Abstract—A survey has been taken on petrol engine crankshafts used in two wheeler made from C45 (EN 8/AISI 1042) steel. It was reported that abnormal sound was heard in crankshaft while in operation and identified as failure of crankshaft. Severe wear has been seen at crankpin bearing location where the oil hole is provided. Crankpin is found as tempered. Mechanical and metallurgical properties of the crankshaft including chemical composition, micro-hardness, microstructure and tensile properties were studied and compared with the specified properties of the crankshaft material. As a result of the analysis, the main reason of failure was determined as lower surface hardness followed by rapid wear due to the contact of crankpin and bearing surface. The contact was resulted due to absence of oil and improper lubrication.

Index Terms—Crankshaft, Failure analysis, Surface hardness, Finite element analysis

Cite: M Senthil Kumar, S Ragunathan, and M Suresh, "Analysis of Crankpin Failure in a Single Cylinder Engine," International Journal of Mechanical Engineering and Robotics Research, Vol.3, No.4, pp. 260-267, October 2014.