An unmanned aerial vehicle (UAV) having a UAV body, a propeller, an engine, a motor and a battery. The engine includes an engine body and an engine output shaft arranged on the engine body. The motor includes a stator, a rotor and a stator connector. The UAV provides the motor rotor, propeller and engine output shaft to be coaxially connected, and the motor can be used as a generator to charge the battery by doing negative work on the engine output shaft, or as an electric motor, that is, to receive the power of the battery and do positive work on the engine output shaft to realize power output, so that the UAV can realize high energy utilization and power redundancy at the same time.

A vibration suppression unit for an aircraft comprising a mass having a center of mass, a first rotor, a second rotor, a first coupling between the first rotor and the mass, a second coupling between the second rotor and the mass, the first and second couplings having first and second coupling centers offset perpendicularly from a central axis of rotation by different radial distances and offset in axially from the center of mass with respect to the central axis by different axial distances, the first and second coupling centers having a selectively variable displacement angle defined by the angle between lines extending between the central axis of rotation and the first coupling center and the second coupling center, respectively, wherein the first rotor and the second rotor are controllable to produce a vibration control force vector having a controllable magnitude and frequency about the central axis.

A rotor-regulation system includes a rotor that includes a plurality of rotor blades, a rotor mast operable to drive the rotor, and a rotor disc-brake system operable to modulate rotation of the rotor mast.

A damping valve for a hydraulic damper (D) comprises a valve housing comprising an inlet chamber and an outlet chamber. A housing valve seat is arranged between the inlet chamber and the outlet chamber. A valve element having a cylindrical first portion is slidably received in a cylindrical bore of the valve housing and a second portion has a valve surface for selectively engaging and disengaging the housing valve seat to allow passage of hydraulic fluid between the inlet chamber and the outlet chamber. A spring element is mounted within the valve housing for biasing the valve element into engagement with the housing valve seat. The bore of the valve housing has a closed end defining a bore chamber between an end of the first portion of the valve element and the closed end of the bore. A first passage provides fluid communication between the bore chamber and the inlet chamber.

Systems and methods relate to a vertical takeoff and landing (VTOL) platform that can include a stator and a rotor magnetically levitated by the stator. The rotor and stator can be annular, such that the rotor rotates about a rotational axis. The stator can include magnets that provide guidance, levitation, and drive forces to drive the rotor, as well as to control operation of rotor blades of the rotor that can be independently rotated to specific pitch angles to control at least one of lift, pitch, roll, or yaw of the VTOL platform. Various controllers can be used to enable independent and redundant control of components of the VTOL platform.

An inner middle rotor is rotated while an inner front rotor, an inner back rotor, and an outer rotor are not rotated. The inner middle rotor is surrounded by the inner front rotor, the inner back rotor, the outer rotor, and a fuselage. After rotating the inner middle rotor while not rotating the inner front rotor, the inner back rotor, and the outer rotor, the inner middle rotor, the inner front rotor, the inner back rotor, and the outer rotor are simultaneously rotated.

An elastomeric bearing assembly has a housing, a centrifugal force bearing axially captured relative to the housing, and a sliding cap disposed between the housing and the centrifugal force bearing.

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.

A tunable mass damper assembly is attachable to a rotor blade. The tunable mass damper assembly comprises a base configured to be attached to the rotor blade and a pendulum mass structure movably attached to the base and configured to move relative to the base in accordance with a rotational speed of the rotor blade about a rotor axis. The pendulum mass structure is configured to reduce vibratory forces of the rotor blade induced by a rotation of the rotor blade about the rotor axis. An entirety of the pendulum mass structure being configured to be contained within and enclosed by the rotor blade.

An introduced autonomous aerial vehicle can include multiple cameras for capturing images of a surrounding physical environment that are utilized for motion planning by an autonomous navigation system. In some embodiments, the cameras can be integrated into one or more rotor assemblies that house powered rotors to free up space within the body of the aerial vehicle. In an example embodiment, an aerial vehicle includes multiple upward-facing cameras and multiple downward-facing cameras with overlapping fields of view to enable stereoscopic computer vision in a plurality of directions around the aerial vehicle. Similar camera arrangements can also be implemented in fixed-wing aerial vehicles.