Fatigue fracture of crankshaft of an aircraft engine

摘要

The crankshaft of a piston engine of a transport aircraft failed during climb. Cracks were found to initiate at the web radius region of journals 2 and 3 and progressed in the transverse direction of the shaft axis causing it to fracture. The initiation of cracks was by surface contact fatigue due to constant rubbing of bearings against the journal webs. The movement of the bearing was caused by some axial load on the crankshaft. An analysis of the failure is presented in this paper.