# US 10,119,412 B2 · Turbine engine adaptive low leakage air seal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,412 B2 - Document ID: US10119412B2 - Status: Granted - Kind: B2 - Application number: 14/768,769 - Filed: 2014-03-10 - Published: 2016-01-07 - Granted: 2018-11-06 - Earliest claimed: 2013-03-13 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Gary D. Roberge - Web page: https://patentgrep.com/patent/US10119412B2 ## CPC - F01D 11/20: Actively adjusting tip-clearance - F16J 15/43: kept in sealing position by magnetic force - F05D 2300/507: Magnetic properties - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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 ## Abstract An air seal includes a sealing gland configured to retain a ferro-fluid and one or more seals. A portion of the one or more seals is configured to extend into the sealing gland. A gas turbine engine, includes the air seal. A method of sealing low pressure air from high pressure air, includes the steps of providing a sealing gland configured to retain a ferro-fluid, distributing the ferro-fluid into the sealing gland, providing one or more seals, wherein a portion of the one or more seals is configured to extend into the sealing gland, and removing the ferro-fluid from the sealing gland. ## Claims ### Claim 1 A seal, comprising: a sealing gland configured to retain a ferro-fluid; and at least one rotating seal, the rotating seal arranged perpendicular to an axis of rotation of a rotating component; wherein at least a portion of the one or more rotating seals extends into the sealing gland, the sealing gland defined by an annular channel having lateral spaced apart walls, the rotating seal arranged at a location axially between the walls, and wherein the at least one rotating seal is an airfoil tip seal, and the rotating component is an airfoil blade. ### Claim 2 (depends on 1) The air seal of claim 1, wherein the sealing gland is subject to a magnetic field. ### Claim 3 (depends on 1) The air seal of claim 1, wherein the at least one rotating seal is a knife-edge seal. ### Claim 4 (depends on 1) The air seal of claim 1, wherein the sealing gland extends circumferentially around a rotor, the rotor including the at least one rotating seal. ### Claim 5 (depends on 1) The air seal of claim 1, further comprising a ferro-fluid collection drain and a ferro-fluid collection tank. ### Claim 6 (depends on 1) The air seal of claim 1, further comprising a cooler configured to receive the ferro-fluid at a temperature and change the temperature of the ferro-fluid. ### Claim 7 (depends on 1) The air seal of claim 1, wherein the at least one rotating seal includes a magnetic field configured to repel the ferro-fluid. ### Claim 8 (depends on 1) The air seal of claim 1, wherein the at least one rotating seal is located on a seal arm extending from a rotating component. ### Claim 9 A gas turbine engine, comprising: a combustor section arranged fluidly between a compressor section and a turbine section: a high pressure area; a low pressure area, the high and low pressure areas arranged in one of the compressor and turbine sections; a sealing gland subject to a magnetic field and configured to retain a ferro-fluid; and a rotating component having at least one seal configured to seal the high pressure area from the low pressure area, at least a portion of the at least one seal extending into the sealing gland; and wherein the at least one rotating seal is a knife edge seal, and the rotating component is one of a turbine and a compressor. ### Claim 10 (depends on 9) The gas turbine engine of claim 9, wherein the at least one seal is located on a seal arm extending from a rotating component, the seal arranged perpendicular to an axis of rotation of the rotating component. ### Claim 11 (depends on 9) The gas turbine engine of claim 9, further comprising a cooler configured to receive the ferro-fluid at a temperature and change the temperature of the ferro-fluid. ### Claim 12 A method of sealing low pressure air from high pressure air in a gas turbine engine, comprising the steps of: providing a sealing gland configured to retain a ferro-fluid; distributing the ferro-fluid into the sealing gland; providing at least one rotating seal, the rotating seal perpendicular to an axis of rotation of a rotating component, wherein at least a portion of the one or more rotating seals extends into the sealing gland, the sealing gland defined by an annular channel having lateral spaced apart walls , the seal arranged at a location axially between the walls; removing the ferro-fluid from the sealing gland; and wherein the at least one rotating seal is an airfoil tip seal, and the rotating component is an airfoil blade. ### Claim 13 (depends on 12) The method of claim 12, wherein the step of distributing the ferro-fluid into the sealing gland further comprises the steps of: applying an alternating magnetic field to the sealing gland; allowing the ferro-fluid to form a uniform layer in the sealing gland; and applying a static magnetic field to the sealing gland. ### Claim 14 (depends on 12) The method of claim 12, further comprising the step of adjusting the magnetic field to adjust the ferro-fluid to air surface. ### Claim 15 (depends on 12) The method of claim 12, wherein the ferro-fluid is distributed into the sealing gland during an engine start-up sequence. ### Claim 16 (depends on 12) The method of claim 12, wherein the ferro-fluid is removed from the sealing gland during engine shut-down.