Fan assembly

Patent metadata

Field	Value
Publication number	US-2016238034-A1
Application number	US-201615042569-A
Country	US
Kind code	A1
Filing date	Feb 12, 2016
Priority date	Feb 17, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

A fan assembly for use in a gas turbine engine includes a fan wheel and a plurality of blades extending radially from the fan wheel away from a central axis of the fan assembly. Each of the blades includes a root coupled with the fan wheel and an airfoil extending radially outwardly from the root. The blades are adapted to rotate about the central axis to push air.

First claim

What is claimed is:

1 . A fan assembly for use in a gas turbine engine, the fan assembly comprising
a fan wheel, a plurality of blades extending radially from the fan wheel away from a central axis, each of the blades including a root coupled with the fan wheel and an airfoil extending radially outwardly from the root, and an annular mistuning band positioned adjacent to the fan wheel along the central axis and engaged with the roots of a predetermined number of more than one but less than all of the plurality of blades.

2 . The fan assembly of claim 1 , wherein the plurality of blades are spaced circumferentially from one another about the fan wheel and the annular mistuning band engages every other root of the plurality of blades.

3 . The fan assembly of claim 1 , wherein the annular mistuning band engages the roots of less than half of the plurality of blades.

4 . The fan assembly of claim 1 , wherein the fan assembly has a fore end and an aft end, the fan assembly further includes a fore retainer located toward the fore end, and the annular mistuning band is located toward the aft end and is spaced apart from the fore retainer to locate the plurality of blades therebetween.

5 . The fan assembly of claim 1 , wherein the fan assembly has a fore end and an aft end, the fan assembly further includes an aft retainer located toward the aft end, and the annular mistuning band is located toward the fore end and is spaced apart from the aft retainer to locate the plurality of blades therebetween.

6 . The fan assembly of claim 1 , wherein the fan wheel is formed to include a plurality of axially extending slots, the root of each blade is received in a corresponding slot, the root of each of the predetermined number of blades extends axially out of the slots, and the annular mistuning band engages a portion of the roots extending axially out of the slots.

7 . The fan assembly of claim 1 , wherein the annular mistuning band includes an annular body and a plurality of engagement flanges extending radially outward away from the annular body and spaced circumferentially apart from one another.

8 . The fan assembly of claim 7 , wherein the annular mistuning band is castellated.

9 . A fan assembly for use in a gas turbine engine, the fan assembly comprising
a fan including a fan wheel and a plurality of blades extending radially outward from the fan wheel relative to a central axis, each of the blades including a root coupled with the fan wheel and an airfoil extending radially outward from the root, a fore retainer coupled to the fan wheel and adapted to limit axial movement of the plurality of blades along the central axis, an aft retainer spaced apart axially from the fore retainer to locate the plurality of blades therebetween, the aft retainer coupled to the fan wheel and adapted to limit axial movement of the plurality of blades, and an annular mistuning band extending around the central axis, the annular mistuning band positioned axially between the fore retainer and the aft retainer and engaging the root of a predetermined number of more than one but less than all of the plurality of blades.

10 . The fan assembly of claim 9 , wherein the annular mistuning band includes an annular body and a plurality of engagement flanges extending radially outward away from the annular body and spaced apart circumferentially from one another.

11 . The fan assembly of claim 10 , wherein the annular body is spaced apart from the roots of the blades and the plurality of engagement flanges engage the predetermined number of blades.

12 . The fan assembly of claim 10 , wherein the annular mistuning band is castellated.

13 . The fan assembly of claim 10 , wherein the fan wheel is formed to include a plurality of axially extending slots, the root of each blade is received in a corresponding slot, the root of each of the predetermined number of blades extends axially beyond the slots, and the engagement flanges engage a portion of the roots extending axially beyond the slots.

14 . The fan assembly of claim 13 , wherein the annular mistuning band further includes a lip extending axially away from the annular body and the lip is located radially between the central axis and the portion of the roots extending axially beyond the slots to center the annular mistuning band relative to the central axis.

15 . The fan assembly of claim 9 , wherein the annular mistuning band engages the roots of less than half of the plurality of blades.

16 . A method of assembling a fan assembly, the method comprising
coupling roots of a plurality of blades to a fan wheel so that the blades extend radially from the fan wheel away from a central axis to provide a fan, and positioning an annular mistuning band that extends around the central axis adjacent to the fan along the central axis such that the annular mistuning band contacts the root of a predetermined subset of more than one but less than all of the plurality of blades.

17 . The method of claim 16 , further including clamping the annular mistuning band and the predetermined subset of blades between a fore retainer and an aft retainer of the fan assembly.

18 . The method of claim 16 , further including clamping the predetermined subset of blades between a fore retainer of the fan assembly and the annular mistuning band.

19 . The fan assembly of claim 16 , wherein the plurality of blades are spaced circumferentially from one another about the fan wheel and the annular mistuning band engages every other root of the plurality of blades.

20 . The fan assembly of claim 16 , wherein the annular mistuning band engages the roots of less than half of the plurality of blades.

Assignees

• Rolls Royce Corp

Inventors

• Fulayter Roy D
• Rivers Jonathan M

Classifications

• F04D29/325

  for axial flow fans (blade mountings F04D29/34, blades F04D29/38) · CPC title

• F04D29/668 Primary

  damping or preventing mechanical vibrations · CPC title

• F01D5/16 Primary

  for counteracting blade vibration · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F05D2260/961

  by mistuning rotor blades or stator vanes with irregular interblade spacing, airfoil shape · CPC title