The Analysis of the Characteristics of Infinitely Short Journal Bearings Modified by Equivalent Viscosity
The characteristics of unlimited short journal bearing has been analyzed by using the equivalent viscosity correction model under thin film lubrication conditions. The interaction between the lubricant and the surface within a very small gap has been seriously considered. The changes of regular pattern of lubricant properties are comprehensive analyzed and researched. Unlimited short journal bearing is regarded as the research object. After researching, the varying regularity of its characteristics has been received. At the same time, the relationship between parameters and bearing performance has been established. The basis are provided for theoretical research and practical engineering calculations.
The Model of Equivalent Viscosity and Test in Thin Film Lubrication
Equivalent viscosity model is proved by comparing calculation results of viscosity correct formation advanced to ultra thin film lubrication with the test data in this paper. The results of calculation agree with the test data. Such a model provides an important tool for engineering design and scientific calculation.
Dynamically Loaded Finite Length Journal Bearings: Analytical Method of Solution
A closed-form pressure distribution, using a combination of short- and long-bearing approximations, is proposed for dynamically loaded journal bearings. The angles for start and finish of positive pressure curve are determined employing simple analytical equations. The mobility method, based on the suggested pressure distribution is easy to use, predicts results of acceptable accuracy and the execution time is comparable to that required for the short bearing approximation. This paper also provides a conceptually simple analytical method for evaluating angular location of the instantaneous maximum pressure using proposed closed form pressure distribution. Simple algebraic equations are derived to obtain the instantaneous maximum pressure in dynamically loaded bearings directly, without involving any iteration. To illustrate the validity of present study, a connecting rod big end bearing and two crankshaft main bearings are analyzed. The mobility components, minimum film thickness and maximum pressure are plotted over a load cycle and compared with established analytical and curve fit methods. The results are also compared with those obtained using finite element method.