Granted Patent B2

US 12,729,627 · App. 17/831,769 · Granted Sep 8, 2026

Inventors: Kerry Lynn Davis-Amendola (Wethersfield, CT); John Harner (Florence, MA); David J. Mathiau, Jr. (East Hartford, CT)

Assignee: RTX CORPORATION

F01D5/18B29C44/18F01D5/147F01D5/282B29L2031/082F05D2220/36F05D2230/31F05D2300/612

Abstract

Claims (22)

1 . A hollow fan blade comprising:

a sheath, wherein the sheath forms a pressure side wall having an exterior surface;

an airfoil, wherein the airfoil forms a suction side wall having an exterior surface;

a plurality of ribs within the airfoil extending between the pressure side wall and the suction side wall, where the plurality of ribs partition an interior of the airfoil into one or more cavities;

a cover disposed in the cavities to protect the plurality of ribs; and

a syntactic polymeric foam disposed in the cavities and bonded to the cover, the syntactic polymeric foam including a thermally expandable microsphere and formed by expanding an organic polymer-blowing agent combination in the cavity, the organic polymer-blowing agent combination comprising a thermoplastic organic polymer and the thermally expandable microsphere, wherein expanding the organic polymer-blowing agent combination includes expanding the thermally expandable microsphere.

2 . The hollow fan blade of claim 1 , wherein the polymeric foam contacts an inner surface of the one or more cavities and also contacts the cover and the airfoil.

3 . The hollow fan blade of claim 1 , wherein the polymeric foam comprises a thermoplastic or thermosetting organic polymer.

4 . The hollow fan blade of claim 1 , wherein the polymeric foam has a density of 0.1 to 0.8 grams per cm 3 .

5 . The hollow fan blade of claim 1 , wherein the polymeric foam has a glass transition temperature of greater than or equal to 100° C.

6 . The hollow fan blade of claim 1 , wherein the polymeric foam has a glass transition temperature of greater than or equal to 200° C.

7 . The hollow fan blade of claim 1 , wherein the polymeric foam has a glass transition temperature of greater than or equal to 250° C.

8 . The hollow fan blade of claim 1 , wherein the polymeric foam comprises an amorphous polymer.

9 . The hollow fan blade of claim 1 , wherein the polymeric foam comprises a crosslinked polymer.

10 . A method comprising:

disposing an organic polymer-blowing agent combination in a cavity of a hollow fan blade, the hollow fan blade comprising an airfoil, a sheath and a cover, where the airfoil and the sheath contact each other and where the airfoil comprises a plurality of ribs that define the cavity, and wherein the cover protects the plurality of ribs, the organic polymer-blowing agent combination including an organic polymer and a thermally expandable microsphere; and

expanding an organic polymer-blowing agent combination to form a polymeric foam, the polymeric foam comprising a syntactic foam that bonds to the cover, wherein the organic polymer-blowing agent combination includes a thermoplastic organic polymer and a thermally expandable microsphere, wherein expanding the organic polymer-blowing agent combination includes expanding the thermally expandable microsphere.

11 . The method of claim 10 , wherein the expanding the organic polymer is accomplished by changing the temperature and/or pressure of the organic polymer-blowing agent combination.

12 . The method of claim 10 , wherein a blowing agent of the organic polymer-blowing agent combination comprises a physical blowing agent.

13 . The method of claim 10 , wherein a blowing agent of the organic polymer-blowing agent combination comprises a chemical blowing agent.

14 . The method of claim 10 , wherein the organic polymer-blowing agent combination is a two-part polymer film that when heated initiates a chemical reaction that forms the foam.

15 . The method of claim 14 , wherein the polymeric foam contacts an inner surface of the cavity.

Assignments (2)

Continuity (1)

References Cited (37)