Study On Running-in Wear Simulation Test For Typical Friction Pairs Of S50MC Diesel Engine

Wear is one of the most common forms of main failure of diesel engine. The cylinder liner-piston ring and crankshaft journal-bearing shells are the important friction pairs in diesel engine. However for the severe working condition, including complicated and changeable operation condition, environment, stress and movement mode etc, abnormal wear failure is easily to occur, which not only reduces machines' service life, but also causes considerable economic loss. Therefore, the friction and wear characteristics of cylinder-piston ring and crankshaft journal-bearing shells are classified as the difficult problem in the field of tribology worldly and have been paid much attention in the last 100 years.In this paper, laboratory simulating test of the friction wear and lubrication of cylinder liner-piston ring and crankshaft journal-bearing shells during running-in period have been designed and conducted. The tribological character of friction pairs has been researched by the complicated analysis of friction coefficient, wear weight loss, surface topography and oil analysis. The friction and wear properties of the cylinder liner-piston ring during running-in period and the effect of different running-in oil on running-in process have been discussed under different lubrication conditions with certain load, and the effect of different test force on the wear performance for crankshaft journal--bearing shells lined AlSn40 have also been studied.It is shown that results of various research methods towards friction-wear and lubrication process of cylinder liner-piston ring and crankshaft journal-bearing shells have consistency. The spectrographic analysis and ferrographic analysis of lubricant could be taken as a judging criterion for the running-in of process, and synthesizing of both methods makes the result more accurate and reliable. Under different test conditions, greater discrepancies also were presence in the running-in and wear properties of friction pairs. The quality of running-in under way in soaking lubrication was better than dropping lubrication. The running-in time can be reduced by use of CD40 lubricant with metal-ceramic additive. The bearing shells lined AlSn40 will obtain a good running-in wear properties in the middle test force. In order to obtain a good quality of the running in, different running-in parameters are required by this two friction pairs.