Posouzení vlivu chemicko-fyzikálních parametrů moderních motorových olejů na funkci spalovacích motorů

Abstract

The dissertation analyzes current methods for evaluating the influence of viscosity and performance classes of engine oils on friction losses, wear, and the overall efficiency of internal combustion engines. Based on a critical evaluation of available knowledge, a methodology for experimental assessment is proposed, combining laboratory measurements on an engine dynamometer and a block-on-ring tribometer. This approach enables simultaneous evaluation of friction losses occurring between contacting surfaces and the assessment of their wear. The proposed methodology was experimentally verified through measurements of eight engine oils representing different viscosity grades, both in a test internal combustion engine on an engine dynamometer and on a prototype block-on-ring tribometer. The results contribute to a better understanding of the influence of engine oil properties on friction losses in internal combustion engines and confirm the possibility of their objective and reproducible evaluation using laboratory experiments.