THE EFFECT OF CLEANLINESS ON THE ATTAINABLE BEARING LIFE IN AEROSPACEAPPLICATIONS

Surface-initiated fatigue and wear caused by contamination is one of t he major causes for bearing failures in aerospace applications. This p aper outlines a method to precisely define cleanliness with the help o f the cleanliness factor s and the contamination factor V. Particle si zes and filtration ratios are defined and allocated to certain V facto rs. These factors can then be entered into a proposed bearing life cal culation method to quantity the effect of system cleanliness/contamina tion on the attainable bearing life. A procedure to improve system cle anliness is described (pre-cleaning concept) so that contamination rel ated damage can be eliminated.