The invention relates to a device comprising a body and a set of vibration absorbers mounted on the body, each absorber being movable relative to the body between a first position and a second position, each absorber being capable of oscillating relative to the body between its first and second positions, a first natural frequency being defined for each absorber, at least one absorber having a first natural frequency different from the first natural frequency of another absorber.

Each absorber comprises at least one deformation part capable of deforming as the vibration absorber oscillates between its first position and its second position, the deformation part having at least two faces configured to rub against each other during the deformation of the deformation part.

Proposed is a rubber bush type vibration damping device for a vehicle, which solves the problem of vibration increase which may occur in the natural frequency of the vibration damping device by changing the shapes of an inner coupling part or an outer coupling part and by using difference in the lengths of rubber insulators due to the changing of the shapes thereof. The vibration damping device includes an inner coupling part, an outer coupling part, and a plurality of rubber insulators having have different natural frequency.

A compacting power tool comprising: a motor; a housing; at least one handle connected to the housing; a reciprocating drive mechanism coupled to the motor; and a compacting foot coupled to the reciprocating drive mechanism and configured to engage a surface to be compacted; a battery carrier coupled to a vibration compensation mechanism moveably mounted on a side of the housing.

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.

An SMA-STF based viscous damper includes a first connector, a piston rod, a piston which is sheathed on the piston rod; a damping cylinder; first and second end covers which are respectively provided at two sides of the damping cylinder; a second connector which is fixedly connected to the second end cover; and first and second SMA springs which are respectively sheathed on the piston rod. The damping cylinder has first and second damping cavities between which the piston is arranged. One end of the piston rod passes through the first end cover and is connected to the first connector, and the other end passes through the second connector. The first and second SMA springs are respectively held in the first and second damping cavities in an elastic state. The first and second damping cavities are respectively filled with the STF.

A dynamic damper includes a hub, a vibration ring located on the outer periphery of the hub, and a pair of elastic bodies made of a rubber-like elastic body located on both sides in the axial direction of the vibration ring and coupling the hub and the vibration ring, in which the vibration ring is provided with a protrusion extending to the vicinity of the outer periphery of the hub, each of the elastic bodies has a shape of being curved outward in the axial direction from the protrusion from the hub to the vibration ring, a projection extending toward the protrusion is integrally molded on a surface on a protrusion side in the elastic bodies, and a gap is set between the protrusion and the projection.

Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

A damping valve arrangement of a vibration damper for a motor vehicle includes a damping valve body having a longitudinal axis A and a throughflow passage is covered by at least one valve disk, a spring arrangement has at least a first substantially disk-shaped spring element; and a force transmission disk arranged between the valve disk and the first spring element so as to be axially displaceable coaxial to the damping valve body. The force transmission disk has a first surface facing the first spring element and comprising a first contact ring with a first diameter, which first contact ring is axially elevated above the first surface, and a second surface opposite the first surface, which second surface faces the valve disk and comprises a second contact ring with a second diameter, which second contact ring is axially elevated above the second surface.

A method for determining a detection sensitivity of a rotation rate sensor, the rotation rate sensor including an oscillatory system. A first quadrature signal of the oscillatory system is determined in a first step. A controlled change of a transfer function of the oscillatory system takes place in a second step. A second quadrature signal of the oscillatory system is determined in a third step. The detection sensitivity is determined in a fourth step on the basis of the first and second quadrature signal. A method is also described for determining a detection sensitivity of a rotation rate sensor, the rotation rate sensor including one first oscillatory system and one second oscillatory system.

Provided is a matrix type double parallel capillary tube shock absorber with a variable system natural frequency, wherein on a pipeline between oil supply ports of an upper oil compartment (14) and a lower oil compartment (16), a capillary tube parallel type damping associated section and a capillary tube parallel type system natural frequency associated section are successively connected from top to bottom; the capillary tube parallel type damping associated section comprises four capillary tubes connected in parallel, with each capillary tube being connected in series with a solenoid valve so as to control the operation of the capillary tube; the capillary tube parallel type system natural frequency associated section comprises four capillary tubes connected in parallel, and each of the four capillary tubes is connected in series with a solenoid valve so as to control the operation of the capillary tube; the diameter of the smallest capillary tube of the frequency adjustment section is much larger than the diameter of the capillary tube of the resistance adjustment section; and in a matrix type operation state table, the configuration value S.sub.mn of the solenoid valves of the frequency adjustment section is selected according to situations, and by way of changing the mass, the problem of the system natural frequency of a hydraulic shock absorber for a vehicle being not adjustable or having a small adjustable range can be solved. Further provided is a method for operating a matrix type double parallel capillary tube shock absorber with a variable system natural frequency.