Evaluation of water turbine hydrodynamic thrust bearing performance on the basis of thermoelastohydrodynamic calculations and operational data

Abstract

An analysis of thrust bearing performance was taken up in order to assess the possibility of bearing installation in a modernized Kaplan turbine. Apart from analysis of the records of machine operation, thermoelastohydrodynamic calculations were carried out. A bearing design incorporating a mechanism of compensation of thermal deformation was of interest, especially as the machine and its bearings were designed earlier than 1952, while the first analyses of such mechanisms known to the authors were published in the 1960s. Apart from direct analysis of the feasibility of the bearing in new operating conditions, the authors carried out a study of the influence of the two most important design parameters on the bearing performance. Thermoelastohydrodynamic calculations showed that the bearing was surprisingly well designed, especially as it was designed without the aid of contemporary calculation methods and techniques. The main conclusion of the analysis was that the bearing pads can be used without any modifications. In addition, it was recommended that the jacking mechanism be redesigned in order to improve load distribution among the pads and facilitate bearing aligning during assembly. The bearing housing was also redesigned in order to reduce the stresses in the welded joints.