Shaft crack diagnostics in a gearbox

Shaft breakage is one of the most catastrophic failures in any transmission system that can ultimately lead to significant financial loss. Although advances in shaft design have lead to improvements in endurance life, shaft failures are still common today. This paper presents an experimental investigation in which several technologies such as Acoustic Emission, vibration and motor current signature analysis, were applied to identify the presence of a naturally fatigued pinion shaft in an operating gearbox. It was concluded that the combination of these methods could offer good diagnostic information though successful diagnosis is very dependent on the diagnostic path taken by the investigator.