A Parametric Study of Elastic Properties of Gasdynamic Foil Thrust Bearings Using a One-Dimensional Fluid Flow Model

A method for calculating thrust gasdynamic bearing characteristics that takes into account contact interaction between the shaft, gas film and elastic elements of the bearing is proposed in this work. The method is based on the solution of a one-dimensional nonlinear elastohydrodynamic contact problem that determines gas flow parameters and deformations of the support structural elements. Gas film flow in the bearing is calculated using nonlinear one-dimensional Reynolds equation for compressible fluid. Stress-strain state of the bearing’s elastic elements is studied using a finite-element model based on the theory of plane strain and taking into account contact interaction between the top foil, bump foil and bearing race. An evaluation of the influence of the main structural parameters that determine geometry of the bearing on the bearing’s load capacity is performed for a rigid gasdynamic bearing. The values of elastic bearing structural parameters (elastic foil dimensions) are obtained based on these calculations. Pressure distribution and gap values are calculated by a coupled solution of the bearing gap gas flow problem and the bearing elastic foil deformations problem using step-by-step approximations. At each sub-step, Reynolds equation for gas film is solved using the self-correction step method. Thrust bearing load capacity is determined depending on the foil initial geometry and installation parameters. The influence of the bearing’s elastic elements deformations on the load capacity is investigated. The stress-strain state of the bearing’s elements is evaluated.

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