# US 11,306,611 B2 · Supressing vibrations of shafts using adjustable bearings

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- Number: US 11,306,611 B2
- Document ID: US11306611B2
- Status: Granted
- Kind: B2
- Application number: 15/635,313
- Filed: 2017-06-28
- Published: 2018-01-04
- Granted: 2022-04-19
- Earliest claimed: 2016-06-29
- Assignees: Dresser, Inc.
- Applicants: General Electric Technology GmbH
- Inventors: Athanasios Chasalevris; Fadi Dohnal
- Web page: https://patentgrep.com/patent/US11306611B2

## CPC

- F01D 25/04: Antivibration arrangements
- F01D 25/166: {Sliding contact bearing (gas bearings F01D25/22)}
- F01D 25/18: Lubricating arrangements (of machines or engines in general F01M)
- F16C 17/02: for radial load only
- F16C 17/022: {with a pair of essentially semicircular bearing sleeves}
- F16C 17/24: with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety
- F16C 23/04: self-adjusting
- F16C 33/108: {with a plurality of elements forming the bearing surfaces, e.g. bearing pads}
- F05D 2220/32: in gas turbines
- F05D 2240/50: Bearings
- F05D 2260/98: Lubrication
- F05D 2300/505: Shape memory behaviour
- F16C 21/00: Combinations of sliding-contact bearings with ball or roller bearings, for exclusively rotary movement (F16C17/24, F16C19/52 take precedence)
- F16C 2233/00: Monitoring condition, e.g. temperature, load, vibration
- F16C 2360/00: Engines or pumps
- F16C 2360/23: Gas turbine engines
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A bearing configured to actively damp vibration of a shaft in a turbine. In one implementation, the bearing can include actuating members that move in a manner that changes properties of fluid, typically a thin film of lubricant, disposed in the bearing to facilitate rotation of the shaft. These changes effectively manipulate the stiffness and damping of the thin film according to a time periodicity that matches a parametric anti-resonance of the bearing. In turn, the resulting interaction of vibrating modes is favorable to damp vibration amplitudes at critical speeds.

## Claims

### Claim 1

A bearing system, comprising:
a casing having a bore with a center axis, the bore having an interior surface with openings disposed between portions having a variable radius measured from the center axis;
a first pad and a second pad disposed in the casing at the openings, each forming an arcuate carrying surface with a constant radius, the arcuate carrying surface being radially moveable in a direction perpendicular to the center axis of the bore;
a port disposed in the casing, the port having an aperture that provides access to interior of the casing, the aperture being located in at least one of the portions having the variable radius;
a first actuator and a second actuator coupled with the first pad and the second pad, respectively; and
a controller that uses feedback about the shaft to actuate the first actuator and the second actuator to displace the first pad and the second pad relative to the center axis in response to conditions inside the casing, and
wherein displacement of the first pad and the second pad results in a film of lubricant having a thickness that varies with respect to the arcuate carrying surface area of the first pad and the second pad.

### Claim 2 (depends on 1)

The bearing of claim 1, wherein the first pad and the second pad are spaced apart annularly from one another about the center axis.

### Claim 3 (depends on 1)

The bearing of claim 1, wherein the first pad and the second pad oppose each other on opposite sides of the center axis.

### Claim 4 (depends on 1)

The bearing of claim 1, wherein the first pad and the second pad have adjacent ends that are annularly offset from one another by less than 180°.

### Claim 5 (depends on 1)

The bearing of claim 1, wherein the arcuate carrying surface has an arc length that is the same on the first pad as on the second pad.

### Claim 6 (depends on 1)

The bearing of claim 1, further comprising a third pad also having the arcuate carrying surface and radially moveable in a direction perpendicular to the center axis, wherein the arcuate carrying surface of the first pad, the second pad, and the third pad, in aggregate, have an arc length that amounts to less than 360°.

### Claim 7 (depends on 1)

The bearing of claim 1, wherein the portions with the variable radius occur at three places in the interior surface.

### Claim 8 (depends on 1)

The bearing of claim 1, wherein the portions with the variable radius are diametrically-opposed to one another.

### Claim 9 (depends on 1)

The bearing of claim 1, wherein the displacement of the first pad and the second pad either introduces parametric anti-resonance into the bearing system or introduces modal interaction that transfers vibration energy from a first mode to a second mode in the bearing system when excitation frequency corresponds to a difference between first and second critical speeds of a turbine rotor.

### Claim 10

Turbo-machinery, comprising:
a shaft;
a bearing system with a casing having a bore receiving the shaft, the bore having a center axis and an interior surface with openings disposed between portions having a variable radius as measured from the center axis, the bearing system comprising a first pad and a second pad disposed in the openings, each having a carrying surface forming an arc of constant radius that circumscribe an annular portion of the shaft, the bearing system further comprising a lubricant disposed between the carrying surface and the shaft, the lubricant forming a film;
a port disposed in the casing, the port having an aperture that provides access to interior of the casing, the aperture being located in at least one of the portions having the variable radius;
a first actuator and a second actuator coupled to the first pad and the second pad, respectively;
sensors to monitor operating conditions of the rotor; and
a controller coupled with the sensors and with the first actuator and the second actuator, the controller uses feedback about the shaft to actuate the first actuator and the second actuator to move the first pad and the second pad relative to the shaft in response to the operating conditions to vary thickness of the film, and
wherein displacement of the first pad and the second pad results in a thickness of the film that varies with respect to the arcuate carrying surface area of the first pad and the second pad.

### Claim 11 (depends on 10)

The turbo-machinery of claim 10, wherein the bearing comprises a third pad, also having the carrying surface, wherein the carrying surface of the first pad, the second pad, and the third pad, in aggregate, have an arc length that amounts to less than 360°.

### Claim 12 (depends on 10)

The turbo-machinery of claim 10, wherein the portions with the variable radius occur at three places in the interior surface.

### Claim 13 (depends on 10)

The turbo-machinery of claim 10, wherein the portions with the variable radius are diametrically-opposed to one another.

### Claim 14 (depends on 11)

The turbo-machinery of claim 11, wherein the displacement of the first pad and the second pad introduces modal interaction that transfers vibration energy from a first mode to a second mode in the bearing system when excitation frequency corresponds to a difference between first and second critical speeds of the turbo-machinery.