DYNAMIC BALANCING

The rotors of the turbochargers, like all rotating elements, often suffer from unbalance, which has to be identified and corrected before (re-) assembly, using the technique of dynamic balancing.
Unbalance is defined as the uneven distribution of mass around a rotor’s rotating centerline. This unbalance condition produces centrifugal force, which increases as the speed increases (by the square of it). The major causes listed as contributing to an unbalance condition of turbocharger rotors include material problems such as misshapen castings, eccentric machining, poor assembly and even inherent rotor design. In addition, when a rotor has been in service for some time, various other factors can contribute to unbalance, such as corrosion, wear, distortion and deposit build up. In the second case, routine inspection and cleaning of the rotor can mimimize the effect, but eventually it will have to be disassembled for balancing. As a result, these mass eccentricities cause rotor vibrations, unwanted noise and may also compromise the integrity of the bearings and even the foundation structure itself due to the excessive stresses and bearing thrusts which are generated.
 
BENEFITS OF DYNAMIC BALANCING
 Minimize vibration Unbalance is still the major source of machine vibration.
 Minimise noise Airborne noise is often attributable to mechanical vibration.
 Minimise structural stress The forces produced by unbalance have to be absorbed by the surrounding structure.
 Increase machine life The time between outages can be extended if the machine is running smoothly.
 Increase bearing life Bearings bear the brunt of the unbalance forces.
 Increase personnel safety Dangers associated with machine failure are minimised.
 Increase productivity Machines running smoothly have more “uptime” availability.
                
Turbomare is equipped with modern dynamic balancing machinery (model SCHENCK HM4/20BU-TL) which guarantees the smooth rotation of the rotor and, combined with its proper assembly (especially proper assembly clearances), secures the safe operation of the turbocharger unit as a whole.





The rotor after being fitted to the dynamic balancing machine, is rotated on high speed in order to determine any possible unbalances. Then, careful weight corrections take place, paying special attention not to have a detrimental effect on the integrity of the rotor. Finally, a dynamic balancing report, confirming the proper dynamic balancing of the rotor, is always provided to the client.