Abstract

The advances in material engineering led to the development of hard carbon based coatings applied in numerous applications in order to prevent or minimize wear of the parts in contact. With Triondur® coatings, the bearing company Schaeffler has succeeded in halving the friction losses in the valve trains of passenger cars. The coatings are optimized for high abrasive wear protection and low sliding friction moments. Altogether an ideal starting position to apply such surfaces also in fluid film bearings, in which rubbing surfaces are normally separated by a fluid film, but also in case of overload or especially during start-ups and stopping mixed friction may occur increasing rapidly wear rate of the bearing surfaces. Therefore the use of Triondur® may substantially increase the durability of tilting pad thrust bearings used in applications with low speeds and/or frequent starts and stops. In some cases probably the novel surface thrust bearings may substitute roller element bearings. Since no detailed, efficient and reliable calculation methods for mixed friction exist and such conditions are probable in the regime of low speed/high load and starts/stops), therefore in order to test and prove the new material concept it was decided to carry out experimental research. Search of the literature proved that experimental results of fluid film bearings tested in the high load and low speed regime are also infrequent, probably because this is not the usual area of operation of the fluid film bearings.

Authors (3)