Airfoil with galvanic corrosion preventive shim

Patent metadata

Field	Value
Publication number	US-9322283-B2
Application number	US-201213630822-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Sep 28, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

An airfoil includes an airfoil body made of a first metal with a leading edge, a trailing edge, pressure side and suction side; a sheath with first and second flanks made of a second metal; a first layer of non-conductive material adhesively bonded between a portion of the end of the first flank and the airfoil body and extending beyond the end of the first flank on the pressure side; and a second layer of non-conductive material adhesively between a portion of the end of the second flank and the airfoil body and extending beyond the end of the second flank on the suction side.

First claim

The invention claimed is:

1. An airfoil comprising:
an airfoil body made of a first material with a leading edge, trailing edge, pressure side and suction side;
a sheath with first and second flanks made of a second material;
a first shim disposed between a portion of an end of the first flank and the airfoil body and extending beyond the end of the first flank on the pressure side;
a first adhesive layer disposed between the first shim and the airfoil and connecting the first shim to the airfoil;
a second shim disposed between a portion of an end of the second flank and the airfoil body and extending beyond the end of the second flank on the suction side; and
a second adhesive layer disposed between the second shim and the airfoil and connecting the second shim to the airfoil.

2. The airfoil of claim 1 , wherein the first shim is fiberglass.

3. The airfoil of claim 2 , wherein the second shim is fiberglass.

4. The airfoil of claim 1 , wherein the first shim and the second shim are positioned to separate the airfoil body from the sheath.

5. The airfoil of claim 4 , and further comprising:
a third adhesive layer connecting the sheath to the first shim, the second shim, and the airfoil body.

6. The airfoil of claim 5 , wherein the third adhesive layer includes a scrim sheet.

7. The airfoil of claim 1 , wherein the first material is aluminum.

8. The airfoil of claim 1 , wherein the second material is titanium.

9. The airfoil of claim 1 , wherein the first shim and the second shim are pre-cured.

10. The airfoil of claim 1 , wherein the airfoil is a fan blade.

11. A method for assembling an airfoil of a first material with a pressure side and a suction side with a sheath of a second material with flanks, the method comprising:
applying a first adhesive to a first side of a first non-conductive shim;
connecting the first side of the first non-conductive shim with first adhesive to the pressure side of the airfoil;
applying a second adhesive to a first side of a second non-conductive shim;
connecting the first side of the second non-conductive shim with the second adhesive to the suction side of the airfoil;
applying a third adhesive to an inside of the sheath; and
connecting the inside of the sheath with the third adhesive to the airfoil with non-conductive shims.

12. The method of claim 11 , and further comprising:
heating the airfoil and sheath.

13. The method of claim 12 , and further comprising:
curing the adhesives.

14. The method of claim 13 , and further comprising:
media blasting excessive adhesive; and
applying an erosion coating to portions of the airfoil and the first and second non-conductive shims.

15. The method of claim 11 , wherein the first and second non-conductive shims are fiberglass shims.

16. The method of claim 11 , wherein the first non-conductive shim and the second non-conductive shim connect to the airfoil where the sheath flanks end.

17. The method of claim 16 , wherein the first and the second non-conductive shims extend on the pressure side and suction side of the airfoil beyond where the sheath flanks end.

18. The method of claim 11 , wherein the first material is aluminum and the second material is titanium.

19. A blade comprising:
an airfoil with a suction side, a pressure side, a leading edge and a trailing edge;
a sheath to connect to the leading edge with a first flank to connect to the pressure side and a second flank to connect to the suction side;
a first fiberglass shim disposed between the sheath and the airfoil on the pressure side around where the first flank ends to separate the airfoil from the sheath;
a first adhesive layer disposed between the first fiberglass shim and the airfoil and connecting the first fiberglass shim to the airfoil;
a second fiberglass shim disposed between the sheath and the airfoil on the suction side around where the second flank ends to separate the airfoil from the sheath;
a second adhesive layer disposed between the second fiberglass shim and the airfoil and connecting the second fiberglass shim to the airfoil;
a third adhesive layer disposed between the sheath and the airfoil and connecting the sheath to the airfoil; and
an erosion coating on the pressure side and the suction side of the airfoil extending from the end of each flank to the trailing edge over a portion of the first fiberglass shim and the second fiberglass shim.

20. The blade of claim 19 , wherein the first fiberglass shim and the second fiberglass shim are precured.

Assignees

• United Technologies Corp

Inventors

• Parkin Michael
• Quinn Mark
• Wiegman Leland
• Gates Brandon A

Classifications

• F05D2300/603

  Composites; e.g. fibre-reinforced · CPC title

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title

• F04D29/324

  Blades · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F05D2300/121

  Aluminium · CPC title