A rotor system includes a rotor assembly and a duct system. The rotor assembly includes rotor blades extending from a mast axis and configured to rotate about the mast axis. The duct assembly includes a moveable duct portion and a stationary duct portion. In a first duct configuration, the moveable duct portion surrounds a first portion of the rotor assembly, the stationary duct portion surrounds a second portion of the rotor assembly, and the moveable duct portion and the stationary duct portion enclose the rotor assembly. In a second duct configuration, the stationary duct portion surrounds the second portion of the rotor assembly, and the moveable duct portion is moved away from the first portion of the rotor assembly, such that the rotor assembly is not enclosed.

A rotor system includes a rotor assembly and a duct system. The rotor assembly includes rotor blades extending from a mast axis and configured to rotate about the mast axis. The duct assembly includes a moveable duct portion and a stationary duct portion. In a first duct configuration, the moveable duct portion surrounds a first portion of the rotor assembly, the stationary duct portion surrounds a second portion of the rotor assembly, and the moveable duct portion and the stationary duct portion enclose the rotor assembly. In a second duct configuration, the stationary duct portion surrounds the second portion of the rotor assembly, and the moveable duct portion is moved away from the first portion of the rotor assembly, such that the rotor assembly is not enclosed.

A control system for a multi-rotor aircraft is described that results in lower operating noise. Allowing blades to flap during flight reduces aerodynamic interference as blades pass by other aircraft components, such as wings or the fuselage. Pitch links coupled to a rotational swashplate can be used to allow flapping during flight. The swashplates can allow the canting of the rotors to change a rotational or out-of-plane angle of the blades to decrease noise.

A method of pitching rotor blades by interrupting torque applied to the hub.

A method of pitching rotor blades by interrupting torque applied to the hub.

An unmanned rotorcraft includes an airframe, rotor blades that are coupled to the airframe for rotation therewith, a propulsion unit having a propeller, and an actuator that is coupled to the airframe and adapted to temporarily reorient the propulsion unit such that an axis of the propeller moves out of alignment with an axis of the rotor blades. Rotation of the propeller causes counter-rotation of the airframe and rotor blades. The rotor blades and blades of the propeller are adapted to deploy from collapsed positions when flight of the rotorcraft is initiated. A method of operation by the rotorcraft includes, when it is determined that a current heading does not correspond to a determined flight path, causing the actuator to temporarily reorient the propulsion unit in accordance with an angular orientation of the actuator relative to the current heading.

A stowable lift rotor is coupled to an airframe of a VTOL aircraft. The VTOL aircraft is convertible between a VTOL flight mode and a forward flight mode. The stowable lift rotor includes a lift arm. The proximal end of the lift arm is coupled to the airframe of the VTOL aircraft. The stowable lift rotor also includes a rotor assembly including rotor blades coupled to the distal end of the lift arm. The lift arm is movable between various positions including an extended position in the VTOL flight mode, a stowed position in the forward flight mode and intermediate positions therebetween such that the distance between the rotor assembly and the airframe is greater in the extended position than in the stowed position.

The present invention relates to the field of air vehicle technologies and provides an unmanned aerial vehicle (UAV), including a vehicle body and arms connected to the vehicle body. The arm is hinged to the vehicle body by using a spherical hinge portion and may be folded or unfolded relative to the vehicle body. Through the forgoing manner, the arm is connected to the vehicle body of the UAV by using the spherical hinge. The arm can be folded and unfolded smoothly without interference, which conforms to known operation habits of users, so that after the entire UAV is folded, the structure becomes more compact and easier to carry. In addition, it can be effectively avoided that the UAV is damaged due to impact in the carrying process.

The present invention relates to the field of air vehicle technologies and provides an unmanned aerial vehicle (UAV), including a vehicle body and arms connected to the vehicle body. The arm is hinged to the vehicle body by using a spherical hinge portion and may be folded or unfolded relative to the vehicle body. Through the forgoing manner, the arm is connected to the vehicle body of the UAV by using the spherical hinge. The arm can be folded and unfolded smoothly without interference, which conforms to known operation habits of users, so that after the entire UAV is folded, the structure becomes more compact and easier to carry. In addition, it can be effectively avoided that the UAV is damaged due to impact in the carrying process.

Disclosed is a blade lock assembly, which may include a drag brace coupled to a fold crank assembly and to a rotary wing blade and may further include an actuator assembly configured to be coupled to a rotary wing cuff. The actuator assembly may include an actuator pin housing, an actuation pin at least partially sheathed by the actuator pin housing, and an actuator configured to extend and retract the actuation pin away from and toward the actuator pin housing.