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.

A vibration control assembly includes a housing having an interior region and an inner mass including a cage disposed within the interior region of the housing and being rotatable within the housing about a first axis and a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis. At least one driving source includes a stator and is operable to interact with a magnetic field of the inner mass to drive rotation of the inner mass about at least one of the first axis and the second axis, wherein the at least one driving source is mounted within the interior region of the housing.

A highly-efficient new-energy vibration controller integrating passive, semi-active and active control, including a multi-cavity beam, a battery assembly, a wound magnetic device, a damping piezoelectric device and an inertia mass assembly. The wound magnetic device includes a connecting rod, an electromagnetic wire wound on a bottom end of the connecting rod and a magnetic box arranged at a bottom of the inertia mass assembly. A top end of the connecting rod is fixedly connected to a bottom of the multi-cavity beam. The bottom end of the connecting rod passes through a center through hole of the inertia mass assembly and arranged in the magnetic box. The magnetic box is provided with a magnetic field. The damping piezoelectric device is sleevedly arranged on an outer wall of the connecting rod. The damping piezoelectric device and the wound magnetic device are both electrically connected to the battery assembly.

A highly-efficient new-energy vibration controller integrating passive, semi-active and active control, including a multi-cavity beam, a battery assembly, a wound magnetic device, a damping piezoelectric device and an inertia mass assembly. The wound magnetic device includes a connecting rod, an electromagnetic wire wound on a bottom end of the connecting rod and a magnetic box arranged at a bottom of the inertia mass assembly. A top end of the connecting rod is fixedly connected to a bottom of the multi-cavity beam. The bottom end of the connecting rod passes through a center through hole of the inertia mass assembly and arranged in the magnetic box. The magnetic box is provided with a magnetic field. The damping piezoelectric device is sleevedly arranged on an outer wall of the connecting rod. The damping piezoelectric device and the wound magnetic device are both electrically connected to the battery assembly.

The invention relates to a method for diagnosing and/or controlling a reciprocating engine having a variable compression ratio, wherein the method comprises the working steps: determining (S30) a first value (U.sub.1,1, U.sub.1,2; Δ.sub.1) of a rotational irregularity parameter of a crankshaft (1) of the reciprocating engine; and determining (S60) a value of a compression ratio parameter for the reciprocating engine based on said first rotational irregularity parameter value.

A balance shaft is proposed that includes: i) an unbalance shaft having an unbalance section and an adjacent bearing pin having a cylindrical partial circumference which is oriented towards the shaft imbalance; ii) a bearing ring which surrounds the bearing pin and bears against the cylindrical partial circumference and delimits a free space with a bearing pin back radially opposite thereto; and, iii) a clamping element which is clamped in the free space and clamps the bearing ring radially against the cylindrical partial circumference. The clamping element is intended to secure the bearing ring against axial sliding on both sides on the bearing pin, and the clamping element is connected in an axially interlocking manner to the unbalance shaft on one side and to the bearing ring on the other side.

A vibration control assembly includes a housing having an interior region and an inner mass including a cage disposed within the interior region of the housing and being rotatable within the housing about a first axis and a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis. At least one driving source includes a stator and is operable to interact with a magnetic field of the inner mass to drive rotation of the inner mass about at least one of the first axis and the second axis, wherein the at least one driving source is mounted within the interior region of the housing.

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.

An embodiment includes generating a sense signal that represents a first vibration of a platform, and reducing a level of the first vibration by generating, in response to the sense signal, a second vibration in the platform. For example, a sensor generates a sense signal representing a first vibration induced (e.g., a shock-induced vibration) in the platform. And a vibration-cancel circuit reduces or eliminates a level of the first vibration in response to the sense signal. For example, the vibration-cancel circuit reduces a magnitude of a first vibration induced in a platform, or eliminates the first vibration altogether, by generating, in the platform, a second vibration having a magnitude approximately equal to the magnitude of the first vibration and having a phase approximately opposite to the phase of the first vibration. That is, the second vibration cancels the first vibration to reduce the net vibration that the platform experiences.

A method for cancelling vibration includes receiving, from a first accelerometer, a first accelerometer measurement; receiving, from a second accelerometer, a second accelerometer measurement; determining a counter torque value based on the first accelerometer measurement and the second accelerometer measurement; and selectively controlling a lift mechanism according to the counter torque value using a motor, the motor being in mechanical communication with the lift mechanism and the lift mechanism being configured to allow a platform to travel in one of a first direction and a second direction.