There are always vibration generated in field dynamic balance. If the balance process did not yield the disturbance, the consequence of dynamic balance would not be a valuable reference for engineer in decision making. While, we analyses the results for determining factors, and figure out the following consultation for field balancing as well ground based dynamic balancing machines utilizing optimization.
We keep testing machines using age in laboratory for collecting data, and explore that vibration of rotating part and machine bearing association cooperation lead to a reliability decrease rather than all of other factors in resulting unbalancing vibration, especially resonance in an exact frequency. However, after the balancing machine engaged, dynamic balance attempting may not eliminated the vibration and engineers may concern that there are other factor in controlling instead of unbalancing force. Certainly, our engineers blame the suspicion to the engagement between rotor and machines supporting and bearing rather than the uneven mass distribution of rotor.
First, there is a defection in the rotor itself that causes a change in its balance, including the shaft stiffness factor and the contact between the stationary part and the rotating part of the machine. The axis may have curved defects, including bending due to angular or parallel displacement of the engaging shaft or defects due to rigid joint coupling. Bearing defects include uneven friction wear on the bearing surface, increased bearing clearance and uneven lubrication. The last two defects may cause self-sustaining rotor oscillation. In gears and belt drives, the main drawback of vibrating the rotational frequency is due to installation errors or gears or pulleys wobbling and beating due to uneven wear of these components. Similar results may be found in the case of cracks on the gear teeth of the rotor balance.