# US 11,306,657 B2 · Gas turbine engine including squeeze film damper with reservoir

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- Number: US 11,306,657 B2
- Document ID: US11306657B2
- Status: Granted
- Kind: B2
- Application number: 16/736,281
- Filed: 2020-01-07
- Published: 2021-07-08
- Granted: 2022-04-19
- Earliest claimed: 2020-01-07
- Assignees: Raytheon Technologies Corporation
- Applicants: United Technologies Corporation
- Inventors: Armando Amador; Ernest Boratgis
- Web page: https://patentgrep.com/patent/US11306657B2

## CPC

- F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M)
- F01D 9/065: {Fluid supply or removal conduits traversing the working fluid flow, e.g. for lubrication-, cooling-, or sealing fluids (see also F01D25/16, F01D25/24 and F01D25/26)}
- F01D 25/164: {Flexible supports; Vibration damping means associated with the bearing}
- F01D 25/18: Lubricating arrangements (of machines or engines in general F01M)
- F01D 25/20: using lubrication pumps
- F01D 25/22: using working-fluid or other gaseous fluid as lubricant
- F16C 27/045: {with a fluid film, e.g. squeeze film damping}
- F16C 33/74: of sliding-contact bearings
- F05D 2220/323: for aircraft propulsion, e.g. jet engines
- F05D 2220/40: in turbochargers
- F05D 2240/50: Bearings
- F05D 2240/55: Seals
- F05D 2240/60: Shafts
- F05D 2260/40311: of the epicyclical, planetary or differential type
- F05D 2260/96: Preventing, counteracting or reducing vibration or noise
- F05D 2260/98: Lubrication
- F16C 2360/23: Gas turbine engines
- F16F 15/0237: {involving squeeze-film damping}
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- 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
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION

## Abstract

A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a shaft configured to rotate during operation of the gas turbine engine, and a squeeze film damper radially outside the shaft. The squeeze film damper includes a cavity including a film of lubricant axially between first and second cavity seals, and further includes a reservoir fluidly coupled to the cavity. A method is also disclosed.

## Claims

### Claim 1

A gas turbine engine, comprising:
a shaft configured to rotate during operation of the gas turbine engine; and
a squeeze film damper radially outside the shaft, the squeeze film damper including a cavity including a film of lubricant axially between first and second cavity seals, and further including a reservoir fluidly coupled to the cavity,
wherein the reservoir is passively fluidly coupled to the cavity such that lubricant is free to flow in and out of the reservoir during operation of the gas turbine engine,
wherein at least one of the first and second cavity seals includes an opening fluidly coupling the cavity to the reservoir and permitting lubricant to flow in and out of the reservoir through the opening.

### Claim 2 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the opening is adjacent a bottom-most location of the cavity.

### Claim 3 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the reservoir is axially spaced-apart from the cavity.

### Claim 4 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the first and second cavity seals each include an opening fluidly coupling the cavity to the reservoir.

### Claim 5 (depends on 4)

The gas turbine engine as recited in claim 4, wherein the reservoir includes a first portion on a first axial side of the cavity and a second portion on a second axial side of the cavity opposite the first axial side.

### Claim 6 (depends on 5)

The gas turbine engine as recited in claim 5, wherein:
the first portion is bound at least in part by the first cavity seal and either a first reservoir seal, a ring, or a projection, and
the second portion is bound at least in part by the second cavity seal and either a second reservoir seal or a projection.

### Claim 7 (depends on 1)

The gas turbine engine as recited in claim 1, further comprising:
a housing; and
a bearing radially inside the housing and radially outside the shaft, the bearing including an inner race mounted to the shaft, an outer race, and a plurality of rolling elements between the inner and outer races.

### Claim 8 (depends on 7)

The gas turbine engine as recited in claim 7, wherein the housing provides a radially outer boundary of the cavity and the outer race provides a radially inner boundary of the cavity.

### Claim 9 (depends on 1)

The gas turbine engine as recited in claim 1, further comprising a source of lubricant fluidly coupled to the cavity.

### Claim 10 (depends on 9)

The gas turbine engine as recited in claim 9, wherein the lubricant is oil or an air-oil mixture.

### Claim 11 (depends on 1)

The gas turbine engine as recited in claim 1, wherein a port is fluidly coupled to a top-most location of the reservoir.

### Claim 12 (depends on 11)

The gas turbine engine as recited in claim 11, wherein the port includes an oil pool.

### Claim 13 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the shaft is one of a low speed spool and a high speed spool.

### Claim 14 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the squeeze film damper is one of a plurality of squeeze film dampers arranged along the shaft.

### Claim 15

A method, comprising:
permitting lubricant to passively flow between a cavity of a squeeze film damper and a reservoir during operation of a gas turbine engine such that the lubricant is free to flow in and out of the reservoir during operation of the gas turbine engine through an opening in a seal between the reservoir and the cavity.

### Claim 16 (depends on 15)

The method as recited in claim 15, wherein:
the cavity is radially between a rotating assembly and a static housing, and
the rotating assembly rotates about an axis spaced-apart from a central longitudinal axis of the gas turbine engine during operation of the gas turbine engine.

### Claim 17 (depends on 16)

The method as recited in claim 16, wherein the rotating assembly creates a leading high pressure wave which causes lubricant to flow through the opening from the cavity into the reservoir, and a trailing low pressure wake which causes lubricant to flow through the opening from the reservoir into the cavity.

### Claim 18 (depends on 1)

The gas turbine engine as recited in claim 1, wherein the squeeze film damper is configured such that:
when the shaft creates a leading high pressure wave, lubricant flows through the opening from the cavity into the reservoir, and
when the shaft creates a trailing low pressure wake, lubricant flows through the opening from the reservoir into the cavity.

### Claim 19 (depends on 5)

The gas turbine engine as recited in claim 5, wherein the squeeze film damper is configured such that:
when the shaft creates a leading high pressure wave, some lubricant flows from the cavity into the first portion of the reservoir through the opening in the first cavity seal, and some lubricant flows from the cavity into the second portion of the reservoir through the opening in the second cavity seal, and
when the shaft creates a trailing low pressure wake, some lubricant flows from the first portion of the reservoir into the cavity through the opening in the first cavity seal, and some lubricant flows from the second portion of the reservoir into the cavity through the opening in the second cavity seal.