Elastomeric bearings exhibit a reactive positive spring effect, i.e., they produce an opposing torque or force when angular displacement or translation is applied upon them, due to shear stress developed within their elastomer parts. The present invention incorporates a device that exhibits an increasingly strong torque or force in the same direction as the displacement, i.e., a negative spring, under similar conditions of movement. When properly calibrated, the subject type of device can be used in paralleled motion with the ordinary reactive elastomeric bearing to produce a combined effect in which at least a part of the torque or force of the elastomeric bearing is compensated or minimized over a range of movement, particularly in helicopter rotor blade retention applications.

A bogie for a railway vehicle 1 includes an elastic element 20 that is arranged between a vehicle body 7 and a bogie frame 3 of a railway vehicle and elastically supports both, and the elastic element 20 is configured in such a manner that a spring constant for displacement in the longitudinal direction in the traveling direction of the vehicle body 7 is smaller than that for displacement in the vertical direction or the left-and-right direction in the traveling direction.

The invention is a system for controlling the relative movement of a load P, comprising at least one main damper having a longitudinal action of stroke C and two ends with one end being connected to a frame and the other being connected to the load. A compensation device is included having at least one secondary damper of longitudinal action with two ends with one end being secured to the frame and the other end is connected to the end of the main damper connected to the load The secondary damper is arranged so that, at one point of stroke C, the secondary damper has an action orthogonal in direction to the direction of the movement.

A metamaterial system for protecting a payload from external energy flux generated by an energy source includes a mechanical, metamaterial framework configured to circulate the external energy flux between the metamaterial system and the energy source.

A rotating machine system include a rotating machine. The rotating machine system can include a housing. The housing can include an inner surface. The housing can surround at least a portion of the rotating machine. The inner surface of the housing can be spaced from the rotating machine such that a space is defined therebetween. The rotating machine system can include a plurality of vibration isolators. The vibration isolators can be positioned in the space and can be operatively connected to the rotating machine and to the inner surface of the housing. The vibration isolators can be compression-type vibration isolators.

The present invention discloses a bidirectional collapse-proof damper with a macroscopic NPR structure and a bridge structure having the same, comprising a sleeve and a sliding rod; by adding a structure of a reducing part and a limiting body, a sliding gap exists between both ends of the limiting body and both inner ends of the reducing part; the rod body is connected with the inner side wall of the sleeve through an elastic element; the limiting body and the rod body can realize bidirectional slip in the sleeve, which have multi-level seismic performance.

A vehicle seat assembly includes a seat frame, a seat pan, and a plurality of vibration isolators interposed between the seat frame and the seat pan for limiting transmission of vibrations from the seat frame to the seat pan.

Systems and methods for limiting transmission of vibrations and forces causing vibrations from one element to another are provided. A vibration isolator may include a compressible inner member and an outer member compressible with the inner member. The outer member may be positioned at least partially around the inner member to provide lateral support to the inner member. The outer member may maintain a consistent diameter and compression force when in a compressed state. The outer member may include a tube with a zero or near-zero Poisson's ratio.

A vibration isolator includes a first conical disc spring member having a first end and a second end. A first-end spacer in contact with the first spring member first end, and a second-end spacer in contact with the first spring member second end. A second conical disc spring member has a first end and a second end. The second spring member first end is in contact with the first-end spacer. Another second-end spacer is in contact with the second spring member second end. A flexible housing of the isolator defines an interior. The housing is in contact with and extends between the second-end spacer and the other second-end spacer so that the first-end spacer and the first and second spring members are received in the housing interior. The housing includes a plurality of spaced-apart through holes formed therealong between the second-end spacer and the other second-end spacer.

A quasi-zero stiffness electromagnetic vibration isolator for ultra-low frequency vibration reduction and isolation is provided. When the vibration isolator is in a static equilibrium position, upper and lower air gaps are equal, and electromagnetic attraction forces of upper and lower stator assemblies to a mover assembly are equal. When the load tends to move upwards, the mover assembly is subjected to an upward resultant force, when the load tends to move downwards, the mover assembly is subjected to a downward resultant force, showing the characteristic of negative stiffness. A negative stiffness mechanism composed of the upper stator assembly, the lower stator assembly and the mover assembly is connected in parallel with the positive stiffness springs to achieve a quasi-zero stiffness.