Abstract
The remaining porosity of a bearing's frictional surface was evaluated after run-in of the bronze-based oilimpregnated sintered bearings. The linear relation was evaluated as a result of the Sommerfeld number and the bearing surface's porosity, the results confirmed the bearing surface's porosity after run-in, using the Sommerfeld number. When the Sommerfeld number was more than 0.45, the bearing surface's porosity was more than 15%. When the Sommerfeld number was between 0.01 and 0.45, the bearing surface's porosity was between 2 and 15%. And, when the Sommerfeld number was less than 0.01, the bearing surface's porosity was less than 2%. A detailed observation of the frictional surface showed that several pores were filled with sludge, when severe wear occurred the Sommerfeld number was less than 0.01. In the case of an enclosed outside diameter and the case of an opened outside diameter, both showed almost the same results.
