Belt tensioner for vehicle, has force limiting device comprising rotation damper that produces high damping torque at high speeds of torsion bar and appropriate smaller damping torque at low speeds of torsion bar

摘要

The tensioner has a force limiting device for limiting torque initiated from a pretensioning drive (16) i.e. drive wheel, into a torsion bar (12) and additionally provided to the torsion bar transferring the rotating motion of the pretensioning drive to a belt shaft (10). The limiting device has a rotation damper arranged in an installation area enclosed by the pretensioning drive and dynamically working depending on speed of the torsion bar. The damper produces high damping torque at high speeds of the torsion bar and appropriate smaller damping torque at low speeds of the torsion bar.