# US 10,767,511 B2 · Anti-cavitation device for oil dampers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,511 B2 - Document ID: US10767511B2 - Status: Granted - Kind: B2 - Application number: 16/252,911 - Filed: 2019-01-21 - Published: 2020-07-23 - Granted: 2020-09-08 - Earliest claimed: 2019-01-21 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Charles Litalien - Web page: https://patentgrep.com/patent/US10767511B2 ## CPC - F01D 25/164: {Flexible supports; Vibration damping means associated with the bearing} - F01D 25/183: {Sealing means} - F16C 27/02: Sliding-contact bearings - F16C 27/045: {with a fluid film, e.g. squeeze film damping} - F16F 15/0237: {involving squeeze-film damping} - F01D 25/04: Antivibration arrangements - F05D 2220/32: in gas turbines - F05D 2240/50: Bearings - F05D 2240/55: Seals - F05D 2240/58: Piston ring seals - F05D 2240/60: Shafts - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F16C 19/26: with a single row of rollers - F16C 2360/23: Gas turbine engines - F16F 2230/30: Sealing arrangements - 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 - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract The disclosure relates to an anti-cavitation device for impeding gas intrusion into oil dampers that support bearings and a rotating shaft. The oil film damper includes an annulus and a pair of piston rings between a structural support and the bearing housing. The piston rings define the axial boundaries of the oil filled annulus. An oil inlet between the pair of piston rings is in communication with a source of pressurized oil. An oil seal is axially spaced from each piston ring defining an annular oil filled reservoir external to each piston ring. The oil seal acts as a one way check valve to impede gas incursion into the oil reservoir and oil filled annulus. ## Claims ### Claim 1 An oil damper for supporting a shaft rotating about an axis, the oil damper comprising: an oil filled annulus radially defined between a structural support and a bearing housing; a pair of sealing rings between the structural support and the bearing housing, the sealing rings defining axial boundaries of the oil filled annulus, the oil contained in the oil filled annulus by the pair of sealing rings; an oil inlet between the pair of sealing rings, the oil inlet being in communication with a source of pressurized oil; and an oil seal axially spaced from each sealing ring defining an annular oil reservoir external to each sealing ring, the oil seal configured to act as a one-way check valve to impede intrusion of ambient gas into the annular oil reservoir while allowing extrusion from the annular oil reservoir in a direction away from the sealing rings. ### Claim 2 (depends on 1) The oil damper according to claim 1, wherein the oil seal has a seal lip resiliently biased against a contact surface. ### Claim 3 (depends on 2) The oil damper according to claim 2, wherein the oil seal has a canted or curved outer surface relative to the contact surface, the canted or curved outer surface being exposed to ambient gas. ### Claim 4 (depends on 2) The oil damper according to claim 2, wherein the oil seal has a canted or curved inner surface relative to the contact surface, the canted or curved inner surface being exposed to oil within the annular oil reservoir. ### Claim 5 (depends on 2) The oil damper according to claim 2, wherein the oil seal has a bevelled seal lip. ### Claim 6 (depends on 2) The oil damper according to claim 2, wherein the oil seal has a base ring opposite the seal lip and the base ring is embedded in a groove disposed in a first one of: the structural support and the bearing housing. ### Claim 7 The oil damper according to 6, wherein the contact surface is provided on a second one of the structural support and the bearing housing. ### Claim 8 An oil film damper for supporting a shaft rotating about an axis and for accommodating radial movement of a bearing housing relative to a structural support, the damper comprising: an oil-filled annulus radially defined between the structural support and the bearing housing; a pair of sealing rings between the structural support and the bearing housing and the sealing rings defining axial boundaries of the oil filled annulus, the oil contained in the oil filled annulus by the pair of sealing rings; an oil inlet between the pair of sealing rings, the oil inlet being in communication with a source of pressurized oil; and an oil seal axially spaced from each sealing ring defining an annular oil reservoir external to each sealing ring, the oil seal having a seal lip resiliently biased against a contact surface to impede intrusion of ambient gas into the oil reservoir and to permit extrusion from the oil reservoir between the seal lip and contact surface. ### Claim 9 (depends on 8) The oil film damper according to claim 8 wherein the oil seal has a canted or curved outer surface relative to the contact surface, the canted or curved outer surface being exposed to ambient gas. ### Claim 10 (depends on 8) The oil film damper according to claim 8 wherein the oil seal has a canted or curved inner surface relative to the contact surface, the canted or curved inner surface being exposed to oil within the annular oil reservoir. ### Claim 11 (depends on 8) The oil film damper according to claim 8 wherein the oil seal has a bevelled seal lip. ### Claim 12 (depends on 8) The oil film damper according to claim 8 wherein the oil seal has a base ring opposite the seal lip and the base ring is embedded in a groove disposed in one of: the structural support; and the bearing housing. ### Claim 13 A gas turbine engine comprising: an oil film damper for supporting an engine shaft rotating about an engine axis and for accommodating radial movement of a bearing housing relative to a structural support, the oil film damper comprising: an oil filled annulus radially defined between the structural support and the bearing housing; a pair of sealing rings between the structural support and the bearing housing and the sealing rings defining axial boundaries of the oil filled annulus, the oil contained in the oil filled annulus by the pair of sealing rings; an oil inlet between the pair of sealing rings, the oil inlet being in communication with a source of pressurized oil; and an oil seal axially spaced from each sealing ring defining an annular oil filled reservoir external to each sealing ring, the oil seal having a seal lip resiliently biased against a contact surface to impede intrusion of ambient gas into the reservoir and to permit extrusion from the reservoir between the seal lip and contact surface. ### Claim 14 (depends on 13) The gas turbine engine according to claim 13 wherein the oil seal has a canted or curved outer surface relative to the contact surface, the canted or curved outer surface being exposed to ambient gas. ### Claim 15 (depends on 13) The gas turbine engine according to claim 13 wherein the oil seal has a canted or curved inner surface relative to the contact surface, the canted or curved inner surface being exposed to oil within the annular oil filled reservoir. ### Claim 16 (depends on 13) The gas turbine engine according to claim 13 wherein the oil seal has a bevelled seal lip. ### Claim 17 (depends on 13) The gas turbine engine according to claim 13 wherein the oil seal has a base ring opposite the seal lip and the base ring is embedded in a groove disposed in one of: the structural support, and the bearing housing. ### Claim 18 (depends on 13) The gas turbine engine according to claim 13, wherein the oil seal has a base ring opposite the seal lip and the base ring is mounted to one of the structural support and the bearing housing. ### Claim 19 (depends on 13) The gas turbine engine according to claim 13, wherein the oil seal has a flat or curved seal lip.