Oil Film Temperature Distribution Research Articles

An analysis of the influence of oil supply conditions on the thermohydrodynamic performance of a single-groove journal bearing

In this work a thermohydrodynamic analysis has been developed in order to investigate the influence of oil supply conditions on the performance of a journal bearing. The supply conditions considered were oil supply temperature, supply pressure, groove length and groove location. To carry out this study, the hydrodynamic pressure distribution inside the bearing has been determined using a mass-conserving cavitation model with realistic supply conditions. The energy equation and the heat conduction equation have been used for the determination of oil film and bush temperature distributions. The agreement observed between theoretical predictions and experimental published data is acceptable. Quantitative information shows that the oil supply conditions affect bearing performance parameters in different ways. Oil flowrate was markedly affected by all supply parameters studied. Power loss, maximum bush temperature and minimum film thickness were mainly dependent on oil supply temperature. The effect of supply pressure on minimum film thickness was dependent on groove location. An axial groove located at 90° to the load line gave rise to more favourable bearing performance characteristics.

Effects of Film Temperature on Piston-Ring Lubrication for Refrigeration Compressors Considering Surface Roughness

This paper describes a theoretical model for piston-ring lubrication considering the combined effects of surface roughness and oil film temperature variation for refrigeration compressors. In the model, the piston-ring is treated as a one-dimensional dynamically loaded bearing with combined sliding and squeezing motion. The one-dimensional modified Reynolds equation, based on the average flow model by Patir and Cheng, is used to determine the pressure distribution, and the one-dimensional energy equation, considering the heat generated due to contact of asperities, is applied to calculate the oil film temperature distribution. In the analysis of the modified Reynolds equation, the flooded condition and Reynolds condition are employed at the leading edge and trailing edge of piston-ring, respectively. On the other hand, in the analysis of the modified energy equation, a constant temperature equivalent to the cylinder wall temperature is assumed at the leading edge. From numerical results of the minimum film thickness, pressure and temperature distributions and friction force, the combined effects of surface roughness and oil film temperature variation on these lubrication characteristics are clarified.

Thermo-EHD Analysis of Lubrication of Helical Gears

The full thermal elastohydrodynamic analysis of lubrication of helical gears is presented. A numerical solution of the coupled Reynolds, elasticity, energy, and Laplace’s equations for the oil film shape, pressure and temperature distributions in the oil film, and temperature distribution in gear teeth is obtained. The effects of gear parameters and operating conditions on EHD performance characteristics is discussed. Based on the obtained results, by regression analysis, equations are derived to calculate the EHD load carrying capacity, maximum oil temperature, and power loss.

Thermo-elastohydrodynamic lubrication of an involute gear

This paper analyses the thermo-elastohydrodynamic lubrication on an involute spur gear tooth surface and the influence of the inlet temperature of the lubricant. The oil film temperature distribution shows a minimum near the point where the pressure distribution is a maximum and the energy loss a minimum. Then the temperature increases slightly in the outlet region. Calculated results show a decrease of a few percent in the maximum pressure distribution compared with an oil film on a rigid surface. Based on oil film thickness and gear tooth deflection, the load sharing coefficient and the relative transmitting errors are calculated. The behaviour of the oil film due to the variation of the normal tooth load at the transition point of the meshing is investigated also

A Three-Dimensional oil film Temperature Distribution in Tilting Thrust Bearings

The oil film temperature and pressure distributions of the finite width Michell tilting thrust pad are determined from a numerical scheme based on the finite element method. These computed results correlate very well with those obtained from the experiment.

Oil-Film Temperature Distribution in an Infinitely wide Slider Bearing: An Application of the Finite-Element Method

From the Glansdorff–Prigogine local potential in non-equilibrium thermodynamics (1)† (2), a variational principle for a thin film incompressible flow with viscous dissipation is formulated as the basis of a finite-element method, which is applied to solve the energy equation. Temperature distributions in tapered land and parallel oil films for infinitely wide bearings are obtained by digital computer. The application of the finite-element method in a three-dimensional oil film with side leakage is also discussed.