# US 8,770,918 B1 · Non-contacting seals for geared gas turbine engine bearing compartments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,918 B1 - Document ID: US8770918B1 - Status: Granted - Kind: B1 - Application number: 14/053,648 - Filed: 2013-10-15 - Granted: 2014-07-08 - Earliest claimed: 2013-03-07 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: M. Rifat Ullah; Robert E. Peters - Web page: https://patentgrep.com/patent/US8770918B1 ## CPC - F01D 25/186: {for sliding contact bearing} - F01D 11/02: by non-contact sealings, e.g. of labyrinth type (for sealing space between rotor blade tips and stator F01D11/08) - F01D 25/166: {Sliding contact bearing (gas bearings F01D25/22)} - F01D 25/168: {for axial load mainly} - F01D 25/22: using working-fluid or other gaseous fluid as lubricant - F02C 7/28: Arrangement of seals - F16C 32/0633: {the liquid being retained in a gap} - F16C 33/72: Sealings - F16J 15/3412: {with cavities (F16J15/3424 takes precedence)} - F16J 15/342: {with means for feeding fluid directly to the face} - F16J 15/441: {with floating ring} - F05D 2220/32: in gas turbines - F05D 2240/50: Bearings - F16C 2360/23: Gas turbine engines - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A rotating element is associated with at least one bearing compartment that includes a bearing to support the rotating element. A seal resists leakage of lubricant outwardly of the bearing compartment and allows air to flow from a chamber across the seal and into the bearing compartment. The seal has a seal face facing a rotating face rotating with the rotating element. The seal is a non-contact seal. A gas turbine engine is also disclosed. ## Claims ### Claim 1 A section for a gas turbine engine comprising: a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing air to flow from a chamber across the seal and into the bearing compartment; said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and said seal is a circumferentially segmented carbon seal. ### Claim 2 (depends on 1) The section as set forth in claim 1, wherein said rotating element is a shaft rotating with a rotor having an axial face facing said seal face. ### Claim 3 (depends on 2) The section as set forth in claim 2, wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said seal face and into the bearing compartment to resist leakage of lubricant from the bearing compartment. ### Claim 4 (depends on 3) The section as set forth in claim 3, wherein said seal being formed with a plurality of passages to allow tapping of additional pressurized air to be delivered to the faces at a location in the proximity of the grooved area for generating hydrostatic lift-off forces. ### Claim 5 (depends on 1) The section as set forth in claim 1, wherein said rotating element is a shaft rotating with a rotor having a circumferential face facing said seal face. ### Claim 6 (depends on 5) The section as set forth in claim 5, wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said seal face and into the bearing compartment to resist leakage of lubricant from the bearing compartment. ### Claim 7 A section for a gas turbine engine comprising: a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing air to flow from a chamber across the seal and into the bearing compartment; said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and said seal is a controlled gap carbon seal having a full hoop seal and a metal band shrunk fit onto the seal, and positioned in a seal carrier. ### Claim 8 (depends on 1) The section as set forth in claim 1, wherein the rotating element is driven by a fan drive turbine. ### Claim 9 (depends on 8) The section as set forth in claim 8, wherein said seal is a carbon seal. ### Claim 10 (depends on 8) The section as set forth in claim 8, wherein said bearing compartment has a seal associated with each of two opposed axial ends, on either axial side of said bearing. ### Claim 11 (depends on 8) The section as set forth in claim 8, wherein said seal face faces radially inwardly. ### Claim 12 A gas turbine engine comprising: a fan, a compressor section, a combustor, and a turbine section with a fan drive turbine driving said fan through a gear reduction; a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing pressurized air to flow from a chamber across said seal into the bearing compartment; said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and the rotating element being driven by the fan drive turbine, and said at least one bearing compartment being associated with said gear reduction. ### Claim 13 (depends on 12) The gas turbine engine as set forth in claim 12, wherein said rotating element is a shaft rotating with a rotor having an axial face facing said seal face. ### Claim 14 (depends on 13) The gas turbine engine as set forth in claim 13, wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said faces and into the bearing compartment to resist leakage of lubricant from the bearing compartment. ### Claim 15 (depends on 14) The gas turbine engine as set forth in claim 14, wherein said seal being formed with a plurality of passages to allow tapping of additional pressurized air to be delivered to the faces at a location in the proximity of the grooved area for generating hydrostatic lift-off forces. ### Claim 16 A gas turbine engine comprising: a fan, a compressor section, a combustor, and a turbine section with a fan drive turbine driving said fan through a gear reduction; a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing pressurized air to flow from a chamber across said seal into the bearing compartment; said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and said seal is a circumferentially segmented carbon seal. ### Claim 17 (depends on 16) The gas turbine engine as set forth in claim 16, wherein said rotating element is a shaft rotating with a rotor having a circumferential face facing said seal face. ### Claim 18 (depends on 17) The gas turbine engine as set forth in claim 17, wherein a grooved area is formed in one of said faces, with said grooved area having a plurality of circumferentially spaced grooves for generating hydrodynamic lift-off forces and allowing leakage of pressurized air across said seal face and into the bearing compartment to resist leakage of lubricant from the bearing compartment. ### Claim 19 A gas turbine engine comprising: a fan, a compressor section, a combustor, and a turbine section with a fan drive turbine driving said fan through a gear reduction; a rotating element and at least one bearing compartment including a bearing for supporting said rotating element, a seal for resisting leakage of lubricant outwardly of said bearing compartment and for allowing pressurized air to flow from a chamber across said seal into the bearing compartment: said seal having a seal face facing a rotating face rotating with said rotating element, and said seal being a non-contact seal; and said seal is a controlled gap carbon seal having a full hoop seal and a metal band shrunk fit onto the seal, and positioned in a seal carrier. ### Claim 20 (depends on 12) The gas turbine engine as set forth in claim 12, wherein said seal is a carbon seal. ### Claim 21 (depends on 20) The gas turbine engine as set forth in claim 20, wherein said bearing compartment has a seal associated with each of two opposed axial ends, on either axial side of said bearing. ### Claim 22 (depends on 20) The gas turbine engine as set forth in claim 20, wherein said seal face faces radially inwardly.