Hydrodynamic Lubrication of Partially Textured Gas Parallel Slider Bearings with Orientation Ellipse Dimples

The hydrodynamic lubrication performance of partially textured gas parallel slider bearings with orientation ellipse dimples is investigated in this paper. By using the multigrid finite element method, the pressure distribution between a partially textured slider and a smooth slider is obtained. The geometric parameters of the ellipse dimples are optimized to maximize the average pressure under a given sliding speed. The numerical results show that geometric parameters such as orientation angle, depth, slender ratio, and area density have an important impact on hydrodynamic pressure. Besides, the effect of textured fraction on hydrodynamic pressure is investigated under a given sliding speed. It is observed that the optimum textured fraction for maximizing the average pressure is dependent on the sliding speed.

Recent Patents on Abnormal Hydrodynamic Thrust Slider Bearings: Part II-the Second Mode of the Bearings

Background: As a successive part, the paper introduces the second mode of abnormal hydrodynamic thrust slider bearings with divergent surface separations registered in the patents, where the boundary slippage is artificially designed both on the stationary surface in the inlet zone and on the whole moving surface. Objective : To introduce a second method for artificially designing the boundary slippage for the formation of abnormal hydrodynamic thrust slider bearings. Methods: The analytical results are presented for the introduced bearings. The performances of the bearings are demonstrated. Result: : In appropriate operating conditions, the introduced bearings can have considerable loadcarrying capacities with low friction coefficients on the scales 10-3 or 10-4. With the weakening of the boundary slippage on the moving surface, the load-carrying capacities of the bearings are all increased, while the friction coefficients of the bearings are all reduced. Conclusion: When the boundary slippage is present both on the stationary surface in the bearing inlet zone and on the whole moving surface, abnormal hydrodynamic thrust slider bearings can be designed with the surface separation in the bearing inlet zone lower than that in the bearing outlet zone. The performances of these bearings are quite satisfactory.

Effect of non-Newtonian magneto-elastohydrodynamic on performance characteristics of slider-bearings

Purpose This study aims to examine the magneto-elastohydrodynamic effect on finite-width slider-bearings lubrication using a non-Newtonian lubricant. Design/methodology/approach Based on the magneto-hydrodynamic (MHD) theory and Stokes micro-continuum mechanics, the modified two-dimensional Reynolds equation including bearing deformation was derived. Findings It is found that the bearing deformation diminishes the load-capacity and increases the friction coefficient in comparison with the rigid case. However, the non-Newtonian effect increases load-capacity but decreases the friction coefficient. Moreover, the use of a transverse magnetic field increases both the friction coefficient and load capacity. Originality/value This study combines for the first time MHD and elastic deformation effects on finite-width slider-bearings using a non-Newtonian lubricant.

APPLICABILITY ANALYSIS OF STRESS STATE CRITERIA FOR DESCRIPTION OF BABBIT LAYER FATIGUE DESTRUCTION IN SLIDER BEARINGS

The criteria of stressed state equivalence used for fatigue process simulation are shown. Different criteria offered by various investigators for slider bearings are described. A procedure is offered for the estimate of different criteria applicability on the basis of experimental investigation results. It is shown that for tin-based babbit layers it is possible to use the first basic stress as a criterion, but at that it is necessary to take into account a propping action of lubricant coming in a crack under pressure (radial stresses).

Magnetohydrodynamic effects on finite and infinite slider bearings

This paper presents a numerical investigation of lubricating slider bearings with conducting couple stress fluids using externally applied magnetics fields. The modified two-dimensional magnetohydrodynamic couple stress Reynolds-type equation is obtained. This governing equation is resolved numerically by using finite difference scheme, which involves the Gauss–Seidel method to compute the bearing characteristics. Numerical results using different considered values of the couple stress and Hartman number are presented. These results demonstrate that the transverse magnetic field and couple stress effects are significant.