Tuned Mass Dampers
Tuned mass dampers
Tuned mass dampers (also called vibration absorbers or vibration dampers) reduce low and high frequency vibrations in machines, systems and structures. The function of a damper is based on a spring/mass system, which counteracts and reduces extraneous vibrations. The weight of the damper depends on the weight of the system being damped.
ESM has developed dampers adjustable in three dimensions, enabling compensation for unwanted vibrations without time-consuming development work.
The dampers are set by ESM to the required frequencies, although they can still be adjusted on site to the prevailing conditions.
Working principleUnwanted resonance vibrations are broken down into two individual vibrations. These peaks are damped simultaneously, so that only two vibrations with a small deflection remain.
Linear structure-borne noise dampers
These adjustable dampers are used to reduce structure-borne noise in the frequency range from approx. 100 to approx. 400 Hz with a mass of 50 - 200 kg.
|Linear structure-borne noise dampers|
Other masses and frequencies are also easily available but have to be checked individually.
Dampers for noise reduction of gear meshing frequenciesIn the example shown here, the use of two dampers with a weight of about 150 kg each enabled the vibrations at 160 Hz in all individual components including the tower and rotor of a wind turbine to be decreased by a factor of about 10.
Lessening the structure-borne noise level throughout the complete system has led to a noticeable improvement in the radiated noise level.
3-D dampers: act and are adjustable in three dimensionsESM has developed dampers adjustable in three dimensions, enabling compensation for unwanted vibrations without time-consuming development work. These 3-D dampers are also simply fixed to the structures to be damped by means of a central screw. The axial and radial natural oscillation of the damper can be adjusted separately from each other.
ESM's adjustable torsion dampers are ideal for the damping of heavy rotating components with high inertial torques.
This torsion damper is adjustable over a wide frequency range.
Low-frequency vibration dampersThis damper is chiefly employed in wind turbines to damp the first natural frequency of the tower. They are used in frequency ranges between 0.3 and 3 Hz, and weigh between 500 kg and 10 t, depending on the size and weight of the wind turbine.
|A new damper for damping the |
first natural frequency of the tower
|This damper is mounted under the|
machine house of a 1 MW wind turbine,
and weighs approx. 500 kg.
Vibration damper for damping of the second natural tower frequency as well as structural applications
|This damper is mounted on the tower |
flange in the area of the greatest vibration
amplitude in the centre of the tower.
|This dampers can be used for example to |
damping staircases with low natural frequencies
Dampers of this type also help
diminish building vibrations
Adjustable vibration damper for reduction of machine vibrationsThis damper is used for damping of test machine frames in a range up to 10,000 rpm (166 Hz).
Damper for the reduction of blade vibrationsDampers of this type are mounted behind the generator frame. They reduce the edge-wise vibrations of rotor blades.
Non-temperature-sensitive tuned mass dampersESM’s non-temperature-sensitive tuned mass damper is a passive rubber-based system that prevents frequency changes when the surrounding temperature alters. This robust tuned mass damper needs no energy supply and is available for a wide range of masses, frequencies, damping and temperatures.
If necessary, these dampers can also be given a desired temperature-frequency response.