Effects of the array modes of laser-textured micro-dimples on the tribological performance of cylinder liner–piston ring

Abstract

A mixed lubrication model of textured cylinder liner-piston ring was built to investigate the effects of four array modes namely, square array, stagger array, stretching, and shortening along liner axis array of micro-dimples on the tribological properties of cylinder liner-piston ring pair. The simulation results indicate that micro-dimples can enhance the hydrodynamic effects of lube oil, improving the film bearing capability. However, the effects differ significantly under the four dimple array modes: for square array, the cylinder liner-piston ring pair is well lubricated due to the synergistic effects of uniformly spaced micro-dimples that form homogeneous bearing film even around the fired top dead center where the lubrication condition is harsh; while the film of stagger array is the thinnest among the four schemes, which means its lubrication is also the worst. From square array mode, to shortening and stretching along liner axis array, then to stagger array mode, the total friction force of cylinder liner-piston ring shows an upward trend. By utilizing laser surface texturing method, square array, stretching along liner axis array, and stagger array of micro-dimples were textured on the gasoline engine cylinder bores, followed by a set of engine bench tests. The experimental results demonstrate that the engine motored torque of the three array modes increases in turns, which validates that the anti-friction effect of square array is optimal whereas that of stagger array is the most inefficient.

Effect of compound texture on lubrication and sealing performance of plunger pump

“…Then, to remove the burrs, the specimens were polished. The bulges around texture can be controlled to around 4 μm, which means the processing quality of this YAG laser is reliable 33,34 . Morphologies of micro‐dimple and groove are shown in Figure 11A,B, respectively.…”

“…The bulges around texture can be controlled to around 4 μm, which means the processing quality of this YAG laser is reliable. 33,34 Morphologies of micro-dimple and groove are shown in Figure 11A,B, respectively. To demonstrate the processing precision, the micro-dimple parameters after LST is shown in Figure 12.…”

“…According to the research of Etsion, 31,32 a texture density of 20% was recommended and a series of works latter have proved its accuracy. The influence of texture parameters on tribological performance of the cylinder linerpiston ring has been studied by our group, [33][34][35] and results suggested that when radius and depth range from 40 to 120 μm and 4 to 10 μm, respectively, better tribological performance can be achieved. Therefore, in this paper, parameters in Table 2 were initially used.…”

Tribofilm formation on the VN/7075 composite surface under sulfur-containing boundary lubrication

“…Besides, as one of the most important friction pairs of internal combustion engines, pistons have an important influence on the reliability and mechanical efficiency of internal combustion engines. [6][7][8][9] During the piston operation process, the corrosive atmosphere (including SO 2 , SO 3 , etc.) will be generated by various sulfur, which is one of the constitutions of the diesel oil and lubricating oil.…”

Analysis of the lubrication process with composition of solid lubricants of laser-modified sliding surfaces

“…[4][5][6][7] The technology of surface texturing has fruitfully been utilized in enhancing the performance of mechanical seals, sliding bearings of hydraulic machines, piston ring of diesel engine, cylinder liner, and thrust bearings. [8][9][10][11][12] Recently, a great deal of research shows that surface textures embedded with solid lubricant can significantly improve the tribological properties of the surfaces, especially under low speed, overload, vacuum, high temperature and pressure working conditions. [8][9][10][11][12][13][14][15] This is mainly because of the characteristics of high temperature, corrosion, radiation, and oxidation resistance as well as excellent lubricating effect of solid lubricants such as molybdenum disulfide, graphite, and tungsten disulfide.…”