Numerical Model of Mechanical Interaction of Rough Surfaces of Journal Bearings of Piston Engine

Abstract

The reliability of many machines and mechanisms is mainly determined by the reliability of friction pairs (in particular, journal bearings). So the journal bearings in the piston engine are mostly operated in the hydrodynamic lubrication regime and, at high loading levels, in the transient and mixed lubrication regimes. The latter is important for the determination of the service life of the tribosystem as a whole. For this aim, in this paper, we describe, develop, and apply an approach proposed earlier to build models of the interaction of rough surfaces for one of the tasks of simulation of tribological systems of the piston engine. Previously suggested models can estimate the area of contact, the friction force, coefficient of friction, wear, etc. However, this approach ignores the surfaces change and, consequently, contact and friction characteristics over the time. We described the general approach to build a model of interaction between rough surfaces, leading to the analysis of the Markov process. This method we applied for friction process and for the fatigue failure mode in which the surface element is destroyed after repeated contacts, the order of many millions. Given the initial data and the method of calculating the trajectory of movable elements on the lubricating layer taking into account rheological characteristics of lubricants, we determined the tribological parameters defining the resource of crankshaft bearings and the “piston–cylinder liner” tribosystem of the high forced piston engine.