A geared turbofan engine include a gas turbine engine for an aircraft, including: an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan assembly located upstream of the engine core; and a gearbox that receives an input from the core shaft and outputs drive to the fan assembly to drive the fan assembly at a lower rotational speed than the core shaft, the hub including a plurality of slots located around a rim of the hub, each slot receiving a root of a corresponding fan blade, the rim having a minimum radial thickness between a base of each slot and an internal cavity within the hub, wherein the minimum radial thickness is within a range of around 0.5% to around 1.1% of the outer fan diameter.

An aircraft turboprop engine has at least one low-pressure body and one high-pressure body. The low-pressure body drives a thrust propeller using a gearbox. The turboprop engine further includes a means for supplying air to an air-conditioning circuit of an aircraft cabin. The supply means includes a load compressor and a rotor that is coupled to the low-pressure body by the gearbox. The supply means further includes a means for controlling the rotation speed of the rotor of the compressor, which means comprise an electric motor, and a mechanical differential for coupling a first output shaft of said electric motor to a second output shaft of said gearbox and to said compressor rotor, such that the rotation speed of said rotor depends on the respective rotation speeds of said first and second output shafts.

A geared architecture for a gas turbine engine includes a fan shaft driving a fan surrounded by an outer housing. A frame that supports the fan shaft and defines a frame lateral stiffness. A plurality of gears are in driving engagement with the fan shaft. The plurality of gears provide an epicyclic gear system which includes a gear mesh defining a gear mesh lateral stiffness and a ring gear defining a ring gear lateral stiffness. The ring gear lateral stiffness is less than 12% of the gear mesh lateral stiffness. A flexible support supports the epicyclic gear system relative to a static structure and defines a flexible support lateral stiffness and a flexible support transverse stiffness. An input coupling to the plurality of gears defines an input coupling lateral stiffness. The flexible support lateral stiffness and the input coupling lateral stiffness are each less than about 11% of said frame lateral stiffness.

Disclosed is an embodiment of a dual seal arrangement for the high-speed shaft of a supercharger with a centrifugal compressor and a mechanical speed step-down transmission to the shaft. A ring located about the shaft splits the rotational speed of the shaft between two seals, so that each seal spins at a speed of roughly half the speed of the shaft. The arrangement can also be used to split the shaft speed between two bearings in the same manner. The high-speed shaft may also have a turbine attached, to form a driven turbocharger.

A method and device is provided for increasing the efficiency of jet drives by recuperating effective power from the propulsion flow. A ducted propeller in the propeller housing, driven by a driving engine via a drive shaft, conveys the fluid for the jet drive out of the interior V.sub.i of a radial turbine . The fluid is accelerated axially and ejected backwards against the direction of travel. This creates thrust. Because the pressure in the interior of the turbine decreases, new fluid from the environment flows directly via the blades of the rotating radial turbine from the outside to the inside, thereby driving them. A guide apparatus is missing. The power of the radial turbine is transmitted via a transmission to the drive shaft of the propeller, which relieves the driving engine and increases the efficiency of the jet drive. The invention is particularly suitable for electric drives.

A fan component and a fan lamp assembly, wherein the fan component includes a blade mounting disc and a plurality of fan blades, one side of the blade mounting disc away from the fan blades is provided with planetary gears synchronously rotating with corresponding fan blades and a solar gear capable of rotating relative to the blade mounting disc, a peripheral surface of the solar gear is provided with first spring mounting structures, the blade mounting disc is provided with a second spring mounting structures, a return tension spring is connected between each pair of the first spring mounting structures and the second spring mounting structures, and each return tension spring is arranged on a circumferential outside of the solar gear.

A fan module with variable pitch blades for a longitudinal axis propulsion assembly. The module includes a rotor through which a rotor shaft runs along the longitudinal axis X and carries the blades of the fan. A system for changing the pitch of the blades includes a mechanism connected to the blades of the fan and a controller acting on the mechanism. The controller has a fixed body and a movable body translatable along the longitudinal axis X relative to the fixed body, and a load transfer bearing arranged between the mechanism and the controller. The fan module includes a power shaft driving the rotor shaft via an epicyclic train speed reducer, the speed reducer including a sun gear connected to the power shaft and a satellite carrier including a fixed annular ferrule secured to a fixed casing. The fixed body of the controller is mounted on the annular ferrule.

A centrifugal compressor includes a low-speed shaft, an impeller, a speed increaser, a housing, a separation wall, a shaft insertion hole, a seal member, an oil pan, an oil supply passage, an oil return passage, and a pressure reduction passage. The impeller is integrally rotated with a high-speed shaft. The housing has therein an impeller chamber accommodating the impeller and a speed increaser chamber accommodating the speed increaser. The centrifugal compressor includes a bypass passage having a first end communicating with the speed increaser chamber and a second end communicating with the oil pan.

A gas turbine engine includes a fan, compressor, combustor, and turbine coupled to the compressor through a shaft. The compressor includes first, second, and third stages with respective rotor blades and stator vanes. The rotor blades and stator vanes are arranged such that a sum of mid-span axial gaps between the trailing edge of the first rotor blades and the leading edge of the first stator vanes, the trailing edge of the first stator vanes and the leading edge of the second rotor blades, the trailing edge of the second rotor blades and the leading edge of the second stator vanes, and the trailing edge of the second stator vanes and the leading edge of the third rotor blades is equal to $a\sqrt{\frac{\mathrm{inlet}\mathrm{flow}\mathrm{function}}{10}}.a75\mathrm{mm}\mathrm{and}\mathrm{the}\mathrm{inlet}\mathrm{flow}\mathrm{function}=\frac{m\sqrt{T}}{P}.$

Disclosed is a two-piece shaft assembly for a driven turbocharger with a traction drive. The turbo shaft is attached to a turbine and compressor, and is inserted into a traction barrel that has traction surfaces to mate to the traction drive. In this way, the traction drive can be assembled with only the traction barrel, and the turbo shaft can be inserted through the barrel at the end to simplify assembly.