A gas turbine engine comprises a gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a planet gear carrier. The sun gear meshes with the planet gears and the planet gears mesh with the annulus gear. Each planet gear is rotatably mounted in the planet gear carrier. The planet gear carrier comprises a plurality of axles arranged parallel to the axis of the gearbox. The axially spaced ends of each axle are secured to the planet gear carrier. Each planet gear is rotatably mounted on a corresponding one of the axles by a bearing arrangement. Each bearing arrangement comprises a journal bearing and a rolling element bearing and each planet gear is rotatably mounted on a journal bearing and each journal bearing is rotatably mounted on an axle by at least one rolling element bearing.

A gas turbine engine comprises a gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a planet gear carrier. The sun gear meshes with the planet gears and the planet gears mesh with the annulus gear. Each planet gear is rotatably mounted in the planet gear carrier. The planet gear carrier comprises a plurality of axles arranged parallel to the axis of the gearbox. The axially spaced ends of each axle are secured to the planet gear carrier. Each planet gear is rotatably mounted on a corresponding one of the axles by a bearing arrangement. Each bearing arrangement comprises a journal bearing and a rolling element bearing and each planet gear is rotatably mounted on a journal bearing and each journal bearing is rotatably mounted on an axle by at least one rolling element bearing.

A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing a fan variable area nozzle in communication with the fan bypass flow path and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

A method of designing a turbofan engine according to an exemplary aspect of the present disclosure includes, among other things, providing a fan section including a plurality of fan blades, providing a low pressure turbine driving the plurality of fan blades through a gear train, providing a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, providing a fan bypass flow path defined between the core nacelle and the fan nacelle, and providing a fan variable area nozzle in communication with the fan bypass flow path and defining a fan nozzle exit area between the fan nacelle and the core nacelle.

A turbine arrangement for a gas turbine engine comprising a turbine shaft. An axial array of turbine rotors, having a first axial end and a second axial end. A drive arm coupled between the turbine shaft and the first axial end. A measurement system arranged to measure a parameter of the turbine arrangement, the measurement system positioned at the second axial end. The parameter may be rotational speed.

A turbine arrangement for a gas turbine engine comprising a turbine shaft. An axial array of turbine rotors, having a first axial end and a second axial end. A drive arm coupled between the turbine shaft and the first axial end. A measurement system arranged to measure a parameter of the turbine arrangement, the measurement system positioned at the second axial end. The parameter may be rotational speed.

The leading edge, the trailing edge, or both may be axially offset for a portion of the airfoils in a disk. By offsetting the airfoils, the downstream wake energy to the next stage of airfoils may be decreased. By staggering airfoils which are offset with airfoils that are not offset, the wake shapes from the airfoils may be out of phase and will not excite the downstream airfoils as much as conventional systems. This may decrease vibration and associated vibratory stresses in the system.

The leading edge, the trailing edge, or both may be axially offset for a portion of the airfoils in a disk. By offsetting the airfoils, the downstream wake energy to the next stage of airfoils may be decreased. By staggering airfoils which are offset with airfoils that are not offset, the wake shapes from the airfoils may be out of phase and will not excite the downstream airfoils as much as conventional systems. This may decrease vibration and associated vibratory stresses in the system.

A turbine and a turbine-generator device for use in electricity generation. The turbine has a universal design and so may be relatively easily modified for use in connection with generators having a rated power output in the range of 50 KW to 5 MW. Such modifications are achieved, in part, through use of a modular turbine cartridge built up of discrete rotor and stator plates sized for the desired application with turbine brush seals chosen to accommodate radial rotor movements from the supported generator. The cartridge may be installed and removed from the turbine relatively easily for maintenance or rebuilding. The rotor housing is designed to be relatively easily machined to dimensions that meet desired operating parameters.

A turbine and a turbine-generator device for use in electricity generation. The turbine has a universal design and so may be relatively easily modified for use in connection with generators having a rated power output in the range of 50 KW to 5 MW. Such modifications are achieved, in part, through use of a modular turbine cartridge built up of discrete rotor and stator plates sized for the desired application with turbine brush seals chosen to accommodate radial rotor movements from the supported generator. The cartridge may be installed and removed from the turbine relatively easily for maintenance or rebuilding. The rotor housing is designed to be relatively easily machined to dimensions that meet desired operating parameters.