Variable pitch fan for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-10473111-B2
Application number	US-201715787294-A
Country	US
Kind code	B2
Filing date	Oct 18, 2017
Priority date	Oct 18, 2017
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A gas turbine engine includes a fan having a plurality of fan blades configured to rotate about a central axis of the gas turbine engine. Each fan blade is configured to pivot about a pitch axis that extends radially away from the central axis to vary a pitch of the fan blade.

First claim

What is claimed is:

1. A variable-pitch fan for use with a gas turbine engine, the variable-pitch fan comprising
a fan disk mounted for rotation about a central axis, the fan disk formed to include a disk aperture that extends radially into the fan disk,
a fan blade coupled to the fan disk for primary rotation with the fan disk about the central axis to produce thrust and for variable-pitch rotation about a pitch axis that extends radially from the central axis, the fan blade including a shank arranged in the disk aperture and an airfoil that extends radially away from the fan disk, and
a mount system configured to support the shank of the fan blade in the disk aperture, the mount system including an inner bearing unit, an outer bearing unit, and a retention plate, the inner and outer bearing units located in the disk aperture and arranged between the fan blade and the fan disk to bear force loads applied between the fan blade and the fan disk, and the retention plate arranged around the shank of the fan blade and configured to couple selectively with the fan disk to block movement of the fan blade with the outer bearing unit out of the disk aperture and configured to uncouple selectively from the fan disk to allow radial outward movement of the fan blade with the outer bearing unit out of the disk aperture relative to the central axis.

2. The variable-pitch fan of claim 1 , wherein the inner bearing unit includes a roller bearing unit configured to bear radial force loads relative to the pitch axis and the outer bearing unit includes a spherical tapered roller bearing unit configured to bear axial and radial force loads and configured to tolerate misalignment of the shank of the fan blade in the disk aperture.

3. The variable-pitch fan of claim 2 , wherein the inner bearing unit and the outer bearing unit are the only bearings arranged around the shank of the fan blade.

4. The variable-pitch fan of claim 3 , wherein the inner bearing unit is spaced apart radially from the retention plate relative to the central axis and the outer bearing unit is located radially between the inner bearing unit and the retention plate.

5. The variable-pitch fan of claim 2 , wherein the inner bearing unit is spaced apart radially from the retention plate relative to the central axis and the outer bearing unit is located radially between the inner bearing unit and the retention plate.

6. The variable-pitch fan of claim 1 , wherein the airfoil comprises composite material and the shank comprises metallic material and the airfoil is coupled to the shank for movement therewith.

7. The variable-pitch fan of claim 5 , wherein the shank includes a shank shaft and a shoulder body, the shank shaft extends axially into the disk aperture relative to the pitch axis from the shoulder body, the shoulder body extends radially outward from the shank shaft relative to the pitch axis, and the shank shaft forms an inner race of the inner bearing unit.

8. The variable-pitch fan of claim 1 , wherein the outer bearing unit includes a tapered roller bearing unit.

9. The variable-pitch fan of claim 1 , further comprising a pitch controller configured to rotate about the central axis with the fan disk, the pitch controller includes a spline shaft that extends radially away from the central axis into the disk aperture and a rotator control coupled to the spline shaft and configured to rotate the spline shaft about the pitch axis.

10. The variable-pitch fan of claim 8 , wherein the shank shaft is formed to include a shank aperture that extends axially into the shank shaft relative to the pitch axis and the spline shaft of the pitch controller extends into the shank aperture to couple the fan blade with the pitch controller.

11. A variable-pitch fan for use with a gas turbine engine, the variable-pitch fan comprising
a fan disk mounted for rotation about a central axis,
a fan blade that extends into the fan disk for primary rotation with the fan disk about the central axis and for variable-pitch rotation about a pitch axis that extends radially from the central axis, the fan blade including a shank that extends into the fan disk and an airfoil that extends radially away from the fan disk, and
a mount system including an outer bearing unit and a retention plate, the outer bearing unit coupled to the shank of the fan blade, and the retention plate arranged around the shank of the fan blade and configured to couple selectively with the fan disk to block movement of the fan blade and the outer bearing unit away from the fan disk and configured to uncouple selectively from the fan disk to allow movement of the fan blade and the outer bearing unit away from the fan disk.

12. The variable-pitch fan of claim 11 , wherein the mount system further includes an inner bearing unit and the outer bearing unit and the inner bearing unit are the only bearing units arranged around the fan blade.

13. The variable-pitch fan of claim 12 , wherein the inner bearing unit includes a roller bearing unit and the outer bearing unit includes a spherical tapered roller bearing unit.

14. The variable-pitch fan of claim 13 , wherein the inner bearing unit is spaced apart radially from the retention plate relative to the central axis and the outer bearing unit is located radially between the inner bearing unit and the retention plate.

15. The variable-pitch fan of claim 11 , wherein the shank includes a shank shaft and a shoulder body, the shank shaft extends into the fan disk, and the shoulder body extends radially outward from the shank shaft relative to the pitch axis.

16. The variable-pitch fan of claim 15 , wherein the mount system further includes an inner bearing unit and the shank shaft forms an inner race of the inner bearing unit.

17. The variable-pitch fan of claim 15 , further comprising a pitch controller configured to rotate about the central axis with the fan disk, the pitch controller includes a spline shaft that extends radially away from the central axis into the spline shaft and a rotator control coupled to the spline shaft and configured to rotate the spline shaft about the pitch axis.

18. A method comprising
providing a variable-pitch fan including a fan disk mounted for rotation about a central axis, a plurality of fan blades coupled to the fan disk for primary rotation around the central axis, and a respective mount system for each of the fan blades, each mount system including an inner bearing unit coupled to the fan disk, an outer bearing unit coupled to the fan blade radially outward of the inner bearing unit, and a retention plate coupled to the fan disk radially outward of the outer bearing unit, and
moving the fan blade, the outer bearing unit, and the retention plate radially outward away from the fan disk to separate the fan blade, the outer bearing unit, and the retention plate from the fan disk.

19. The method of claim 18 , wherein the fan blade includes an airfoil and a shank coupled to the airfoil and the shank forms an inner race of the inner bearing unit.

20. The method of claim 18 , wherein the inner bearing unit includes a roller bearing unit and the outer bearing unit includes a spherical tapered roller bearing.

Assignees

• Rolls Royce Corp

Inventors

• Vetters Daniel K

Classifications

• F04D29/323 Primary

  adjustable · CPC title

• F04D29/059

  Roller bearings · CPC title

• F04D29/362 Primary

  during rotation · CPC title

• F04D29/329

  Details of the hub · CPC title

• F04D29/38

  Blades {(for axial flow compressors F04D29/324)} · CPC title