Damper Isolator Pulleys combine torsional vibration damping and a function for isolating the belt drive system from crankshaft irregularities. The damper reduces the torsional vibration amplitudes of the crankshaft, while the integrated isolator isolates the belt drive system from irregularities which cause belt effects like flapping.

Crankshaft irregularities, especially at low speed, can lead into noise or to an early failure of the belt and belt drive components. A crankshaft isolator rubber effectively eliminates these vibrations directly at source. At the same time, the torsional vibration damper in the isolator pulley reduces torsional vibrations within the crankshaft.

The vulcanized rubber spring provides an elastic connection to the belt drive. A dry bearing enables relative movement of the pulley.

About Torsional Vibration Dampers

Torsional Vibration Dampers absorb rotational vibrations in internal combustion engines. The dampers are particularly effective in conjunction with decoupled pulleys, which keep crankshaft irregularities away from the belt drive and auxiliaries. In fuel-efficient start-stop systems, they eliminate the effects of an engine that is constantly starting and stopping. With an additional one-way-clutch feature, they can enable further savings in fuel consumption and CO2 emissions.


Light vehicle manufacturers are being increasingly challenged to downsize components to reach ambitious global targets for fuel consumption and CO2 emissions. The result is smaller engines with fewer cylinders that compensate for reduced capacity by building up increased pressure and enabling more efficient combustion. This generates stronger vibrations in the crankshaft. Torsional vibration dampers compensate rotational vibrations in the engine and the irregularities of the crankshaft are kept away from the belt drive, also ensuring optimized durability.

Torsional Vibration Dampers are offered in a wide range of processes and in a variety of materials – from pressed, high torque, vulcanized and fluid torsional vibration dampers, through damper isolator pulleys with an overrunning feature, to sprocket dampers.