Kobzar I. Increasing the Reliability and Prolonging the Service Life of Thrust Bearings of Hydrogenerators

The dissertation work is purposed to the topical issue of increasing the reliability of the hydrogenerator thrust bearings for rotors weighing more than 300 tons by means of mathematical modeling of the thermal stress-strain state at rated and emergency modes of operation. The assessment of the possibility of operation of the shaft conduit system with damage to the mirror surface was carried out using the finite element method in a three-dimensional resolution with clearly modeled defects based on the second theory of strength. The goal of the dissertation is the development of effective methods for assessing the stress-strain state of structural elements of high-power hydrogenerators and hydro-generators-motors in rated and emergency modes based on modern methods of three-dimensional computer modeling, which will allow for a refined analysis of the strength of structural elements and contribute to increasing the reliability of the operation of electric high power machines. The important scientific and technical problem is solved in the dissertation on the basis of a unified methodology, which consists in the development of effective methods of researching the stress-strain state of structural elements and assemblies of hydrogenerators and hydrogenerators-motors under the influence of force and temperature loads. The obtained results are the theoretical and practical basis for engineering calculations of the strength of structural elements of high-power generators. Scientific novelty of the work: 1. For the first time, temperatures and all loads affecting the period of operation of hydrogenerators and hydrogenerators-motors are taken into account in the calculations. 2. The method of calculating the stress-strain state of the support elements (thrust bearings) of high-power hydrogenerators was developed, and the study of the strength of double-row thrust bearings of rigid and hydraulic types under operational loads was carried out. Practical significance of the obtained results. The methodology for calculating the stress-strain state in structural elements of hydrogenerators and high-power hydrogenerators-motors under the influence of rated and emergency loads has been developed, which is aimed at solving real, practically important problems. The methodology is based on calculations of three-dimensional models of structural elements, which significantly increases the accuracy of assessing their strength. The obtained scientific results can be used by research and design organizations, design bureaus, organizations of the energy industry, aerospace universities and other organizations that specialize in the field of energy equipment research.