Shafts of high-performing rotating equipment experience a certain mass unbalance distribution resulting from manufacturing tolerances, component assembly and material non-homogeneities. The residual unbalance generates unbalance forces on the rotor as it spins, resulting in vibrations and the transfer of dynamic loads to the bearings and supporting structure.
To limit the negative effects of rotor vibration, ISO and API standards set balancing criteria and acceptance levels for residual rotor unbalance. Whether magnetic or fluid film bearings are used in the machine, a prerequisite for spinning a rotor to its rated speed is that the rotor has been balanced to meet an acceptable residual unbalance level.
Download the "Efficient Balancing of Active Magnetic Bearing-Supported Rotors" white paper to learn more about: