Dynamic Characteristics of a 5-kN Thrust Gas Turbine Front Bearing Composed of a Vibration Absorber Element and Deep Groove Ball Bearing

Abstract

Rolling bearings enable the development of high rotational speeds with a good load-bearing capacity and low frictional resistance. Therefore, rolling bearings can be used on a wide variety of rotating machines. This study investigated the dynamic stiffness and damping coefficients of the front bearing of a 5-kN thrust gas turbine. A Barden® 206(T) deep-groove ball bearing was the main part of the front bearing. Computational models were developed using MATLAB® for both the structural dynamics problem governed by Hertzian contact theory and the lubricated problem governed by elastohydrodynamic theory. In addition, the front bearing was composed of a vibration absorber element, which was also considered. Finite element analysis was performed on both the ball bearing and the vibration-absorbing element to assist in its final characterization. As the main results, the stiffness and damping dynamic coefficients of the front bearing were estimated and can be used to predict the rotordynamic behavior of the aeronautical gas turbine rotating set to avoid possible vibration problems during operation.