Abstract: A rotor for a hover-capable aircraft includes an attenuating device to attenuate the transmission of vibrations from a mast to the aircraft. The attenuating device includes a first mass free to oscillate parallel to a hub rotation axis with respect to a casing of the attenuating device and elastically connected to the casing. The attenuating device further includes a second mass free to oscillate parallel to the hub rotation axis, connection means adapted to make the first and second masses integrally movable along the hub rotation axis when the angular speed of the mast assumes a first value, and actuator means activatable to decouple the first and second masses when the angular speed of the mast assumes a second value, different from the first value.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis; and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses; and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and each control unit comprises: a belt coupled to the support assembly and a drive unit coupled to the first belt, to cause the rotation of the first support assembly with respect to said transmission device.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis, and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses, and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and comprises a set of drive gear teeth integral with the first support assembly, a cogwheel with a set of control gear teeth meshing with the drive gear teeth, and an actuator to cause the rotation of the cogwheel about a second axis and of the first mass about said first axis.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis, and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses, and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and comprises a set of drive gear teeth integral with the first support assembly, a cogwheel with a set of control gear teeth meshing with the drive gear teeth, and an actuator to cause the rotation of the cogwheel about a second axis and of the first mass about said first axis.

Abstract: A rotor for a hover-capable aircraft is described that comprises: a hub rotating about an axis and, in turn, comprising a plurality of blades, a mast connectable to a power unit of the aircraft and operatively connected to the hub to drive the hub in rotation about said axis, and an attenuating device to attenuate the transmission of vibrations from the mast to the aircraft parallel to said; the attenuating device, in turn, comprising a casing, a first mass free to oscillate parallel to said axis with respect to the casing and elastically connected to the casing, a second mass free to oscillate parallel to said axis, connection means adapted to make the first and second masses integrally movable along said axis when the angular speed of the mast assumes a first value, and actuator means activatable to decouple the first and second masses when the angular speed of the mast assumes a second value, different from the first value.

Abstract: A rotor for an aircraft is described that has a mast, an attenuating device to attenuate the transmission of vibrations from the mast in a plane orthogonal to the first axis; and a transmission device interposed between the mast and the attenuating device; the attenuating device comprises a first and a second mass unit with a first and a second mass rotatable about the first axis with a first and a second rotational speed, two control units operable to cause an additional rotation of at least one of the first and second masses and a first and a second support assembly carrying the first and second masses; each control unit controls the angle between the first and second masses and each control unit comprises: a belt coupled to the support assembly and a drive unit coupled to the first belt, to cause the rotation of the first support assembly with respect to said transmission device.

Abstract: A rotor for an aircraft is described that comprises: a hub rotatable about an axis and, in turn, comprising a plurality of blades; a mast connectable to a drive member of the aircraft and connected to the hub to drive the hub in rotation about the axis; and damping means to dampen the transmission of vibrations to the mast in a plane orthogonal to the axis; the damping means comprising at least a first mass and a second mass that can eccentrically rotate about the axis with a first and a second speed of rotation, respectively; the first mass and second mass are operatively connected to the mast to generate, respectively, a first and a second damping force on the mast having a main component in a direction radial to the axis; the rotor comprises a transmission unit, which is interposed between the mast and the first and second masses so as to drive the first and second masses in rotation.

Abstract: A rotor for an aircraft is described that comprises: a hub rotatable about an axis and, in turn, comprising a plurality of blades; a mast connectable to a drive member of the aircraft and connected to the hub to drive the hub in rotation about the axis; and damping means to dampen the transmission of vibrations to the mast in a plane orthogonal to the axis; the damping means comprising at least a first mass and a second mass that can eccentrically rotate about the axis with a first and a second speed of rotation, respectively; the first mass and second mass are operatively connected to the mast to generate, respectively, a first and a second damping force on the mast having a main component in a direction radial to the axis; the rotor comprises a transmission unit, which is interposed between the mast and the first and second masses so as to drive the first and second masses in rotation.