Paper 10: An Experimental Investigation into the Performance of Sleeve Bearings Subjected to a Range of Alternating Loads

Abstract

Two dynamically loaded testing machines are described. These testing machines utilize a balanced pressure piston for the detection of tensile stresses in the oil film, and a test bearing housing mounted in an externally pressurized bearing for the measurement of bearing friction. Oil film pressure surveys indicate areas of general cavitation preceded by troughs of subcavity pressures in which the oil film sustains tensile stresses during periods of increasing dynamic load. Typical journal centre paths and summary curves of eccentricity ratio versus Sommerfeld number are presented for a range of alternating loads and load/journal speed ratios. None of the speed ratios examined displayed zero load capacity. Greater cyclic variations of bearing friction than those previously reported for journal friction were measured under alternating loads. Thin film operation occurred within the range of alternating loads examined, and in all cases the mean friction force was greater than that measured under static loads.