Vibrations that affect the chassis when driving an automobile are not just annoying. In extreme cases, restless steering and body vibrations can present a serious safety risk. Help can be had in the form of dozens of chassis mounts on the transverse control arms, subframe, suspension struts, and anti-roll bar. These small but crucial components influence handling and reduce unwanted vibrations and noise.
On the trailing arm axle used in compact and lower-medium-sized vehicles, two elastomer mounts basically determine comfort levels. They carry the axle lengthways, and they have to transmit braking forces and fulfill stringent acoustic requirements. Tailored carefully, they can reduce bothersome vibrations on cross-joints and uneven road surfaces. The mixture of rubber used in conventional chassis mounts is always a compromise. It has to be as soft as possible to insulate road noise, but it also has to damp as effectively as possible in order to reduce low-frequency axle vibrations.
The DualRubber mount resolves this compromise by employing two different rubber mixtures for both spatial directions. It insulates road noise excellently, and controls low-frequency axle vibrations more effectively. Initial measurements show a noise reduction of up to 7 dB and a considerable reduction in vibration. The reverberation period after crossing a transverse joint is cut by 40%. The axle is also much quieter even under permanent stimulation, which makes driving more pleasant.
TrelleborgVibracoustic employed a special production process to manufacture this mount, in which the elastomers are injected simultaneously using two different rubber compounds. This approach places great demands on the processing technology and the materials developed for the purpose. The high-damping elastomer has to fulfill high service life requirements under every peripheral condition such as heat, cold, salt, and dirt.
With its new DualRubber mount, TrelleborgVibracoustic is offering an attractively priced alternative to conventional chassis bushings and more expensive hydraulic mounts. It is also highly suitable for electric cars and plug-in hybrids, in which there is no combustion engine to drown out other noises, meaning higher acoustic demands on the chassis.