A suspension system for a vehicle and method for operating the same includes a shock absorber housing having a longitudinal axis, a spring disposed around the shock absorber housing and a retainer collar disposed around the shock absorber housing. An actuator coupled to the retainer housing moves at least a portion of the retainer housing to move the spring in a direction corresponding the longitudinal axis.

A torsional vibration damper that can reduce collision noise of an inertia body when a rotary member is stopped, and a control device therefore. In the torsional vibration damper, a rotary member is mounted on an output shaft of an engine such that none of rolling masses is situated within a predetermined angle range above a rotational center axis of the rotary member when the engine is stopped. Therefore, when the engine is stopped, the inertia body will not be supported by only one of the rolling masses situated within the predetermined angle range.

A method and apparatus are disclosed for cooling damping fluid in a vehicle suspension damper unit. A damping unit includes a piston mounted in a fluid cylinder. A bypass fluid circuit having an integrated cooling assembly disposed therein is fluidly coupled to the fluid cylinder at axial locations that, at least at one point in the piston stroke, are located on opposite sides of the piston. The cooling assembly may include a cylinder having cooling fins thermally coupled to an exterior surface of the cylinder and made of a thermally conductive material. The bypass channel may include a check valve that permits fluid flow in only one direction through the bypass channel. The check valve may be remotely operated, either manually or automatically by an electronic controller. A vehicle suspension system may implement one or more damper units throughout the vehicle, controlled separately or collectively, automatically or manually.

The invention relates to a spring-damper element (2) for mounting a punching press (1), with a hydraulic damper unit (3) with a first fluid chamber (4) and a second fluid chamber (5), wherein, in the intended operation, a hydraulic fluid is displaced from the first fluid chamber (4) via a throttle point (6) into the second fluid chamber (5) when the spring-damper element (2) is compressed. The damper unit further comprises an overload valve (7) arranged between the first fluid chamber (4) and the second fluid chamber (5), which overload valve opens when a specific fluid pressure is reached in the first fluid chamber (4) or when a specific pressure difference is reached between the first fluid chamber (4) and the second fluid chamber (5) and releases a bypass (8) via which hydraulic fluid then flows from the first fluid chamber (4) into the second fluid chamber (5) bypassing the throttle point (6). Thereby, the spring-damper element (2) is designed in such a way that the fluid pressure or the pressure difference, respectively, at which the overload valve (7) opens can be adjusted when the spring-damper element (2) is installed as intended. With such spring-damper elements according to the invention, it becomes possible to create a mounting arrangement for a punching press, the damping characteristics of which can be adjusted without significant effort, such that a variable operation of the press in wide ranges becomes possible while keeping the ground loading to a minimum in each case.

A reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.

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.

An object of the invention is to provide a vibration damping system that can avoid the occurrence of resonance of an elevator rope regardless of the vibration frequency of a vibration source. A vibration damping system (200) includes a displacement amplifier (7), a calculation unit (66), and a displacement amplification control unit (67). The displacement amplifier (7) is arranged along a given position in the longitudinal direction of the elevator rope. The displacement amplifier (7) amplifies a displacement due to vibration of the elevator rope based on a variable amplification factor. The calculation unit (66) calculates the natural frequency of the elevator rope. The displacement amplification control unit (67) controls the displacement amplification of the displacement amplifier (7) based on the natural frequency calculated by the calculation unit (66) and a preset vibration frequency.

An object of the present invention is to provide a vibration damping device including an instability preventing means, for efficiently suppressing amplification of vibration of a long structure, which is mechanically flexible, due to a resonance phenomenon. A vibration damping device (100) for reducing vibration of a long structure (1) includes a displacement amplifier (7) and limiting members (8). The displacement amplifier (7) is arranged along a given position in the longitudinal direction of the structure (1). The displacement amplifier (7) amplifies a displacement of the structure (1). The limiting members (8) control displacement amplification performed by the displacement amplifier (7) such that the displacement of the structure (1) amplified by the displacement amplifier (7) does not become greater than a first displacement, the first displacement being a displacement of the structure (1) by which the structure (1) is not allowed to return to the equilibrium position of the vibration.

An object of the present invention is to provide a sway amount estimation system that can suppress a reduction in user convenience that would occur if the operation method is switched more than necessary. A sway amount estimation system (300) includes a sensing unit (78), a judgment unit (80), and an estimation unit (79). The estimation unit (79) calculates an estimated value of the amount of sway of an elevator rope due to vibration caused by building sway based on the sway sensed by the sensing unit (78) and an estimation model incorporating the effect of the displacement amplification of the displacement amplifier (7). The judgment unit (80) judges if the estimated value calculated by the estimation unit (79) is greater than a threshold for switching the operation method for the elevator apparatus (11).

A suspension system includes a spring assembly including a gas spring and an accumulator, and a controller. The accumulator is coupled to the gas spring and includes a bladder. The accumulator has a compressed state and an uncompressed state. The controller is configured to a) determine a target amount of gas in the spring assembly and b) adjust the amount of gas in the spring assembly towards the target amount of gas based on a pressure difference across the bladder.