FAN BLADE WITH INTEGRATED COMPOSITE FAN BLADE COVER

• US 20170023007A1
• Filed: 09/29/2014
• Published: 01/26/2017
• Est. Priority Date: 11/26/2013
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Roche, Charles H.
• Granted Patent: US 10,337,521 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 5/147 Construction, i.e. structural features, e.g. of weight-saving hollow blades F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18
• CPC Class Codes: F01D 5/282 Selecting composite materials, e.g. blades with reinforcing filaments
• CPC Class Codes: F04D 29/023 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/324 Blades
• CPC Class Codes: F04D 29/325 for axial flow fans blade mountings F04D29/34, blades F04D29/38
• CPC Class Codes: F04D 29/388 characterised by construction
• CPC Class Codes: F05D 2220/36 specially adapted for the fan of turbofan engines
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

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. The body also includes a leading edge, a trailing edge, a distal tip and a base that is coupled to a hub. The suction side of the body includes at least one cavity for purposes of reducing the weight of the fan blade. The at least one body is surrounded by a slot that extends outwardly away from the cavity. A lip that extends inwardly towards the body further defines the slot. A cover is provided that overlays the cavity and includes a peripheral edge that is received in the slot and that is at least partially covered by the lip for a robust connection between the fan blade body and the cavity cover.

Claims

1. A fan blade comprising:

a body including a pressure side and a suction side, the pressure and suction sides being disposed between and connected to a leading edge and a trailing edge, the pressure side and suction side also being disposed between and connected to a base and a tip;

the suction side including at least one cavity that extends through the suction side and towards the pressure side, the cavity being surrounded by a slot that extends outwardly away from the cavity and into the body, the body further including a lip that extends inwardly towards the cavity and that at least partially defines the slot;

a cover that overlays the cavity and that includes a peripheral edge that is received in the slot and that is at least partially covered by the lip.

2. The fan blade of claim 1 further including a coating disposed over the cover.

3. The fan blade of claim 2 wherein thicknesses of the coating and the lip are substantially equal.

4. The fan blade of claim 2 wherein the coating and the lip each include outer surfaces that are flush with each other.

5. The fan blade of claim 1 wherein the cavity includes a plurality of cavities that are surrounded by the slot.

6. The fan blade of claim 5 wherein the cavities are separated by walls that extend towards the suction side of the body.

7. The fan blade of claim 6 wherein walls each terminate at an outer edge that is substantially coplanar with the slot.

8. The fan blade of claim 1 wherein the slot includes an inner wall disposed opposite the slot from the lip,

the cavity includes a plurality of cavities, the cavities being separated by a wall that terminates at an outer edge,

the outer edge of the wall being substantially coplanar with the inner wall of the slot.

9. The fan blade of claim 1 wherein the cavity accommodates a filler material.

10. The fan blade of claim 1 wherein the cavity is filled with a sacrificial material that decomposes when exposed to heat.

11. The fan blade of claim 1 wherein the cover is fabricated from fibers and resin.

12. The fan blade of claim 1 wherein the cover is fabricated from a fluoroelastomer.

13. A fan blade assembly comprising:

a hub coupled to a plurality of radially outwardly extending fan blades, each fan blade including

a body including a pressure side and a suction side, the pressure and suction sides being disposed between and connected to a leading edge and a trailing edge, the pressure side and suction side also being disposed between and connected to a base and a tip;

the suction side including at least one cavity that extends through the suction side and towards the pressure side, the cavity being surrounded by a slot that extends outwardly away from the cavity and into the body, the body further including a lip that extends inwardly towards the cavity and that at least partially defines the slot;

a cover that overlays the cavity and that includes a peripheral edge that is received in the slot and that is at least partially covered by the lip;

a coating disposed over the cover;

wherein the coating is flush with the lip.

14. The fan blade assembly of claim 13 wherein the cavity includes a plurality of cavities that are surrounded by the slot.

15. The fan blade of claim 14 wherein the cavities are separated by walls that extend towards the suction side of the body,

the slot includes an inner wall disposed opposite the slot from the lip,

the outer edges of the walls that separate the cavities being substantially coplanar with the inner wall of the slot.

16. The fan blade assembly of claim 14 wherein at least one cavity accommodates a filler material.

17. A method for fabricating a fan blade of a turbofan gas turbine engine, the method comprising:

manufacturing a body including a pressure side and a suction side, the pressure and suction sides being disposed between and connected to a leading edge and a trailing edge, the pressure side and suction side also being disposed between and connected to a base and a tip, the suction side including a plurality of cavities that extend through the suction side and towards the pressure side, the cavities being surrounded by a slot that extends outwardly away from the cavities and into the body, the body further including a lip that extends inwardly towards the cavities and that at least partially defines the slot;

providing a cover that includes a peripheral edge, the cover being sized so that the peripheral edge is received in the slot;

covering the cavities with the cover by inserting the peripheral edge of the cover into the slot of the body so that the lip at least partially covers the cover; and

coating the cover with a coating layer sufficiently thick so that the coating layer is flush with the lip.

18. The method of claim 17 further including:

at least partially filling the cavities with a sacrificial material before the cavities are covered with the cover, the sacrificial material decomposing when exposed to heat; and

curing the cover and the coating.

19. The method of claim 17 wherein the cover is fabricated from a fluoroelastomer.

20. The method of claim 17 wherein the body is manufactured from a material selected from the group consisting of aluminum, an aluminum alloy, titanium, a titanium alloy and combinations thereof.