Abstract: A gas turbine engine includes a fan section. A speed change mechanism drives the fan section. The speed change mechanism is an epicyclic gear train. A torque frame includes a ring and a plurality of fingers that extend from the ring with the plurality of fingers surrounding the speed change mechanism. A bearing support is attached to the plurality of fingers. A first fan section support bearing is mounted on a first axial side of the speed change mechanism and a second fan section bearing is mounted on a second axial side of the speed change mechanism. The second fan section bearing is a fan thrust bearing.

Abstract: A gas turbine engine includes a fan, a fan shaft coupled with the fan and arranged along an engine central axis, and a frame supporting the fan shaft. The frame defines a lateral frame stiffness (LFS). A non-rotatable flexible coupling and a rotatable flexible coupling support an epicyclic gear system. The couplings are subject to a Motion II of cantilever beam free end motion with respect to the engine central axis. The non-rotatable and the rotatable flexible couplings each have a stiffness of a common stiffness type under a common type of motion. The common stiffness type is a Stiffness B and the common type of motion is the Motion II. The Stiffness B of the rotatable flexible coupling is greater than the stiffness B of the non-rotatable flexible coupling, and a ratio of LFS/Stiffness B of the non-rotatable flexible coupling is in a range of 10-40.

Abstract: A turbofan engine includes a fan section. A turbine section is in driving engagement with the fan section through a planetary gear system. The planetary gear system includes a plurality of planet gears surrounding a sun gear. A carrier supports the plurality of planet gears and includes a first carrier bearing flange. A ring gear surrounds the plurality of planet gears and includes a ring gear bearing flange. At least one ring gear carrier bearing engages the carrier bearing flange and the ring gear bearing flange. A speed change mechanism for a gas turbine is also disclosed.

Abstract: A seal system has: a first member; a seal carried by the first member and having a seal face; and a second member rotatable relative to the first member about an axis. The second member has: a seat, the seat having a seat face in sliding sealing engagement with the seal face; and a circumferential array of passageway legs open to the seat face; and an oil pump for delivering oil via one or more first outlets to the passageway legs in at least a first mode of operation. The oil pump is coupled to one or more second outlets to deliver oil to a backside of the seat in at least a second mode of operation.

Abstract: A method of assembling a fan drive gear system for a gas turbine engine according to an example of the present disclosure includes the steps of providing a unitary carrier defining a central axis and that includes spaced apart walls and circumferentially spaced mounts defining spaced apart apertures at an outer circumference of the carrier, gear pockets defined between the walls and extending to the apertures, and a central opening in at least one of the walls. The method includes the steps of inserting a plurality of intermediate gears through the central opening, moving the intermediate gears radially outwardly relative to the central axis into the gear pockets, inserting a sun gear through the central opening, moving the plurality of intermediate gears radially inwardly relative to the central axis to engage the sun gear, and coupling a fan shaft to the carrier such that the fan shaft and intermediate gears are rotatable about the central axis. A fan drive gear system is also disclosed.

Abstract: A gas turbine engine comprises a fan drive turbine, a fan rotor, and a gear reduction driven by the fan drive turbine to, in turn, drive the gear architecture. A main oil supply system supplies oil to components within the gear reduction, and an auxiliary oil supply system. The auxiliary oil system operates to ensure that the gear reduction will be adequately supplied with lubricant for at least 30 seconds at power should the main oil supply system fail.

Abstract: A turbofan engine includes a geared architecture for driving a fan about an axis. The geared architecture includes a sun gear rotatable about an axis, a plurality of planet gears driven by the sun gear and a ring gear circumscribing the plurality of planet gears. A carrier supports the plurality of planet gears. The geared architecture includes a power transfer parameter (PTP) defined as power transferred through the geared architecture divided by gear volume multiplied by a gear reduction ratio and is between 219 and 328.

Abstract: A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.

Abstract: A gas turbine engine comprises a fan drive turbine driving a shaft. The shaft engages a gear reduction. The gear reduction drives a fan rotor at a speed that is less than the speed of the fan drive turbine. The gear reduction is a non-epicyclic gear reduction.

Abstract: Aspects of the disclosure are directed to a gas turbine engine, having a fan that rotates about a central longitudinal axis. The gas turbine engine may comprise a nacelle having an outer wall that radially circumscribes the fan. The gas turbine engine may further comprise a fan drive gear system that drives the fan, and a rotating shaft that is coupled to and drives the fan drive gear system. The gas turbine engine may further comprise an air vent line in fluid communication with a bearing compartment to remove air from the bearing compartment and provide the removed air to a deoiler that removes oil droplets from the removed air and provides deoiler filtered air. A vent output line receives the deoiler filtered air and discharges the deoiler filtered air along a radially interior surface of the nacelle outer wall.

Abstract: A gas turbine engine according to an exemplary embodiment of this disclosure includes among other possible things, a fan section including a plurality of fan blades, a first electric motor assembly that provides a first drive input for driving the fan blades about an axis, a turbine section, and a geared architecture driven by the turbine section and coupled to the fan section to provide a second drive input for driving the fan blades, and second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure controls a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

Abstract: A method of assembling an epicyclic gear train includes positioning a carrier, the carrier being a unitary structure with side walls and mounts unitary with one another, inserting intermediate gears through a central opening of the carrier, moving each of the intermediate gears into intermediate gear pockets, inserting baffles into the carrier, inserting a sun gear through the central opening, and moving the intermediate gears to intermesh with the sun gear, and moving a ring gear into engagement with the intermediate gears.

Abstract: A turbofan engine includes a fan section. A turbine section is in driving engagement with the fan section through a star gear system. The star gear system includes a plurality of star gears surrounding a sun gear. A carrier supports the plurality of star gears and includes a first carrier bearing flange. A ring gear surrounds the plurality of star gears and includes a ring gear bearing flange. At least one ring gear carrier bearing engages the carrier bearing flange and the ring gear bearing flange. A speed change mechanism for a gas turbine engine is also disclosed.

Abstract: A speed change device includes a sun gear. A plurality of intermediate gears surround the sun gear. Each of the plurality of intermediate gears includes a forward set of teeth and an aft set of teeth. A ring gear surrounds the plurality of intermediate gears. The ring gear includes a forward portion with a forward set of teeth in meshing engagement with the forward set of teeth on each of the plurality of intermediate gears and an aft portion with an aft set of teeth in meshing engagement with the aft set of teeth on each of the plurality of intermediate gears. A carrier includes a carrier forward portion and a carrier aft portion. Each of the plurality of intermediate gears are located axially between the carrier forward portion and the carrier aft portion.

Abstract: A gas turbine engine includes a fan section and a speed change mechanism for driving the fan section. The speed change mechanism is an epicyclic gear train. A torque frame surrounds the speed change mechanism and includes a plurality of fingers. A bearing support is attached to the plurality of fingers. A first fan section support bearing is mounted forward of the speed change mechanism and a second fan section bearing is mounted on the bearing support aft of the speed change mechanism. The second fan section bearing is a fan thrust bearing.

Abstract: A gas turbine engine includes a fan section that includes a fan drive shaft. A star gear system for driving the fan section has a carrier mounted to a static structure to prevent the carrier from rotating. A ring gear is attached to a ring gear attachment point on the fan drive shaft. A first fan section support bearing supports a fan drive shaft and is mounted forward of the ring gear attachment point. A second fan section bearing supports the fan drive shaft and is mounted aft of the ring gear attachment point on the fan drive shaft. An outer race of the second fan section bearing is fixed relative to an engine static structure.

Abstract: A gas turbine engine includes a fan, a fan shaft coupled with the fan and arranged along an engine central axis, and a frame supporting the fan shaft. The frame defines a lateral frame stiffness (LFS). An epicyclic gear system is coupled to the fan shaft, and a non-rotatable flexible coupling and a rotatable flexible coupling support the epicyclic gear system. The non-rotatable flexible coupling and the rotatable flexible coupling each have a stiffness of a common stiffness type under a common type of motion with respect to the engine central axis. The stiffness is defined with respect to the LFS. The stiffness of the rotatable flexible coupling is greater than the stiffness of the non-rotatable flexible coupling.

Abstract: A turbofan gas turbine engine includes, among other things, a fan section including a fan hub and an outer housing, the fan hub including a hub diameter supporting a plurality of fan blades, a turbine section including a fan drive turbine, and a geared architecture that interconnects the fan drive turbine and the fan hub, the geared architecture including a gear volume.

Abstract: A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.