A system includes a propeller assembly comprising a propeller, a drive shaft coupled to the propeller assembly, wherein the drive shaft when in operation generates rotation of the propeller, a reduction gearbox coupled to the drive shaft, wherein the reduction gearbox when in operation alters a rotation speed between a power turbine shaft and the drive shaft, and an electric motor disposed between the propeller assembly and the reduction gearbox, wherein the electric motor is coupled to the drive shaft, wherein the electric motor when in operation imparts torque to at least partially rotate the drive shaft.

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 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 method is provided for an HEP system that includes a gas turbine engine and an electric motor configured to assist the gas turbine engine by rotating a first shaft of the gas turbine engine. The method includes receiving a throttle command, and determining, based on an amount of electric power available to the electric motor, a power allocation between the gas turbine engine and the electric motor for an acceleration period during which a rotational speed of the first shaft is accelerated to implement the throttle command. The method also includes determining a target clearance between a tip of a rotor blade and a case structure for the acceleration period and, during the acceleration period, implementing the power allocation and operating an active clearance control (ACC) system to establish the target clearance. A system for an aircraft and a method for a HEP system are also disclosed.

Propulsion system for a helicopter comprising a main engine, a main rotor, a main gearbox including an output mechanically connected to the main rotor, a reduction gearbox mechanically coupled between the main engine and a first input of the main gearbox, and an assistance device. The assistance device comprises a first electric machine mechanically coupled to the reduction gearbox and configured to operate as an electric generator to take off energy produced by the main engine, and a second electric machine mechanically coupled to a second input of the main gearbox, the second electric machine being supplied with electrical power by the first electric machine and configured to operate as an electric motor to deliver additional mechanical power to the main gearbox.

Propulsion system for a helicopter comprising a main engine, a main rotor, a main gearbox including an output mechanically connected to the main rotor, a reduction gearbox mechanically coupled between the main engine and a first input of the main gearbox, and an assistance device. The assistance device comprises a first electric machine mechanically coupled to the reduction gearbox and configured to operate as an electric generator to take off energy produced by the main engine, and a second electric machine mechanically coupled to a second input of the main gearbox, the second electric machine being supplied with electrical power by the first electric machine and configured to operate as an electric motor to deliver additional mechanical power to the main gearbox.

A hybrid power drive system for an aircraft comprises a rotor that receives power and a first power drive sub-system including at least one engine in connection with the rotor is configured to provide a first power to the rotor. Further, the hybrid power drive system also includes a second power drive sub-system connected in parallel to the first power drive sub-system. The second power drive sub-system is configured to provide a second power to the rotor a second power drive sub-system connected in parallel to the first power drive sub-system and configured to provide a second power to the rotor when the first power provided by the first power drive sub-system is less than a power demand of the rotor.

A rotor system for a rotorcraft includes a first rotor assembly defining a rotation axis, a second rotor assembly offset from the first rotor assembly along the rotation axis, and a drive system connected to the first and second rotor assemblies. The drive system includes a first electric motor disposed along the rotation axis and operably connected to the first rotor assembly, and a second electric motor disposed along the rotation axis and operably connected to the second rotor assembly to rotate the second rotor assembly about the rotation axis independent of rotation of the first rotor assembly about the rotation axis.

A manned aircraft having wing parts, an internal combustion engine which is connected via a shaft to a left thrust nacelle and to a right thrust nacelle, which are pivotable from a vertical position for a hovering flight phase into a horizontal position for the forward flight phase, and having a left thrust unit and a right thrust unit which are driven by electric motors, and having a control unit which carries out a moment-dynamic flight control and which controls the thrust units to generate thrust for the hovering flight phase and at least partially stops them for the forward flight phase.

A manned aircraft having wing parts, an internal combustion engine which is connected via a shaft to a left thrust nacelle and to a right thrust nacelle, which are pivotable from a vertical position for a hovering flight phase into a horizontal position for the forward flight phase, and having a left thrust unit and a right thrust unit which are driven by electric motors, and having a control unit which carries out a moment-dynamic flight control and which controls the thrust units to generate thrust for the hovering flight phase and at least partially stops them for the forward flight phase.