Analysis of regional wear failure of crankshaft pair of heavy duty engine

This study focuses on investigating the underlying causes of localized wear failure on one side of the oil hole in the third crankpin of a straight-six-cylinder internal combustion engine, con-structed using 42CrMo material. A comprehensive analysis of this wear phenomenon was con-ducted through a series of meticulous experimental investigations and advanced finite element analysis. The experimental campaign encompassed macroscopic morphology observation, precise metallographic structure analysis, microscopic structure observation, iron spectrum abrasive particle detection, micro-hardness testing, and rigorous chemical composition analysis. Further-more, finite element analysis was employed to simulate the stress and strain distribution of the crankshaft under realistic operating conditions, enabling a deeper understanding of the mecha-nisms driving the localized wear in the third crankpin region. The research results revealed that the primary driver behind the localized wear in the third crankpin region is the ingress of grinding debris and contaminated particles from the oil passage into the contact surface between the third crankpin and the bearing shell, leading to abrasive particle wear. Moreover, the synergistic effects of friction and elevated temperatures facilitate the migration of carbon elements from lubricants or other materials to the surface of the third crankpin, resulting in their accumulation. This carbon accumulation causes non-uniform stress distribution on the surface, exacerbating fatigue wear on the crankshaft crankpin. The finite element simulation outcomes demonstrated that the center of the oil hole on one side of the third crankpin experiences the most pronounced defor-mation. Under actual operating conditions, the deformation of the crankpin leads to an increase in clearance between the crankpin and the bearing shell, thereby impeding the formation of a complete oil film. Consequently, the occurrence of dry friction and elevated temperatures leads to the melting of the alloy on the bearing shell surface, giving rise to adhesive wear.

Automated summary

This study investigates the causes of localized wear failure on one side of the oil hole in the third crankpin of a straight-six-cylinder internal combustion engine. Through experimental investigations and finite element analysis, the research reveals that the ingress of grinding debris and contaminated particles, migration of carbon elements, and non-uniform stress distribution are the primary drivers of wear in this region.