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The article proposes a method for controlling the quality of plain bearings materials in internal combustion engines that affect the failure of such important and expensive parts as a crankshaft and a cylinder block. Quality control of materials, which have been used for plain bearings manufacture, during repair action of construction machinery and equipment, as well as reduction of cost and duration of technical control operations implementation are among the issues of the day for repair service organizations. In this paper a thermal method of plain bearings materials quality assessment in internal combustion engines is suggested. This method is remarkable for its comparative simplicity; it does not require destruction of the material and application of expensive equipment. A thermal calculation of the compared plain bearings has been improved and carried out, taking into account the obtained thermophysical parameters, the minimum clearances for the coupling “crankpin - liner” for the studied samples of foreign production, which can be used in manufacture as guidelines, have been defined. The calculation of the specific heat, the coefficients of thermal conductivity and linear expansion of plain bearings permits to select the right kind of lubricant, the required clearances, and thus prevent accidental breakdowns after major repairs of internal combustion engines.

Introduction. The implementation of production and technological processes of machines on the vast territory of the Russian Federation is related to the necessity to operate them in low temperatures conditions. The article presents the results of the applied scientific research of the factors that have a negative impact on the operation process of internal combustion engines at low ambient temperatures. The use of the modern methods and means of diagnostics of the cylinder-piston group and the crank- engine mechanism make it possible to reliably establish the causes of the internal combustion engines failures.Materials and methods. In the course of the experimental studies the non-destructive testing, organoleptic, measuring and expert methods were used.Results. As a result of a comprehensive assessment of the engine failures causes, it was found that the breakdowns in the use of inappropriate operating materials at low temperatures, measures to prepare for the launch of diesel generator sets were the main reason for untimely start-up and the faults in cylinder-piston group and the crank mechanism elements, which led to emergency failure of the internal combustion engine.Discussion and conclusion. The proposed research results will make it possible to specificate the development prospects in the field of providing the reliability of internal combustion engines operation.