The technique of an interconnection problem of the hydrodynamic lubrication theory and the nonlinear dynamics for mechanical systems “an elastic crankshaft on film lubrication bearings”

The technique features of the connected task of the hydrodynamic theory and nonlinear dynamics for mechanical system “a crankshaft on film lubrication bearings” are considered. The research objective consists in development of a complex technique of an operability assessment of crankshaft main bearings for the accounting of the boundary effects caused by axes skewness of mobile and immobile elements of journal bearings. The system of the main bearings interconnected by means of a crankshaft and a crankcase is considered. The technique is based on the simultaneous numerical solution of the movement equations of crankshaft necks on lubricant layers, the thermal balance and the Reynolds differential equation for non-Newtonian liquid equations for definition of hydromechanical characteristics of bearings, and also the five moments equations for definition of the loadings acting on all main bearings taking into account elastic properties of a crankcase, multisupporing crankshaft, and also nonlinear properties of lubricant layers, displacements of the bearing and necks centers caused by technological, thermal, etc. factors. When modeling a lubricant flow in a gap of each bearing the model of the structured lubricant layer considering high-viscosity boundary layers is used. For determination of elastic properties of a crankcase and a crankshaft of the engine the three-dimensional finite element models of designs are used. The technique allows to estimate simultaneous influence of some efficiency, technology and operational factors on operability of main bearings system. The calculation of the main bearing hydromechanical characteristics for the ChN 13/15 diesel is executed. Influence of gas forces on elastic displacements of crankshaft supports is shown.