Few things irritate the owner of a new car more than experiencing vibrations, rattling or humming in the car’s interior on driving off. Internet forums on the topic are full of such complaints: “At a kilometer reading of 6,400, high-frequency vibrations suddenly started in the steering wheel and could also be felt on the foot support, through the accelerator and in the high-comfort seat, especially in the headrest,” claims the owner of a German premium-range model in one such forum, for example. “At first, it only feels like a very subtle vibration, but after 20 minutes, it’s quite irritating.”
However, vibrations are not just a source of irritation that, at least subjectively, leave an impression of poor quality – they can even cause material fatigue. They are generated by the drive unit and chassis, as a result of the tires making contact with the road. Typically, as described above, they are transmitted to other parts that can vibrate, such as the gearstick, dashboard and steering wheel. If the vibrating parts are big enough, they emit sound waves. This additionally creates unwelcome buzzing and humming noises.
Two Options Available
To counteract vibrations and related noises without having to modify the basic design of the vehicle, car manufacturers essentially have two options: they can either prevent the transmission of vibrations from a strongly vibrating area to other areas, or steady the vibrating components. For the first remedy, they need vibration-decoupling damping elements; for the second, vibration dampers (also known as mass dampers). Both methods increase ride comfort, enhance quality and help to avoid vibration-related damage.
Over recent years, problems relating to undesirable vibrations have intensified in the automotive sector. This is due to engine downsizing and lightweight construction. Powerful engines with reduced cylinder capacity vibrate more strongly than traditional four- or six-cylinder engines with larger capacities. Lighter components and assemblies lead to considerable weight savings, but can vibrate much more easily than heavier parts. As a result, the use of vibration dampers, in particular, is gaining in popularity.