Abstract: A gas turbine engine includes a fan shaft rotatable about an axis, a fan connected to the fan shaft, and an outer housing surrounding the fan to define a bypass passage. A compressor section has both a low pressure compressor that is fixed to rotate with the fan shaft and a high pressure compressor. A turbine section has a low pressure turbine driving a low speed spool and a high pressure turbine driving the high pressure compressor. The low pressure turbine includes rotating blades and a static structure aft of the rotating blades. A fan drivetrain includes a geared architecture connecting the low speed spool to the fan shaft such that the fan and low pressure compressor rotate at a lower speed than the low pressure turbine. A thrust bearing is axially aft of the geared architecture and axially forward of the high pressure compressor. A tower shaft is rotatably driven by the low speed spool.

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 according to an example of the present disclosure includes, among other things, a fan section including a turbo fan supported on a turbo fan shaft, a turbine section including a turbine shaft, and an epicyclic gear train interconnecting the turbo fan shaft and the turbine shaft. The epicyclic gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth, the first and second portions arranged about and intermeshing with the intermediate gears, the first and second portions abutting one another at a radial interface, the first and second portions including respective flanges extending along the radial interface radially outward from the teeth, and the teeth of the first and second portions being oppositely angled teeth.

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 includes a fan section that has fan blades that drive air along a bypass flow path in a bypass duct. A fan shaft is drivingly connected to the fan. A turbine section includes a turbine drive shaft. A gear system is connected to the turbine draft shaft through an input and connected to the fan shaft through an output. At least one of the input and the output include a flexible coupling. A gear system flex mount arrangement accommodates misalignment of the fan shaft and the turbine drive shaft during operation. The gear system flex mount arrangement includes a gear mesh that defines a gear mesh lateral stiffness and a ring gear that defines a ring gear lateral stiffness that is less than 12% of the gear mesh lateral stiffness.

Abstract: A gas turbine engine includes a fan shaft that drives a fan that has fan blades. The fan delivers airflow to a bypass duct. A gear system is connected to the fan shaft and is driven through an input defining an input lateral stiffness and an input transverse stiffness. A gear system flex mount arrangement accommodates misalignment of the fan shaft and the input during operation. A frame for supporting the fan shaft defines a frame lateral stiffness and a frame transverse stiffness. The input lateral stiffness is less than 11% of the frame lateral stiffness and the input transverse stiffness is less that 11% of the frame transverse stiffness.

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 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 turbofan engine includes a fan section that drives air along a bypass flow path in a bypass duct. An epicyclic gear system in driving engagement with the fan shaft and has a gear mesh lateral stiffness and a gear mesh transverse stiffness. A gear system input to the gear system defines a gear system input lateral stiffness and a gear system input transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness. A first performance quantity is defined as the product of a first speed squared and a first area and a second performance quantity is defined as the product of a second speed squared and a second area. A performance quantity ratio of a first performance quantity to a second performance quantity is between 0.5 and 1.5.

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 includes a fan shaft that drives a fan that has fan blades. An outer housing surrounds the fan. A bypass flow path is within the outer housing. A fan shaft support that supports the fan shaft defines a fan shaft support transverse stiffness. A gear system is connected to the fan shaft. The gear system includes a gear mesh that defines a gear mesh transverse stiffness. A flexible support which supports the gear system relative to a static structure defines a flexible support transverse stiffness. The flexible support transverse stiffness is less than 11% of the fan shaft support transverse stiffness. The flexible support transverse stiffness is less than 8% of the gear mesh transverse stiffness.

Abstract: A gas turbine engine may include a high speed spool, a low speed spool, a first epicyclic gear system, and a second epicyclic gear system. Generally, the high speed spool mechanically connects a high pressure turbine to a high pressure compressor, and the low speed spool mechanically connects a low pressure turbine to at least one of a fan and a prop via the first epicyclic gear system and to a low pressure compressor via the second epicyclic gear system, according to various embodiments. The first epicyclic gear system and the second epicyclic gear system may include a common sun gear shaft.

Abstract: A method of assembling an epicyclic gear train includes providing a unitary carrier that includes spaced apart walls and circumferentially spaced mounts interconnecting the walls, spaced apart apertures provided between the mounts at an outer circumference of the carrier, gear pockets provided between the walls and mounts extending to the apertures, and a central opening in at least one of the walls, inserting an intermediate gear through the central opening and moving the intermediate gear radially into the gear pocket to extend through the aperture, inserting a baffle into the carrier, and inserting a sun gear through the central opening to intermesh with the intermediate gear.

Abstract: A turbine engine according to an example of the present disclosure includes, among other things, a fan shaft, at least one tapered bearing mounted on the fan shaft, the fan shaft including at least one passage extending in a direction having at least a radial component, and adjacent the at least one tapered bearing, a fan mounted for rotation on the at least one tapered bearing. An epicyclic gear train is coupled to drive the fan, the epicyclic gear train including a carrier supporting intermediate gears that mesh with a sun gear, and a ring gear surrounding and meshing with the intermediate gears, wherein the epicyclic gear train defines a gear reduction ratio of greater than or equal to 2.3. A turbine section is coupled to drive the fan through the epicyclic gear train, the turbine section having a fan drive turbine that includes a pressure ratio that is greater than 5. The fan includes a pressure ratio that is less than 1.45, and the fan has a bypass ratio of greater than ten (10).

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with some flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is relatively high.

Abstract: A fan drive gear system for a turbofan engine according to an exemplary embodiment of this disclosure, among other possible things includes a sun gear that is rotatable about an axis, a plurality of intermediate gears driven by the sun gear, and a baffle that is disposed between at least two of the plurality of intermediate gears for defining a lubricant flow path from an interface between the sun gear and at least one of the plurality of intermediate gears. The baffle includes a channel with at least one ramp portion directing lubricant.

Abstract: A gas turbine engine includes a geared architecture with a multiple of intermediate gears, and a baffle with an oil scavenge scoop adjacent to each of the multiple of intermediate gears. A geared architecture and method are also disclosed.

Abstract: A turbine engine system includes a gutter and a gear train with an axial centerline. The gutter is disposed radially outside of the axial centerline. The gutter includes an inner surface and a channel that receives fluid directed out of the gear train. The inner surface at least partially defines a bore in which the gear train is arranged. The channel extends radially into the gutter from the inner surface, and circumferentially to a channel outlet. The bore has a cross-sectional bore area, and the channel has a cross-sectional channel area that is substantially equal to or less than about two percent of the bore area.

Abstract: A turbine engine system includes a gutter and a gear train with an axial centerline. The gutter is disposed radially outside of the axial centerline. The gutter at least partially circumscribes the gear train, and includes an inner surface and a channel. The channel receives fluid directed out of the gear train. The channel extends radially into the gutter from the inner surface to a channel end, and circumferentially to a channel outlet. At least a portion of the channel has a cross-sectional channel geometry that tapers axially as the channel extends radially towards the channel end.

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with defined flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is between 0.5 and 1.5.