One example of a mount for a rotorcraft comprises a structural support member, a bracket, and an elastomer. The bracket is configured to attach to a component of the rotorcraft. The component of the rotorcraft produces vibrations at a first frequency. The structural support member configured to transfer a weight of the component of a rotorcraft to an airframe of the rotorcraft. A rotor system of the aircraft vibrates the airframe of the rotorcraft at a second frequency. The elastomer is located between a structural support member and a bracket. The elastomer is configured to attenuate noise caused by the vibrations at the first frequency by isolating the vibrations at the first frequency from reaching the airframe of the rotorcraft while the airframe vibrates at the second frequency.

A linear vibration damper and/or absorber includes a centre shaft (12) having bearing regions (18) and friction contact regions (20), and a housing (2) including finger assemblies (22) which are mounted with a small radial clearance for accurate location on the bearing regions (18) for axial displacement with respect to the centre shaft (12) along a central axis (X), the finger assemblies (22) each including resilient fingers (38) which extend axially from respective body sections (26) and have contact faces (40) which resiliently engage, i.e. are pressed by the resilience of the fingers (40) into contact with, friction surfaces (20) of the contact regions of the centre shaft (12), whereby relative linear displacement between the centre shaft (12) and the housing (2) is opposed by frictional contact between the friction surfaces (20) and the contact faces (40).

A liquid inertia vibration elimination (“LIVE”) system for a rotor system having n number of blades. The LIVE system includes a first tuned vibration reduction component configured to provide a maximum vibratory isolation at a frequency below 2*n/rev and a second tuned vibration reduction component configured to provide a maximum vibratory isolation at a frequency above 3*n/rev.

One example of a mount for a rotorcraft comprises a structural support member, a bracket, and an elastomer. The bracket is configured to attach to a component of the rotorcraft. The component of the rotorcraft produces vibrations at a first frequency. The structural support member configured to transfer a weight of the component of a rotorcraft to an airframe of the rotorcraft. A rotor system of the aircraft vibrates the airframe of the rotorcraft at a second frequency. The elastomer is located between a structural support member and a bracket. The elastomer is configured to attenuate noise caused by the vibrations at the first frequency by isolating the vibrations at the first frequency from reaching the airframe of the rotorcraft while the airframe vibrates at the second frequency.

One example of a mount for a rotorcraft comprises a structural support member, a bracket, and an elastomer. The bracket is configured to attach to a component of the rotorcraft. The component of the rotorcraft produces vibrations at a first frequency. The structural support member configured to transfer a weight of the component of a rotorcraft to an airframe of the rotorcraft. A rotor system of the aircraft vibrates the airframe of the rotorcraft at a second frequency. The elastomer is located between a structural support member and a bracket. The elastomer is configured to attenuate noise caused by the vibrations at the first frequency by isolating the vibrations at the first frequency from reaching the airframe of the rotorcraft while the airframe vibrates at the second frequency.

An advancing blade concept rotorcraft includes an airframe and a pylon assembly subject to vibration. The pylon assembly includes a dual rotor system having coaxially disposed top and bottom rotor assemblies that counter rotate relative to one another. The advancing blade concept rotorcraft includes a vibration isolation system including at least one pylon link coupled to the airframe and the pylon assembly. The pylon link includes a Liquid Inertia Vibration Eliminator unit operable to reduce transmission of the pylon assembly vibration to the airframe. The advancing blade concept rotorcraft includes active force generators adjacent to the pylon assembly. The active force generators include a first active force generator producing a force in a first direction and a second active force generator producing a force in a second direction to counteract multidirectional oscillations of the pylon assembly, thereby reducing vibration of the advancing blade concept rotorcraft.

Spring-integrated rotors are disclosed. A disclosed example apparatus includes a bracket defining a first rotational axis and coupled to a motor for rotating the bracket about the first rotational axis, a pivot body defining a second rotational axis extending along a direction different than the first rotational axis, the pivot body coupled to the bracket for rotation about the second rotational axis, and at least one spring device positioned at the bracket, the at least one spring device urging the pivot body toward a central position when the bracket is rotating.

A kit for a helicopter is described, the helicopter comprising a fuselage and a rotor; the kit comprises at least one device adapted to dampen the vibrations transmitted from the rotor to the fuselage and to be interposed between the fuselage and the rotor; the device, in turn, comprises a first threaded element operatively connectable to the rotor and adapted to, in use, vibrate parallel to a first axis; a second threaded element operatively connectable to the fuselage and operatively connected to the first threaded element so as to, in use, rotationally vibrate about the first axis; and a plurality of threaded rollers, which are screwed on the first and second threaded elements; the rollers being rotatable about their respective second axes parallel to and separate from the first axis with respect to the first and second threaded elements; the rollers are also rotatable about the first axis with respect to the first threaded element and the second threaded element.

A liquid inertia vibration eliminator unit for an aircraft having first and second components includes an outer housing coupled to the first component of the aircraft, the outer housing forming an outer housing cavity. The liquid inertia vibration eliminator unit includes a spherical bearing disposed in the outer housing cavity and forming a spherical bearing cavity. A piston is disposed in the spherical bearing cavity and coupled to the second component of the aircraft. Top and bottom fluid chambers are disposed in the spherical bearing cavity on opposite sides of the piston. A tuning passage provides fluid communication between the top and bottom fluid chambers. A tuning fluid moves between the top and bottom fluid chambers via the tuning passage to isolate vibration between the first and second components of the aircraft.

A liquid inertia vibration eliminator unit for an aircraft having first and second components includes an outer housing coupled to the first component of the aircraft, the outer housing forming an outer housing cavity. The liquid inertia vibration eliminator unit includes a spherical bearing disposed in the outer housing cavity and forming a spherical bearing cavity. A piston is disposed in the spherical bearing cavity and coupled to the second component of the aircraft. Top and bottom fluid chambers are disposed in the spherical bearing cavity on opposite sides of the piston. A tuning passage provides fluid communication between the top and bottom fluid chambers. A tuning fluid moves between the top and bottom fluid chambers via the tuning passage to isolate vibration between the first and second components of the aircraft.