A vibration suppression method for a servo motor and a load multistage drive system is provided. For a number N of fixed vibration frequencies and one vibration frequency varying with a load position existing in a multistage drive mechanism, a number of N+1 vibration suppression filters are adopted, and each filter is configured to eliminate a corresponding vibration frequency. Fixed vibration frequencies and a vibration frequency varying with a load position in a multistage drive system are measured by using an offline method, and the varied vibration frequencies are made into a two-dimensional table related to the load positions. The fixed vibration frequencies are eliminated by using fixed-frequency parameter vibration suppression filters; and the varied vibration frequencies are eliminated by using a variable-frequency parameter vibration suppression filter, and the vibration frequencies are obtained in real time according to the load positions and the two-dimensional table.

Hydraulic damper with load regulation as a function of frequency by means of hydraulic inertia composed of a cylinder, comprising an inner chamber, a rod, a main piston and an inertia piston, immersed in a hydraulic fluid, so that the inner chamber is divided into 3 sub-chambers, the main piston comprises a flow path controlled by valves to allow bidirectional flow of fluid between the sub-chambers and the inertia piston comprises a flow path called the inertia channel configured to allow fluid flow between sub-cameras at both sides of the inertia piston.

A vibration damping device including: a first attachment member and a second attachment member disposed apart from each other; and a main rubber elastic body connecting the first attachment member and the second attachment member, the main rubber elastic body being of a frustoconical-like shape having an outer peripheral surface whose diameter gradually increases from the first attachment member toward the second attachment member, the main rubber elastic body including a recess opening onto a center portion thereof on a large-diameter side that is a second attachment member side, and the main rubber elastic body that constitutes a bottom part of the recess integrally including a vibration-damping protrusion protruding into the recess.

A mowing sickle drive system comprises a knife bar supported by a frame and drive apparatus operable to drive the knife bar in a reciprocating linear motion at a variable drive frequency. A spring is coupled to the knife bar for applying a restoring force to the knife bar toward a neutral position when in motion. The spring has a variable modulus of elasticity that is controlled dependent upon the drive frequency.

A damper valve (100) comprises a controlled flow channel (115) between a valve inlet side (100.1) and a valve outlet side (100.2); a controlled valve (130) provided in the controlled flow channel; a movable valve body (120) acting on the controlled valve so as to change a closing force of the controlled valve; and a control chamber (126). The control chamber comprises a control chamber inlet (125) in fluid connection with the valve inlet side (100.1) upstream of the controlled valve (130); a configuration providing a variable volume of the control chamber, a change in volume of the control chamber acting to cause a movement of the movable valve body (120); and a pressure relief valve (160) to allow a relief fluid flow from the control chamber (126) to the valve inlet side (100.1) bypassing the flow restriction (160.1) of the control chamber inlet (125).

A power transmission device is provided, which includes a vibration reducing damper provided on a power transmission path, and a clutch mechanism having a plurality of friction plates, a hydraulic pressure chamber, and a centrifugal balance chamber provided opposed to the hydraulic pressure chamber. The clutch mechanism is provided adjacent to an axial side part of the damper, and an oil drain port for hydraulic fluid supplied to the centrifugal balance chamber of the clutch mechanism is provided at a location radially inward of the damper and axially overlapping with the damper.

The present invention relates to a vibration damper (1) comprising a damper tube (2) which is at least partially filled with damping fluid and in which a piston rod (3) is movable back and forth, wherein a working piston (4) is movable jointly with the piston rod (3), by means of which working piston the interior space of the damper tube is divided into a piston-rod-side working space (5) and a piston-rod-remote working space (6), a damping module (7) for the frequency-dependent control of a comfort bypass which is formed between the piston-rod-side working space (5) and the piston-rod-remote working space (6) and which comprises a comfort path via which damping fluid can be caused to flow hydraulically in parallel with respect to the flow through the working piston (4), a control piston (8) which is received, such that it can perform stroke movements, in the damping module (7) and which, remote from the piston rod, delimits a pressure chamber (9) arranged in the damping module (7), wherein the pressure chamber (9) comprises at least one inlet (10),
wherein the damping module (7) comprises a damping module housing, with a housing cover (11) arranged at the piston rod side and with a housing pot (12) arranged remote from the piston rod, comprises the control piston (8) and comprises at least one first disk valve assembly (13), wherein the at least one first disk valve assembly (13), in the comfort path with the housing cover (11), forms a comfort valve, and the at least one first disk valve assembly (13) comprises at least one bypass control valve with at least one bypass inlet opening (16), wherein, via the at least one bypass control valve, bypassing the comfort valve, damping fluid can be caused to flow via a bypass control path hydraulically in parallel with respect to the flow through the working piston (4), wherein the bypass control valve is controlled by means of the stroke of the control piston (8) and wherein the disk valve assembly (13) comprises at least one bypass disk (17) with at least one bypass disk opening (18), comprises at least one spacer disk (19) and comprises a comfort disk (20).

A damper unit for use in a vibration-reducing assembly for a steering wheel is disclosed. An elastomeric damper element is molded on an inner sleeve and includes a plurality of elastomeric ribs forming a radially outer engagement surface, and a plurality of elastomeric support studs, which are mutually spaced in a circumferential direction are flexible in all directions transverse to said axis. Methods for making a damper unit and a damper assembly are also disclosed.

A mowing sickle drive system comprises a knife bar supported by a frame and drive apparatus operable to drive the knife bar in a reciprocating linear motion at a variable drive frequency. A spring is coupled to the knife bar for applying a restoring force to the knife bar toward a neutral position when in motion. The spring has a variable modulus of elasticity that is controlled dependent upon the drive frequency.

A vibration damper for a vehicle, includes at least one cylinder tube forming a fluid chamber, in which a piston assembly is axially and slidingly arranged and divides the cylinder tube into two working chambers, an upper and a lower working chamber, and wherein the piston assembly has an axially moveable main piston which is axially fixed to a piston rod that can move axially relative to the cylinder tube, and which has a piston valve influencing the fluid flow between the upper and lower working chambers, and wherein a further stroke-dependent piston is arranged on an axial extension of the piston rod in the direction of the cylinder base, which operates once a determined damper stroke is achieved. The stroke-dependent piston has a smaller diameter than the main piston and only operates when plunging into a smaller diameter of an inner casing surface. The stroke-dependent piston therefore has a stroke-dependent valve, and the stroke-dependent piston also has a frequency-dependent valve in addition to the stroke-dependent valve.