 wherein the step of forming a first filler body of lightweight cellular material on a leading edge of the braided spar assembly and a second filler body of lightweight cellular material on a trailing edge of the spar assembly to form a blade subassembly comprises:

a. disposing the braided spar assembly into a molding die; and

b. injecting a lightweight cellular material into the molding die to form the leading edge foam filler and the trailing edge foam filler on the braided spar subassembly.