- Dynamic Unbalance Theory
A rotating system of mass is in dynamic balance when the rotation does not produce any resultant centrifugal force or couple. The system rotates without requiring the application of any external force or couple, other than that required to support its weight. If a system is initially unbalanced, to avoid the stress upon the bearings caused by the centrifugal couple, counterbalancing weight must be added. This is commonly done, for example: in the case of an automobile tire, where the imbalance is due to imperfections of manufacture that make the tire composition inhomogeneous