Torsional Dampers and Alternative Systems to Reduce Driveline Vibrations

Fuel saving means vehicle operation at low engine speed and accordingly high engine torque. For that, recent engines have been tallored, developing up to 85% of the max, torque at 1.000 rpm. However, when applying this driving mode, the driver may be irritated by rattling noise and body humming. This is due to the fact that all drivelines have a natural frequency between 1.000 and 2.000 rpm, which cannot be displaced below 1.000 rpm by means of tuning of conventional torsion dampers.

Diesel engines and more and more gasoline engines require an idling noise isolation stage. This stage adds to the total lash in the driveline and contributes to clonk and load reversal reactions.

This paper describes various systems suitable to overcome these concerns.