Variable pitch fan for gas turbine engine and method of assembling the same

Patent metadata

Field	Value
Publication number	US-10072510-B2
Application number	US-201514873382-A
Country	US
Kind code	B2
Filing date	Oct 2, 2015
Priority date	Nov 21, 2014
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A gas turbine engine is provided. The gas turbine engine includes a core and a variable pitch fan arranged in flow communication with the core. The variable pitch fan has a disk and at least nine fan blades coupled to the disk for rotation together with the disk. The gas turbine engine further includes a rotatable nacelle covering the disk such that the engine has a fan hub radius ratio of between about 0.1 and about 0.4.

First claim

What is claimed is:

1. A gas turbine engine comprising:
a core;
a variable pitch fan arranged in flow communication with said core, said variable pitch fan comprising a polygonal-shaped disk, said disk comprising a plurality of segments and a plurality of fan blades coupled to said disk for rotation together with said disk, each discrete portion of said disk comprising a single segment of the plurality of segments and a single fan blade of the plurality of fan blades;
a trunnion mechanism coupling each of said fan blades to the respective segment of said disk such that said fan blades are rotatable relative to said disk about a pitch axis; and
a rotatable nacelle covering said disk such that said gas turbine engine has a fan hub radius ratio of between 0.1 and 0.4.

2. The gas turbine engine in accordance with claim 1 , wherein said fan hub radius ratio is between 0.2 and 0.35.

3. The gas turbine engine in accordance with claim 1 , wherein said fan hub radius ratio is between 0.2 and 0.3.

4. The gas turbine engine in accordance with claim 1 , wherein each of said trunnion mechanisms comprises a line contact bearing.

5. The gas turbine engine in accordance with claim 4 , wherein said trunnion mechanism comprises a first line contact bearing and a second line contact bearing, wherein said first line contact bearing is oriented at a different angle than said second line contact bearing relative to the pitch axis.

6. The gas turbine engine in accordance with claim 1 , further comprising:
an actuation mechanism for varying a pitch of said fan blades; and
a pitch correction device operatively coupled to said fan blades via said actuation mechanism.

7. The gas turbine engine in accordance with claim 6 , wherein said pitch correction device is one of a remote counterweight device and a remote pitch lock device.

8. The gas turbine engine in accordance with claim 1 , further comprising a fan cowl surrounding said fan to form a bypass duct.

9. The gas turbine engine in accordance with claim 1 , wherein said variable pitch fan is unducted.

10. The gas turbine engine in accordance with claim 1 , further comprising a plurality of outlet guide vanes aft of said variable pitch fan.

11. A method of assembling a gas turbine engine, said method comprising:
providing a core;
combining a plurality of segments to form a polygonal-shaped disk;
coupling a variable pitch fan to a turbine that is configured to be powered by combustion gas from the core, the variable pitch fan including the disk and a plurality of fan blades coupled to the disk for rotation together with the disk, each discrete portion of the disk comprising a single segment of the plurality of segments and a single fan blade of the plurality of fan blades; and
covering the disk with a rotatable nacelle such that the gas turbine engine has a fan hub radius ratio of between 0.1 and 0.4,
wherein coupling said variable pitch fan to said turbine comprises coupling each of the fan blades to respective segments of the disk via a trunnion mechanism such that each of the fan blades is rotatable relative to the disk about a pitch axis.

12. The method in accordance with claim 11 , wherein each of the trunnion mechanisms has a first line contact bearing and a second line contact bearing that is oriented at a different angle than the first line contact bearing relative to the pitch axis.

13. The method in accordance with claim 12 , further comprising providing each of the line contact bearings with a different number of rollers.

14. The method in accordance with claim 11 , further comprising:
coupling an actuation mechanism to the fan blades, wherein the actuation system is configured for varying a pitch of the fan blades; and
coupling one of a remote counterweight device and a remote pitch lock device to the fan blades via the actuation mechanism.

15. The method in accordance with claim 11 , further comprising surrounding the variable pitch fan with a fan cowl to form a bypass duct.

16. The method in accordance with claim 11 , further comprising providing the variable pitch fan as an unducted fan.

17. The method in accordance with claim 11 , further comprising mounting a plurality of outlet guide vanes aft of the variable pitch fan.

18. A gas turbine engine comprising a core;
a variable pitch fan arranged in flow communication with said core, said variable pitch fan comprising a polygonal-shaped disk said disk comprising a plurality of segments and a plurality of fan blades each coupled to a respective segment of said disk via a trunnion mechanism for rotation together with said disk, each discrete portion of the disk comprising a single segment of the plurality of segments and a single fan blade of the plurality of fan blades, said trunnion mechanism comprising a pair of line contact bearings; an actuation mechanism for varying a pitch of said fan blades;
one of a remote counterweight device and a remote pitch lock device operatively coupled to said fan blades via said actuation mechanism;
a plurality of outlet guide vanes aft of said variable pitch fan; and a rotatable nacelle covering said disk such that said gas turbine engine has a fan hub radius ratio of between 0.1 and 0.4.

Assignees

• Gen Electric

Inventors

• Miller Brandon Wayne
• Prentice Ian Francis
• Niergarth Daniel Alan

Classifications

• F04D29/323

  adjustable · CPC title

• F01D5/02

  Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) · CPC title

• F05D2260/74

  by turning around an axis perpendicular the rotor centre line · CPC title

• F01D25/24

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F01D17/105

  by passing part of the fluid · CPC title