Before the balancing is started it must be checked whether there is an unbalance and where it is. At rotating machines there can also be vibrations not caused by an unbalance.
E.g. caused by:
- Defective bearings
- Bent shafts
- mechanical looseness
With this simplified vibration analysis the vibrations can be assigned to the corresponding frequencies resp. rpms.
In order to determine such vibrations there is the FFT-analysis function for all BMT230M units as an option.
By that the error diagnosis and correction of the real reason is much easier.
A belt driven fan shows the following values: main shaft is rotating 1800min-1, belt approx. 600min-1 and the motor 3000min-1.
If you have the highest vibration speed at 3000 min-1 it would make no sense to balance the main shaft as the reason for the vibrations is undoubtedly the motor. Here the maximum vibration is measured at approx. 609 U/min. This points to a strong vibration caused by the drive-belt.