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 propeller assembly with at least two propeller blades that are interconnected by associated connection means, the associated connection means defining a common pitch axis for the at least two propeller blades in operation, each one of the at least two propeller blades comprising associated leading and trailing edges that define a respective chord and quarter chord line thereof, wherein the common pitch axis is arranged with a predetermined offset relative to the quarter chord line of each one of the at least two propeller blades, and wherein the associated connection means is adapted to enable, at least in operation in a non-axial inflow field, a passive pitch adjustment of the at least two propeller blades around the common pitch axis.

A rotor for a rotary wing aircraft having a single blade with a longitudinal pitch axis and that is hinge mounted on the rotary shaft for rotating the rotor, the hinge being about an axis that is transversal relative to the rotary shaft, said rotary wing describing a cone when its pitch angle is not zero, the rotor possessing a balancing flyweight device for balancing the resultant of the horizontal component of the lift force and of the rotary drag force of the blade, the device being mounted to rotate with the rotary wing about its rotary shaft and, under the effect of the centrifugal force to which it is subjected while the rotary wing is rotating, generating a horizontal force that is applied to the rotary shaft of the motor and that opposes the above-mentioned resultant with a magnitude of that is a function of the position of the flyweight(s) of the balancing device relative to the rotary shaft of the rotor.

A rotor for a rotary wing aircraft having a single blade with a longitudinal pitch axis and that is hinge mounted on the rotary shaft for rotating the rotor, the hinge being about an axis that is transversal relative to the rotary shaft, said rotary wing describing a cone when its pitch angle is not zero, the rotor possessing a balancing flyweight device for balancing the resultant of the horizontal component of the lift force and of the rotary drag force of the blade, the device being mounted to rotate with the rotary wing about its rotary shaft and, under the effect of the centrifugal force to which it is subjected while the rotary wing is rotating, generating a horizontal force that is applied to the rotary shaft of the motor and that opposes the above-mentioned resultant with a magnitude of that is a function of the position of the flyweight(s) of the balancing device relative to the rotary shaft of the rotor.

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 propeller arrangement for an aircraft, and an aircraft having a propeller arrangement of said type, are specified. The propeller arrangement has a first propeller blade and a second propeller blade, and a propeller mount on which both the first propeller blade and the second propeller blade are mounted. The propeller arrangement furthermore has a drive shaft with a holding unit, and a first connecting unit. The first propeller blade is rotatable about a first axis of rotation and the second propeller blade is rotatable about a second axis of rotation. The propeller mount is pivotable about a pivot axis. The first connecting unit is coupled to the first propeller blade and to the holding unit, such that, in the event of a pivoting of the propeller mount about the pivot axis, the first propeller blade is set in rotational motion about the first axis of rotation.

A propeller related vehicle in accordance with one embodiment of the present invention is described as a helicopter having an airframe housing a motor mechanism for powering a main propeller attached to a main drive shaft that extends vertically through the airframe and for powering a tail rotor. The helicopter further includes a horizontal stabilizing mechanism attached between the main propeller and the main drive shaft, which permits the main propeller to freely pivot about the main drive shaft independently from the airframe. As such when the main propeller is rotating and the main propeller begins to pitch, the rotating main propeller has a centrifugal force created by the rotation thereof and will tend to pivot about the horizontal stabilizing mechanism in a manner that offsets the pitch such that the helicopter remains in a substantially horizontal position. In addition various main propeller configurations may be employed that provide additional self-stabilization.

A propeller related vehicle in accordance with one embodiment of the present invention is described as a helicopter having an airframe housing a motor mechanism for powering a main propeller attached to a main drive shaft that extends vertically through the airframe and for powering a tail rotor. The helicopter further includes a horizontal stabilizing mechanism attached between the main propeller and the main drive shaft, which permits the main propeller to freely pivot about the main drive shaft independently from the airframe. As such when the main propeller is rotating and the main propeller begins to pitch, the rotating main propeller has a centrifugal force created by the rotation thereof and will tend to pivot about the horizontal stabilizing mechanism in a manner that offsets the pitch such that the helicopter remains in a substantially horizontal position. In addition various main propeller configurations may be employed that provide additional self-stabilization.

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.