Vertical takeoff and landing (VTOL) aircraft are provided with fixed-position port and starboard wings extending laterally from an elongate fuselage having an empennage at an aft end of the fuselage and a propeller to provide horizontal thrust to the aircraft in a direction of the longitudinal axis thereof. A series of port and starboard rotor units are provided, each of which includes axially opposed rotor blades, and a motor to rotate the rotor blades and provide vertical thrust to the aircraft. A logic control unit (LCU) controllably sets an angular position of the opposed rotor blades along a position axis relative to the longitudinal axis of the aircraft in response to determining an optimal position of the rotor blades during cruise flight operation to thereby minimize airflow disruption over the fixed-position wings.

An aircraft has a pilot compartment and a power source, apparatus adapted to control attitude and direction, apparatus adapted to vary power of the power source, sensors sensing at least altitude, airspeed, power level, and aircraft attitude, a CPU coupled to a data repository, to the sensors and to actuators adapted to change the flight attitude and direction and to vary power, and safe flight envelope data and conditions stored in the data repository defining flight conditions at boundaries of safe and unsafe operation. The CPU monitors the sensors while the aircraft is in operation, determines if flight status is outside the safe flight envelope, and if so, drives appropriate actuators to manipulate the apparats adapted to control flight attitude and direction and/or the apparatus adapted to vary power of the power source in a programmed manner until the flight status is within the safe flight envelope.

An aircraft has a pilot compartment and a power source, apparatus adapted to control attitude and direction, apparatus adapted to vary power of the power source, sensors sensing at least altitude, airspeed, power level, and aircraft attitude, a CPU coupled to a data repository, to the sensors and to actuators adapted to change the flight attitude and direction and to vary power, and safe flight envelope data and conditions stored in the data repository defining flight conditions at boundaries of safe and unsafe operation. The CPU monitors the sensors while the aircraft is in operation, determines if flight status is outside the safe flight envelope, and if so, drives appropriate actuators to manipulate the apparats adapted to control flight attitude and direction and/or the apparatus adapted to vary power of the power source in a programmed manner until the flight status is within the safe flight envelope.

A technique for operating an aerial vehicle involves enabling a vertical takeoff and landing (VTOL) propeller of the aerial vehicle to rotate freely. The VTOL propeller is coupled with a VTOL motor (e.g., a 3-phase brushless DC motor). The technique further involves detecting when the VTOL propeller rotates to a predefined position relative to a direction of flight for the aerial vehicle (e.g., when blades of the VTOL propeller extend along an axis that is parallel to the direction of flight). The technique further involves, in response to detecting that the VTOL propeller has rotated to the predefined position, providing a load from the VTOL motor that inhibits further rotation of the VTOL propeller. Accordingly, while the aerial vehicle is in fixed wing horizontal flight, the controller is able to align the VTOL propeller in the direction of horizontal flight to minimize drag from the VTOL propeller.

A technique for operating an aerial vehicle involves enabling a vertical takeoff and landing (VTOL) propeller of the aerial vehicle to rotate freely. The VTOL propeller is coupled with a VTOL motor (e.g., a 3-phase brushless DC motor). The technique further involves detecting when the VTOL propeller rotates to a predefined position relative to a direction of flight for the aerial vehicle (e.g., when blades of the VTOL propeller extend along an axis that is parallel to the direction of flight). The technique further involves, in response to detecting that the VTOL propeller has rotated to the predefined position, providing a load from the VTOL motor that inhibits further rotation of the VTOL propeller. Accordingly, while the aerial vehicle is in fixed wing horizontal flight, the controller is able to align the VTOL propeller in the direction of horizontal flight to minimize drag from the VTOL propeller.

A power transmission system includes a shaft, a stator disposed within the shaft and substantially concentric with the shaft; and at least one supporting element positioned between the stator and the shaft and configured to support the shaft on the stator to reduce a vibration of the shaft and allow the shaft to rotate relative to the stator. A gas turbine engine including the power transmission system is also described.

A propeller-type propulsion system for aircraft comprising a propeller, a plurality of electric motors and a gearbox. The gearbox has an output shaft onto which the propeller is mechanically coupled, and has an input shaft onto which the plurality of electric motors is mechanically coupled, the input shaft being off-center with respect to the output shaft. All of the electric motors are mechanically coupled one after the other along the input shaft such that the electric motors are at least partially integrated into a space, on the opposite side of the gearbox from the propeller, that is left free owing to the input shaft and the output shaft being off-center with respect to one another. As a result, the diameter of the propulsion system, in a plane perpendicular to the axis of rotation of the propeller, is reduced. This improves the aerodynamics and the fuel consumption of the aircraft.

A propeller-type propulsion system for aircraft comprising a propeller, a plurality of electric motors and a gearbox. The gearbox has an output shaft onto which the propeller is mechanically coupled, and has an input shaft onto which the plurality of electric motors is mechanically coupled, the input shaft being off-center with respect to the output shaft. All of the electric motors are mechanically coupled one after the other along the input shaft such that the electric motors are at least partially integrated into a space, on the opposite side of the gearbox from the propeller, that is left free owing to the input shaft and the output shaft being off-center with respect to one another. As a result, the diameter of the propulsion system, in a plane perpendicular to the axis of rotation of the propeller, is reduced. This improves the aerodynamics and the fuel consumption of the aircraft.

A propeller-type propulsion system for aircraft, comprises a propeller, a plurality of electric motors comprising nested coaxial respective driveshafts, and a gearbox having an output shaft onto which the propeller is mechanically coupled, and an input shaft to which the coaxial driveshafts of the electric motors are mechanically coupled. As a result, the diameter of the propulsion system, in a plane perpendicular to the axis of rotation of the propeller, is reduced. This improves the aerodynamics and the fuel consumption of the aircraft.

A propulsion device includes: a duct in which a flow path extending in a direction of an axis; a fan which is provided with a) an outer peripheral ring formed in an annular shape surrounding the axis and installed to be relatively rotatable around the axis with respect to the duct, b) a plurality of fan blades arranged at intervals in a circumferential direction such that each blade is extended from the outer peripheral ring toward the inside of the flow path, and c) an inner peripheral ring formed in an annular shape being connected radially inner end portions of the plurality of fan blades and in which an air flow passage is formed so that air flows therethrough in the direction of the axis; and a motor which drives the fan to rotate around the axis.