Predicting dynamic imbalance in rotors

This paper derives probability models which predict dynamic imbalance of rotors. The models are based on physical laws and specific knowledge of how the rotors are made. Several sources of imbalance are considered. It is shown that wider tolerances in the orientation of a rotor lead to more likely worst-case imbalances. It is shown that the expected dynamic imbalance of a cylinder is proportional to the square root of the feed rate of the cutting tool over the speed. Thus, such models show how various parameters in the manufacturing process affect the distribution of imbalance. In this way, manufacturing decisions on how to effectively reduce imbalance can be made prior to observing any data.