Experimental Identification and Evaluating the Effect of Various Oil Supply Sources on Friction in the Power Unit of a Diesel-Electric Generator Set

The article presents the results of experiments performed in order to investigate the relevant, though understudied, issues concerning the contribution of various sources of oil supply to the friction of the cylinder piston group (CPG) of a piston engine with a conventional crank mechanism (CM); the relationship between the oil amount supplied to the area of movable contact of parts and their frictional losses. The methodology and equipment used in the experiments are described, and the measurement errors of the control values are estimated. The experimental results enabled identifying the dominant source of oil supply to the CPG parts, as well as verified the reliability of previously obtained calculation data on the uneven distribution of the oil quantity on the loaded and unloaded sides of the cylinder wall. Furthermore, the hypothesis was confirmed that matching the oil quantity supplied to the friction area of the parts with the level of their dynamic loading contributes to minimizing the friction of these parts. Experimental methods and their results are proposed for use in the design and operation of lubrication systems, as well as for improving the efficiency and reliability of modern piston engines, including those operating as power units of electric generating sets.