Aircraft hybrid electric propulsion system

A hybrid-electric propulsion (HEP) system for powering an aircraft, comprising:

• a reduction gearbox;
• an inlet case including an inlet duct, the inlet case forming a cavity;
• an engine output shaft disposed within the cavity and extending axially along a first rotational axis, the engine output shaft rotatably engaged with the reduction gearbox;
• a gas turbine engine in drive communication with the engine output shaft;
• an electric motor, wherein at least a portion of the electric motor is disposed within the cavity;
• a gear system configured to rotatably engage the electric motor with the engine output shaft, the gear system coupled to the engine output shaft independent of the reduction gearbox;
• and
• a controller;
• wherein the HEP system is configured to operate in a first mode of operation, or a second mode of operation, one at a time, wherein:
• the first mode of operation includes controlling the gas turbine engine to provide rotational drive to the reduction gearbox through the engine output shaft, and controlling the electric motor to not operate;
• and
• the second mode of operation includes controlling the gas turbine engine to provide a first rotational drive to the reduction gearbox through the engine output shaft and controlling the electric motor to provide a second rotational drive to the reduction gearbox through the engine output shaft;
• and
• wherein the controller is in communication with the electric motor and a non-transitory memory storing instructions, wherein the instructions when executed cause the system controller to selectively operate the HEP system in one of the first mode of operation or the second mode of operation, and to subsequently operate the HEP system in another of the first mode of operation or the second mode of operation.

An assembly for a hybrid-electric propulsion (HEP) system for powering an aircraft, the assembly comprising:

• an inlet case including an inlet duct, the inlet case forming a cavity;
• an engine output shaft disposed within the cavity and extending axially along a first rotational axis;
• a gearbox in drive communication with the engine output shaft, the gearbox configured to drive rotation of a propulsion unit;
• an electric motor in drive communication with the engine output shaft, wherein at least a portion of the electric motor is disposed within the cavity and laterally offset from the engine output shaft;
• and
• a gear system configured to rotatably engage the electric motor with the engine output shaft.