The microgeometrical structure has a great impact on lubricating performance of the cylinder liner–piston ring assembly. Extensive investigations have been done upon the various texture types for better lubrication. However, rarely do they focus on the morphological alteration of the friction surfaces during the initial wearing process. In this study, the pits and grooves at the liner inner surface are processed and experiments are conducted to investigate the influence of the surface texturing structure on the piston ring assembly during the initial wearing process at different rotating speeds. Then, the tribology information of cylinder liner–piston ring assembly is obtained and the mechanism between surface texturing structure and lubricating performance was analyzed. Experimental results show that some pits and grooves on the inner surface of the cylinder liner can properly improve the wear performance of cylinder liner–piston ring at a high rotating speed in diesel engine, and hence reducing friction and wear. Moreover, it provides experimental data for theoretical analysis and knowledge for improving the friction surface texturing of cylinder liner.

Nonlinear friction-induced vibration deteriorated the performance of marine rubber stern tube bearings (RSTB) in a wide variety of propulsion system. In the paper, this study was performed on the level of both practical and experimental bifurcation analysis. Hereto, an experimental set-up of SSB-100 marine stern tube bearing test machine was applied to carry on this project. The synthesis of these practical and experimental results confirmed that nonlinear frictioninduced vibration was due to a subtle balance of negative damping at lower speeds or viscous friction at higher speeds. Furthermore, it was shown how these essential friction characteristics depended on physical conditions such as temperature, normal forces and the material properties in the frictional contact.

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