Theoretical and Numerical Analysis on the Load Capacity of Hydrodynamic Thrust Bearings with Fourier Series Decomposition

Abstract

As an indispensable part of modern supporting technology, advanced hydrodynamic bearing still plays an irreplaceable role in turbomachinery. The high-speed turbomachinery in the 21st century still needs stable, low-friction bearings to support their rotors to run both smoothly and efficiently. Although various types of thrust bearings have been investigated in the recent year, they suffer from load capacity and instability problems. Nonetheless, the hydrodynamic bearing current design methodology still dependents on empirical design, lacking corresponding theoretical guidance. There needs to establish a universal rule about topology structure for a variety of non-circular bearings. The purpose of this paper is to focus on the static characteristics of hydrodynamic thrust bearings with topology design theory of Fourier series expansion of film thickness. Firstly, a universal mathematical expression for thrust bearings has been put forward based on the Fourier series theory. Secondly, the influence of periodic harmonics of film thickness on the static performance of different types of thrust bearings has been studied for the incompressible lubricant. Finally, the relationship between the k-th order harmonic component of the film thickness H 0,k and the static pressure component P 0,k of thrust bearing was established for various geometry parameters including the stepped, tapered and tapered-flat type. This method can be used to rapidly estimate the bearing capacity of the component, designed more excellent lubricating film carrier curve to significantly improve its carrying capacity. This new investigation method can be used to improve the performance of the new type of hydrodynamic thrust bearings.