Axially spaced restricted damper

1. A bearing assembly, comprising:

a bearing housing comprising a first bearing housing surface and a second bearing housing surface where the first and second bearing housing surfaces are substantially axially parallel with respect to a rotor centerline;

a damped outer race, comprising

a first outer race surface radially adjacent to and opposing the first bearing housing surface which is located radially interior to the first outer race surface;

a first piston ring groove in the first outer race surface, where the first piston ring groove comprises a first piston ring that seals between the first bearing housing surface and the first outer race surface;

a second outer race surface radially adjacent to and opposing the second bearing housing surface which is located radially exterior to the second outer race surface; and

a second piston ring groove in the second outer race surface, where the second piston ring groove comprises a second piston ring that seals between the second bearing housing surface and the second outer race surface;

where the bearing housing comprises an oil passage that is configured to provide oil from an outlet to a first space of axial length L 1 radially between the first outer race surface and the first bearing housing surface, and configured to provide oil to a second space of axially length L 2 radially between the second outer race surface and the second bearing housing surface.

2. The bearing assembly of claim 1 , where the damped outer race is held axially adjacent to the bearing housing by a retainer ring.

3. The bearing assembly of claim 1 , where the first piston seal is axially offset from the second piston seal.

4. The bearing assembly of claim 1 , where the first piston seal is axially aligned with the second piston seal.

5. The bearing assembly of claim 1 , where the oil passage extends in a substantially axial direction with respect to the rotor centerline to provide oil to a third space that connects the first space and the second space.

6. An assembly, comprising:

a bearing housing comprising a first bearing housing surface and a second bearing housing surface where the first and second bearing housing surfaces are substantially parallel with respect to a rotor centerline;

a damped outer race comprising

a first outer race surface radially adjacent to and opposing the first bearing housing surface which is located radially interior to the first outer race surface;

a first piston ring groove in the first outer race surface, where the first piston ring groove comprises a first piston ring that seals between the first bearing housing surface and the first outer race surface;

a second outer race surface radially adjacent to and opposing the second bearing housing surface which is located radially exterior to the second outer race surface;

a second piston ring groove in the second outer race surface, where the second piston ring groove comprises a second piston ring that seals between the second bearing housing surface and the second outer race surface; and

a bearing radially interior to the damped outer race;

where the bearing housing comprises a fluid passage configured to provide a fluid film to a first space radially between the first outer race surface and the first bearing housing surface, and configured to provide the fluid film to a second space radially between the second outer race surface and the second bearing housing surface to damp radial motion of the bearing.

7. The assembly of claim 6 , where the fluid passage extends in a substantially axial direction with respect to the rotor centerline to provide oil to a third space that interconnects and provides oil to the first space and the second space.

8. The assembly of claim 7 , where the first piston seal is axially offset from the second piston seal.

9. The assembly of claim 7 , where the first piston seal is axially aligned with the second piston seal.

10. An assembly, comprising:

a bearing housing comprising a first bearing housing surface and a second bearing housing surface where the first and second bearing housing surfaces are substantially parallel with respect to a rotor centerline;

a damped outer race comprising

a first outer race surface radially adjacent to and opposing the first bearing housing surface which is located radially interior to the first outer race surface;

a second outer race surface radially adjacent to and opposing the second bearing housing surface which is located radially exterior to the second outer race surface;

a rotary bearing radially interior to and radially adjacent to the damped outer race;

a first piston ring groove in the first outer race surface, where the first piston ring groove comprises a first piston ring that seals between the first bearing housing surface and the first outer race surface; and

a second piston ring groove in the second outer race surface, where the second piston ring groove comprises a second piston ring that seals between the second bearing housing surface and the second outer race surface;

where the bearing housing comprises a passage configured to provide an lubricant to a first space radially between the first outer race surface and the first bearing housing surface, and provide lubricant to a second space radially between the second outer race surface and the second bearing housing surface to damp radial motion of the bearing.

11. The assembly of claim 10 , where the first piston seal is axially offset from the second piston seal.

12. The assembly of claim 10 , where the first piston seal is axially aligned with the second piston seal.