Rotary Vibration Damper

Rotary vibrations occur very often, not only in the crank mechanism of the piston engine. In this case the piston transfers the linear movement to the crankshaft. What happens, however, if, as is the case with modern diesel direct fuel injection, this movement is not consistent? If enormous torque is abruptly released, the whole system can vibrate through the play in the crank mechanism and lead to, apart from possible noise development, mechanical damage. For this reason, early absorbing of rotary vibrations are very important.

Important with this kind of vibration cushioning, is a large, heavy damper-ring. In addition it should have a large diameter, and be mounted as far outside as possible. Differently than, for example, when the flywheel is connected by rubber dampers and/or springs to the rotating part to be damped. In the above figure the rear damping mass is on the rubber layer, this again, is connected to the front V-belt pulley by Vulcanisation. This permits the more sluggish masses to compensate for the not quite consistently rotating crankshaft. In the meantime, there are now the vibration dampers in the form of external ring-shaped hollow blocks which are filled with silicone oil. These are able to react even faster to compensate for irregular cranking movements.

In the automobile there are still many other places where rotary vibration blockers can be installed. These can be mounted, e.g., on (longer) axle drive shafts. The close proximity to the source of the vibration is important. For this reason, vibration dampers are integrated into the crankshaft over springs as a counterbalance, with less total weight, and apart from their actual job, they also take over the job of vibration blockers. 09/08