ANALYSIS OF GROOVED HYDRODYNAMIC JOURNAL BEARINGS

Abstract

Vbith the increased use of grooved journal bearings in rotating machineries, the necessity for design data and their performance characteristics, is also increasing. The knowledge of the performance characteristics in various operating flow regimes before the finalization of design permits more freedom in choice of bearing parameters to It obtain the optimum design. This thesis is an attempt to obtain various perfor-mance characteristics in different flow regimes (laminar, transient, turbulent) of grooved journal bearings as well as plain journal bearings. In case of plain journal bearings L/D ratio and eccentricity ratio, both are varied. In case of grooved journal bearings two different groove patterns (helical and herringbone) are considered for various other bearing para-meters, which are same for the two cases. The stability margin for all the bearing configurations - is studied and they were shown either in terms of threshold speed and/or critical mass of the journal bearing system. The roots of the characteristic polynomial, which represents the journal motion, under lateral displacement conditions were studied. The performance characteristics, static and dynamic, were presented.