Wear debris analysis for condition monitoring of gears

A technique of wear debris image analysis was applied to monitoring of wear of spur gears. Six feature parameters were determined for a number of wear debris collected at different stages of run. In a pitting test under a constant load, initial running-in wear was followed by steady state wear and finally the fatigue failure. The progress of wear was characterised by wear debris features; the increase in the average diameter and roundness was indicative of fatigue wear that lead to severe pitting. In the tests in which load was increased in steps, relatively dark and large rough particles were generated at latter stages, which could be a sign of the fatal scuffing failure to occur by further increase in load. Quantitative examination was made by the averages of the feature parameter and by classification of the debris according to the parameter values.