# US 12,760,685 B2 · Gas turbine engine with front support arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,760,685 B2 - Document ID: US12760685B2 - Status: Granted - Kind: B2 - Application number: 19/280,235 - Filed: 2025-07-25 - Published: 2025-11-20 - Granted: 2026-10-13 - Earliest claimed: 2014-03-07 - Assignees: Rtx Corporation - Applicants: Rtx Corporation - Inventors: William G. Sheridan - Web page: https://patentgrep.com/patent/US12760685B2 ## CPC - 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) - F01D 5/02: Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) - F01D 15/12: Combinations with mechanical gearing (driven by multiple engines F01D13/00) - F01D 25/16: Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) - F01D 25/162: {Bearing supports} - F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16) - F02C 3/107: with two or more rotors connected by power transmission - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - F05D 2220/32: in gas turbines - F05D 2230/60: Assembly methods - F05D 2260/40311: of the epicyclical, planetary or differential type - 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) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A gas turbine engine may include a propulsor section including a propulsor having propulsor blades extending from a propulsor hub. A speed reduction device interconnects a turbine and a propulsor shaft that drives the propulsor. Bearings are positioned on opposite sides of the speed reduction device. A propulsor drive gear module is also disclosed. ## Claims ### Claim 1 A gas turbine engine comprising: a propulsor section including a propulsor having propulsor blades extending from a propulsor hub, wherein the propulsor is rotatable about a longitudinal axis; a propulsor shaft that drives the propulsor; a compressor section including a first compressor and a second compressor; a speed reduction device including an epicyclic gear system, wherein the epicyclic gear system includes a sun gear, a ring gear, a carrier and a plurality of intermediate gears supported on respective support members of the carrier, wherein the support members extend from the carrier to respective free ends; a turbine section including a first turbine and a second turbine, wherein the first turbine drives the second turbine, and the speed reduction device interconnects the second turbine and the propulsor shaft; a first bearing that supports rotation of the propulsor hub; and a second bearing that supports rotation of the propulsor hub, wherein the first and second bearings are positioned on opposite sides of the speed reduction device with respect to the longitudinal axis; wherein an outer race of the first bearing and an outer race of the second bearing are rotatable with the propulsor hub. ### Claim 2 (depends on 1) The gas turbine engine of claim 1, wherein the first compressor includes a plurality of stages. ### Claim 3 (depends on 2) The gas turbine engine of claim 2, wherein the propulsor and the first compressor are rotatable together at the same rotational speed. ### Claim 4 (depends on 3) The gas turbine engine of claim 3, wherein the ring gear is adapted to turn the propulsor hub and the first compressor at the same rotational speed. ### Claim 5 (depends on 2) The gas turbine engine of claim 2, wherein the epicyclic gear system is radially inward and axially aligned with the first compressor with respect to the longitudinal axis. ### Claim 6 (depends on 1) The gas turbine engine of claim 1, wherein the outer race of the first bearing and the outer race of the second bearing are rotatable with the propulsor hub in the same direction and at the same rotational speed. ### Claim 7 (depends on 1) The gas turbine engine of claim 1, wherein the support members are posts. ### Claim 8 (depends on 7) The gas turbine engine of claim 7, wherein the intermediate gears are mounted on respective bearing assemblies coupled to the carrier. ### Claim 9 (depends on 8) The gas turbine engine of claim 8, wherein the posts are flexible and are adapted to support torsional loads from the intermediate gears and the bearing assemblies. ### Claim 10 (depends on 1) The gas turbine engine of claim 1, further comprising: an oil feed tube fluidly coupled to the carrier. ### Claim 11 (depends on 1) The gas turbine engine of claim 1, further comprising: an oil baffle extending from a forward end of the carrier, wherein the oil baffle is adjacent to the free ends of the support members. ### Claim 12 (depends on 1) The gas turbine engine of claim 1, wherein the carrier is fixed from rotation relative to an engine static structure. ### Claim 13 (depends on 12) The gas turbine engine of claim 12, wherein the first bearing includes an inner race, the second bearing includes an inner race, and the inner races are fixed from rotation relative to the engine static structure. ### Claim 14 (depends on 1) The gas turbine engine of claim 1, further comprising: a compartment wall that is rotatable with the first compressor and forms a seal with an engine static structure. ### Claim 15 (depends on 1) The gas turbine engine of claim 1, wherein: the propulsor is a fan, and an outer housing surrounds the fan to establish a bypass flow path. ### Claim 16 A propulsor drive gear module for a gas turbine engine, comprising: a sun gear; a ring gear; a plurality of intermediate gears surrounding the sun gear; and a carrier including a plurality of support members that support the respective intermediate gears, wherein the carrier includes first and second bearings on opposite sides of the carrier that are adapted to support a propulsor hub, the carrier is adapted to be fixed from rotation relative to an engine static structure, and the support members extend from the carrier at respective proximal ends to respective distal free ends; wherein the first bearing includes an inner race and an outer race, the outer race is adapted to be fixed relative to the propulsor hub such that the outer race is rotatable with the propulsor hub in the same direction and at the same rotation speed, the inner race of the first bearing is fixed from rotation relative to the carrier, the carrier is adapted to be fixed from rotation relative to the engine static structure, and an outer race of the second bearing is adapted to be fixed relative to the propulsor hub. ### Claim 17 (depends on 16) The propulsor drive gear module of claim 16, wherein the intermediate gears are mounted on respective intermediate gear bearings, and the support members are adapted to support the respective intermediate gears and the respective intermediate gear bearings. ### Claim 18 (depends on 16) The propulsor drive gear module of claim 16, further comprising: an oil baffle extending from a forward end of the carrier adjacent the distal free ends of the support members. ### Claim 19 (depends on 16) The propulsor drive gear module of claim 16, wherein the ring gear is adapted to be fixed relative to the propulsor hub. ### Claim 20 (depends on 16) The propulsor drive gear module of claim 16, wherein the inner races are disposed along and axially aligned with an outer periphery of the carrier with respect to a longitudinal axis.