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http://dx.doi.org/10.9725/kstle.2014.30.1.1

Analysis of Three-Pad Gas Foil Journal Bearing for Increasing Mechanical Preloads  

Lee, Jong Sung (Graduate School, Dept. of Mechanics and Design, Kookmin University)
Kim, Tae Ho (School of Mechanical Systems Engineering, Kookmin University)
Publication Information
Tribology and Lubricants / v.30, no.1, 2014 , pp. 1-8 More about this Journal
Abstract
In this study, a three-pad gas foil journal bearing with a diameter of 40 mm and an axial length of 35 mm was modeled to predict the static and dynamic performances with regard to an increasing mechanical preload. The Reynolds equation for an isothermal and isoviscous ideal gas was coupled with a simple elastic foundation foil model to calculate the hydrodynamic pressure solution iteratively. In the prediction results, the journal eccentricity, journal attitude angle, and minimum film thickness decreased, but the friction torque increased with the preload. A quick comparison implied a lower load capacity but higher stability for a three-pad gas foil bearing compared to a one-pad gas foil journal bearing. The direct stiffness coefficients increased with the preload, but the cross-coupled stiffness coefficients decreased. The direct damping coefficient increased in the horizontal direction but decreased in the vertical direction as the preload increased. These model predictions will be useful as a benchmark against experimental test data.
Keywords
gas foil bearing; oil-free; preload; load capacity; stiffness; damping; high-speed stability;
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