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 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.