A propeller blade for an unmanned aerial vehicle (“UAV”) is disclosed. The UAV includes a plurality of lift propellers and at least one thrust propeller. Each of the plurality of thrust propellers includes a thrust propeller blade coupled to a hub of the thrust propeller. The thrust propeller blade is configured such that a centrifugal force acting on the thrust propeller blade causes a thrust propeller disk area to increase from a first disk area when the UAV is in a first operational state to a second disk area when the UAV is in a second operational state.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

Provided are a flap drive device and a rotorcraft blade, and more particularly, a flap drive device using a two-section link mechanism, which may be applied to a rotorcraft blade, and a rotorcraft blade including the same.

Provided are a flap drive device and a rotorcraft blade, and more particularly, a flap drive device using a two-section link mechanism, which may be applied to a rotorcraft blade, and a rotorcraft blade including the same.

A propeller blade for an unmanned aerial vehicle (“UAV”) is disclosed. The UAV includes a plurality of lift propellers and at least one thrust propeller. Each of the plurality of thrust propellers includes a thrust propeller blade coupled to a hub of the thrust propeller. The thrust propeller blade is configured such that a centrifugal force acting on the thrust propeller blade causes a thrust propeller disk area to increase from a first disk area when the UAV is in a first operational state to a second disk area when the UAV is in a second operational state.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

A UAV preferably has 6 rotors mounted on an H-Frame setup with two parallel longitudinally extending support beams with a cross beam. The rotors are mounted along the longitudinal extending support beams, with one rotor mounted at each end and one motor mounted at the cross beam. Such an arrangement is more efficient than a helicopter of similar disk size and will be more efficient than a traditional hex rotor setup when lifting heavy payloads at a construction site.

A rotary wing air vehicle has a body; at least one engine located on the body; a rotor that extends outwards from the body and rotates around its own axis in connection with the engine; at least one shaft extending outward from the rotor and triggered by the engine to rotate around an axis that the shaft extends from the rotor; at least two blades connected with the shaft and triggered by the shaft to move; at least one flap on the blade which provides drag force to the rotor by its movement to a closed position or an open position; at least one brake system which is located on the body in connection with the rotor to enable the flap to move to the closed position and/or open position so that a rotational speed of the rotor is adjusted by a user.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.

According to one aspect, a lubricant level sensing system for an actuator is provided. The lubricant level sensing system includes a pressure port in an outer housing of the actuator, a pressure sensor, and a pathway from the pressure port to the pressure sensor. The pathway establishes fluid communication between the pressure sensor and a free volume of an internal cavity of the outer housing relative to a lubricant level in the internal cavity such that the pressure sensor detects a pressure of the free volume used to derive the lubricant level.