In accordance with at least one aspect of this disclosure, there is provided a drive shaft system. In embodiments, the drive shaft system includes a generator shaft extending along a longitudinal axis with a longitudinal bore defined through the generator shaft. A thru shaft extends through the longitudinal bore of the generator shaft. In embodiments, the thru shaft includes, a front coupler mount at a first end operative to receive torque input, and a rear coupler mount at a second end opposite the first end.

In one embodiment of the present disclosure, there is provided a drive tube and swashplate trunnion assembly. The drive tube and swashplate trunnion assembly includes a drive tube having a plurality of grooves formed on an outer surface of the drive tube; a swashplate trunnion having a plurality of grooves formed on an inner surface of the swashplate trunnion, wherein individual grooves of the plurality of grooves on the swashplate trunnion mate with individual grooves of the plurality of grooves on the drive tube to form a plurality of channels; and a plurality of cylindrical bearings, wherein each of said cylindrical bearings is disposed within an individual channel of the plurality of channels.

In one embodiment of the present disclosure, there is provided a drive tube and swashplate trunnion assembly. The drive tube and swashplate trunnion assembly includes a drive tube having a plurality of grooves formed on an outer surface of the drive tube; a swashplate trunnion having a plurality of grooves formed on an inner surface of the swashplate trunnion, wherein individual grooves of the plurality of grooves on the swashplate trunnion mate with individual grooves of the plurality of grooves on the drive tube to form a plurality of channels; and a plurality of cylindrical bearings, wherein each of said cylindrical bearings is disposed within an individual channel of the plurality of channels.

A gas turbine engine comprises a gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier. The carrier comprises a primary structure and at least one reinforcing structure. The primary structure comprises a first material and the at least one reinforcing structure comprises a second material. The primary structure includes a first ring, a second ring spaced axially from the first ring and a plurality of circumferentially spaced axles extending axially between the first ring and the second ring. Each planet gear is rotatably mounted on a respective one of the axles by a bearing. The reinforcing structure is secured to the primary structure and the reinforcing structure comprises a particulate reinforced material or a fibre reinforced material. The reinforcing structure increases the stiffness of the carrier and reduces the weight of the carrier.

An aircraft propulsion unit includes a drive unit with a static part and a rotary part which rotates a fan situated downstream from the drive unit, an assembly of fixed blades situated downstream from the fan, and a nacelle in which the fan and the assembly of fixed blades are accommodated. The propulsion unit also includes an assembly of at least two coaxial shafts, wherein a fan shaft connects the fan to the rotary part, and a stator blading shaft connecting the assembly of fixed blades to the static part extends concentrically, and for at least part of its length in the interior of the fan shaft. This rigid and compact configuration limits the variations of distance between the end of the fan blades and a fan housing situated in the inner duct of the nacelle.

An aircraft propulsion unit includes a drive unit with a static part and a rotary part which rotates a fan situated downstream from the drive unit, an assembly of fixed blades situated downstream from the fan, and a nacelle in which the fan and the assembly of fixed blades are accommodated. The propulsion unit also includes an assembly of at least two coaxial shafts, wherein a fan shaft connects the fan to the rotary part, and a stator blading shaft connecting the assembly of fixed blades to the static part extends concentrically, and for at least part of its length in the interior of the fan shaft. This rigid and compact configuration limits the variations of distance between the end of the fan blades and a fan housing situated in the inner duct of the nacelle.

A drone including a front section, a wing structure supported by a rotor located behind the front section, and a propeller at the rear. The wing structure including two wings rotating the rotor, the wing structure being able to move between a flight configuration, in which the rotor is immobile relative to the front section and the propulsion provided by the propeller, and a flight configuration with the wing structure rotating, in which the rotor is rotated relative to the front section, the rotor being connected to the front section with a possibility of orienting its axis of rotation relative thereto in order able to direct the drone in the rotary wing structure configuration by acting on said orientation.

A drone including a front section, a wing structure supported by a rotor located behind the front section, and a propeller at the rear. The wing structure including two wings rotating the rotor, the wing structure being able to move between a flight configuration, in which the rotor is immobile relative to the front section and the propulsion provided by the propeller, and a flight configuration with the wing structure rotating, in which the rotor is rotated relative to the front section, the rotor being connected to the front section with a possibility of orienting its axis of rotation relative thereto in order able to direct the drone in the rotary wing structure configuration by acting on said orientation.

An aircraft control system includes: a first engine attached to an airframe of an aircraft; a second engine attached to the airframe; a first power generator connected to an engine shaft of the first engine; a second power generator connected to an engine shaft of the second engine; an electric motor driven with electric power supplied from one or both of the first power generator and the second power generator; a rotor driven with a driving force output from the electric motor; and a controller configured to estimate whether noise excess conditions have been satisfied on the basis of information for estimating noise and to change one or both of a rotation speed and a magnitude of a torque such that noise is lower than that before the noise excess conditions have been satisfied when it is estimated that the noise excess conditions have been satisfied.

An aircraft control system includes: a first engine attached to an airframe of an aircraft; a second engine attached to the airframe; a first power generator connected to an engine shaft of the first engine; a second power generator connected to an engine shaft of the second engine; an electric motor driven with electric power supplied from one or both of the first power generator and the second power generator; a rotor driven with a driving force output from the electric motor; and a controller configured to estimate whether noise excess conditions have been satisfied on the basis of information for estimating noise and to change one or both of a rotation speed and a magnitude of a torque such that noise is lower than that before the noise excess conditions have been satisfied when it is estimated that the noise excess conditions have been satisfied.