A torsional damper comprises: a hub fixed to a rotating shaft and having an outer peripheral surface on the circumference centered on the rotating shaft; an annular vibrating ring having an inner peripheral surface having a diameter larger than that of the outer peripheral surface of the hub, on the circumference centered on the rotation axis; and a rubber ring, composed of a rubber composition containing EPDM as a main component, provided in a compressed state between the outer peripheral surface of the hub and the inner peripheral surface of the vibrating ring, and has a loss coefficient of 0.18 or more when the surface temperature is 60±5° C., wherein when the rubber ring is subjected to the resonance point tracking method, the maximum surface reaching temperature of the rubber ring at the time of continuous vibration at the resonance point and the vibration ring thickness satisfy a specific relational expression.

A torsional damper is provided with: a hub affixed to a rotary shaft and having an outer-circumferential surface along a circle centered on the rotary shaft; an annular oscillation ring having an inner-circumferential surface the diameter of which is larger than the outer-circumferential surface of the hub on a circle centered on the rotary shaft; and a rubber ring that exists in a compressed state between the outer-circumferential surface of the hub and the inner-circumferential surface of the oscillation ring, comprises a rubber composition the main component of which is EPDM, and has a loss coefficient (tan δ) of 0.18 or higher when the surface temperature is 60±5° C. When subjected to resonance point tracking, the fitting diameter (d) and the maximum attained surface temperature (Tmax) of the rubber ring during continuous excitation at the resonance point satisfy a prescribed relational expression.

A shock absorber includes a bearing unit having a bearing and a bearing holding member, and a seal unit having a seal member and a seal holding member. The seal holding member includes a seal accommodating portion being configured to accommodate the seal member, and an insertion hole through which a piston rod is inserted. The seal member is pressed against an outer circumferential surface of the piston rod and the seal accommodating portion by working-fluid pressure in the extension-side chamber. And the bearing is provided such that a first end surface of the bearing facing the seal member matches an aperture plane of a through hole of the bearing holding member or such that the first end surface of the bearing projects out from the aperture plane of the through hole.

A shock isolator is arranged between two automated coupler parts in a vibration testing unit. When the coupler parts are engaged and coupled during vibration testing of a component, the shock isolator is disabled, and when the coupler parts are disengaged and decoupled after vibration testing, the shock isolator is activated to absorb excess shock energy and prevent shock transfer between the coupler parts that would damage the test component. The shock isolator includes a bushing that is inserted in a lower part of the two automated coupler parts and a compressive fit rod that is press-fit into the bushing. The bushing has a chamfered volume and the compressive fit rod has a corresponding compressible volume that is displaced into the chamfered volume to disable the shock isolator. After vibration testing, the compressive fit rod is expandable to a regular shape to activate the shock isolator.

The present invention is directed to a spray boom for an agricultural machine in which the boom is arranged as a truss with interior diagonal struts of the truss being configured to absorb tension and compression energy imparted by deflections over the length of the boom with such energy being dissipated as heat. In one aspect, the diagonal strut could comprise a rod moveable with respect to a tube with a polymer, such as an elastomeric material, arranged in the tube to dampen the movement. The tension and compression of the diagonal strut could subject the dampener to a shearing force which could be absorbed by the dampener rather than transferred to the machine.

A hydraulic mount assembly includes a first track insert (or shell), a second track insert (or shell), and a separating diaphragm (e.g., rubber membrane) as part of a body (e.g., a rubber body) disposed between the first track insert and the second track insert. In embodiments the separating diaphragm forms a seal between a first chamber disposed between a portion of the first track insert and the separating diaphragm, and forms a seal between a second chamber disposed between a portion of the second track insert and the separating diaphragm.

An apparatus comprised of a first portion comprising a generally flexible fabric, and a second portion or layer comprising a gel material formed in a generally planar rectangular shape. Positioned below the second layer is a third portion or a damping layer having a series of dampers positioned thereon, where the dampers are elastomeric flexible and compressible. The three portions are laminated together.

Various embodiments provide a bush for isolating vibrations, the bush comprising: a first anchor part defining a longitudinal axis; a second anchor part disposed coaxially with respect to the first anchor part; a first resilient body operably engaged with the first anchor part; a second resilient body operably engaged with the second anchor part; and an inertial mass element disposed between the first anchor part and the second anchor part. The inertial mass element is independently connected to the first resilient body and the second resilient body. Also, the first resilient body, second resilient body and inertial mass element are arranged to isolate vibrations between the first anchor part and the second anchor part within a predetermined operational frequency range. Further, the inertial mass element is arranged to isolate the first anchor part and second anchor part from dynamic stiffness increases associated with eigenmodes of the first resilient body and the second resilient body in the predetermined operational frequency range.

A dual rate jounce bumper and a vehicle containing the dual rate jounce bumper are useful.

An acrylic rubber containing: an alkyl acrylate unit; a crosslinking monomer unit; a unit of a bifunctional monomer represented by the following formula (A-1):

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wherein n represents 1 to 9, R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents an alkanediyl group having 2 to 4 carbon atoms; and an ethylene unit, wherein the acrylic rubber has a toluene insoluble content of 4 to 40% by mass.