Abstract: A vibration attenuator is configured for use on an aircraft rotor rotatable about a mast axis and has upper and lower weight assemblies, each comprising a weight with a center of gravity being a radial distance from the mast axis. The weight assemblies are configured for rotation together relative to the rotor at a selected angular rate about the mast axis, the weights being located on opposing sides of the mast axis. A first motor is configured for selective translation of one of the weight assemblies relative to the other weight assembly along the mast axis between a minimum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in the same plane, and a maximum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in different planes for producing a whirling moment about the mast axis.

Abstract: A vibration attenuator has a first spinner configured for rotation about a first axis and a first mass coupled to the first spinner for rotation therewith, the first mass being movable radially relative to the first axis between an inner position and an outer position. An actuator is coupled to the first mass for selectively controlling a radial location of the first mass relative to the axis, and a first motor is configured for driving the first spinner in rotation about the first axis.

Abstract: A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

Abstract: A vibration attenuator for a rotor of an aircraft has a first ring with an eccentric weight, a coaxial second ring with an eccentric weight, and a central ring coaxial with the first and second rings and located therebetween. A first post extends from the first ring toward the central ring and is received in a first arcuate groove formed on the central ring, whereas a second post extends from the second ring toward the central ring and is received in a second groove formed on the central ring. A motor is configured for driving the central ring in rotation about the axis relative to the motor. The grooves are equal in length, and a center of the first groove is located on an opposite side from a center of the second groove. Rotation of the central ring by the motor causes rotation of the first and second rings.

Abstract: A vibration attenuator for a rotor of an aircraft has a first ring with an eccentric weight, a coaxial second ring with an eccentric weight, and a central ring coaxial with the first and second rings and located therebetween. A first post extends from the first ring toward the central ring and is received in a first arcuate groove formed on the central ring, whereas a second post extends from the second ring toward the central ring and is received in a second groove formed on the central ring. A motor is configured for driving the central ring in rotation about the axis relative to the motor. The grooves are equal in length, and a center of the first groove is located on an opposite side from a center of the second groove. Rotation of the central ring by the motor causes rotation of the first and second rings.

Abstract: A vibration attenuator is configured for use on an aircraft rotor rotatable about a mast axis and has upper and lower weight assemblies, each comprising a weight with a center of gravity being a radial distance from the mast axis. The weight assemblies are configured for rotation together relative to the rotor at a selected angular rate about the mast axis, the weights being located on opposing sides of the mast axis. A first motor is configured for selective translation of one of the weight assemblies relative to the other weight assembly along the mast axis between a minimum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in the same plane, and a maximum-moment configuration, in which the centers of gravity of the weights revolve about the mast axis in different planes for producing a whirling moment about the mast axis.

Abstract: A vibration attenuator for a rotor of an aircraft has a track housing adapted for rotation relative to the rotor and configured for rotation at a second angular velocity greater than a first angular velocity of the rotor. A track is located within the track housing and has a reaction surface, a pair of weights being configured for movement within the track and in contact with the reaction surface. A stop assembly has a pair of stops spaced 180 degrees apart, the stops separating the weights from each other, and each weight being allowed to travel within the track between the stops. A motor rotates the track housing relative to the rotor. The weights are free to travel relative to each other between a minimum-force configuration, in which the weights are positioned 180 degrees apart, and a maximum-force configuration, in which both weights are adjacent one of the stops.

Abstract: A vibration attenuator for an aircraft has first and second coaxial spinners configured for rotation about a mast axis and relative to a rotor. Upper and lower weights of each spinner are spaced radially from the axis and positioned 180 degrees from each other about the axis. The weights of each spinner are spaced from each other a distance parallel to the mast axis, each weight rotating about the mast axis in a different plane. The spinners rotate together relative to the rotor at a selected angular rate and are selectively rotatable relative to each other between a minimum-moment configuration, in which the upper weight of each spinner is angularly aligned with the lower weight of the other spinner, and a maximum-moment configuration, in which the upper weights are angularly aligned and the lower weights are angularly aligned, producing a whirling moment about the mast axis as the spinners rotate.

Abstract: A vibration attenuation system as shown and described.

Abstract: A vibration attenuator for a rotor is rotatable about a mast axis and has a frame configured for rotation about the mast axis relative to the rotor. A first mass is axially translatable in a first direction relative to the frame parallel to a first axis, and a first biasing force urges the first mass toward a first-mass rest position in which the first mass is symmetric about the mast axis. A second mass is axially translatable in a second direction relative to the frame parallel to a second axis, and a second biasing force urges the second mass toward a second-mass rest position in which the second mass is symmetric about the mast axis. A selected first or second mass moves radially outward from the rest position to oppose vibrations in the rotor.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A vibration attenuator for an aircraft has first and second coaxial spinners configured for rotation about a mast axis and relative to a rotor. Upper and lower weights of each spinner are spaced radially from the axis and positioned 180 degrees from each other about the axis. The weights of each spinner are spaced from each other a distance parallel to the mast axis, each weight rotating about the mast axis in a different plane. The spinners rotate together relative to the rotor at a selected angular rate and are selectively rotatable relative to each other between a minimum-moment configuration, in which the upper weight of each spinner is angularly aligned with the lower weight of the other spinner, and a maximum-moment configuration, in which the upper weights are angularly aligned and the lower weights are angularly aligned, producing a whirling moment about the mast axis as the spinners rotate.

Abstract: A vibration attenuator for a rotor of an aircraft has a track housing adapted for rotation relative to the rotor and configured for rotation at a second angular velocity greater than a first angular velocity of the rotor. A track is located within the track housing and has a reaction surface, a pair of weights being configured for movement within the track and in contact with the reaction surface. A stop assembly has a pair of stops spaced 180 degrees apart, the stops separating the weights from each other, and each weight being allowed to travel within the track between the stops. A motor rotates the track housing relative to the rotor. The weights are free to travel relative to each other between a minimum-force configuration, in which the weights are positioned 180 degrees apart, and a maximum-force configuration, in which both weights are adjacent one of the stops.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency. A vertically oriented vibration attenuator is configured to oppose and attenuate vertical rotor induced oscillatory forces that would otherwise travel vertical down the rotor mast and into the airframe. A vibration attenuator having weights rotating about separate axes offset from each other.

Abstract: A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

Abstract: A vibration attenuator for a rotor is rotatable about a mast axis and has a frame configured for rotation about the mast axis relative to the rotor. A first mass is axially translatable in a first direction relative to the frame parallel to a first axis, and a first biasing force urges the first mass toward a first-mass rest position in which the first mass is symmetric about the mast axis. A second mass is axially translatable in a second direction relative to the frame parallel to a second axis, and a second biasing force urges the second mass toward a second-mass rest position in which the second mass is symmetric about the mast axis. A selected first or second mass moves radially outward from the rest position to oppose vibrations in the rotor.