Intense vibrations of the rotating equipment create an undesirable level of noise, damage to the bearings and bearing housing, damage to the equipment foundations, the electric motor etc.
Apart from misaligned axles, the most common cause of an increase in vibrations is unbalance.
In the case of an increase in vibrations, spectral analysis of vibrations can helps us detect the cause of the occurrence (misalignment, unbalance etc.), and so with corrective balancing of the bearings in their housing, restore and bring the vibrations to an acceptable level.
Balancing in their own journal boxes (in situ), implies that all procedures (for measuring and correcting) happen on the machine on-site and without the need for expensive disassembling, transport of parts, the use of the so-called, dynamic balancing machines etc.
The unbalance of the rotational mass occurs when the centre of the mass is off the axis of rotation and this occurs as a result of:
- An uncorrected unbalance during production
- A deformation of the parts of the body and connections as a result of the aging of the equipment
- A change in the external environment, usually in temperature
- Wearing (out) of the materials of the machinery
Measuring the balance of the massive vertical rotor
The process of balancing implies discerning the position of the “heavy spot” and so correcting the mass distribution, by adding or removing weight, so that the centre of the masses is brought as close to the rotor’s rotating centreline as possible.
If the rotor which we are balancing has a diameter that is significantly larger in comparison to the width, it is enough to only balance in one direction. On the other hand, corrective weight is necessary in two directions – this is called dynamic balancing.
The laboratory at RWlab has the most modern equipment for two-plane balancing of the SKF manufacturer, Microlog series.
The equipment is regularly calibrated in the Technical Test Center of the Serbian Armed Forces.