Methods for preventing vibration or noise are as follows:
Removing the vibrating force
Stopping the resonance
Stopping the transmission
Preventing vibration and noise
Vibration or noise can be prevented by removing any part of the transmitting passage. The most effective way to prevent vibration and noise is to remove the vibrating force. However, it is difficult to remove it completely due to the vehicle structure. Therefore, we explain here the methods for preventing vibration and noise which are mainly used for vehicles, such as preventing resonance, stopping transmission, and insulating vibration and noise.
Isolating Automotive Vibrations
A mass damper is a weight attached to the vibrating portion, which shifts resonance point by reducing natural frequency. By this method, vibration and noise are shifted to the outside of the normal driving range, resulting in lower vibration and noise level.
If you place a mass damper carelessly, it may increase the weight applied to that particular portion and cause the risk of durability loss.
A dynamic damper is a weight and a spring attached to the vibrating portion, which devides one natural frequency into two smaller natural frequencies. By this method, resonance point is shifted resulting in lower vibration and noise level.
In general, the natural frequency of a dynamic damper should be the same as that of the resonating portion. In this case, the natural frequency of a dynamic damper will be set by the relationship between a spring constant and the weight of a sinker in the same definition of a mass damper.