Hybrid propulsion is obtained by arranging, around a conventional turbomachine, a reversible electric machine linked to the low-pressure shaft via a mechanical movement transmission, a one-way clutch being arranged on the low-pressure shaft between the fan and a low-pressure compressor. The low-pressure shaft includes two aligned portions which can be separated and reconnected. A casing includes a first portion able to tilt around a horizontal transverse axis of the aircraft relative to a second portions of the casing. One portion of the low-pressure shaft, the fan and the reversible electric machine are mounted on the first portion of the casing, and the other portion of the low-pressure shaft is mounted on the second portion of the casing. This device facilitates electric taxiing of the aircraft, using the machine as a motor, whereas the rear of the low-pressure shaft remains stationary.

Hybrid propulsion is obtained by arranging, around a conventional turbomachine, a reversible electric machine linked to the low-pressure shaft via a mechanical movement transmission, a one-way clutch being arranged on the low-pressure shaft between the fan and a low-pressure compressor. The low-pressure shaft includes two aligned portions which can be separated and reconnected. A casing includes a first portion able to tilt around a horizontal transverse axis of the aircraft relative to a second portions of the casing. One portion of the low-pressure shaft, the fan and the reversible electric machine are mounted on the first portion of the casing, and the other portion of the low-pressure shaft is mounted on the second portion of the casing. This device facilitates electric taxiing of the aircraft, using the machine as a motor, whereas the rear of the low-pressure shaft remains stationary.

One embodiment is an electric drive system for an aircraft comprising a plurality of redundant motors, wherein power generated by the plurality of motors is used to drive a rotor system comprising a rotor shaft having a plurality of rotor blades connected thereto; a gear box associated with the plurality of redundant motors; a collective actuator for controlling a collective pitch of the rotor blades connected to the rotor shaft; and at least one structural element for retaining the redundant motors, the gear box, and the collective actuator together as a single integrated unit.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

A ducted fan assembly includes a duct having an inlet, an inner surface, an expanding diffuser and an outlet. A fan disposed within the duct between the inlet and the expanding diffuser is configured to rotate about a fan axis to generate airflow. An active flow control system includes a plurality of injection zones circumferentially distributed about the inner surface. The expanding diffuser has a diffuser angle configured to create flow separation when the airflow is uninfluenced by the active flow control system such that the airflow has a thrust vector with a first direction that is substantially parallel to the fan axis. Injection of pressurized air from one of the injection zones asymmetrically reduces the flow separation between the airflow and the expanding diffuser downstream of that injection zone such that the thrust vector of the airflow has a second direction that is not parallel to the first direction.

A hybrid multirotor propulsion system for an aircraft includes a plurality of propulsion units, each propulsion unit having a propeller, an electromotor and a peripheral differential gearbox; a plurality of driving elements, each of which is coupled to a respective one of the plurality of propulsion units; a mechanical power source; a main distributor gearbox; at least one electric machine; and a power management unit. The power management unit is configured according to a predetermined operating mode, which causes the mechanical power source to output first and second mechanical power components; and distributing the first mechanical power component to provide each driving element with a direct mechanical propeller power; and causes the electric machine to convert the second mechanical power component into electric power, part of which provides each electromotor with an electric propeller power. The direct mechanical propeller power causes each electromotor to convert the electric propeller power into an indirect mechanical propeller power, outputted to the peripheral differential gearbox; and causes the peripheral differential gearbox of each propulsion unit to aggregate the direct mechanical propeller power and the indirect mechanical propeller power to a total mechanical propeller power which drives the propeller of each propulsion unit.

A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor is configured to drive a motor shaft. A transmission system includes at least one gear box. The transmission system is configured to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. The motor shaft includes a disconnect mechanism to allow the heat engine to rotate with the electric motor stopped. The heat engine shaft includes a disconnect mechanism to allow the electric motor to rotate with the heat engine stopped.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.

A propulsion system for providing propulsion of an aircraft includes a plurality of electric motors coupled with a rotor of the aircraft to drive the rotor and a propulsion motor control. The propulsion motor control includes at least one processor electrically connected with at least one electric motor to actuate the at least one electric motor and at least one battery electrically connected with the at least one processor and at least one electric motor to provide power to the at least one processor and the at least one electric motor. The propulsion motor control actuates the plurality of electric motors based on a desired torque level to drive the rotor to provide propulsion of the aircraft.