An apparatus and associated method is disclosed for a riser hanging system. The apparatus includes a first elongated member with a provision for a first external mechanical coupling at a distal location on the first elongated member. A second elongated member is mechanically coupled to the first elongated member at proximal locations on the first elongated member and the second elongated member. A third member is mechanically coupled to a first portion of the first elongated member. The third member includes a fourth member to move through at least a second portion of a length of the second elongated member. Mechanical couplers associated with the second elongated member are provided for a second external mechanical coupling of the riser to the apparatus. The riser may be hoisted using the apparatus for better control during coupling to the wellhead.

In an anti-vibration apparatus having a bracket where an anti-vibration apparatus body in which a first mounting member and the second mounting member are connected by a body rubber elastic body is horizontally mounted to the bracket by fitting parts disposed on two sides of a width direction of the second mounting member in the anti-vibration apparatus body to fitting grooves disposed on opposite inner surfaces on two sides of a width direction of the bracket, a locking hole is provided on a deep wall part located on a deep side in a mounting direction of the second mounting member in the bracket, and a locking part is disposed at a tip portion in the mounting direction of the second mounting member to the bracket, and prevents return in a direction opposite to the mounting direction by inserting and locking the locking part to the locking hole.

A tuned mass system has a bulk mass acted upon by an excitation amplitude and a reaction mass coupled to the bulk mass. A resistance-to-motion controlled coupling mechanism associated with the reaction mass is configured to proportionally modulate independent of excitation force such that the relative phase of the bulk mass and the reaction mass is substantially constant throughout an extended range of excitation amplitude. The resistance-to-motion controlled coupling mechanism is a Variable Aperture Reciprocating Reed (VARR) Valve in one embodiment, and operates as a passive mechanism. In other embodiments, active resistance-to-motion controlled coupling mechanisms are employed.

A tuned mass system has a bulk mass acted upon by an excitation amplitude and a reaction mass coupled to the bulk mass. A resistance-to-motion controlled coupling mechanism associated with the reaction mass is configured to proportionally modulate independent of excitation force such that the relative phase of the bulk mass and the reaction mass is substantially constant throughout an extended range of excitation amplitude. The resistance-to-motion controlled coupling mechanism is a Variable Aperture Reciprocating Reed (VARR) Valve in one embodiment, and operates as a passive mechanism. In other embodiments, active resistance-to-motion controlled coupling mechanisms are employed.

Provided is a shock absorber for a railway vehicle, in which an eccentric disk is disposed on a rear surface of a valve disk to set a supporting force for an initial opening position of the valve disk to a relatively low value and continuously open the valve disk from the initial opening position of the valve disk during strokes, thereby controlling a damping force in a low speed section and realizing a soft damping force.

Provided is a shock absorber for a railway vehicle, in which an eccentric disk is disposed on a rear surface of a valve disk to set a supporting force for an initial opening position of the valve disk to a relatively low value and continuously open the valve disk from the initial opening position of the valve disk during strokes, thereby controlling a damping force in a low speed section and realizing a soft damping force.

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.

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 low vibration cryostat includes a cryocooler with a cold head having a flange and a cooling body extending from the flange. A housing is coupled to the cold head, with the housing having an opening receiving at least a portion of the cooling body. A first bellows extends between the housing and the flange to mitigate the transfer of vibrational forces between the housing and the flange. The first bellows, the flange, and the housing collectively define a first chamber. A force balancing assembly containing a second bellows is coupled to the housing and includes a second chamber spaced from the first chamber. The two chambers are arranged to create a net zero force on the cold head when the pressure in the bellows changes. A viscous damping assembly mitigates bouncing of the cold head on support springs.

A compound helicopter includes a fuselage including a fuselage airframe, a translational thrust system coupled to the fuselage airframe and a pylon assembly subject to vibration. The pylon assembly includes a transmission and a rotor system having a main rotor assembly. The compound helicopter also includes a main rotor vibration isolation system including a plurality of augmented liquid inertia vibration eliminator units each having an isolation frequency and each coupled between the fuselage airframe and the pylon assembly to reduce transmission of the pylon assembly vibration to the fuselage airframe at the isolation frequency. Each augmented liquid inertia vibration eliminator unit includes at least one active tuning element movable to tune the isolation frequency thereof.