The invention relates to a device for damping vibrations in a structure, comprising a first element (2) rotatably mounted around a rotational axis (3) and a second element (4) rotatably mounted around said rotational axis (3), a radius (R1) of a circle portion (10) delimitating the first element with respect to the rotational axis, being smaller than a radius (r2) of a circle portion (16) delimitating the second element with respect to the rotational axis, the first element being called inner element, and the second element being called outer element.

A vibration suppression unit for an aircraft comprising a mass having a center of mass, a first rotor, a second rotor, a first coupling between the first rotor and the mass, a second coupling between the second rotor and the mass, the first and second couplings having first and second coupling centers offset perpendicularly from a central axis of rotation by different radial distances and offset in axially from the center of mass with respect to the central axis by different axial distances, the first and second coupling centers having a selectively variable displacement angle defined by the angle between lines extending between the central axis of rotation and the first coupling center and the second coupling center, respectively, wherein the first rotor and the second rotor are controllable to produce a vibration control force vector having a controllable magnitude and frequency about the central axis.

The disclosure is directed at a method and apparatus for controlling unwanted vibrations in a mechanical system. The apparatus includes a set of different eccentric and/or concentric masses mounted to the mechanical system for generating forces to counteract the sensed unwanted vibrations. The apparatus further includes a set of motors that control movement of the set of masses.

A vibration-cancelling module includes a first rotor having a first eccentric body, a second rotor having a second eccentric body, and a stator assembly in electromagnetic communication with the first and second rotors. A central shaft extends between the first and second rotors. The first and second rotors rotationally operate about a common rotational axis with respect to one another between a balanced position and a plurality of eccentric positions. A controller has an accelerometer assembly and a rotor-position sensor assembly. The controller delivers an electrical current to the stator assembly at least based upon the accelerometer assembly. A common housing contains the first and second rotors, the stator assembly, the central shaft and the controller.

A built-in piezoelectric type online dynamic balance actuator which includes two structurally identical left and right piezoelectric drive adjustment mechanisms at two sides of a housing. The piezoelectric drive adjustment mechanism includes a shaft having one end supported inside a housing chamber by bearing, a middle portion connected to an end cover by bearing, and the other end supported on bearing housing by bearing, a weight mass coupled to the shaft and positioned inside a tightening sleeve with one side connected to the bearing housing and another side connected to the end cover and the housing, and a stator fixedly connected to one side of the end cover, a mover pressed against a surface of the stator through a disk. Through a control center, the mass weights of the left and right piezoelectric drive adjustment mechanisms are fixed to a preset angle. As the main shaft rotates at a high speed, the two weight masses generate centrifugal force which combine to a balance vector to cancel the imbalance vector of the main shaft, improve the mass distribution of the main shaft and better fit the online dynamic balance requirements.

A built-in piezoelectric type online dynamic balance actuator which includes two structurally identical left and right piezoelectric drive adjustment mechanisms at two sides of a housing. The piezoelectric drive adjustment mechanism includes a shaft having one end supported inside a housing chamber by bearing, a middle portion connected to an end cover by bearing, and the other end supported on bearing housing by bearing, a weight mass coupled to the shaft and positioned inside a tightening sleeve with one side connected to the bearing housing and another side connected to the end cover and the housing, and a stator fixedly connected to one side of the end cover, a mover pressed against a surface of the stator through a disk. Through a control center, the mass weights of the left and right piezoelectric drive adjustment mechanisms are fixed to a preset angle. As the main shaft rotates at a high speed, the two weight masses generate centrifugal force which combine to a balance vector to cancel the imbalance vector of the main shaft, improve the mass distribution of the main shaft and better fit the online dynamic balance requirements.

A motor control device of a vehicle including an engine and a motor generator, a transmission transmitting an engine torque and/or a motor torque to a wheel, and a damper reducing vibration of a crankshaft of the engine includes: a damper torque calculation unit calculating a damper torque generated by the damper according to fluctuation in engine torque based on a difference between a crank angle and a motor angle; a reverse-phase torque calculation unit calculating a reverse-phase torque with a reverse phase to the damper torque; a correction amount calculation unit calculating a first value calculated at least based on the crank angle and the motor angle; and a motor torque command output unit outputting a motor torque command given to the motor generator based on the reverse-phase torque corrected by the correction amount.

A vibration suppression unit for an aircraft comprising a mass assembly having a center of mass and a frequency rotor having a frequency center axis offset from a central axis of rotation and driven to rotate about the central axis, a vibration control amplitude rotor rotationally coupled to the mass assembly and having an amplitude center axis offset from the central axis driven independently of the frequency rotor to rotate about the central axis, the amplitude center axis and the frequency center axis having a selectively variable displacement angle defined by an inclusive angle between a line extending between the central axis and the amplitude center axis and a line extending between the central axis and the frequency center axis, wherein the amplitude rotor and the frequency rotor are controllable to produce a vibration control force vector having a controllable magnitude and frequency about the central axis of rotation.

A vibration suppression unit for an aircraft comprising a vibration control frame adapted to be mounted to the aircraft and to rotate about a central axis, a first motor configured to rotate the vibration control frame about the central axis, a second motor configured to rotate a first and second center of mass about a first and second axis or rotation, a third motor configured to adjust a variable distance between the first and second centers of mass and the first and second axis of rotation, respectively, and a controller for receiving input signals and outputting command signals to the first, second and third motors.

Provided is a dynamic force generator having a supporting shaft, a first rotor including an internal bore housing the supporting shaft and bearings arranged between the supporting shaft and the internal bore so that the first rotor is mounted rotatably in relation to the supporting shaft, an external bore having an inner face provided with a first set of permanent magnets. A first unbalanced mass is within the internal bore of the first rotor and mounted opposite an outer face of the external bore of the first rotor. A second rotor is mounted rotatably in relation to the first rotor, via an antifriction component provided between the first rotor and the second rotor, and includes an internal bore housing the internal bore of the first rotor so that the internal bores of the first and second rotors are concentric, and an external bore with a second set of permanent magnets.