The remedial practice of vibration troubles repeatedly occurred in recent years on two 330 MW turbo-generator sets imported from Romania has been summarized

involving overall balance of shafts for high_-

medium_-

and low_-pressure rotors;the hot bending vibration resulting from fraction between movable and stable parts in speed up process

as well as slight rubbing vibration between shaft neck and bearing shoe in constant speed process;the distorsion display of vibration signal component below frequency 12 Hz coming from the contact type absolute shaft vibration measuring system

which even can lead to false trip of the unit;diagnosis and judgement of brocken blades occurred in operation

and for the stability of generator's bearing.