New Torsional Damper Concept to Reduce Idle Rattle in Truck Transmissions

Comfort requirements have significantly increased in recent years, even in the commercial vehicle sector. Transmission noise, caused by higher engine excitation (due to emission changes), can be reduced with a new torsional damper in the clutch disc, with a special idle damper. Up until now, free play (sometimes referred to as backlash) in the clutch or transmission helped reduce idle rattle. In many cases this simple solution is no longer adequate. This paper explains dynamic behavior during idling and provides the background for understanding the causes of rattle noise.