Geometrical analysis of elliptical journal bearings and its effects on friction and load capacity

Abstract

Elliptical bearings are one type of non-circular journal bearings which has two main advantages over the conventional circular bearings: lower temperature rise and lower vibrations. In this study, the energy equation and Reynolds equation are simultaneously solved under adiabatic boundary conditions. The predicted pressure and temperature are compared to the results of published literature for verification purposes. A parametric study is then conducted on the effect of geometrical parameters of the elliptical journal bearing on the load capacity, friction force, pressure, and oil temperature. Effect of geometric parameters of the bearing on the performance is studied. The results show that non-circularity parameter is the most influential parameter in the bearing, and an increase in the non-circularity results in the decrease in maximum pressure and temperature as well as the friction force. Increasing the eccentricity ratio, on the other hand, will cause an increase in the pressure, temperature, and the friction force. Changes in the angle between the major axis of the bearing and load direction decrease the load-carrying capacity and the non-dimensional pressure and results in an increase in the friction coefficient.

Transient analysis for offset-elliptical journal bearings under misalignment and dynamic loading

“…Among the non-circular journal bearings, offset-halves, [12][13][14] elliptical, [15][16][17][18] tilting-pad, 19 and multilobe 20 configurations are the most common. 21 Several experimental and theoretical studies have been conducted on the performance of non-circular journal bearings by adopting various numerical methods and mathematical models.…”

“…15,16 In their analysis, the load-carrying capacity of elliptical journal bearings was lower while power loss was higher than those of offset-halves journal bearings. The effect of non-circularity on the performance of elliptical journal bearings, such as the friction force, film pressure, film thickness, and load-carrying capacity is studied by Ebrahimi et al 17 The results show that the non-circularity is the most influential parameter in this type of bearings, and an increase in the non-circularity can lead to a decrease in the friction force and the maximum film pressure. By separation of variables, Zhang et al 18 presented a very time-efficient approximate solution of the Reynolds equation for elliptical journal bearings.…”

Effect of Ellipticity on Cavitation Mechanism and Thermal Effect of Elliptical Journal Bearings

“…Chauhan et al [13] presented thermohydrodynamic study of elliptical journal bearings. Ebrahimi et al [14] studied the geometrical parameters effect of elliptical journal bearing on oil film pressure, loading capacity, friction force, and oil film temperature. Solghar et al [15] studied the effect of geometrical parameters on hydrodynamic lubrication of elliptical journal bearing.…”

Shear-Driven Flow in an Elliptical Enclosure Generated by an Inner Rotating Circular Cylinder

“…However, when the inner cylinder is eccentrically placed, non-axisymmetric flow distributions with multiple vortices are observed. Flow in an elliptical enclosure with rotating inner cylinder has relevance to elliptical bearings, and several studies have computed the drag and lift in such flows [46][47][48][49][50][51]. The intent of this study is to characterize the two-dimensional vortical flow patterns that develop in a stationary elliptical enclosure with a rotating inner cylinder placed concentrically or eccentrically.…”