Post FBO windmilling bumper

Patent metadata

Field	Value
Publication number	US-10815825-B2
Application number	US-201816201183-A
Country	US
Kind code	B2
Filing date	Nov 27, 2018
Priority date	Dec 23, 2013
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A bearing arrangement rotatably supports a shaft of an aircraft engine. The bearing arrangement comprises a bearing having rolling elements disposed between inner and outer races. The inner race is affixed to the shaft. A decoupler normally structurally couples the outer race of the bearing to a stator structure of the engine. The decoupler is configured to release the bearing from the stator structure when subject to a predetermined critical load. A bumper is mounted to the stator structure and encircles the bearing. The bumper has a radially inwardly facing surface disposed in close proximity to a radially outer surface of the outer race of the bearing and defines therewith a radial gap to accommodate and constrain an orbiting motion of the rotor about the central axis of the engine after decoupling at the bearing. The bumper further has an axially forwardly facing surface which is axially spaced by a predetermined axial fore gap from a first flange projecting radially outwardly from a front end portion of the outer race of the bearing. The first flange of the outer race is axially trapped between the stator structure and the bumper. After decoupling, the bearing is free to axially and radially move within the radial gap and the axial fore gap.

First claim

What is claimed is:

1. A bearing arrangement for supporting a fan rotor of an aircraft engine, comprising: a bearing having rolling elements disposed between inner and outer races, a bearing support for supporting the bearing on a stator structure of the engine, the bearing axially engaged on a spigot projecting axially rearwardly from the bearing support, a decoupler between the bearing and the bearing support, the decoupler being configured to release the bearing from the bearing support when subject to a predetermined critical load, a bumper surrounding the bearing, a portion of the bearing being axially trapped between the bearing support and the bumper to provide rotor axial retention upon decoupling of the bearing from the bearing support structure, the bumper and the outer race of the bearing defining a radial gap and an axial gap therebetween, the bearing being free to move within said radial and axial gaps when the fan rotor rotates at windmilling speed after decoupling of the bearing from the bearing support, wherein the portion of the bearing trapped between the bearing support and the bumper is spaced from the bumper by an axial gap sized to allow the bearing to move off from the spigot upon decoupling of the bearing from the bearing support.

2. The bearing arrangement defined in claim 1 , wherein the radial gap is sized to tune the natural frequency of vibration of the fan rotor at higher speeds than the windmilling speed.

3. The bearing arrangement defined in claim 1 , wherein the outer race has a front mounting flange, wherein the decoupler comprises a set of frangible fasteners, the front mounting flange being attached to the bearing support by said frangible fasteners.

4. The bearing arrangement defined in claim 3 , wherein the bearing support has a radially inwardly projecting flange, the front mounting flange projecting radially outwardly from the outer race and forming with the radially inwardly projecting flange of the bearing support an inverted flange arrangement.

5. The bearing arrangement defined in claim 3 , wherein the axial gap is an axial fore gap defined between the front mounting flange of the outer race and a front axially facing surface of the bumper, the front mounting flange being disposed axially forwardly of the front axially facing surface of the bumper.

6. The bearing arrangement defined in claim 5 , wherein the outer race has an arresting surface projecting radially outwardly from a rear end portion thereof, the arresting surface being axially spaced rearwardly from a corresponding rear abutting surface on the bumper.

7. A bearing arrangement for supporting a fan rotor of an aircraft engine, the bearing arrangement comprising: a bearing having rolling elements disposed between an inner race and an outer race, a bearing support for supporting the bearing on a stator structure of the aircraft engine, a decoupler between the bearing and the bearing support, the decoupler being configured to release the bearing from the bearing support when subject to a predetermined critical load, a bumper surrounding the bearing, a portion of the bearing being axially trapped between the bearing support and the bumper to provide rotor axial retention upon decoupling of the bearing from the bearing support structure, the bumper and the outer race of the bearing defining a radial gap and an axial gap therebetween, the bearing being free to move within said radial and axial gaps when the fan rotor rotates at windmilling speed after decoupling of the bearing from the bearing support, wherein the outer race of the bearing has an arresting surface projecting radially outwardly from a rear end portion thereof, the arresting surface being axially spaced rearwardly from a corresponding rear abutting surface on the bumper.

8. The bearing arrangement defined in claim 7 , wherein the radial gap is sized to tune the natural frequency of vibration of the fan rotor at higher speeds than the windmilling speed.

9. The bearing arrangement defined in claim 7 , wherein the outer race has a front mounting flange, wherein the decoupler comprises a set of frangible fasteners, the front mounting flange being attached to the bearing support by said frangible fasteners.

10. The bearing arrangement defined in claim 9 , wherein the bearing support has a radially inwardly projecting flange, the front mounting flange projecting radially outwardly from the outer race and forming with the radially inwardly projecting flange of the bearing support an inverted flange arrangement.

11. The bearing arrangement defined in claim 9 , wherein the front mounting flange of the outer race is spaced axially forwardly of a front axially facing surface of the bumper by an axial fore gap.

12. The bearing arrangement defined in claim 11 , wherein the axial fore gap is sized to allow the outer race to move off from a spigot projecting axially rearwardly from the bearing support.

Assignees

• Pratt & Whitney Canada

Inventors

• Denis David
• Bonniere Philippe
• Kojovic Milica
• Korshikov Oleg
• Raykowski Lena
• Wojtyczka Czeslaw

Classifications

• F16C19/06

  with a single row or balls · CPC title

• F16C2360/23

  Gas turbine engines · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F01D21/045 Primary

  special arrangements in stators or in rotors dealing with breaking-off of part of rotor · CPC title

• F16C33/586

  outside the space between the races, e.g. end faces or bore of inner ring · CPC title