SERVICE LIFE OF ROTORS UNDER MECHANICAL AND THERMAL STRESS

Dynamic balancing of a rigid rotor should, at least in its final stage, be carried out at its operational speed, where its rotational frequency is often close to its resonance frequency. It is an adverse phenomenon, since even a minor constraint may induce high amplitude vibrations, limited by the attenuation. The service life of a rotor, mainly its bearings is thus significantly reduced. Balancing the rotor using the influence coefficient method at a frequency close to its resonance frequency is difficult due to the rapid changes in phase angle of a vector of the rotor response to constraints from the attached test weights. An optimal solution is to operate outside the rotor's resonance zone. A quick and efficient method is to change its rotational speed, however, it may have some side effects.