The correction of the workpiece imbalance requirement exceeds the accuracy of the dynamic balancing machine itself to the minimum unbalanced amount, that is, the balance accuracy of the dynamic balancing machine cannot meet the requirements of the workpiece balance accuracy.

The roundness of the journal at the support itself is not so good and the surface roughness is too low.

The rigidity of the workpiece itself is not good, causing deformation due to deformation at high speed, or the workpiece itself has unchanging parts moving or loosening in a rotating state.

At the beginning and end of the balance, the rotor will have obvious vibration in practical application, which is not caused by the imbalance of the rotor itself, but because of the high degree of harmonics caused by the difference in the stiffness of the rotor supporting journal or the rotor structure. Wave, the vibration caused by electromagnetic excitation, caused by the influence of the vortex of the blade rotor during the rotation process, the resonance of the system, etc.

Because of the frequent activation of the remaining equipment connected to the grid, the power supply vibration and noise or the beat frequency disturbance caused by the diameter of the support roller and the rotor journal are similar. The difference between the diameter of the roller and the size of the journal of the workpiece should exceed 20%.

Because of the imbalance of the process mandrel itself or the coaxiality error between the mandrel mounting and the support, and the gap error between the mandrel and the rotor, the balanced rotor is repeatedly mounted because of the verification of the non- journal rotor. At the time or application, it causes a large imbalance.

The essential working form of the workpiece rotor and the state of the balance check are not uniform.

When correcting the imbalance of the rotor of the workpiece, the position of the centroid of the weighting or de-weighting is corrected with the correction position of the balancer.