US-12618340-B2 - Controlled contact induced buckling of spoked bearing support

Abstract

A bearing arrangement of a gas turbine engine includes a first bearing supportive of a shaft, and a second bearing axially offset from the first bearing. A first bearing support extends from a bearing housing to the first bearing, and a second bearing support extends from a bearing housing to the second bearing. One or more radial bearing supports including a plurality of radial spokes extend between the bearing housing and the second bearing. The spokes are configured to buckle under compression when radial loads at the second bearing exceed a predetermined force threshold. An axially-extending spoke foot extends from at least one radial spoke. The axially-extending foot is configured to contact the second bearing in the event of a tilt of the second bearing beyond a predetermined angle threshold, reducing the buckling force of the plurality of radial spokes below a second predetermined force threshold.

Inventors

• Nathan TOMES

Assignees

• PRATT & WHITNEY CANADA CORP.

Dates

Publication Date

20260505

Application Date

20240620

Claims (20)

1. 1 . A bearing arrangement of a gas turbine engine, comprising: a first bearing supportive of a shaft; a second bearing axially offset from the first bearing and supportive of the shaft; a first bearing support extending from a bearing housing to the first bearing to support the first bearing; a second bearing support extending from a bearing housing to the second bearing to support the second bearing; one or more radial bearing supports including a plurality of radial spokes extending between the bearing housing and the second bearing, the plurality of radial spokes configured to buckle under compression when radial loads at the second bearing exceed a predetermined force threshold; and an axially-extending spoke foot extending from at least one radial spoke of the plurality of radial spokes, the axially-extending foot configured to contact the second bearing in the event of a tilt of the second bearing beyond a predetermined angle threshold, reducing the buckling force of the plurality of radial spokes below a second predetermined force threshold.
2. 2 . The bearing arrangement of claim 1 , wherein the radial bearing support includes an outer ring disposed at the bearing housing, and the plurality of radial spokes extend from the outer ring to a spoke tip at the second bearing.
3. 3 . The bearing arrangement of claim 2 , wherein the spoke foot is disposed nearer to the spoke tip than to the outer ring.
4. 4 . The bearing arrangement of claim 1 , wherein a spoke tip of each of the radial spokes are configured to contact the second bearing while not being secured thereto.
5. 5 . The bearing arrangement of claim 1 , further comprising one or more bumpers axially offset from the radial bearing support configured to limit radial travel of the second bearing following buckling of the radial spokes.
6. 6 . The bearing arrangement of claim 1 , wherein the spoke foot extends from the spoke in a first axial direction toward the first bearing.
7. 7 . The bearing arrangement of claim 1 , wherein the spoke foot extends from the spoke in a second axial direction away from the first bearing.
8. 8 . The bearing arrangement of claim 1 , wherein the spoke foot is configured to contact the bearing outer race of the second bearing when the second bearing tilts.
9. 9 . The bearing arrangement of claim 1 , wherein each spoke of the plurality of radial spokes includes a spoke foot.
10. 10 . The bearing arrangement of claim 1 , wherein the second threshold radial load is a fan blade off load of the gas turbine engine, and the threshold angle is exceeded only following fan blade off of the gas turbine engine.
11. 11 . A gas turbine engine, comprising: a combustor; a turbine driven by combustion products of the combustor; a shaft driven by rotation of the turbine; and a bearing arrangement supportive of the shaft, the bearing arrangement including: a first bearing; a second bearing axially offset from the first bearing; a first bearing support extending from a bearing housing to the first bearing to support the first bearing; a second bearing support extending from a bearing housing to the second bearing to support the second bearing; one or more radial bearing supports including a plurality of radial spokes extending between the bearing housing and the second bearing, the plurality of radial spokes configured to buckle under compression when radial loads at the second bearing exceed a predetermined threshold; and an axially-extending spoke foot extending from at least one radial spoke of the plurality of radial spokes, the axially-extending foot configured to contact the second bearing in the event of a tilt of the second bearing beyond a predetermined angle threshold, reducing the buckling force of the plurality of radial spokes below a second predetermined force threshold.
12. 12 . The gas turbine engine of claim 11 , wherein the radial bearing support includes an outer ring disposed at the bearing housing, and the plurality of radial spokes extend from the outer ring to a spoke tip at the second bearing.
13. 13 . The gas turbine engine of claim 12 , wherein the spoke foot is disposed nearer to the spoke tip than to the outer ring.
14. 14 . The gas turbine engine of claim 11 , wherein a spoke tip of each of the radial spokes are configured to contact the second bearing while not being secured thereto.
15. 15 . The gas turbine engine of claim 11 , further comprising one or more bumpers axially offset from the radial bearing support configured to limit radial travel of the second bearing.
16. 16 . The gas turbine engine of claim 11 , wherein the spoke foot extends from the spoke in a first axial direction toward the first bearing.
17. 17 . The gas turbine engine of claim 11 , wherein the spoke foot extends from the spoke in a second axial direction away from the first bearing.
18. 18 . The gas turbine engine of claim 11 , wherein the spoke foot is configured to contact the bearing outer race of the second bearing when the second bearing tilts.
19. 19 . The gas turbine engine of claim 11 , wherein each spoke of the plurality of radial spokes includes a spoke foot.
20. 20 . The gas turbine engine of claim 11 , wherein the second threshold radial load is a fan blade off load of the gas turbine engine, and the threshold angle is exceeded only following fan blade off of the gas turbine engine.

Description

BACKGROUND Exemplary embodiments pertain to the art of turbomachinery such as gas turbine engines. In particular, the present disclosure relates to bearing assemblies and support of bearing assemblies of gas turbine engines. During a fan blade off event (FBO), some designs require that two bearings on the engine be broken to help limit the load and vibrations transferred from the rotor to the engine and aircraft structure caused by the unbalance resulting from the FBO. A typical bearing support 200 configuration is illustrated in FIG. 8. A first bearing 202 is a roller bearing supporting radial loads, and requires low support stiffness and is broken by buckling of a first bearing support 204. A second bearing 206 is a ball bearing, supportive of axial and radial loads. The second bearing 206 requires high support stiffness and is broken by fracturing bolts 210 between the second bearing 206 and a second bearing support 208. Configuring the bolts 210 to always break at FBO, requiring high stress, but to not yield at limit loads or during installation and have a full low-cycle fatigue life, all requiring low stress, is very difficult. BRIEF DESCRIPTION In one exemplary embodiment, a bearing arrangement of a gas turbine engine includes a first bearing supportive of a shaft, and a second bearing axially offset from the first bearing and supportive of the shaft. A first bearing support extends from a bearing housing to the first bearing to support the first bearing, and a second bearing support extends from a bearing housing to the second bearing to support the second bearing. One or more radial bearing supports including a plurality of radial spokes extend between the bearing housing and the second bearing. The plurality of radial spokes are configured to buckle under compression when radial loads at the second bearing exceed a predetermined force threshold. An axially-extending spoke foot extends from at least one radial spoke of the plurality of radial spokes. The axially-extending foot is configured to contact the second bearing in the event of a tilt of the second bearing beyond a predetermined angle threshold, reducing the buckling force of the plurality of radial spokes below a second predetermined force threshold. Additionally or alternatively, in this or other embodiments the radial bearing support includes an outer ring positioned at the bearing housing, and the plurality of radial spokes extend from the outer ring to a spoke tip at the second bearing. Additionally or alternatively, in this or other embodiments the spoke foot is positioned nearer to the spoke tip than to the outer ring. Additionally or alternatively, in this or other embodiments a spoke tip of each of the radial spokes are configured to contact the second bearing while not being secured thereto. Additionally or alternatively, in this or other embodiments one or more bumpers axially offset from the radial bearing support are configured to limit radial travel of the second bearing following buckling of the radial spokes. Additionally or alternatively, in this or other embodiments the spoke foot extends from the spoke in a first axial direction toward the first bearing. Additionally or alternatively, in this or other embodiments the spoke foot extends from the spoke in a second axial direction away from the first bearing. Additionally or alternatively, in this or other embodiments the spoke foot is configured to contact the bearing outer race of the second bearing when the second bearing tilts. Additionally or alternatively, in this or other embodiments each spoke of the plurality of radial spokes includes a spoke foot. Additionally or alternatively, in this or other embodiments the second threshold radial load is a fan blade off load of the gas turbine engine, and the threshold angle is exceeded only following fan blade off of the gas turbine engine. In another exemplary embodiment, a gas turbine engine includes a combustor, a turbine driven by combustion products of the combustor, a shaft driven by rotation of the turbine, and a bearing arrangement supportive of the shaft. The bearing arrangement includes a first bearing and a second bearing axially offset from the first bearing. A first bearing support extends from a bearing housing to the first bearing to support the first bearing, and a second bearing support extends from a bearing housing to the second bearing to support the second bearing. One or more radial bearing supports including a plurality of radial spokes extend between the bearing housing and the second bearing. The plurality of radial spokes are configured to buckle under compression when radial loads at the second bearing exceed a predetermined threshold. An axially-extending spoke foot extends from at least one radial spoke of the plurality of radial spokes. The axially-extending foot is configured to contact the second bearing in the event of a tilt of the second bearing beyond a predetermined angle threshold, reducing