Study of supply cut‐off and bearing geometric parameters on design of hybrid journal bearing

Abstract

PurposeHybrid bearings have found increasing applications in various machines owing to their large number of favorable characteristics like high load carrying capacity, increased minimum fluid film thickness, long life and increased damping making them attractive for various applications such as turbo machinery, machine tool spindles, precision grinder spindles, etc. A careful design of such bearing for optimum performance has always been among the key issues of the researchers. The present work has been carried out to study the effect of bearing geometric parameters on performance of hybrid journal bearing and supply cut‐off behavior has also been studied for the improved performance.Design/methodology/approachThe generalized Reynold's equation governing the fluid flow in the clearance space between bearing and journal has been solved using finite element method to determine the pressure distribution, subsequently performance of hole‐entry hybrid journal bearing are computed. The journal centre equilibrium position for the given load is computed and the formulation is explained. The geometric parameters include aspect ratio, land width ratio, number of rows and number of holes per row. Further, performance of the bearing is computed with increasing the load, which induces negative pressure or the backpressure at the supply holes subsequently those are plugged to support the higher load.FindingsThe obtained results are presented in graphical form and logical conclusions are drawn and the modified configurations with reduced number of holes are suggested for higher load. It is observed that the bearing configuration with aspect ratio = 1.0 and land width ratio = 0.2 is best for high load support for low power requirement as less lubricant is required to be pumped in the bearing yet it provides sufficient fluid film thickness and lower values of maximum pressure. The load carrying capacity of the bearing can be further increased by plugging the holes on which backpressure is obtained for same bearing configuration. A feedback control with hybrid bearing system will sustain the sudden increase of load by shutting off the supply of the lubricant through supply hole where negative pressure is encountered.Originality/valueThe paper addresses the performance of non recessed hybrid journal bearings with wide range of geometric parameter. The results are quite useful for the bearing designer. The supply cut‐off is another aspect of originality of the paper as it provides the better load support.

Static performance characteristics of hybrid journal bearings with plugged entry holes

“…Duvedi et al (2006) carried out the theoretical analysis of capillary compensated non‐recessed hole‐entry hybrid journal bearing lubricated with non‐Newtonian lubricant. Jadon and Singh (2007) studied the effect of the cut‐off the supply of the lubricant to the holes of the hybrid journal bearing and found that the performance of the bearing is affected. Nagaraju et al (2007) investigated the combined influence of surface roughness, non‐Newtonian behavior of lubricant and thermal effects on the performance of a hole‐entry hybrid journal bearing system.…”

The Stability’s Influencing Factors and Active Control of Hydrostatic Journal Bearing

“…If designed reasonably, this kind of bearing is better than traditional bearing in terms of wear and thermal characteristics, and can reduce risk due to bearing's catastrophic failure in safety. Jadon, et al [11] study the impacts of parameters of bearing structure and oil-supply hole on bearing's performance, and present relevant optimized methods of structure parameter and oil-supply hole's arrangement.…”