Performance of a noncircular 2‐lobe multirecess hydrostatic journal bearing with wear

Abstract

Purpose -Noncircular journal bearings are used in industry because of their simplicity, efficiency and low cost. During the life time of a machine, these are required to be operated over a number of years and are submitted to several stops and starts. As a result, the bush becomes progressively worn out and the bearing performance changes. The purpose of this paper is to study theoretically the influence of wear on the performance of a non-circular 2-lobe four-pocket multirecess hybrid journal bearing system. Design/methodology/approach -The Reynolds equation governing the flow of lubricant in the clearance space of a non-circular 2-lobe multirecess worn hybrid journal bearing system has been solved using FEM along with appropriate boundary conditions. The defects caused by wear are centered on the load line and range from 10 per cent to 50 per cent of the bearing radial clearance. Findings -The numerically simulated results based on a Newtonian lubricant and the steady state flow field system have been presented in terms of maximum fluid film pressure, minimum fluid film thickness, lubricant flow rate, direct fluid film stiffness and damping coefficients and stability threshold speed margin. The paper demonstrates that, for the bearing configurations studied, the bearing behavior is clearly affected by wear. The numerically simulated results indicate that for an offset factor of d ¼ 1.2, the value of h min reduces by 21.21 per cent atOriginality/value -The presented results have valuable data in case of 2-lobe four pocket hybrid journal bearing compensated with constant flow valve restrictor. The paper outcomes are sure to be of interest for researchers and useful for bearing designers.

Effect of wear on the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation

“…Thus, modified Reynolds equation in dimensionless form that governs the laminar fluid flow of an iso-viscous incompressible lubricant is expressed as follows 28 where the nondimensional parameters β=rsinγ/Rj: ptrue¯ = pps: h¯ = hc: t¯ = t[μRj 2/c2ps]: (α=ϕ) coordinate is the nondimensional parameter (angle in radians).…”

“…In 2012, Sharma et al. 28 reported that the value of minimum fluid film thickness reduces with wear in case of a noncircular two-lobe, four-pocket multirecess externally pressurized bearing. In recent years, Kushare and Sharma 29 analyzed non-recessed worn journal bearing operating with non-Newtonian lubricant.…”

“…After the experimental studies, need for developing geometrical model was successfully completed by Dufrane et al 16 to quantify scope and nature of worn region. Considering this model, several researchers 17,21,[25][26][27][28] have studied the effect of wear on the bearing performance. From these mentioned studies, it is obviously concluded that wear is the main reason behind the changed bearing performance.…”

Theoretical investigation of surface texture effects on the performance characteristics of hydrodynamic two-lobe journal bearing

“…Practically all the non-circular journal bearing geometries improve the shaft stability and under legitimate conditions this will likewise decrease power losses and increase oil and thus reducing the fluid-film temperature. The authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14] investigated the various performance parameters of smooth two-lobe hydrodynamic journal bearing system.…”

The Analysis of Film Thickness of Dynamic and Hydrostatic Thrust Bearing with Different Oil-supply Method

“…Constant pressure and quantitative oil supply mainly adopts capillary restrictor, slide valve throttling device for oil supply. When the load increases, the oil flow of the throttle decreases or remain, the change of the film thickness is larger, the stiffness of oil slick is poor [3][4]. The control film of PM controller was adjusted according to pressure.…”