A rotor hub assembly that includes a yoke configured to attach blades thereto, a universal joint configured to attach to, and transmit forces between, a mast and the yoke, and an elastomeric member configured to attenuate vibrations transmitted from the universal joint to the mast.

A rotor hub assembly that includes a yoke configured to attach blades thereto, a universal joint configured to attach to, and transmit forces between, a mast and the yoke, and an elastomeric member configured to attenuate vibrations transmitted from the universal joint to the mast.

A coaxial rotor system for a rotorcraft includes a mast, a top rotor assembly and a bottom rotor assembly. The top rotor assembly is coupled to the distal end of the mast. The bottom rotor assembly includes a motor configured to provide rotational energy to the mast, thereby rotating the top rotor assembly. The bottom rotor assembly experiences a torque reaction force responsive to the motor rotating the mast such that the top and bottom rotor assemblies counter rotate.

A gimbal joint may employ a plurality of wear sleeves, each disposed between a pin or pin receptive bore of a first structure and a corresponding bore or pin of a second structure and between another pin or bore of the second structure and a corresponding bore or pin of a third structure. Each of these structures may be adapted to rotate in a single plane, with one structure adapted to also tilt about a first axis, and one other structure adapted to tilt about a second axis. Each integral flanged wear sleeve may comprise a right circular hollow cylindrical body portion, which may be interiorly sized to be retained on one of the pins and externally sized to be retained in one of the pin receptive bores, and a flange portion may radiate from one end of the cylindrical body portion.

A gimbal joint may employ a plurality of wear sleeves, each disposed between a pin or pin receptive bore of a first structure and a corresponding bore or pin of a second structure and between another pin or bore of the second structure and a corresponding bore or pin of a third structure. Each of these structures may be adapted to rotate in a single plane, with one structure adapted to also tilt about a first axis, and one other structure adapted to tilt about a second axis. Each integral flanged wear sleeve may comprise a right circular hollow cylindrical body portion, which may be interiorly sized to be retained on one of the pins and externally sized to be retained in one of the pin receptive bores, and a flange portion may radiate from one end of the cylindrical body portion.

A vertical takeoff and landing (VTOL) vehicle that includes a flight controller and a rotor. During a vertical landing state, during which the VTOL vehicle is performing a vertical landing, the flight controller decides whether to switch from the vertical landing state to a self adjusting state and in the event it is decided to do so, the flight controller switches from the vertical landing state to the self adjusting state. During the self adjusting state, the flight controller generates a control signal for a rotor where the control signal causes: (1) the rotor to rotate during the self adjusting state and (2) the VTOL vehicle to stay in place during the self adjusting state, such that an occupant is able to enter or exit the VTOL vehicle during the self adjusting state.

A vertical takeoff and landing (VTOL) vehicle that includes a flight controller and a rotor. During a vertical landing state, during which the VTOL vehicle is performing a vertical landing, the flight controller decides whether to switch from the vertical landing state to a self adjusting state and in the event it is decided to do so, the flight controller switches from the vertical landing state to the self adjusting state. During the self adjusting state, the flight controller generates a control signal for a rotor where the control signal causes: (1) the rotor to rotate during the self adjusting state and (2) the VTOL vehicle to stay in place during the self adjusting state, such that an occupant is able to enter or exit the VTOL vehicle during the self adjusting state.

A rotor assembly includes a hub assembly and a shaft assembly. The hub assembly includes a hub and a first coupling, and the shaft assembly may be coupled to the hub assembly with a second coupling. The second coupling may be configured to facilitate rotation of the hub relative to a shaft of the shaft assembly. A rotor blade may be coupled to the hub assembly with a third coupling and be configured to rotate with the shaft. The first coupling may be configured to couple the hub to an actuator and transmit movements of the actuator to the hub to facilitate cyclic pitch control of the rotor blade. The rotor shaft may include arms and the hub may include a body coupled to the rotor blade by the third coupling and pairs of extensions that extend from a surface of the body to receive the arms.

A passive hub flapping lock including: one or more lever arms, each lever arm rotatably coupled to a pivot and comprising a first lever arm end and a second lever arm end; one or more stop wedges; one or more frames coupled to the one or more stop wedges, each frame coupled to the first lever arm end of one of the one or more lever arms; one or more weight sets, each weight set comprising one or more weights coupled to the second lever arm end of one of the one or more lever arms; and one or more pivot torsion springs, each pivot torsion spring positioned at the pivot.

Embodiments are directed to a double Hooke's joint gimbal in a rotor system. An upper Hooke's joint has four arms extending radially outward to define first and second axes, and a lower Hooke's joint has four arms extending radially outward to define third and fourth axes. A pair of connectors couple the upper Hooke's joint and the lower Hooke's joint. A first set of bearings are positioned between arms on the upper and lower Hooke's joints and the connectors. The first set of bearings comprise an elastomer, such as elastomeric journal bearings. The upper Hooke's joint is coupled to a yoke and rotor blades by a driver assembly that allows rotor blade flapping. The lower Hooke's joint is coupled to and driven by a mast. A spherical bearing allows the upper Hooke's joint to move laterally along the mast.