A radial control shaft for a device for controlling the pitch of fan blades of a turbine engine having an unducted fan, is disclosed. The shaft includes an external portion that is designed to be mounted in the control device from its outside and to be coupled to at least one fan blade in order to adjust its pitch, and an internal portion, independent of the external portion, that is designed to be mounted from the inside of the control device, to be connected to a load transfer bearing in order to pivot the shaft about a radial axis, and to close an oil enclosure in which the bearing is housed, the external and internal portions of the shaft being coupled to each other. A method of mounting such a shaft and a control device including such a shaft are also disclosed.

A turbomachine of an aircraft comprising an outer casing delimiting with an inner hub, a flow path of a gas stream in which is disposed a low-pressure turbine configured to rotationally drive a low-pressure shaft; said turbomachine comprising, in the direction of flow of the gas stream, a first propeller; and a second propeller downstream of the first propeller, the first propeller being rotationally driven by said low-pressure shaft and the second propeller being rotationally driven by an electric motor, the second propeller being further disposed at a distance between 1.5 and 4 cord lengths from the first propeller defined between the respective axes of shimming of each of the first and second propellers.

A propeller ring of a turbomachine including an annular body substantially coaxial to a principal axis and a plurality of radial housings uniformly distributed about the principal axis, each radial housing being configured to receive a root of a blade, the annular body being made of composite material including a fibrous reinforcement densified by a polymer matrix and further including a plurality of metallic inserts configured to each receive the root of a blade, said metallic inserts being anchored in the composite material of the annular body.

Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.

A device for controlling a collective pitch and a cyclic pitch of rotor blades of a rotoreraft of a direct turbine driven type and. contra-rotating coaxial rotor type (DTDR) includes: a lower rotor and an upper rotor that are mounted concentrically on a shared rotor shaft; a first plate, that is not rotatable, fastened to a structure of the rotorcraft and connected to an actuator that communicates collective pitch and cyclic pitch controls to it, the first plate being mounted so as to be movable in translation along the shared rotor shaft and to oscillate relative to the shared rotor shaft, via a lower ball joint mechanism; and a second plate, that is rotatable, housed on the lower bail joint mechanism so as to be always parallel to the first plate, the second plate being driven in rotation by a member connecting it to the lower rotor.

An unmanned aerial vehicle includes a propulsion system having at least one propulsion module comprised of at least one propeller and at least two motors/engines, one or more of the motors/engines providing mechanical energy to drive the propeller, wherein the difference between the angular velocities of the motors/engines provides energy input to a mechanical or magneto-mechanical linkage system to change the blade pitch angle of the propeller, in cyclic and/or collective manner.

Multiple propeller blades may be joined by tip connectors to form a closed propeller apparatus. The tip connectors may create continuous structure between adjacent tips of a first propeller and a second propeller. Use of the tip connectors may reduce vortices created near the tips of the propeller blades, which cause drag and slow the rotation of the propeller blades. The tip connectors may also reduce noise caused by rotation of propeller blades. Further, the tip connectors reduce or eliminate deflection of the propeller blades by creating a support structure to counteract forces that would otherwise cause deflection of the propeller blades, thereby improving propeller blade loading. In some embodiments, the tip connectors may be formed of a malleable material and/or include one or more joints that enable at least one of the propellers to modify a pitch of blades of the propeller.

An aircraft turbomachine includes a speed reduction gear having an input pinion connected to a power shaft and an output pinion connected to a propeller shaft. An electric machine is integrated into the speed reduction gear and is configured to provide electrical power to the propeller shaft or to take mechanical power from the propeller shaft. The electric machine has a rotor driven in rotation about an axis coaxial with a longitudinal axis of the turbomachine and a stator connected to a casing. The input pinion includes an input shaft offset from an axis of the output pinion, and the speed reduction gear has two parallel intermediate transmission lines configured to transmit the torque from the input pinion to the output pinion to drive the rotor in rotation.

An aircraft comprising a fuselage and propelled by a turbine engine having two coaxial and contrarotating fans, the turbine engine comprising a power turbine having two contrarotating rotors, one of which drives a fan upstream from the turbine, the other a fan downstream from the turbine, each fan comprising a ring of blades, and the assembly of the fans and the power turbine being incorporated at the rear of the fuselage, in the extension of same. The aircraft comprises, for at least one of the fans, a device for blocking the rotation of the fan and a device configured to modify the pitch of the blades of the fan in such a way as to make it operate as a flow straightener with respect to the other fan.

The present invention relates to a propulsion unit comprising a pair of contra-rotating coaxial propellers, that are referred to as upstream (2) and downstream (3), the downstream propeller, forming a rotating reference frame, being mounted for rotation about a central member forming a stationary reference frame, and being provided with a device for changing the pitch of the blades, characterized in that the downstream propeller is supported by bearings arranged externally on the cylindrical central support, an upstream bearing (40) of which is arranged downstream of a device for changing the pitch of the blades of the upstream propeller, and in that said device for changing the pitch of the downstream propeller comprises a linear actuator (23) in the stationary reference frame with an element (235) that is able to move axially along the axis of the downstream propeller, the upstream bearing comprising an inner ring that is rigidly connected to the linear actuator and an outer ring that is rigidly connected to a rotating casing (20) of the downstream propeller, and a movement-transmission mechanism (24) connecting said movable element of the linear actuator to the blades, comprising a load-transfer bearing arranged to transmit the axial forces from the linear actuator to the rotating reference frame of the downstream propeller.