A closure package for a vibration damper may include a base body that is connectable to a damper tube and comprises a first end and a second end. The first end forms an end side of the damper tube and the second end is disposed in the damper tube. A seal for sealing a piston rod may be disposed in the base body. A seal holder may be disposed between the seal and the base body at the first end. The seal holder for axially fixing the seal may be connected to the base body in a form-fitting and/or force-fitting manner. The seal holder may be fusible in an emergency. For releasing the connection to the base body, the seal holder may be thermoplastically deformable upon overheating of the vibration damper.

Provided is a gas strut, including: an outer working space arranged radially to the stroke axis between the working cylinder and the equalizing cylinder, the outer working space being connected to the inner working space in a gas-conducting manner; an equalizing piston enclosing the working cylinder radially to the stroke axis, the equalizing piston) being mounted displaceably along the stroke axis, delimiting the outer working space on one side transversely to the stroke axis and being subjected to a pressure of the working medium and a pressure of the equalizing medium so as to increase the volume of the outer working space; and a restoring medium arranged in a restoring space radially to the stroke axis between the working cylinder and the equalizing cylinder, the equalizing piston being subjected to a pressure of the restoring medium so as to decrease the volume of the outer working space.

A vibration isolation system includes multiple isolators between an inner object and an outer housing that surrounds the object. In one example the inner object may be a rack or container that holds electronics, such as printed circuit boards, and the outer housing may be a housing for a missile, such as a supersonic or hypersonic missile. The isolators have flexures to attenuate vibrations, isolating the inner object at least in part from vibrations encountered by the outer housing. The flexures may be oriented in different directions for different isolators to change the resonant frequency of the system for a given axis. In addition the isolators are able to compensate for differences in expansion between the inner object and the outer housing. The isolators may also include multi-part isolators that have spring-loaded wedge elements used to expand the isolators in one or more radial directions.

A method of attenuating annular pressure buildup within a wellbore. The method includes accessing a wellbore, with the wellbore having an annulus disposed between first and second strings of casing. The method also includes placing a column of cement around the second string of casing generally below the first string of casing. The method further includes pumping a fluid mixture into the annulus, forming a fluid column. The fluid mixture comprises a carrier fluid, and a plurality of compressible particles dispersed in the carrier fluid. Each of the compressible particles is fabricated to partially collapse in response to thermal expansion of the fluid mixture. The method also includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore. The method additionally includes at least partially sealing the annular region along at least one depth above the column of cement to inhibit vertical migration of the compressible particles.

Embodiments of the present invention generally relate to a novel system, device, and methods for providing an isolator for components and instrumentation to isolate vibrations, shock, static or quasi-static loads, thermal loads, and electrical currents. The novel isolator has an asymmetrical shape, experiences uniform motion under quasi-static loading, and reduces the effective modal mass across a range of frequencies. The novel isolator outperforms conventional vibration isolators in terms of cost, schedule (manufacturing time and lead time), heat dissipation, and performance.

A crossbar assembly for facilitating isolation of a sensor assembly from vibration of a payload mounting system on a vehicle comprises an outer crossbar segment, an inner crossbar segment, and an isolator. The outer crossbar segment comprises a payload mount interface operable to mount to a payload mount, and an outer isolator interface operable to mount to an isolator. The inner crossbar segment comprises a structure interface to mount to a structure, and an inner isolator interface operable to mount to the isolator. The isolator can be supported by the outer and inner crossbar segments. The isolator comprises an elastomeric component operable to elastically deform in response to relative movement between the outer and inner crossbar segments. The isolator operates to partially decouple the outer crossbar segment from the inner crossbar segment and dampen vibrations propagating between the outer and inner crossbar segments.

A rotary damper includes a rotating input member rotating about a rotation axis; a first cylinder and a second cylinder coaxially arranged on opposite sides of the rotation axis; a first and a second pistons slidable inside the first and second cylinders and defining a first and a second working chambers containing incompressible working fluids, respectively; motion conversion mechanisms converting the rotary motion of the rotating input member about the rotation axis into reciprocating motion of the first and second pistons; a third cylinder; a fourth cylinder; and a third and fourth pistons, slidable inside the third and fourth cylinders, respectively and separating the inner volume of the respective cylinder into a respective main chamber in fluid communication with the first working chamber and auxiliary chambers; and the second working chamber and auxiliary chambers respectively.

A centrifugal pendulum for damping rotational irregularities of a driveshaft of an internal combustion engine, having a carrier flange element connectable indirectly or directly to the driveshaft, and having multiple pendulum elements displaceable in relation to the carrier flange element, and guided via rollers in pendulum paths. Each pendulum element is displaceable in relation to the carrier flange element in the circumferential direction between a first and a second stop position. At least one friction element having defined thermal expansion properties, which are different in particular from the carrier flange element and/or the pendulum elements, is associated with the carrier flange element, and is designed and arranged in such a way that in a defined temperature range of the centrifugal pendulum, upon a movement of at least one pendulum element corresponding to the friction element in the direction of a stop position.

A vibration isolating coupler including a first coupler portion, a second coupler portion including an external surface and an internal surface portion, and a vibration isolating portion extending between the first coupler portion and the second coupler portion. The vibration isolating portion including a first solid annular portion and a second solid annular portion. The vibration isolating portion including a plurality of slots extending from the first solid annular portion toward the second solid annular portion forming a plurality of vibration isolating elements. Each of the plurality of vibration isolating elements is disconnected from adjacent ones of the plurality of vibration isolating elements by a corresponding one of the plurality of slots. The plurality of vibration isolating elements enabling torsional rotation of the first coupler portion relative to the second coupler portion.

Systems and methods for damping torsional oscillations of downhole systems are described. The systems include a downhole drilling system disposed at an end of the downhole system in operative connection with a drill bit. A damping system is installed on the downhole drilling system, the damping system having at least one damper element configured to dampen at least one HFTO mode. At least one mode-shape tuning element is arranged on the drilling system. The at least one mode-shape tuning element is configured and positioned on the drilling system to modify at least one of a shape of the HFTO mode, a frequency of the HFTO mode, an excitability of the HFTO mode, and a damping efficiency of the at least one damper element.