The clutch system in a vehicle performs two main functions:
• Power interruption and modulation during start up and when shifting
• Reduction of rotational vibrations in the drive train induced by engine
During the LuK Clutch Symposium, LuK will introduce some new
developments which successfully fulfill these functions for our customers.
The following presentation will illustrate a cross-section of development
efforts aimed at reducing engine-induced rotational vibrations in the drive
Rotational vibrations affect durability of the drive train components and
• Gear rattle
• Body boom
• Tip-in/back-out vibrations
These factors produce considerable noise and a loss in driving comfort.
The main cause of these rotational vibrations is variation in torque. This
variation results from the discrete piston combustion cycle of the engine as
a function of the ignition frequency.
The vehicle drive train is a vibrating system. Figure 1 shows a simple model
designed to simulate fundamental vibration behavior. The engine,
transmission and vehicle are represented as rotating inertias connected by
springs. The spring C3 represents the stiffness of the drive train, while
spring C2, located between engine and transmission, represents the spring
characteristic of the torsion damper.