A gas turbine engine includes a compressor section and a turbine section together defining a core air flowpath. Additionally, a rotary component is rotatable with at least a portion of the compressor section and at least a portion of the turbine section. An electric machine is mounted coaxially with the rotary component and positioned at least partially inward of the core air flowpath along a radial direction of the gas turbine engine. An electric communication bus is electrically connected to the electric machine and extends through the core air flowpath to, e.g., electrically connect the electric machine to one or more systems of the gas turbine engine or a propulsion system including the gas turbine engine.

A propulsion system for an aircraft includes an electric propulsion engine configured to be mounted at an aft end of the aircraft. The electric propulsion engine includes an electric motor and a fan rotatable about a central axis, the fan driven by the electric motor. The electric propulsion system additionally includes a cooling system operable with an airflow over the aft end the aircraft when the electric propulsion system is mounted to the aircraft. The cooling system is configured to cool the electric motor during operation of the electric propulsion engine.

A gas turbine engine has a fan drive turbine for selectively driving a fan rotor. A drive shaft between the fan drive turbine and the fan rotor includes a clutch, and an electric motor. The electric motor is positioned such that it is not downstream of a flow path relative to the fan drive turbine. A method of operating a gas turbine engine is also disclosed.

An electromechanically controlled aircraft power transmission system includes a first planetary gear set, a first gas turbine engine, a first electric machine, a second planetary gear set, a second gas turbine engine, a second electric machine, a propulsor shaft, and at least one propulsor. The first gas turbine engine is coupled to the first planetary gear set. The first electric machine is coupled to the first planetary gear set and is configured vary the gear ratio of the first planetary gear set. The second gas turbine engine is coupled to the second planetary gear set. The second electric machine is coupled to the second planetary gear set and is configured to vary the gear ratio of the second planetary gear set. The propulsor shaft is coupled to the first and second planetary gear sets and the at least one propulsor is coupled to the propulsor shaft.

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.

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 propulsion system for an aircraft includes an electric generator and a turbomachine. The turbomachine is configured to be mounted to a first wing of the aircraft and is operable with the electric generator. The propulsion system additionally includes a first propulsor mechanically coupled to a shaft of the turbomachine and a second propulsor assembly configured to be mounted at a location away from the turbomachine and the first propulsor. The electric generator is in electrical communication with the second propulsor assembly for powering the second propulsor assembly.