Patent ID: 8196856
Filing Date: 2012-06-12
Classification: B64C

Abstract:
1. A method for suppressing vibration in an aircraft having at least one pair of non-intermeshing multiple-blade rotors, the method comprising: (a) locating in the aircraft at least one pair of vibration suppression devices to form a system, the devices of each system being mounted on opposing sides of the aircraft; (b) providing a nacelle pivotally coupled to a wing of the aircraft, being configured to pivot the rotors about the wing in relation to a fuselage; (c) determining the indexing angle for the at least one pair of non-intermeshing multiple-blade rotors, the rotors being indexed according to the number of blades, for achieving a phasing of generated forces exhibited in a plane parallel to that of the rotation of the blades, the forces generated from the reduction of rotor speed as the rotors pivot about the wing; (d) selecting a phasing angle configured to be selected in relation to the phasing of the generated force; and (e) indexing each non-intermeshing multiple-blade rotor prior to flight, so that the blades of one rotor are selectively indexed in relation to the blades of the other rotor, so that each rotor rotates out-of-phase to the other rotor, the indexing between each pair of rotors remains consistently out of phase during flight such that the revolutions per minute of each rotor remains constant with respect to the other rotor; and (f) during operation of the aircraft, using the system to suppress vibrations caused by the out-of-phase rotation of the rotors.