Abstract: A disclosed gas turbine engine includes a first electric motor assembly that provides a first drive input for driving fan blades about an axis. A geared architecture is driven by a turbine section and is coupled to the fan section to provide a second drive input for driving the fan blades. A second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure for controlling a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: A gas turbine engine includes a fan shaft diving a fan having fan blades. The gas turbine engine also includes a gear system including a sun gear surrounded by a plurality of intermediate gear, a carrier at least partially supporting said plurality of intermediate gears, and a ring gear surrounding said plurality of intermediate gears, wherein said sun gear is driven by a turbine. The gas turbine engine also includes a flexible coupling fixing said ring gear from rotation relative to an engine static structure and a lubricating system for said gear system. Said lubricating system includes a lubricant input, there being a stationary first bearing receiving lubricant from said lubricant input. Said bearing has an inner first race in which lubricant flows, and a second bearing for rotation within said first bearing. Said second bearing has a first opening in registration with said inner first race such that lubricant may flow from said inner first race through said first opening into a first conduit.

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: In an embodiment of the present disclosure, a gas turbine engine includes a fan, a first compressor stage and a second compressor stage, a first turbine stage and a second turbine stage, and wherein said first turbine stage drives said second compressor stage as a high spool, and wherein said second turbine stage drives said first compressor stage as part of a low spool, and a gear train driving said fan with said low spool, and such that said fan and said first compressor stage rotate in the same direction, and wherein said high spool operates at higher pressures than said low spool.

Abstract: A gear reduction for a gas turbine engine includes intermediate gears, a single structure establishing a carrier centered on an axis and having a pair of axially spaced apart side walls, axially extending circumferentially spaced connecting structure for connecting the pair of side walls, a central opening in at least one of the side walls, and circumferentially spaced smaller openings spaced radially outwardly of the central opening, with internal surfaces of the circumferentially spaced connecting structure defining intermediate gear pockets that extend away from the central opening to the circumferentially spaced openings. The intermediate gears are receivable through the central opening and are secured in the intermediate gear pockets. A ring gear includes a first ring gear half and a second ring gear half placed on an outer periphery of the intermediate gears such that ring gear teeth of the first and second ring gear halves engage with teeth of the intermediate gears.

Abstract: An exemplary gas turbine engine assembly includes a fan section including a fan, a first spool having a first turbine operatively mounted to a first turbine shaft, and a second spool having a second turbine operatively mounted to a second turbine shaft. The first and second towershafts are respectively coupled to the first and second turbine shafts. An accessory drive gearbox includes a set of gears. A compressor is driven by the first towershaft. A transmission couples a starter generator assembly to the set of gears. The transmission is transitionable between a first mode where the starter generator assembly is driven at a first speed relative to the second towershaft in response to rotation of the second towershaft, and a second mode where the starter generator assembly is driven at a different, second speed relative to the second towershaft in response to rotation of the second towershaft.

Abstract: A gas turbine engine has a fan drive turbine for driving a gear reduction. The gear reduction drives a fan rotor. A lubrication system supplies oil to the gear reduction, and includes a lubricant pump to supply an air/oil mixture to an inlet of a deaerator. The deaerator includes a separator for separating oil and air, delivering separated air to an air outlet, and delivering separated oil back into an oil tank. The separated oil is first delivered into a pipe outwardly of the oil tank, and then into a location beneath a minimum oil level in the tank. Air within the oil tank moves outwardly through an air exit into the deaerator. A method of designing a gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes a propulsor having blades extending from a propulsor hub. A compressor section includes a first compressor and a second compressor. A speed reduction device includes an epicyclic gear system. The epicyclic gear system includes a sun gear, a plurality of intermediate gears, a carrier supporting the intermediate gears and the propulsor hub, and a ring gear. A turbine section includes a first turbine and a second turbine. The second turbine drives the propulsor through the epicyclic gear system. The epicyclic gear system is straddled by forward and aft bearings that engage the carrier.

Abstract: A gas turbine engine includes a fan shaft diving a fan having fan blades. A gear system includes a sun gear surrounded by a plurality of intermediate gears. A carrier at least partially supports the plurality of intermediate gears. A ring gear surrounds the plurality of intermediate gears. The sun gear is driven by a turbine. At least one fan shaft support bearing is located forward of the gear system. A coupling fixes the ring gear from rotation relative to an engine static structure. A lubrication system lubricates components across a rotation gap. The lubrication system includes a lubricant input. A stationary first bearing receives lubricant from the lubricant input and has a first race in which lubricant flows. A second bearing rotates within the first bearing. The second bearing has a first opening in registration with the first race such that lubricant may flow from the first race through the first opening into a first conduit.

Abstract: A gas turbine engine has a fan drive turbine for driving a gear reduction. The gear reduction drives a fan rotor. A lubrication system supplies oil to the gear reduction, and includes a lubricant pump to supply an air/oil mixture to an inlet of a deaerator. The deaerator includes a separator for separating oil and air, delivering separated air to an air outlet, and delivering separated oil back into an oil tank. The separated oil is first delivered into a pipe outwardly of the oil tank, and then into a location beneath a minimum oil level in the tank. Air within the oil tank moves outwardly through an air exit into the deaerator. A method of designing a gas turbine engine is also disclosed.

Abstract: A method of assembling a gear train includes providing a unitary carrier. The unitary carrier has a central axis that includes spaced apart walls and circumferentially spaced connecting structure defining spaced apart apertures provided at an outer circumference of the carrier, gear pockets provided between the walls and extending to the apertures, and a central opening in at least one of the walls. The method includes inserting a plurality of intermediate gears through the central opening and moving the intermediate gears radially outwardly into the gear pockets to extend into the apertures, placing a ring gear on an outer periphery of the intermediate gears to engage the intermediate gears, and securing the gear train to a fan shaft by a connection.

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 for driving a gear reduction. The gear reduction drives a fan rotor. A lubrication system supplies oil to the gear reduction. The lubrication system includes a lubricant pump supplying a mixed air and oil to a deaerator inlet. The deaerator includes a separator that for separating oil, and delivering separated air to an air outlet, and for delivering separated oil back into an oil tank. The separator includes a member having lubricant flow paths on both of two opposed sides. A method of designing a gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes a propulsor and a fan drive turbine. The fan drive turbine drives the propulsor through a geared architecture. The geared architecture includes a sun gear, a ring gear, and intermediate gears supported on journal support pins. The sun gear engages the intermediate gears and the intermediate gears engages the ring gear. The journal support pins include a titanium body and an outer surface outside of the titanium body that has a surface hardness that is harder than the titanium body. The outer surface is provided by a steel sleeve. Oil supply holes extend from a central bore in the titanium body through the steel sleeve. At least one pin extends through the steel sleeve to secure the steel sleeve to the titanium body.

Abstract: An epicyclic gear assembly includes a carrier that includes a first plate axially spaced from a second plate. At least one epicyclic gear set is located between the first plate and the second plate. The first plate is configured to rotate with an output of the epicyclic gear assembly. A first bearing race is attached to the first plate for supporting a first bearing. A second bearing race is attached to the second plate for supporting a second bearing.

Abstract: A gas turbine engine includes a propulsor and a drive gear system. The drive gear system includes at least one ring gear, a plurality of intermediate gears positioned between and enmeshing with a sun gear and the at least one ring gear, with the plurality of intermediate gears carried by a gear carrier. A first bearing is configured to rotate with the gear carrier. A second bearing is on an opposite side of the drive gear system from the first bearing.

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 gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan and a braking system. The braking system is configured to selectively engage the fan during ground windmilling to apply a first level of braking to slow rotation of the fan. Further, when the rotation of the fan sufficiently slows, the braking system is further configured to apply a second level of braking more restrictive than the first level of braking.

Abstract: An exemplary gas turbine engine includes a fan section including a fan rotor and at least one fan blade. A fan pressure ratio across the at least one fan blade is less than 1.45, noninclusive of the pressure across any fan exit guide vane system. The engine further includes a low-pressure compressor having a low-pressure compressor rotor that rotates together with the fan rotor at a common speed in operation, and a geared architecture that drives the low-pressure compressor rotor and the fan rotor. The geared architecture has a gear reduction ratio of greater than 2.5. The engine further includes a high-pressure compressor having a pressure ratio greater than 20, a low-pressure turbine having a pressure ratio greater than 5, and a bypass ratio greater than 10.

Abstract: A gas turbine engine includes a propulsor section and a speed change mechanism for driving the propulsor section. The speed change mechanism is an epicyclic gear train. A torque frame includes a ring and a plurality of fingers extending 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 propulsor section support bearing is mounted on a first axial side of the speed change mechanism and a second propulsor section support bearing is mounted on the bearing support on a second axial side of the speed change mechanism. The second propulsor section support bearing is a propulsor thrust bearing. Each of the plurality of fingers include a pin opening with a pin extending through the pin opening and into the epicyclic gear train.