A twin-spool turbojet engine includes: a low-pressure spool having a low-pressure compressor, a low-pressure turbine, and a low-pressure shaft connecting the low-pressure turbine to the low-pressure compressor; an exhaust casing through which exhaust gases flow downstream of the low-pressure turbine; and a low-pressure shaft thrust bearing having an inner ring and an outer ring, one of the rings being fastened on the low-pressure shaft and the other of the rings being fastened on the exhaust casing.

A gear system for a gas turbine engine includes a planet gear system which includes an output attached to a carrier for rotating a first fan assembly in a first direction. A star gear system includes an output attached to a ring gear for rotating a second fan assembly in a second direction. A sun gear of the star gear system is mechanically attached to a sun gear of the planet gear system.

A fan system includes a rotor having plurality of blades and a ring airfoil, the plurality of blades being rotatably joined to a hub and the ring airfoil. The fan system may include a second contra-rotationally disposed rotor having a plurality of blades and a ring airfoil. The first and second ring airfoils having a cambered shape and an angle of attack between about 5 degrees and about 45 degrees, more preferably between about 5 degrees and about 30 degrees. Optionally, an outlet guide vane may be mounted rearward of the one or more rotors having a ring airfoil.

A fan for a gas turbine engine includes: an annular casing; a disk disposed inside the casing and mounted for rotation about an axial centerline, the disk including a row of fan blades extending radially outwardly therefrom; each of the fan blades including an airfoil having circumferentially opposite pressure and suction sides extending radially in span from a root to a tip, and extending axially in chord between spaced-apart leading and trailing edges, with the airfoils defining corresponding flow passages therebetween for pressurizing air; the row including no more than 21 and no less than 13 of the fan blades; and wherein each of the fan blades has a solidity defined by a ratio of the airfoil chord over a circumferential pitch of the fan blades, measured at 60% of a radial distance from the root to the tip, of less than about 1.6.

The invention relates to a gas turbine engine, in particular an aircraft engine, comprising: a turbine connected via an input shaft device to a gearbox device having a sun gear, a planet carrier having a plurality of planet gears attached thereto, and a ring gear, the sun gear is connected to the input shaft device, the planet carrier or the ring gear is connected to a propulsive fan via an output shaft device of the gearbox device, with an inter-shaft bearing system being positioned radially between the input shaft device and the planet carrier of the gearbox device.

A stator assembly including plural stator vanes distributed around an axis of revolution of the stator assembly, a chord of the stator vane, taken at a root of the stator vane, not overlapping, in the direction of the axis of revolution, a chord of an adjacent stator vane, taken at a root of the adjacent stator vane, and a chord of the stator vane, taken at a tip of the stator vane, overlapping, in the direction of the axis of revolution, a chord of the adjacent stator vane, taken at a tip of the adjacent stator vane.

A convertible ducted fan engine and mounting system. The convertible ducted fan engine has a shroud encircling a mechanical fan. The convertible ducted fan engine includes a fluid-propulsion configuration in which the mechanical fan rotates freely with respect to the shroud to produce thrust through fluid flow, and a drive-wheel configuration in which the shroud rotates about the rotational axis.

Methods and systems for operating a turboprop engine having a high pressure spool and a low pressure spool rotating independently from one another. Each spool contains at least one compressor stage and the low pressure spool is connected to a propeller. The method comprises determining a target temperature-corrected rotational speed of the low pressure spool for a given set of operating parameters; and controlling a mechanical speed of the low pressure spool to maintain the temperature-corrected rotational speed of the low pressure spool substantially constant throughout at least a portion of a range of a power demand on the turboprop engine.

A fan for a gas turbine engine includes: an annular casing; a disk disposed inside the casing and mounted for rotation about an axial centerline, the disk including a row of fan blades extending radially outwardly therefrom; each of the fan blades including an airfoil having circumferentially opposite pressure and suction sides extending radially in span from a root to a tip, and extending axially in chord between spaced-apart leading and trailing edges, with the airfoils defining corresponding flow passages therebetween for pressurizing air; the row including no more than 21 and no less than 13 of the fan blades; and wherein each of the fan blades has a solidity defined by a ratio of the airfoil chord over a circumferential pitch of the fan blades, measured at 60% of a radial distance from the root to the tip, of less than about 1.6.

A gas turbine engine, including: a low pressure spool having a low pressure compressor and a low pressure turbine connected by a low pressure shaft; a reduction gear train having a sun gear, a carrier having a plurality of planet gears attached thereto, and a ring gear, wherein one of the sun gear, carrier or ring gear is connected to the low pressure shaft, and another of the sun gear, carrier and ring gear provides an output drive; a propulsive fan mounted fore of the gear train; a fan shafting arrangement comprising a fan shaft which is connected to the output drive of the gear train and a fan support shaft which passes through center of the gear train along the axis of rotation of the gearbox and fan, wherein the fan shafting arrangement is rotatably supported by at least two axially separated bearings.