Bearing support apparatus for a gas turbine engine
A bearing support cage includes: an annular forward ring; an annular aft ring; an annular mounting flange disposed between the forward and aft rings; an annular array of axially-extending first spring fingers interconnecting the forward ring and the aft ring; and an annular array of axially-extending second spring fingers interconnecting the mounting flange and the aft ring, wherein the first spring fingers are interdigitated with the second spring fingers. The forward and aft rings, the mounting flange, and the spring fingers are all part of a single monolithic component.
1. A bearing support cage comprising:
an annular forward ring;
an annular aft ring;
an annular mounting flange disposed between the forward and aft rings;
an annular array of axially-extending first spring fingers interconnecting the forward ring and the aft ring; and
an annular array of axially-extending second spring fingers interconnecting the mounting flange and the aft ring, wherein the first spring fingers are interdigitated with the second spring fingers, and wherein the forward and aft rings, the mounting flange, and the spring fingers are all part of a single monolithic component.
2. The bearing support cage of claim 1 wherein single ones of the second spring arms alternate with single ones of the first spring arms around the periphery of the bearing cage.
3. The bearing support cage of claim 1 wherein a plurality of notches are formed in the mounting flange, the notches aligned with the first spring arms.
4. The bearing support cage of claim 1 wherein the first spring arms have a first radial stiffness, and the second spring arms have a second radial stiffness which is substantially greater than the first radial stiffness.
5. A bearing support apparatus for a gas turbine engine, comprising:
a stationary, annular frame;
a monolithic bearing cage comprising: an annular forward ring, an annular mounting flange, an annular aft ring, an annular array of axially-extending first spring fingers, and an annular array of axially-extending second spring fingers, wherein:
the mounting flange is mounted to the frame;
the forward ring and the aft ring are interconnected by the first spring fingers,
the mounting flange and the aft ring are interconnected by the second spring fingers; and
the first spring fingers are interdigitated with the second spring fingers;
a roller bearing carried by the aft ring of the bearing cage;
a ball bearing carried by the forward ring of the bearing cage; and
a shaft mounted in the roller and ball bearings.
6. The bearing support apparatus of claim 5 wherein the ball bearing is configured to transmit axial loads between the frame and the shaft.
7. The bearing support apparatus of claim 5 wherein single ones of the second spring arms alternate with single ones of the first spring arms around the periphery of the bearing cage.
8. The bearing support apparatus of claim 5 wherein a plurality of notches are formed in the mounting flange, the notches aligned with the first spring arms.
9. The bearing support apparatus of claim 5 wherein the ball bearing is laterally offset relative to the roller bearing.
10. The bearing support apparatus of claim 5 further including a squeeze film damper disposed between the frame and the bearing cage.
11. The bearing apparatus of claim 5 wherein the first spring arms have a first radial stiffness, and the second spring arms have a second radial stiffness which is substantially greater than the first radial stiffness.