MECHANICAL BEHAVIOR AND STRUCTURAL PERFORMANCE OF A SN-CU-SN-PB COATED AND EPOXY COMPOSITE PLAIN BEARING.

Plain bearings, such as those used in crankshafts and connecting rod bearings in the engine block, are an essential component of many mechanical systems. They are characterized by a simple design, comprising a fixed bearing surface and a journal, which is the part of the shaft in direct contact with the bearing, ensuring sliding on the bearing surface. To minimize friction and wear, a continuous supply of lubricating oil is required. However, if the oil pressure is insufficient or if the quality of the oil used does not meet the specific requirements in terms of viscosity and rheological properties, plain bearings can wear prematurely, leading to potentially serious engine failures. To remedy these problems and improve the durability of plain bearings, technological advances have been made. Engineers have developed coated plain bearings and even composite material bearings. These innovative designs aim to reduce wear, increase the reliability of internal combustion engines, and ensure that the whole engine is lightweight. This numerical study aims to carry out an in-depth analysis of the structural behaviour of two types of plain bearing used in internal combustion engines: coated-based tin (Sn,) bronze-based (Cu), and lead-based (Pb), and those made of epoxy composite. The main objective is to provide accurate predictions of the elastic behaviour of these structures under different operating conditions. The structural parameters examined include displacement and shear stress concentration at the inner surface of the bearings. To achieve this objective, a numerical approach is adopted, using the finite element method to solve the displacement equations. This method allows detailed modeling of the mechanical behaviour of plain bearings, taking into account the material properties of the Sn-Cu-Pb coatings and epoxy composites, as well as the load and rotational speed conditions. The results obtained highlight several important conclusions. It was observed that the shear stresses were more pronounced for the bronze-coated bearings, particularly at a rotational speed of 6,000 rpm. The, elastic deformations are higher for epoxy composite plain bearings, compared with those observed for a coated bearing. [ABSTRACT FROM AUTHOR]