Bending stiffening feature used for compliant journal bearing

Patent metadata

Field	Value
Publication number	US-10851671-B2
Application number	US-201916369808-A
Country	US
Kind code	B2
Filing date	Mar 29, 2019
Priority date	Mar 29, 2019
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A journal bearing for a gas turbine engine is described. The journal extends along a central axis from a first axial end face to a second axial end face thereof, and has at least one undercut defined circumferentially about the central axis in one of the first and second axial end faces. The undercut extends toward the other one of the first and second axial end faces of the journal. A stiffening member extends across the undercut to interconnect opposite surfaces thereof. Also described, a journal bearing comprising a tubular body extending axially along a central axis, where the tubular body has a first and a second opposite axial end faces with holes projecting into the first axial end face toward the second axial end face and having a finite depth. The holes are circumferentially disposed about the central axis, and respective webs of material are defined between adjacent holes. A method of operating a journal bearing is also provided.

First claim

The invention claimed is:

1. A journal bearing for a gas turbine engine, comprising:
a journal extending along a central axis from a first axial end face to a second axial end face thereof, the journal having a pin receiving aperture extending along the central axis through the journal from the first axial end face to the second axial end face, and having at least one undercut defined circumferentially about the central axis in the first and/or second axial end faces and extending toward the other one of the first and second axial end faces of the journal,
a stiffening member extending across the undercut to interconnect opposite surfaces of the undercut.

2. The journal bearing as defined in claim 1 , wherein the journal bearing comprises a plurality of said stiffening member interconnecting the opposite surfaces of the undercut.

3. The journal bearing as defined in claim 2 , wherein the journal bearing comprises two stiffening members interconnecting the opposite surfaces of the undercut, the two stiffening members disposed on opposed sides of the pin receiving aperture.

4. The journal bearing as defined in claim 3 , wherein the two stiffening members are disposed axisymmetrically about the central axis.

5. The journal bearing as defined in claim 1 , wherein the pin receiving aperture defines a pin engaging surface, the pin engaging surface defining one or more annular recess opened toward the pin receiving aperture.

6. The journal bearing as defined in claim 1 , wherein the opposite surfaces of the undercut taper until converging to form a bend of the undercut, the stiffening member extending axially and tapering from the first axial end face to the bend.

7. The journal bearing as defined in claim 1 , wherein the undercut is a first undercut and the stiffening member is a first stiffening member, the journal having a second undercut defined circumferentially about the central axis at the second axial end face of the journal and extending toward the first axial end face, a second stiffening member extending radially across the second undercut and interconnecting opposite surfaces of the second undercut.

8. The journal bearing as defined in claim 1 , wherein the stiffening member has a radially tapering profile such that a thickness of the stiffening member decreases from a radially outward portion to a radially inward portion of the stiffening member when viewed in a plane normal to the central axis of the journal bearing.

9. The journal bearing as defined in claim 1 , wherein the stiffening member has a radially convergent-divergent profile such that a thickness of a radially outward portion and a radially inward portion of the stiffening member decreases toward one another when viewed in a plane normal to the central axis of the journal bearing.

10. The journal bearing as defined in claim 1 , wherein the stiffening member and the journal are integrally formed as a monolithic piece.

11. A method of operating a journal bearing, the journal bearing having a journal extending along a central axis, the journal having at least one undercut defined circumferentially about the central axis at an axial end face thereof, and having a pin receiving aperture extending through the journal along the central axis, the method comprising:
transmitting a journal bearing load to the journal in a direction transverse to the central axis,
responsive to said journal bearing load, deforming elastically an axial end portion of the journal, the axial end portion extending from the axial end face of the journal, and
limiting a local deformation of the axial end portion of the journal via a stiffening member extending radially across the undercut and interconnecting opposite surfaces of the undercut.

12. The method as defined in claim 11 , wherein limiting the local deformation of the axial end portion of the journal includes transmitting at least part of the journal bearing load to a plurality of said stiffening member extending across the undercut and interconnecting the opposite surfaces of the undercut.

13. The method as defined in claim 12 , wherein limiting the local deformation of the axial end portion of the journal includes transmitting at least part of the journal bearing load to a plurality of said stiffening member forming an array of spiral shaped ribs circumferentially distributed in the undercut.

14. The method as defined in claim 11 , wherein limiting the local deformation of the axial end portion of the journal includes transmitting at least part of the journal bearing load to two of said stiffening member interconnecting the opposite surfaces of the undercut, the two stiffening members disposed on opposed sides of the pin receiving aperture of the journal.

15. The method as defined in claim 11 , wherein limiting the local deformation of the axial end portion of the journal includes transmitting at least part of the journal bearing load to two stiffening members interconnecting the opposite surfaces of the undercut, the two stiffening members disposed on opposed sides of the pin receiving aperture of the journal axisymmetrically about the central axis.

16. The method as defined in claim 11 , wherein limiting the local deformation of the axial end portion of the journal includes transmitting at least part of the journal bearing load to the stiffening member integrally with the journal as a monolithic piece.

17. A journal bearing for a gas turbine engine, comprising a tubular body extending axially along a central axis, the tubular body having a pin receiving aperture extending along the central axis from a first axial end face to a second opposite axial end face, holes projecting into the first axial end face toward the second axial end face and having a finite depth, the holes circumferentially disposed about the central axis, and respective webs of material defined between adjacent holes.

18. The journal bearing as defined in claim 17 , wherein the webs of material have a radially tapering profile such that a thickness of the webs decreases from a radially outward portion to a radially inward portion of the webs when viewed in a plane normal to the central axis of the journal bearing.

19. The journal bearing as defined in claim 17 , wherein the tubular body has two holes in the first axial end face and two webs of material each defined between respective circumferential ends of said holes.

20. The journal bearing as defined in claim 17 , wherein the webs are circumferentially skewed.

Assignees

• Pratt & Whitney Canada

Inventors

• Simard-Bergeron Julien
• Brillon Louis

Classifications

• F01D5/027

  Arrangements for balancing (for balancing rotating bodies in general F16F15/32; for compensating imbalance G01M1/36) · CPC title

• F16C2360/23

  Gas turbine engines · CPC title

• F16C33/1055

  from radial inside, e.g. via a passage through the shaft and/or inner sleeve · CPC title

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title

• F16C27/02

  Sliding-contact bearings · CPC title