Experimental Study of Tribological Performance of Bearing-Seal Assembly of Hydrokinetic Devices in Sedimented Water

In this study, wear of polymer and ceramic coated bearings for use in hydrokinetic devices were investigated in sedimented water under the loading conditions similar to those expected in the field using a customized flume. This work is a continuation of the study performed in [1, 2] in which three polymer bearings, namely Vesconite, CIP, Feroform T814, and one ceramic coated bearing, namely Poly Crystalline Diamond Coated (PCD) along with two mechanical seals were tested in clean water for 60 hours. The results showed that PCD bearings experienced least amount of wear followed by Feroform T814, CIP, and Vesconite. The load side surfaces of polymer bearings exhibited a circular wear pattern whereas PCD bearings did not show any distinctively identifiable wear pattern. Following the same testing methodology, 60 hours long tests were conducted in fresh sedimented water on the same types of (new) bearings and seals. The data showed that bearings had similar (or less) total wear in sedimented water as compared to clean water, however, the drive shaft experienced a significant surface wear. In addition, the loading side of polymer bearing surfaces developed a circular wear pattern with significantly higher wear on the edge surfaces.