A linear actuator comprising a housing with first and second ends, and defining a central cavity extending axially therethrough; a tube having first and second portions, the first portion arranged to slide within the central cavity of the housing, and the second portion extending outwardly from the second end of the housing; a first elongated rotatable screw positioned axially within the central cavity and coaxial with the tube; a first nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second nut and the second end of the housing.

This disclosure relates to an active inerter damper configured to be disposed on or in a building structure. The active inerter damper includes a base, a lead screw, a rotational mass block, a driving device and a controller. The lead screw is movably disposed above the base along an axial direction. The rotational mass block is engaged with the lead screw so as to be rotatable with respect to the base. The driving device is connected to the lead screw. The controller is electrically connected to the driving device, and the controller is configured to activate the driving device to move the lead screw along the axial direction so as to rotate the rotational mass block via the lead screw.

The invention relates to a mass-decoupling device for a motor vehicle, having: a mass-receiving element (10) and a mass object (11) accommodated therein, which mass-receiving element (10) and mass object (11) are point symmetrically formed and mounted opposite a body (36) of the motor vehicle; at least one guide means (13) that moveably mounts the mass-receiving element (10) and the mass object (11) accommodated therein along a longitudinal axis (L) of the vehicle; decoupling means (14) designed to decouple the mass-receiving element (10) and the mass object (11) accommodated therein from the body (36) of the motor vehicle; first energy-receiving means (15) designed to transmit kinetic energy of a movement of the mass-receiving element (10) and the mass object (11) accommodated therein to the body (36) of the motor vehicle in a predetermined time interval, said movement occurring along the longitudinal axis (L) of the vehicle, from a first position (P1) to a second position (P2); and second energy receiving means (16) designed to convert, at least partially, the kinetic energy of the movement of the mass-receiving element (10) and the mass object (11) accommodated therein along the longitudinal axis (L) of the vehicle into kinetic energy of a rotation of the mass object (11). The invention also relates to a corresponding method for decoupling mass for a motor vehicle.

The present invention relates to an actuator system with a magnetic lead screw, comprises a magnetic rotor and a translator cylinder, the translator cylinder comprises a magnetic stator, the translator cylinder has a closed first end and a second end confined by a lid, the lid having a shaft opening for a shaft coupled to the magnetic rotor, wherein the magnetic rotor, when inserted in the translator cylinder, is arranged to translate a linear movement of the translator cylinder into a rotational movement of the magnetic rotor by using magnetic flux interacting between the magnetic stator and the magnetic rotor, said rotational movements is being transferred through a shaft, the lid with a shaft opening arranged for receiving the shaft, wherein the shaft is arranged to make both the linear and the rotational movement in the shaft opening, the lid being arranged for confining the second end of the translator cylinder, the translator cylinder confined by the lid forms, when divided by the magnetic rotor, a first chamber with a first volume and a second chamber with a second volume, wherein the first volume and the second volume changes as a function of the linear movement. The invention also relates to a method of operating an actuator system with a magnetic lead screw.

An apparatus for damping an actuator includes an inerter. The inerter includes a first terminal and a second terminal movable relative to one another along an inerter axis and configured to be mutually exclusively coupled to a support structure and a movable device actuated by an actuator. The inerter further includes a rod coupled to and movable with the first terminal and a threaded shaft coupled to and movable with the second terminal. The inerter further includes a flywheel having a flywheel annulus coupled to one of the rod and the threaded shaft. The flywheel is configured to rotate in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the movable device by the actuator.

Solar tracker systems include a torque tube, a solar panel attached to the torque tube, and a damper assembly. The damper assembly includes an outer shell, a first chamber wall and a second chamber wall within the outer shell at least partially defining a chamber, and a piston to direct fluid through the chamber. A valve is within the chamber that includes a first axial end, a second axial end, and a seal positioned on the first axial end. The damper assembly further includes a biasing assembly that biases the valve into a first position within the chamber in which the seal is spaced from the first chamber wall. The valve is moveable within the chamber from the first position to a second position in which the seal contacts and seals against the first chamber wall to prevent the flow of fluid through the chamber.

A vibration absorber which, in addition to a main mass which is fixed thereto and moved along a curved trajectory by a driving mechanism, comprises a substantially smaller variably adjustable rotating flywheel mass which is moved together with the main mass along the trajectory thereof, enabling the adjustment of the frequency of the absorber. The rotating flywheel mass is driven by a novel belt device independently of the driving mechanism. A rotating vibration absorber which, along with the main mass and the rotating flywheel mass, comprises its own damping unit, such as an eddy-current damping unit.

An eddy current damper includes a screw shaft, first permanent magnets, second permanent magnets, a cylindrical magnet holding member, a cylindrical conductive member, and a ball nut meshing with a screw shaft. The screw shaft is movable in the axial direction. The first permanent magnets are arrayed along the circumferential direction around the screw shaft. The second permanent magnet is arranged between the first permanent magnets, wherein the arrangement of magnet poles is inverted between the second permanent magnet and the first permanent magnet. The magnet holding member holds the first permanent magnet and the second permanent magnet. The conductive member is opposed to the first permanent magnets and the second permanent magnets with a gap therebetween. The ball nut is disposed inside the magnet holding member and the conductive member, and is fixed to the magnet holding member or the conductive member.

A large-size axial eddy current damper manufactured by use of screw drive comprises a drive assembly and an eddy current damping generator; the drive assembly comprises a screw drive pair, and a stator and a rotor respectively made of magnetic conductive materials; the screw drive pair comprises a screw rod and a nut sleeved on the screw rod; the screw rod sequentially penetrates through central holes of upper and lower flanges of the stator; the nut is within the stator; the rotor comprises an outer rotor and an inner rotor having the bottom provided with a lower connecting flange; one or more eddy current damping generators are arranged between the stator and the outer rotor. Problems of having difficulty in manufacturing axial dampers with a large damping coefficient and simulating anti-vibration dampers with a speed index of less than 1, by use of eddy current damping, can be solved simultaneously.

These teachings relate to a device that includes a base having an axis that is centered and perpendicular relative to the base and two or more arms each connected to the base at a base hinge The base hinge rotates the two or more arms away from the axis, and one or more expandable bands are connected with distal ends of the two or more arms. The one or more expandable bands absorb energy from rotating of the two or more arms. The device absorbs energy when an external force is applied along the axis of the base.