ADT consists of pulley, rocker arm, base, torsion spring, locating pin. The pulley is fixed on the rocker arm with bearings and bolts. Through damping, the rocker arm and the torsion spring are riveted on the base that can rotate relatively with rocker arm. The base is fixed on the engine hood that ensures belt tension under the action of torsion spring in the course of operating. In this way, the service life of the belt is increased and the noise inside the engine is reduced.