Theoretical Study of the Dynamic Quality of an Aerostatic Thrust Bearing with a Microgroove and Simple Diaphragms

This paper presents the results of a study of the dynamic performance of an aerostatic thrust bearing with a microgroove and simple diaphragms. The objective of this study was to determine the influence of the lubrication gap thickness and the volume of the microgroove and pockets on the structural dynamics. Unlike most studies that typically use the second-order harmonic oscillator equation as the characteristic equation, the root criteria are determined with high accuracy when the characteristic equation is of an order no lower than the fourth order. The presented formulas allow one to find the optimal calculated dimensional gap, microgroove and pocket volume in terms of the best dynamic performance. For a well-damped thrust bearing, the required response speed and sufficient stability margin can only be achieved within a narrow range of 1–2 times the bearing gap volume. Calculations have shown that to ensure satisfactory thrust bearing dynamics, the calculated gap should not exceed 10–15 µm.