# US 2014/0196471 A1 · Fan drive gear system flexible support features > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196471 A1 - Document ID: US20140196471A1 - Status: Published application - Kind: A1 - Application number: 13/653,548 - Filed: 2012-10-17 - Published: 2014-07-17 - Earliest claimed: 2012-10-01 - Assignees: United Technologies Corporation - Inventors: John R. Otto; Sunil Sharma - Web page: https://patentgrep.com/patent/US20140196471A1 ## CPC - F16H 1/2809: {with means for equalising the distribution of load on the planet gears} - F02C 7/36: Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) - F05D 2260/30: Retaining components in desired mutual position - F05D 2260/40311: of the epicyclical, planetary or differential type - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - Y10T 29/49231: I.C. [internal combustion] engine making - F16H: GEARING - 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) - 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 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A disclosed gear assembly support for a gas turbine engine includes a first portion configured for attachment to a case of the gas turbine engine and a second portion configured for supporting a gear assembly. The support further includes a snap portion defining a fit within the case. The snap portion includes a tunable feature for adjusting a fit within the case. A torque reacting portion of the support transfers torque from the second portion to the first portion separate from the snap portion and include separately tunable features fore adjusting the snap fit independent of the torque transfer portions. ## Claims ### Claim 1 A gear assembly support for a gas turbine engine comprising: a first portion configured for attachment to a case of the gas turbine engine; a second portion configured for supporting a gear assembly; a snap portion defining a fit within the case, the snap portion including a tunable feature for adjusting the fit within the case; and a torque reacting portion for transferring torque from the second portion to the first portion independent of the snap portion. ### Claim 2 (depends on 1) The gear assembly support as recited in claim 1, wherein the snap portion comprises an outer diameter defining the fit within the case and the tunable feature comprises a thickness between an undercut and the outer diameter. ### Claim 3 (depends on 2) The gear assembly support as recited in claim 2, wherein the outer diameter comprises a complete uninterrupted outer diameter and the undercut comprises a plurality of undercuts spaced circumferentially apart proximate the outer diameter. ### Claim 4 (depends on 3) The gear assembly support as recited in claim 3, wherein the plurality of undercuts include an axial width and a radial width adjustable for tuning the fit within the case. ### Claim 5 (depends on 1) The gear assembly support as recited in claim 1, wherein the torque reacting portion includes a width between the tunable feature and an inner surface of the gear assembly support. ### Claim 6 (depends on 1) The gear assembly as recited in claim 1, including a flex portion disposed between the second portion and the torque reacting portion. ### Claim 7 (depends on 1) The gear assembly as recited in claim 1, wherein the snap portion includes an annular groove on a radially outer surface that fits within the case. ### Claim 8 (depends on 7) The gear assembly as recited in claim 7, wherein the first portion comprise a plurality of flanges extending radially outward from the outer surface. ### Claim 9 A gas turbine engine comprising: a fan including a plurality of fan blades rotatable about an axis A; a compressor section; a combustor in fluid communication with the compressor section; a turbine section in fluid communication with the combustor; a geared architecture driven by the turbine section for rotating the fan about the axis A; and a support member that supports the geared architecture, the support member including a first portion configured for attachment to a case, a second portion configured for supporting the geared architecture, a snap portion including a tunable feature for adjusting a fit within the case, and a torque reacting portion for transferring torque from the second portion to the first portion independent of the snap portion. ### Claim 10 (depends on 9) The gas turbine engine as recited in claim 9, wherein the snap portion comprises an outer diameter defining an interference fit with an inner diameter of the case and the tunable feature comprises a thickness between an undercut and the outer diameter. ### Claim 11 (depends on 10) The gas turbine engine as recited in claim 10, wherein the outer diameter comprises a complete uninterrupted outer diameter and the undercut comprises a plurality of undercuts spaced circumferentially apart proximate the outer diameter. ### Claim 12 (depends on 9) The gas turbine engine as recited in claim 9, wherein the torque reacting portion includes an axial width. ### Claim 13 (depends on 9) The gas turbine engine as recited in claim 9, wherein the snap portion includes an annular groove on a radially outer surface that fits within the case. ### Claim 14 A method of supporting a gear assembly within a gas turbine engine comprising: defining a fit between a support member and a static structure within the gas turbine engine with a snap portion; defining a torque transfer path between a first portion configured for attachment to the static structure and a second portion configured for attachment to the gear assembly independent of the snap portion; attaching the gear assembly to the second portion; and attaching the support member to the static structure such that the snap portion positions the support member relative to the static structure. ### Claim 15 (depends on 14) The method as recited in claim 14, wherein defining the fit between the support member and the static structure comprises defining a thickness between an outer diameter of the snap portion and an undercut proximate the outer diameter. ### Claim 16 (depends on 15) The method as recited in claim 15, including defining a plurality of undercuts, spacing the plurality of undercuts circumferentially apart and defining the torque transfer path at least partially between the plurality of undercuts. ### Claim 17 (depends on 16) The method as recited in claim 16, wherein defining the torque transfer path comprises defining an axial thickness of the torque transfer path.