Oil debris monitoring in misaligned spline couplings subjected to fretting wear

Mechanical components may be subjected to wear damage that may cause the component failure. From the experimental point of view, the wear damage may be detected by analyzing the debris produced by the wear phenomena into the lubrication oil. This technique may be used to monitor the structural integrity of bearings and gear health by means of dedicated sensors. In this work, the oil debris production due to fretting wear in spline couplings has been investigated; in particular, the aim of this work is to identify both entity and onset phase of the surface damage by means of parameters obtained from the oil debris monitoring. Experimental tests have been performed by means of a dedicated test that allows to reproduce the real working conditions on spline coupling specimens, by varying both transmitted torque and misalignment angle. The oil debris production has been monitored by means of an optical sensor, in terms of particles size and numerosity. Results show that the wear damage may be identified by monitoring the variation of both Kurtosis of the particle distribution and amount of the particles production, both for as concerns phenomenon entity and corresponding onset.