A method of quality control of plain bearings by their thermophysical properties

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.