The present application relates to a propulsion device having a motor, a mast connected to the motor, an angle sensing device detecting the angle of the mast, a controller receiving the angle of the mast as an input and outputting a motor torque signal to the motor in response thereto, a hub attached to the mast via a single skewed hinge, and a propeller assembly with one or more blades connected to a hub.

The application discloses a coaxial helicopter, the cyclic pitch-changing mechanism simultaneously adjusts the pitches of the upper and the lower rotor systems, to make uniformity cyclic pitch-changing adjustment of the upper and lower rotors, and make independent collective pitch adjustment of the upper rotor system; the differential pitch-changing mechanism and the cyclic pitch-changing mechanism jointly act on the lower rotor system, to perform differential collective pitch adjustment of the upper and lower rotor systems. The synchronous rotating mechanism drives the swashplate members to synchronously rotate along with the drive shaft. The application achieves a simpler hybrid pitch-changing control system of the coaxial rotor pitch, a plurality of flight operations of the coaxial aircraft are performed synchronously, and a plurality of flight control modes, such as semi-differential and full-differential in a variable speed or a fixed speed mode, are supported, and thus the present application has wider application space.

The application discloses a coaxial helicopter, the cyclic pitch-changing mechanism simultaneously adjusts the pitches of the upper and the lower rotor systems, to make uniformity cyclic pitch-changing adjustment of the upper and lower rotors, and make independent collective pitch adjustment of the upper rotor system; the differential pitch-changing mechanism and the cyclic pitch-changing mechanism jointly act on the lower rotor system, to perform differential collective pitch adjustment of the upper and lower rotor systems. The synchronous rotating mechanism drives the swashplate members to synchronously rotate along with the drive shaft. The application achieves a simpler hybrid pitch-changing control system of the coaxial rotor pitch, a plurality of flight operations of the coaxial aircraft are performed synchronously, and a plurality of flight control modes, such as semi-differential and full-differential in a variable speed or a fixed speed mode, are supported, and thus the present application has wider application space.

An exemplary length adjustable link includes a tube having an internal bore and internal surface, a first rod end having a first shaft disposed in a first end of the internal bore, a second rod end having a second shaft disposed in a second end of the internal bore, and a member threadably connecting the first rod end to the second rod end.

An exemplary length adjustable link includes a tube having an internal bore and internal surface, a first rod end having a first shaft disposed in a first end of the internal bore, a second rod end having a second shaft disposed in a second end of the internal bore, and a member threadably connecting the first rod end to the second rod end.

Disclosed is an apparatus (100) for an aerial transportation of a payload. The apparatus (100) includes a propeller unit (10) to provide a primary thrust whereas a plurality of propellers (50) is fitted around a body of the apparatus (100) to help in maneuvering and orientation control. The apparatus (100) employs gasoline as a primary source of energy that has a higher energy density than lithium polymer batteries. The apparatus (100) facilitates longer flight times. The apparatus (100) is useful for safe transportation of higher payloads and has vertical takeoff and land capability.

In an embodiment, a method includes: obtaining a first signal from a first sensor of a rotorcraft, the first signal indicating measured angular velocity around a first axis of the rotorcraft; filtering the first signal with a lag compensator to estimate angular position around the first axis of the rotorcraft; and adjusting flight control devices of the rotorcraft according to the estimated angular position and the measured angular velocity around the first axis of the rotorcraft, thereby changing flight characteristics of the rotorcraft around the first axis of the rotorcraft.

In an embodiment, a method includes: obtaining a first signal from a first sensor of a rotorcraft, the first signal indicating measured angular velocity around a first axis of the rotorcraft; filtering the first signal with a lag compensator to estimate angular position around the first axis of the rotorcraft; and adjusting flight control devices of the rotorcraft according to the estimated angular position and the measured angular velocity around the first axis of the rotorcraft, thereby changing flight characteristics of the rotorcraft around the first axis of the rotorcraft.

An anti-torque rotor is described for a helicopter, comprising: a mast rotatable about a first axis; a plurality of blades hinged on the mast, extending along respective second axes transversal to said first axis and rotatable about respective said second axes to alter the respective angles of attack; a control element sliding and rotating with respect to the mast, and operatively connected to said blades to cause the rotation of said blades about respective second axes following a translation of said element along the first axis; a control rod sliding axially along first axis with respect to the mast and angularly fixed with respect to the first axis; and a connection element interposed between the control rod and the control element, sliding along the first axis with respect to the mast and integrally with the control rod; the anti-torque rotor further comprises an interface made of an antifriction material interposed between said control rod and said connection element.

An anti-torque rotor is described for a helicopter, comprising: a mast rotatable about a first axis; a plurality of blades hinged on the mast, extending along respective second axes transversal to said first axis and rotatable about respective said second axes to alter the respective angles of attack; a control element sliding and rotating with respect to the mast, and operatively connected to said blades to cause the rotation of said blades about respective second axes following a translation of said element along the first axis; a control rod sliding axially along first axis with respect to the mast and angularly fixed with respect to the first axis; and a connection element interposed between the control rod and the control element, sliding along the first axis with respect to the mast and integrally with the control rod; the anti-torque rotor further comprises an interface made of an antifriction material interposed between said control rod and said connection element.