# US 10,119,474 B2 · Vibration damping apparatus for hydrostatic seal of gas turbine engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,474 B2 - Document ID: US10119474B2 - Status: Granted - Kind: B2 - Application number: 14/766,192 - Filed: 2013-12-18 - Published: 2016-03-10 - Granted: 2018-11-06 - Earliest claimed: 2013-03-15 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Dave J. Hyland; Joseph T. Caprario; Timothy Dale - Web page: https://patentgrep.com/patent/US10119474B2 ## CPC - F02C 7/28: Arrangement of seals - F01D 11/001: {for sealing space between stator blade and rotor} - F01D 11/025: {Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations} - F01D 19/00: Starting of machines or engines; Regulating, controlling, or safety means in connection therewith (warming-up before starting F01D25/10; turning or inching gear F01D25/34) - F01D 25/04: Antivibration arrangements - F01D 25/22: using working-fluid or other gaseous fluid as lubricant - F16J 15/44: Free-space packings - F16J 15/442: {segmented} - F05D 2240/53: Hydrodynamic or hydrostatic bearings - F05D 2260/85: Starting - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - 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) - 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 A hydrostatic seal and vibration damping apparatus for a gas turbine engine adapted to reduce vibrations during cold engine start-ups is disclosed. In one disclosed configuration, the vibration damping apparatus is comprised of a temperature sensitive control ring having a relatively high coefficient of thermal expansion adapted to expand quickly at relatively low temperatures to protect the hydrostatic seal during such gas turbine engine startups. At operational temperatures, the control ring is adapted to become separated from the hydrostatic sea. ## Claims ### Claim 1 A hydrostatic seal and vibration damping assembly for a gas turbine engine, comprising: a hydrostatic seal having a shoe; and a vibration damping apparatus operatively associated with the shoe, the vibration damping apparatus having a different coefficient of thermal expansion than the hydrostatic shoe, wherein the hydrostatic seal further comprises a spacer plate and a front plate which cooperate with the shoe to define a channel, and wherein the vibration damping apparatus is positioned within the channel and the vibration damping apparatus engages the shoe and limit vibrations of the shoe during a cold start-up of the gas turbine engine, and wherein the vibration damping apparatus disengages from the shoe after the gas turbine engine reaches an operational temperature. ### Claim 2 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus is annular in shape. ### Claim 3 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus is one of an oval in shape or a discontinuous loop. ### Claim 4 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus comprises an Inconel material. ### Claim 5 (depends on 4) The hydrostatic seal and vibration damping assembly of claim 4, wherein the vibration damping apparatus comprises an Inconel 718 material. ### Claim 6 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus has a circular cross-section. ### Claim 7 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus has a rectangular cross-section. ### Claim 8 (depends on 1) The hydrostatic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus has an extended oval cross-section. ### Claim 9 (depends on 1) The hydrodynamic seal and vibration damping assembly of claim 1, wherein the vibration damping apparatus is positioned against a radially outer diameter of the shoe. ### Claim 10 A gas turbine engine, comprising: a stator; a rotor rotating within the stator and defining a circumferential gap therebetween; a hydrostatic seal and a vibration damping assembly, the hydrostatic seal being positioned within the circumferential gap and including a plurality of spring biased shoes and wherein the vibration damping apparatus is operatively associated with the hydrostatic seal to limit vibrations of the plurality of spring biased shoes, wherein the vibration damping assembly has a different coefficient of thermal expansion than the plurality of spring biased shoes, and wherein the hydrostatic seal further comprises a spacer plate and a front plate which cooperate with the plurality of spring biased shoes to define a channel, and wherein the vibration damping apparatus is positioned within the channel and the vibration damping apparatus engages the plurality of spring biased shoes and limits vibrations of the plurality of spring biased shoes during a cold start-up of the gas turbine engine, and wherein the vibration damping apparatus disengages from the plurality of spring biased shoes after the gas turbine engine reaches an operational temperature. ### Claim 11 (depends on 10) The gas turbine engine of claim 10, wherein the vibration damping apparatus is one of circular and oval in shape. ### Claim 12 (depends on 10) The gas turbine engine of claim 10, wherein the vibration damping apparatus is a discontinuous loop. ### Claim 13 (depends on 10) The gas turbine engine of claim 10, wherein the vibration damping apparatus comprises an Inconel material. ### Claim 14 (depends on 13) The gas turbine engine of claim 13, wherein the vibration damping apparatus comprises an Inconel 718 material. ### Claim 15 (depends on 10) The gas turbine engine of claim 10, wherein the vibration damping apparatus has one of a circular, rectangular and extended oval cross-section. ### Claim 16 A method of damping vibrations in a hydrostatic seal of a gas turbine engine, comprising: positioning a hydrostatic seal between a rotor and stator of the gas turbine engine; extending a shoe of the hydrostatic seal into a gap between the rotor and the stator; engaging the shoe with a vibration damping apparatus when the gas turbine engine initiates a cold start-up; and disengaging the shoe from the vibration damping apparatus when the gas turbine engine reaches an operational temperature, wherein the hydrostatic seal further includes a front plate and a spacer plate which cooperate with the shoe to form a channel, and wherein the method further includes positioning the vibration damping apparatus within the channel and wherein the vibration damping apparatus is formed from a material having a different coefficient of thermal expansion than the shoe. ### Claim 17 (depends on 16) The method of claim 16, further including manufacturing the vibration damping apparatus from an Inconel material.