An aircraft propulsion system with an internally cooled electric motor adapted for use in an aerial vehicle. The motor may have its stator towards the center and have an external rotor. The rotor structure may be air cooled and may be a complex structure with an internal lattice adapted for airflow. The stator structure may be liquid cooled and may be a complex structure with an internal lattice adapted for liquid to flow through. A fluid pump may pump a liquid coolant through non-rotating portions of the motor stator and then through heat exchangers cooled in part by air which has flowed through the rotating portions of the motor rotor. The drag reduction portion and the cooled electric motor portion may share the same inlet.

An electric propulsion system for a vertical take-off and landing (VTOL) aircraft, the electric propulsion system including an electrical motor having a stator and a rotor. The electric propulsion system may include a main shaft possessing at least one shoulder on an outer surface of the main shaft. The electric propulsion system may include a gearbox assembly comprising a sun gear that is concentrically aligned with the main shaft at least one planetary gear that interfaces with the sun gear. The electric propulsion system may include a planetary carrier, wherein a center of the planetary carrier is concentrically aligned with the main shaft. The electric propulsion system may include a propeller flange assembly that travels through the rotor, and an axial buttress positioned in the at least one shoulder located on the main shaft.

An electric propulsion system for a vertical take-off and landing (VTOL) aircraft, the electric propulsion system including an electrical motor having a stator and a rotor. The electric propulsion system may include a main shaft possessing at least one shoulder on an outer surface of the main shaft. The electric propulsion system may include a gearbox assembly comprising a sun gear that is concentrically aligned with the main shaft at least one planetary gear that interfaces with the sun gear. The electric propulsion system may include a planetary carrier, wherein a center of the planetary carrier is concentrically aligned with the main shaft. The electric propulsion system may include a propeller flange assembly that travels through the rotor, and an axial buttress positioned in the at least one shoulder located on the main shaft.

A heat exchanger for an electric machine. The electric machine includes a stator having a stator core and stator slots extending along a longitudinal axis of the stator, and a rotor assembly having a rotor configured to rotate about the longitudinal axis. The electric machine includes a coolant system having a stator cooling path providing a first coolant fluid in direct contact with the stator to flow around the stator core and through the stator slots. The coolant system also includes a coolant circuit providing a second coolant fluid to at least one rotatable component of the electric machine, such as at least one bearing. The coolant circuit and the stator cooling path are fluidically isolated from one another and arranged such that heat is exchanged between the first coolant fluid and the second coolant fluid at the stator.

A heat exchanger for an electric machine. The electric machine includes a stator having a stator core and stator slots extending along a longitudinal axis of the stator, and a rotor assembly having a rotor configured to rotate about the longitudinal axis. The electric machine includes a coolant system having a stator cooling path providing a first coolant fluid in direct contact with the stator to flow around the stator core and through the stator slots. The coolant system also includes a coolant circuit providing a second coolant fluid to at least one rotatable component of the electric machine, such as at least one bearing. The coolant circuit and the stator cooling path are fluidically isolated from one another and arranged such that heat is exchanged between the first coolant fluid and the second coolant fluid at the stator.

An axial flux electric motor for an aircraft includes a first motor section having a first stator and a first rotor, and a second motor section having a second stator and a second rotor. The first and second rotors are mounted on a common axle. The first rotor is secured to the common axle by a first set of connecting elements. The second rotor is secured to the common axle by a second set of connecting elements. The first set of connecting elements is arranged to break when the relative torque between the common axle and the first rotor is greater than a first particular threshold. The second set of connecting elements is arranged to break when the relative torque between the common axle and the second rotor is greater than a second particular threshold.

An axial flux electric motor for an aircraft includes a first motor section having a first stator and a first rotor, and a second motor section having a second stator and a second rotor. The first and second rotors are mounted on a common axle. The first rotor is secured to the common axle by a first set of connecting elements. The second rotor is secured to the common axle by a second set of connecting elements. The first set of connecting elements is arranged to break when the relative torque between the common axle and the first rotor is greater than a first particular threshold. The second set of connecting elements is arranged to break when the relative torque between the common axle and the second rotor is greater than a second particular threshold.

Embodiments of the present disclosure provide systems and methods for averting, shedding, or otherwise managing ice accretions that may develop during flight of an aircraft. Example systems and methods selectively modulate propeller parameters in a way that does not disrupt a flight trajectory; direct oil from a lubrication and cooling path to targeted sections of ice-prone surfaces to manage ice accretion in a way that does not unduly increase the total volume of oil, require larger pumps, or complicate the system; or generate heat at targeted areas of a propeller assembly by electric heating systems that utilize propeller motion.

An electric propulsion system for a vertical takeoff-and-landing aircraft having an inverter assembly, a gearbox assembly, an electric motor assembly. The inverter assembly, the gearbox assembly, and the electric motor assembly may be substantially aligned along an axis. The inverter assembly, a gearbox assembly, and electric motor assembly may each abut at least one of the others. The electric engine may use a liquid, such as oil, for cooling and lubricating components of the inverter assembly, gearbox assembly, and electric motor assembly. Further, the electric engine may use volumes of oil for cooling and lubricating components below a threshold volume so that the electric engines do not require a fire protective barrier.

An electric propulsion system for a vertical takeoff-and-landing aircraft having an inverter assembly, a gearbox assembly, an electric motor assembly. The inverter assembly, the gearbox assembly, and the electric motor assembly may be substantially aligned along an axis. The inverter assembly, a gearbox assembly, and electric motor assembly may each abut at least one of the others. The electric engine may use a liquid, such as oil, for cooling and lubricating components of the inverter assembly, gearbox assembly, and electric motor assembly. Further, the electric engine may use volumes of oil for cooling and lubricating components below a threshold volume so that the electric engines do not require a fire protective barrier.