Abstract: An epicyclic gear system includes a sun gear, a ring gear, and two or more star gear assemblies enmeshed between the sun gear and the ring gear. Each star gear assembly includes a star gear and a journal bearing supportive of the star gear. The journal bearing includes one or more lubricant passageways to deliver a flow of lubricant to a selected location of the star gear assembly, wherein a first cross-sectional area of a lubricant passage of a first journal bearing of the two or more star gear assemblies is greater than a second cross-sectional area of the corresponding lubricant passage of a second journal bearing of the two or more star gear assemblies.

Abstract: A gas turbine engine has a fan drive turbine driving a gear reduction, the gear reduction, in turn, driving a fan rotor, the fan rotor delivering air into a bypass duct as bypass air and into a compressor section as core flow. A forward bearing is positioned between the gear reduction and the fan rotor and supports the gear reduction. A second bearing is positioned aft of the gear reduction and supports the gear reduction. The second bearing is a thrust bearing. A fan drive turbine drive shaft drives the gear reduction. The fan drive turbine drive shaft has a weakened link which is aft of the second bearing such that the fan drive turbine drive shaft will tend to fail at the weakened link, and at a location aft of the second bearing.

Abstract: A gear reduction for a gas turbine engine comprises a carrier driven to rotate gears. The gears are supported by journal bearings. The carrier extends through a transfer bearing, which provides oil to passages within the carrier to supply oil to the gears and to the journal bearings. A device limits leakage oil from the transfer bearing to axial ends of the transfer bearing to a controlled amount. A gas turbine engine is also disclosed.

Abstract: A gas turbine engine comprises a low speed spool and a high speed spool, with each of the spools including a turbine to drive a respective one of the spools. The high speed spool rotates at a higher speed than the low speed spool. A high speed power takeoff is driven to rotate by the high speed spool, and a low speed power takeoff is driven to rotate by the low speed spool. The high speed power takeoff drives a starter generator and a permanent magnet alternator. The low speed power takeoff drives a variable frequency generator.

Abstract: A turbo fan engine includes a housing that supports a compressor section. At least one compressor hub is within the compressor section. A compressor shaft is arranged in the compressor section. An epicyclic gear train is coupled to the compressor shaft. At least one compressor hub and the compressor shaft are coupled at a common attachment point. The epicyclic gear train includes a carrier. A sun gear and intermediate gears are arranged about and intermeshing with the sun gear. The intermediate gears are supported by the carrier. A baffle is supported relative to the carrier and includes a lubrication passage near at least one of the sun gear and intermediate gears for directing a lubricant on at least one of the sun gear and the intermediate gears.

Abstract: An epicyclic gear train for a gas turbine engine according to an example of the present disclosure includes, among other things, a gutter having an annular channel, a sun gear rotatable about an axis, intermediary gears arranged circumferentially about and meshing with the sun gear, and a carrier supporting the intermediary gears, and a ring gear arranged about and intermeshing with the intermediary gears, the ring gear having an aperture axially aligned with the annular channel. The ring gear includes axially spaced apart walls that extend radially outward to define a passageway, and the passageway is arranged radially between the aperture and the annular channel such that the walls inhibit an axial flow of an oil passing from the aperture toward the annular channel.

Abstract: A gas turbine engine includes a fan shaft that drives a fan that has fan blades. 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 and includes a gear mesh that defines a gear mesh transverse stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The flexible support transverse stiffness is less than 11% of the fan shaft support transverse stiffness and less than 8% of the gear mesh transverse stiffness.

Abstract: A gas turbine engine assembly includes a turbine section having first and second turbines mounted for rotation about a common rotational axis within an engine static structure, first and second turbine shafts coaxial with one another and to which the first and second turbines are respectively operatively mounted, first and second towershafts respectively coupled to the first and second turbine shafts, an accessory drive gearbox mounted to the engine static structure, and a transmission transitionable between a first mode where an electric machine is driven at a first speed relative to the first towershaft, and a second mode where the electric machine is driven at a different, second speed relative to the first towershaft.

Abstract: A gas turbine engine assembly includes a turbine section having first and second turbines mounted for rotation about a common rotational axis within an engine static structure, first and second turbine shafts coaxial with one another and to which the first and second turbines are respectively operatively mounted, first and second towershafts respectively coupled to the first and second turbine shafts, an accessory drive gearbox mounted to the engine static structure, a hydraulic pump, and a transmission. The transmission is transitionable between a first mode where the hydraulic pump is driven at a first speed relative to a first towershaft, a second mode where the hydraulic pump is driven at a different, second speed relative to the first towershaft, and a third mode where the hydraulic pump is driven at a different, third speed relative to the first towershaft.

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 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 system is provided for a turbine engine. This turbine engine system includes a rotating assembly, a bearing and a lubrication system. The bearing is configured with the rotating assembly. The lubrication system is configured to lubricate the bearing. The lubrication system includes a lubricant pump and a lubricant reservoir. The lubricant pump is mechanically coupled with and driven by the rotating assembly. The lubricant pump is configured with the lubricant reservoir so as to be at least partially submersed in lubricant contained within the lubricant reservoir.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a turbo fan shaft and a turbo fan supported on the fan shaft, a compressor section having compressor hubs with blades driven about an axis, and an epicyclic gear system driving the fan shaft. The gear system includes a carrier supporting intermediate gears that mesh with a sun gear, a ring gear surrounding and meshing with the intermediate gears, the ring gear including first and second portions each having an inner periphery with teeth, the first and second portions abutting one another at a radial interface, each of the first and second portions including a flange extending radially outward, and the first and second portions having grooves at the radial interface which form a hole that expels oil through the ring gear to a gutter, and an input shaft driving the fan shaft through the gear system, the input shaft connected to the sun gear.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan delivering air into a bypass duct and into a core engine, a fan drive gear system having a gear carrier, and a fan shaft coupling the fan drive gear system to the fan. The core engine includes a low spool including a low pressure turbine and a low pressure shaft, and a high spool including a high pressure turbine, a compressor, and a high pressure shaft coupling the high pressure turbine to the compressor. A first bearing is forward of the fan drive gear system, and supporting said fan shaft and said fan drive gear system, and a second bearing is aft of the fan drive gear system, and supporting the fan drive gear system.

Abstract: A disclosed lubrication system for a turbofan engine includes a pump for driving lubricant through a lubrication circuit, at least one sensor generating a signal indicative of an engine operating condition and at least one valve for controlling a flow of lubricant through the lubrication circuit. A controller controls operation of the valve to vary the flow of lubricant based on the engine operating condition to maintain lubricant flow within predefined operating limits.

Abstract: A gas turbine engine includes a fan shaft that drives a fan that has fan blades. 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 and includes a gear mesh that defines a gear mesh transverse stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The flexible support transverse stiffness is less than 11% of the fan shaft support transverse stiffness and less than 8% of the gear mesh transverse stiffness.

Abstract: A gas turbine engine includes a bypass ratio greater than about ten (10). A fan is supported on a fan shaft and has a plurality of fan blades. There is a gutter with an annular channel. A gear system is connected to the fan shaft. There is a plurality of planetary gears and a ring gear with an aperture that is axially aligned with the annular channel. The ring gear includes a first portion with a first set of opposed angled teeth separated by a trough from a second portion with a second set of opposed angled teeth. A torque frame at least partially supports the gear system. A low pressure turbine has an inlet, an outlet, and a low pressure turbine pressure ratio greater than 5:1 and a low fan pressure ratio of less than 1.45 across the fan blade alone.

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 gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades. A fan shaft support supports the fan shaft and defines a support transverse stiffness. A gear system is connected to the fan shaft and includes a gear mesh defining a gear mesh transverse stiffness and a reduction ratio greater than 2.3. A gear system input is connected to the gear system and defines a gear system input lateral stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness and the flexible support transverse stiffness is less than 20% of the fan shaft support transverse stiffness.

Abstract: A geared architecture for a gas turbine engine includes a fan shaft and a frame which supports said fan shaft. The frame defines a frame stiffness. A plurality of gears drives the fan shaft and includes a gear mesh that defines a gear mesh stiffness. A stiffness of a ring gear of the plurality of gears is less than about 20% of the gear mesh stiffness. A flexible support supports the geared architecture and defines a flexible support stiffness. An input coupling to the plurality of gears defines an input coupling stiffness. The flexible support stiffness and the input coupling stiffness are each less than about 11% of the frame stiffness.