An experimental study of the influence of loading direction on the thermohydrodynamic behaviour of twin axial groove journal bearing

Abstract

An experimental assessment of the influence of angle between the groove axis and the load line on the thermohydrodynamic behaviour of twin groove hydrodynamic journal bearings has been undertaken. At nine different loading direction angles, the oil-bush interface temperature profiles, oil outlet temperature, maximum bush temperature, total flow rate, and oil flow rate through each groove were measured for variable applied load and oil supply pressure while the feeding temperature was kept constant (40 C). To the authors' knowledge, this is the first study of the influence of loading direction on the performance of journal bearing with two axial grooves in which the flow rate were measured in each groove for different working conditions under laminar regime. It was found that the variation of loading direction has a strong effect on the bearing performance. Under some running conditions, negative lubricant flow rate (hot oil reflux) at one groove was detected. This seldom-reported phenomenon was found to affect the bearing performance dramatically. Increasing supply pressure yielded a temperature decrease, especially for high loads, and sometimes prevented the occurrence of hot oil reflux.

Numerical study of twin groove journal bearings performance under steady-state condition

“…To verify the accuracy of the numerical model, the results for a full journal bearing with two axial grooves were compared against the experimental measurements and the numerical simulations of Brito et al . and Arab Solghar et al . Sample results are shown in Figure , which indicate that the THD analysis predictions for temperature and pressure match the measurements fairly well.…”

“…They concluded that heavily loaded twin groove journal bearings might, under certain circumstances, be deleterious for bearing performance. Not only the power loss is normally higher than that of single groove bearings but also the cooling effect of feeding oil might be poorer, under certain combinations of high eccentricity and low feeding pressure, namely due to negative flow rate inception in one of the grooves, as already confirmed in for a bearing with the plane of grooves located at ±90° to the load line and in for a bearing with the grooves located at various angles with the load line.…”

“…Twin groove journal bearings are widely used to support rotating shafts with high loads and speeds, especially when the journal rotates in both rotations. During the past decades, some experimental and theoretical studies have been carried out to investigate the performance of twin groove journal bearings and to assess the influence of lubricant feeding conditions …”

“…Arab Solghar et al . assessed experimentally the thermohydrodynamic (THD) characteristics of twin groove journal bearings under different loading angles.…”

Thermohydrodynamic modelling of journal bearings under varying load angle and negative groove flow rate

“…9 The increase of load angle was found to decrease the flow rate at the upstream groove and to increase the flow rate at the downstream groove. Negative flow rate was detected in either groove (although, naturally, never simultaneously) for wide ranges of load.…”