Increasing Wear-resistance of Connectings Rod Bushing Supporting Surfaces in Crank Mechanisms

摘要

The article deals with the issues of Improving the reliability and durability of connecting rod supporting surfaces in crank mechanisms and internal combustion engines. The disadvantages of the currently used connecting rods are considered. In the process of the crank mechanism operation, due to intensive wear of the connecting rod and crankshaft journal contacting surfaces, it is often necessary to replace the connecting rod support pads. In this case, it is necessary to disassemble and subsequently assemble the entire crank mechanism or engine. On the basis of calculations using known formulas of the elasticity theory, it is shown that the presence of a gap between the hole in the connecting rod and the crankpin of the crankshaft, with the established tolerances, leads to the fact that they contact only on a part of the are of the circle. In order to reduce contact stresses between the connecting rod and crankpin of the crankshaft and increase the contact area, the possibility of using a collapsible connecting rod is considered in the article, which makes it possible to provide a practically zero clearance when assembling the crank mechanism on the basis of the fit method, in return for group selection of the connecting rod liners. This allows you to compensate for wear on the bearing surfaces of the connecting rod and crankshaft without additional disassembly of the entire mechanism.