A rotorcraft having a body and a propulsion system wherein the propulsion system includes a main thrust rotor and multiple control rotors, wherein the main thrust rotor is coupled to the body, whereby the main thrust rotor is driven by a main thrust drive shaft having an axis of rotation maintained in a fixed orientation to the body of the rotorcraft and wherein the multiple control rotors are arranged to control roll, pitch and yaw of the rotorcraft and are driven by respective control drive shafts offset to the axis of rotation of the main thrust drive shaft.

A helicopter rotor hub assembly for coupling a pair of helicopter blades to a helicopter mast. It includes a yoke assembly and a pitch assembly. The yoke assembly includes a central section and first and second sections extending respectively on opposite sides of the central section. Each one of the first and second sections has a pair of elongated arms defining inbetween a bearing-receiving interspace. The pitch assembly includes first and second attachment plates extending respectively along the first and second sections of the yoke assembly and first and second pitch bearing assemblies. Each attachment plate is connected to a respective one of the helicopter blades. Each pitch bearing assembly extends in the bearing-receiving interspace of a respective one of the first and second sections of the yoke assembly. Each pitch bearing assembly contacts a respective one of attachment plates to allow a pitch movement of the helicopter blades.

A helicopter rotor hub assembly for coupling a pair of helicopter blades to a helicopter mast. It includes a yoke assembly and a pitch assembly. The yoke assembly includes a central section and first and second sections extending respectively on opposite sides of the central section. Each one of the first and second sections has a pair of elongated arms defining inbetween a bearing-receiving interspace. The pitch assembly includes first and second attachment plates extending respectively along the first and second sections of the yoke assembly and first and second pitch bearing assemblies. Each attachment plate is connected to a respective one of the helicopter blades. Each pitch bearing assembly extends in the bearing-receiving interspace of a respective one of the first and second sections of the yoke assembly. Each pitch bearing assembly contacts a respective one of attachment plates to allow a pitch movement of the helicopter blades.

The present invention includes a rotor hub system, comprising: a teetering rotor hub disposed about a mast, the teetering rotor hub comprising: a first and a second yoke; each connected to a set of rotor blades, wherein the second set of rotor blades and the first set of rotor blades are disposed in a common plane, but the first and the second yoke do not come in contact.

A rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

A rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

A rotor system of a rotary wing aircraft, such as a helicopter, is provided. The rotor system includes a rotor mast, a rotor hub and at least four, angularly generally even distributed rotor blades and swash plate struts for pitch and subsequently flap control. The rotor blades are pairwise to each other with zero offset to the rotor hub. The rotor hub is provided with a hollow bearing with at least one further bearing inside. A first pair of rotor blades is mounted on the hollow bearing and is pivotable in a first flap direction generally perpendicular to the rotation axis. A second pair of rotor blades is mounted inside the hollow bearing on the at least one further bearing and is pivotable in a second flap direction generally perpendicular to the first flap direction and the rotation axis, and independently of the first pair of rotor blades.

A rotor system of a rotary wing aircraft, such as a helicopter, is provided. The rotor system includes a rotor mast, a rotor hub and at least four, angularly generally even distributed rotor blades and swash plate struts for pitch and subsequently flap control. The rotor blades are pairwise to each other with zero offset to the rotor hub. The rotor hub is provided with a hollow bearing with at least one further bearing inside. A first pair of rotor blades is mounted on the hollow bearing and is pivotable in a first flap direction generally perpendicular to the rotation axis. A second pair of rotor blades is mounted inside the hollow bearing on the at least one further bearing and is pivotable in a second flap direction generally perpendicular to the first flap direction and the rotation axis, and independently of the first pair of rotor blades.

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 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.