Static performance characteristics of hybrid journal bearings with plugged entry holes

Abstract

PurposeThis paper aims to investigate the effect of plugging of holes on the static performance characteristics of a constant flow valve compensated hole‐entry hybrid journal bearing system operating with Newtonian and non‐Newtonian lubricants. The analysis considers the generalized Reynolds equation governing the flow of lubricant having variable viscosity in the clearance space and equation of flow of lubricant through constant flow valve restrictor. The non‐Newtonian lubricant is assumed to follow the power law. The performance characteristics are computed for the two values of power law index (n=1.0 and 0.566). The computed results indicate that the blockage of holes during operation will not be the likely causes for the imminent failure of a well‐designed non‐recessed hole‐entry hybrid journal bearing.Design/methodology/approachFinite element method has been used to solve generalized Reynolds equation governing the flow of lubricant having variable viscosity in the clearance space and equation of flow of lubricant through constant flow valve restrictor.FindingsThe computed results indicate that the blockage of holes during operation will not be the likely causes for the imminent failure of a well‐designed non‐recessed hole‐entry hybrid journal bearing. The bearing configuration with plugged holes provides sufficient fluid film thickness and low power requirement as less lubricant is required to be pumped in the bearing.Originality/valueTo the best of the author's knowledge, no study which considers the influence of plugging of holes on the static performance characteristics of a constant flow valve compensated hole‐entry hybrid journal bearing system operating with Newtonian and non‐Newtonian lubricant is yet available in the literature.

Influence of lubricants on the performance of journal bearings – a review

“…The results showed the decrease in static performance characteristics such as pressure intensity, load-carrying capability, friction force and temperature for pseudo-plastic lubricant whereas these characteristics increased for the dilatant lubricant. Garg and Kumar [9] investigated the influence of blocking of holes on the static performance characteristics of hybrid journal bearing operated with powerlaw lubricants using flow behaviour index (n = 1 and 0.566). It was found that the journal bearing with blocked holes provided more lubricant film thickness and load-carrying capability of the journal bearing.…”

“…The blocking of holes was not recommended due to high wear rate during starting and stopping of operation. The fluid film thickness (h) for journal bearings was determined by using Equation (2) [5,9,10];…”

“…Garg and Kumar [9] investigated the influence of blocking of holes on the static performance characteristics of hybrid journal bearing operated with power-law lubricants using flow behaviour index ( n = 1 and 0.566). It was found that the journal bearing with blocked holes provided more lubricant film thickness and load-carrying capability of the journal bearing.…”

“…The blocking of holes was not recommended due to high wear rate during starting and stopping of operation. The fluid film thickness ( h ) for journal bearings was determined by using Equation (2) [5,9,10]; Prasad et al [11] conducted the study of circular journal bearing operated with power-law lubricants under steady-state conditions including squeezing effect. The results showed the increase in pressure intensity and temperature with the increase of flow behaviour index ( ).…”