A mechanical power transmission that pivots about an axis to vary an angle between an input shaft and an output shaft. The mechanical power transmission includes an input gear having an input shaft that couples to a drive shaft, an output gear having an output shaft that couples to a tail rotor, a first intermediate gear rotationally coupled to the input gear, and a second intermediate gear rotationally coupled to the output gear. The mechanical power transmission further comprises a shaft that mechanically couples the first intermediate gear with the second intermediate gear, where a centerline of the shaft is coincident with the axis.

A mount system for tiltably supporting a pylon assembly of a rotorcraft. First, second, third and fourth pylon links are each coupled between the pylon assembly and the airframe of the rotorcraft. The first pylon link has a first axis, the second pylon link has a second axis, the third pylon link has a third axis and the fourth pylon link has a fourth axis. Each of the axes intersects at a focal point located proximate a coaxial rotor system having counter-rotating upper and lower rotor assemblies such that the focal point provides a virtual pivot point about which the pylon assembly tilts to generate a control moment about a center of gravity of the rotorcraft that counteracts lateral and fore/aft moments generated by the upper and lower rotor assemblies during rotorcraft maneuvers.

A multi-rotor aircraft includes a fuselage, a propulsion engine coupled to the fuselage that generates thrust to propel the aircraft along a first vector during forward flight, and rotors coupled to the fuselage, each rotor comprising blades, each rotor coupled to a motor, and each motor configured to supply power to and draw power from the coupled rotor. The aircraft includes a flight control system configured to control the motors coupled to the rotors in a power managed regime in which a net electrical power, consisting of a sum of the power being supplied to or drawn from each rotor by its motor, is maintained within a range determined by a feedback control system of the flight control system. The flight control system can also be leveraged to adjust rotor control inputs to modify at least one of thrust, roll, pitch, or yaw of the multi-rotor aircraft.

A rotary wing aircraft and a rotor assembly of a rotary wind aircraft is disclosed. The rotary wing aircraft includes at least one engine, and the rotor assembly is coupled to the at least one engine. The rotor assembly includes a first rotor hub, a second rotor hub, and a shaft fairing between the first rotor hub to the second rotor hub, the shaft fairing defined by a chord that varies between the first rotor hub and the second rotor hub.

A rotary wing aircraft that extends along an associated roll axis between a nose region and an aft region and that comprises a fuselage with a front section and a rear section, the rotary wing aircraft comprising: a main rotor that is rotatably mounted at the front section, a shrouded duct that is arranged in the aft region, and a propeller that is rotatably mounted to the shrouded duct, wherein the rear section extends between the front section and the shrouded duct and comprises an asymmetrical cross-sectional profile in direction of the associated roll axis.

An aircraft includes a main body having an empennage, a main rotor assembly mounted on the main body, and a movable control surface assembly supported on the empennage. The movable control surface assembly includes a tube extending from the empennage along a tube axis to a free end, the tube being supported for rotation about the tube axis with respect to the empennage, and a movable control surface mounted on the tube for rotation therewith. The movable control surface is supported on the tube by a connection element that couples the movable control surface to the free end of the tube to rotatably fix the movable control surface with respect to the tube.

Tail boom drive systems for helicopters are described which utilize a fan internal to the tail boom to provide yaw control, and an external propulsor to provide forward thrust. In one embodiment, the tail boom drive system includes a shaft, a fan, and a propulsor. The shaft is disposed lengthwise within an interior space of the tail boom, and the shaft has a first end and a second end. The fan is mechanically coupled coaxially to the shaft within the interior space between the first end and the second end, and the fan generates a variable airflow directed towards the second end that is ejected from the interior space substantially perpendicular to the tail boom. The propulsor is external to the tail boom and is mechanically coupled coaxially to the shaft at the second end, and the propulsor generates a variable thrust directed towards the first end.

The invention discloses a multi-rotor manned vehicle, comprising man-carried cabin, lifting rotor, equipment bin and steering rudder; the upper part of the said man-carried cabin is provided with a window, the bottom edge is provided with a landing gear or taxiing wheels, the outer wall is provided with a cabin door, the outer wall of both sides or the top is provided with a side-push rotor separately, and the back end of the said side-push rotor is provided with a first power device to drive the said side-push rotor; the said lifting rotors are provided of a quantity of at least two, which are arranged side-by-side in parallel around or on both sides of the said man-carried cabin, and the lower end of each said lifting rotor is respectively provided with a second power device to drive the said lifting rotor; the said equipment bin is arranged at the bottom of the said man-carried cabin, in which a power source is provided for the operation of the said first power device and the second power device; the said steering rudder is arranged at the rear or top of the said man-carried cabin. The flight, take-off and landing of the invention is similar to the unmanned aerial vehicle, having the advantages of small and flexible, low altitude and low speed, vertical lifting, economic and practical.

A rotary wing vehicle includes a body structure having an elongated tubular backbone or core, and a counter-rotating coaxial rotor system having rotors with each rotor having a separate motor to drive the rotors about a common rotor axis of rotation. The rotor system is used to move the rotary wing vehicle in directional flight.

An aircraft includes an airframe, and a coaxial main rotor assembly including a static mast and an upper rotor assembly and a lower rotor assembly rotatable about a main rotor axis defined by the static mast. The upper rotor assembly and the lower rotor assembly are independently rotatable about the static mast. A propulsion system includes at least one propulsion source for directly driving at least one of the upper rotor assembly and the lower rotor assembly and a flight control system is operably coupled to the propulsion system. The flight control system is operable to independently control a rotational speed of the upper rotor assembly and the lower rotor assembly relative to the static mast.