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Damaged
rotor blades can cause imbalance. When this imbalance exceeds
the permissible tolerance, vibrations are produced which
weardown the bearings and in the long term cause major damage
to the entire Turbocharger. Extensive repairs and downtime
are then unavoidable. |
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Dynamic balancing is performed using a Schenck CAB 690 H Balancing Machine with
H40 / 20 BUTL pedestals. |
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Prior
to balancing the rotor, it is necessary to check if the runout
of the shaft and the deflection of the compressor wheel is
still within the permitted tolerances. If these measurements
are satisfactory, or after remedial work, the rotor is examined
for imbalance on a microprocessor controlled test bench,
according to the ISO 1940 and VDI 2060 standards. |
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The
complete rotor is placed on the balancing machine and the
partition wall is independently supported. Even though imbalance
may not have been evident before overhaul and calibration,
it is possible that it could be introduced during dismantling
and repair procedures, and it is therefore paramount that
dynamic balancing is carried out before the rotor is returned
for service. |
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If
the imbalance is found to exceed the permissible value, it
is corrected by grinding / thermal means / weight addition
(depending on Turbocharger type) at the appropriate correction
planes on the rotor. Accurate balancing is of utmost importance
and not a single rotor leaves the TurboNed Mid East workshop
without having been tested and, if necessary, corrected. |
