Analysis of a vehicle crankshaft failure

✍ Scribed by F.S Silva

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 481 KB
• Volume: 10
• Category: Article
• ISSN: 1350-6307
• DOI: 10.1016/s1350-6307(03)00024-4

✦ Synopsis

This paper reports an investigation that was carried out on two damaged crankshafts. They were diesel van crankshafts that were sent to be ground, after a life of about 300,000 km each. Some journals were damaged on each crankshaft. After grinding, and assembling on the diesel van, the crankshafts lasted about 1000 km each, and the journals were damaged again. The crankshafts were then sent to be investigated. Different laboratory tests were carried out in order to discover what could have been the cause of the damage. Different typical crankshaft failures were assessed, and will be discussed in this paper. The cause of the damaged journals was found to be a wrong grinding process that originated small thermal fatigue cracks at the center of the journals, on both crankshafts. These almost invisible cracks, with sharp edges, acted as knives originating a very quick damaging of the journal bearings, and as a consequence damaged the journals themselves.