Understanding rotor balance for electric motors

A balanced rotor is essential for smooth operation of rotating equipment. There are many factors that can cause unbalance in rotating machineries. This paper discusses some common causes of unbalance, different balancing methods and how they apply to rigid and flexible rotors, the difference and the relationship between balancing grades, vibration as a result of unbalance, and how to diagnose rotor unbalance from the rotor vibration response.