Fan blade composite cover with tapered edges

Patent metadata

Field	Value
Publication number	US-9896941-B2
Application number	US-201514597812-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jan 16, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A fan blade for a turbofan gas turbine engine is disclosed. The fan blade includes a body having a pressure side and a suction side and a cover. The suction side of the body includes an opening exposing at least one cavity to reduce the weight of the fan blade. The cover overlays the opening and includes a leading portion and a trailing portion that are tapered in the direction of the cover leading edge and cover trailing edge.

First claim

What is claimed:

1. A fan blade comprising:
a body having a pressure side, a suction side adjoining the pressure side along a fan blade leading edge and a fan blade trailing edge, the suction side defining an opening having a perimeter and communicating with one or more cavities disposed in the body; and
a cover configured to fit over the opening and comprising a cover leading edge and a cover trailing edge which generally align with the fan blade leading edge and the fan blade trailing edge respectively, the cover further comprising a central portion, a cover leading portion extending forward of the central portion and terminating at the cover leading edge, and a cover trailing portion extending aft of the central portion and terminating at the cover trailing edge;
wherein one or both of the cover leading portion and the cover trailing portion are chamfered; and
wherein at least one of the cover leading portion or the cover trailing portion comprises a flat chamfered surface.

2. The fan blade of claim 1 wherein: the leading portion is chamfered.

3. The fan blade of claim 1 wherein: the trailing portion is chamfered.

4. The fan blade of claim 1 wherein:
the leading portion is chamfered; and the trailing portion is chamfered.

5. The fan blade of claim 1 wherein:
the leading portion tapers in the direction of the cover leading edge; and the trailing portion tapers in the direction of the cover trailing edge.

6. The fan blade of claim 4 wherein:
the leading portion comprises a flat chamfered surface; and the trailing portion comprises a flat chamfered surface.

7. The fan blade of claim 4 wherein:
one of the leading portion or the trailing portion comprises a curved chamfered surface.

8. The fan blade of claim 4 wherein:
one of the leading portion or the trailing portion comprises a stepped chamfered surface.

9. The fan blade of claim 1 wherein:
the leading portion has substantially the same thickness as the central portion, then tapers to a smaller thickness at the cover leading edge; and
the trailing portion has substantially the same thickness as the central portion, then tapers to a smaller thickness at the cover trailing edge.

10. The fan blade of claim 2 wherein:
the area of minimal thickness of the fan blade body is located inward of the cover trailing edge.

11. The fan blade of claim 4 wherein:
the body comprises chamfered portions near the fan blade leading edge and the fan blade trailing edge; and
the body and the cover abut along their respective chamfered portions.

12. The fan blade of claim 1 wherein:
the opening communicates with one or more cavities disposed in the suction side of the body.

13. The fan blade of claim 1 wherein:
the opening communicates with one or more cavities disposed in the pressure side of the body.

14. The fan blade of claim 1 wherein:
the fan blade body is made of a denser material than the cover.

15. A fan blade cover configured to fit over an opening in a fan blade body, the cover comprising:
a cover leading edge;
a cover trailing edge downstream of the cover leading edge;
a central portion disposed between the cover leading edge and the cover trailing edge; a leading portion extending forward of the central portion and terminating at the cover leading edge; and
a trailing portion extending aft of the central portion and terminating at the cover trailing edge; wherein
one or both of the cover leading portion and the cover trailing portion are chamfered; and
wherein at least one of the cover leading portion or the cover trailing portion comprises a flat chamfered surface.

16. The fan blade cover of claim 14 wherein:
the leading portion has the same thickness as the central portion along an area adjoining the central portion and tapers to a smaller thickness at the cover leading edge.

17. The fan blade cover of claim 14 wherein:
the trailing portion has the same thickness as the central portion along the area adjoining the central portion and tapers to a smaller thickness at the cover trailing edge.

18. The fan blade cover of claim 14 wherein:
the opening communicates with one or more cavities disposed in a suction side of the fan blade body.

19. A method for fabricating a fan blade of a turbofan gas turbine engine comprising the steps of:
manufacturing a body including a pressure side and a suction side, the pressure side and the suction side being disposed between and connected to a leading edge and a trailing edge, the suction side defining an opening communicating with one or more cavities in the suction side;
providing a cover configured to fit over the opening and comprising a cover leading edge and a cover trailing edge, the cover further comprising a central portion, a chamfered leading portion extending forward of the central portion and terminating at the cover leading edge, and a chamfered trailing portion extending aft of the central portion and terminating at the cover trailing edge, at least one of the chamfered leading portion or the chamfered trailing portion comprises a flat chamfered surface; and
covering the opening with the cover.

20. The method of claim 14 wherein:
the cover leading portion tapers in the direction of the cover leading edge; and
the cover trailing portion tapers in the direction of the cover trailing edge.

Assignees

• United Technologies Corp

Inventors

• Hui Kwan
• Weisse Michael A
• Foster Larry

Classifications

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• Y02T50/673

  Cross-Sectional Technologies · mapped topic

• F04D29/324

  Blades · CPC title

• Y02T50/672

  Cross-Sectional Technologies · mapped topic

• F01D5/18

  Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades · CPC title