# US 12,760,682 B2 · Gearbox assembly with lubricant extraction volume ratio > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,760,682 B2 - Document ID: US12760682B2 - Status: Granted - Kind: B2 - Application number: 19/003,582 - Filed: 2024-12-27 - Published: 2025-05-01 - Granted: 2026-10-13 - Earliest claimed: 2022-06-22 - Assignees: General Electric Company; GE Avio S.r.l. - Applicants: General Electric Company; GE Avio S.r.l. - Inventors: Bugra H. Ertas; Xiaohua Zhang; Miriam Manzoni; Flavia Turi; Andrea Piazza; Arthur W. Sibbach - Web page: https://patentgrep.com/patent/US12760682B2 ## CPC - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - 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) - F16H 57/0423: {Lubricant guiding means mounted or supported on the casing, e.g. shields or baffles for collecting lubricant, tubes or pipes} - F16H 57/0435: {Pressure control for supplying lubricant; Circuits or valves therefor} - F16H 57/0436: {Pumps} - F16H 57/0442: {for supply in case of failure, i.e. auxiliary supply} - F16H 57/045: {Lubricant storage reservoirs, e.g. reservoirs in addition to a gear sump for collecting lubricant in the upper part of a gear case} - F16H 57/0471: {Bearing} - F16H 57/0475: {Engine and gearing, i.e. joint lubrication or cooling or heating thereof} - F16H 57/0476: {Electric machines and gearing, i.e. joint lubrication or cooling or heating thereof} - F16H 2057/02034: {Gearboxes combined or connected with electric machines} - F16H 2057/02073: {Reduction gearboxes for industry} - F16H 57/0443: {for supply of lubricant during tilt or high acceleration, e.g. problems related to the tilt or extreme acceleration of the transmission casing and the supply of lubricant under these conditions} - F16H 57/0482: {Gearings with gears having orbital motion} - F16H 57/0486: {with fixed gear ratio (axle or inter-axle differentials F16H57/0483)} - H02K 7/116: with gears - 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) - F16H: GEARING - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A gas turbine engine includes a gearbox assembly that includes a gearbox and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox. The gutter is characterized by a lubricant extraction volume ratio between 0.01 and 0.3. The lubricant extraction volume ratio defined by: V G V GB . V G is a gutter volume of the gutter and VGB is a gearbox volume. The gas turbine engine includes a lubrication system that includes a lubricant tank that stores lubricant, one or more primary gearbox lubricant supply lines, one or more secondary gearbox lubricant supply lines, and a lubricant pump for supplying the lubricant to the gearbox assembly through the primary gearbox lubricant supply lines and the secondary gearbox lubricant supply lines. The lubrication system modulates a mass flow rate of the lubricant to the gearbox assembly through the primary gearbox lubricant supply lines or the secondary gearbox lubricant supply lines. ## Claims ### Claim 1 A gas turbine engine comprising: a turbo-engine including a compressor section, a combustion section, and a turbine section, the turbo-engine having a turbo-engine shaft that couples the compressor section to the turbine section; a fan section having a fan shaft; a gearbox assembly, the fan shaft being drivingly coupled to the turbo-engine shaft through the gearbox assembly, the gearbox assembly comprising: a gearbox having a plurality of gears and a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox; and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints, the lubricant extraction volume ratio defined by: V G V GB , wherein VG is the gutter volume of the gutter and VGB is the gearbox volume; and a lubrication system comprising: a lubricant tank that stores lubricant therein; a primary gearbox lubricant supply line in fluid communication with the lubricant tank and a component of the gearbox assembly; a secondary gearbox lubricant supply line in fluid communication with the lubricant tank and the component of the gearbox assembly in parallel with the primary gearbox lubricant supply line; a lubricant pump for supplying the lubricant to the component of the gearbox assembly from the lubricant tank through the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line in parallel; a primary valve disposed in the primary gearbox lubricant supply line, the primary valve including a primary valve member that moves between a fully opened position and a fully closed position; and a controller having one or more processors and a memory, the controller configured to control the primary valve between the fully opened position and the fully closed position to modulate a mass flow rate of the lubricant through the primary gearbox lubricant supply line to the gearbox assembly and the primary valve returning a portion of the lubricant to the lubricant tank when the primary valve member is between the fully opened position and the fully closed position. ### Claim 2 (depends on 1) The gas turbine engine of claim 1, further comprising an electric machine drivingly coupled to the turbo-engine shaft, wherein the lubrication system further comprises: a primary electric machine lubricant supply line in fluid communication with the lubricant tank and the electric machine; and a secondary electric machine lubricant supply line in fluid communication with the lubricant tank and the electric machine, wherein the lubricant pump supplies the lubricant to the electric machine from the lubricant tank through the primary electric machine lubricant supply line and the secondary electric machine lubricant supply line, the lubrication system modulating a mass flow rate of the lubricant to the electric machine through at least one of the primary electric machine lubricant supply line or the secondary electric machine lubricant supply line. ### Claim 3 (depends on 1) The gas turbine engine of claim 1, further comprising one or more engine bearings that support rotation of the turbo-engine shaft, wherein the lubrication system further comprises: a primary engine lubricant supply line in fluid communication with the lubricant tank and the one or more engine bearings; and a secondary engine lubricant supply line in fluid communication with the lubricant tank and the one or more engine bearings, wherein the lubricant pump supplies the lubricant to the one or more engine bearings from the lubricant tank through the primary engine lubricant supply line and the secondary engine lubricant supply line, the lubrication system modulating a mass flow rate of the lubricant to the gas turbine engine through at least one of the primary engine lubricant supply line or the secondary engine lubricant supply line. ### Claim 4 (depends on 1) The gas turbine engine of claim 1, wherein the plurality of gears meshes with each other at a mesh, the component of the gearbox assembly being the mesh such that the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line directing the lubricant to the mesh in parallel. ### Claim 5 (depends on 4) The gas turbine engine of claim 4, wherein the primary gearbox lubricant supply line is a first primary gearbox lubricant supply and the lubrication system further comprises a second primary gearbox lubricant supply line in fluid communication with one or more bearings of the plurality of gears. ### Claim 6 (depends on 5) The gas turbine engine of claim 5, wherein the secondary gearbox lubricant supply line is a first secondary gearbox lubricant supply line and the lubrication system further comprises a second secondary gearbox lubricant supply line in fluid communication with the one or more bearings. ### Claim 7 (depends on 1) The gas turbine engine of claim 1, wherein the gearbox includes one or more bearings, the component of the gearbox assembly being the one or more bearings such that the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line direct the lubricant to the one or more bearings in parallel. ### Claim 8 (depends on 1) The gas turbine engine of claim 1, wherein the lubrication system further comprises a secondary valve disposed in the secondary gearbox lubricant supply line for modulating the mass flow rate of the lubricant to the gearbox assembly through the secondary gearbox lubricant supply line. ### Claim 9 (depends on 8) The gas turbine engine of claim 8, wherein the secondary valve is a shut-off valve that includes a secondary valve member that moves between an opened position and a closed position to turn on or to turn off the lubricant through the secondary gearbox lubricant supply line. ### Claim 10 (depends on 1) The gas turbine engine of claim 1, wherein the lubricant extraction volume ratio is between 0.01 and 0.3, inclusive of the endpoints, for a maximum gearbox power between 35 kHP and 90 kHP. ### Claim 11 (depends on 10) The gas turbine engine of claim 10, wherein the lubricant extraction volume ratio is between 0.03 and 0.3, inclusive of the endpoints, for a maximum gearbox power less than 35 kHP. ### Claim 12 (depends on 1) The gas turbine engine of claim 1, wherein the lubrication system includes one or more lubricant supply lines in fluid communication with the lubricant pump, wherein the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line branch from the one or more lubricant supply lines to the component of the gearbox assembly in parallel. ### Claim 13 A gas turbine engine comprising: a turbo-engine including a compressor section, a combustion section, and a turbine section, the turbo-engine having a turbo-engine shaft that couples the compressor section to the turbine section; a fan section having a fan shaft; a gearbox assembly, the fan shaft being drivingly coupled to the turbo-engine shaft through the gearbox assembly, the gearbox assembly comprising: a gearbox including a plurality of gears that mesh with each other at a mesh and having a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox; and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the end points, the lubricant extraction volume ratio defined by: V G V GB wherein VG is the gutter volume of the gutter and VGB is the gearbox volume; and a lubrication system comprising: a lubricant tank that stores lubricant therein; a primary gearbox lubricant supply line in fluid communication with the lubricant tank, wherein the primary gearbox lubricant supply line directs the lubricant to the mesh; a secondary gearbox lubricant supply line in fluid communication with the lubricant tank in parallel with the primary gearbox lubricant supply line, wherein the secondary gearbox lubricant supply line directs the lubricant to the mesh; one or more valves disposed in at least one of the primary gearbox lubricant supply line or the secondary gearbox lubricant supply line, the one or more valves including a primary valve disposed in the primary gearbox lubricant supply line, the primary valve including a primary valve member that moves between a fully opened position and a fully closed position to modulate a mass flow rate of the lubricant through the primary gearbox lubricant supply line to the mesh and returns a portion of the lubricant to the lubricant tank when the primary valve member is between the fully opened position and the fully closed position; and a lubricant pump for supplying the lubricant to the mesh from the lubricant tank through the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line in parallel. ### Claim 14 (depends on 13) The gas turbine engine of claim 13, further comprising an electric machine drivingly coupled to the turbo-engine shaft, wherein the lubrication system further comprises: a primary electric machine lubricant supply line in fluid communication with the lubricant tank and the electric machine; and a secondary electric machine lubricant supply line in fluid communication with the lubricant tank and the electric machine, wherein the lubricant pump supplies the lubricant to the electric machine from the lubricant tank through the primary electric machine lubricant supply line and the secondary electric machine lubricant supply line, the lubrication system modulating a mass flow rate of the lubricant to the electric machine through at least one of the primary electric machine lubricant supply line or the secondary electric machine lubricant supply line. ### Claim 15 (depends on 13) The gas turbine engine of claim 13, further comprising one or more engine bearings that support rotation of the turbo-engine shaft, wherein the lubrication system further comprises: a primary engine lubricant supply line in fluid communication with the lubricant tank and the one or more engine bearings; and a secondary engine lubricant supply line in fluid communication with the lubricant tank and the one or more engine bearings in parallel with the primary engine lubricant supply line, wherein the lubricant pump supplies the lubricantto the one or more engine bearings from the lubricant tank through the primary engine lubricant supply line and the secondary engine lubricant supply line in parallel, the lubrication system modulating a mass flow rate of the lubricant to the one or more engine bearings through at least one of the primary engine lubricant supply line or the secondary engine lubricant supply line. ### Claim 16 (depends on 13) The gas turbine engine of claim 13, wherein the one or more valves include a secondary valve disposed in the secondary gearbox lubricant supply line for modulating the mass flow rate of the lubricant to the gearbox assembly through the secondary gearbox lubricant supply line. ### Claim 17 (depends on 13) The gas turbine engine of claim 13, wherein the lubricant extraction volume ratio is between 0.01 and 0.3, inclusive of the endpoints, for a maximum gearbox power between 35 kHP and 90 kHP. ### Claim 18 (depends on 17) The gas turbine engine of claim 17, wherein the lubricant extraction volume ratio is between 0.03 and 0.3, inclusive of the endpoints, for a maximum gearbox power less than 35 kHP.