Elasto-Hydrodynamic Lubrication Performance of Cylinder Liner-Piston Ring and the Friction Experimental Verification

Author(s):  
Xingyu Liang ◽  
Yin Liu ◽  
Ge-Qun Shu ◽  
Zhengnan Yuhan ◽  
Yuesen Wang
2011 ◽  
Vol 199-200 ◽  
pp. 734-738 ◽  
Author(s):  
Qiu Ying Chang ◽  
Xian Liang Zheng ◽  
Qing Liu

Surface texturing has been successfully employed in some tribological applications in order to diminish friction and wear. This technology may be used in a piston ring to decrease the friction and wear of the contact between a piston ring and cylinder liner. A numerical simulation of lubrication between a surface textured piston ring and cylinder liner based on the hydrodynamic lubrication theory was conducted. The influence of surface texture parameters on piston ring lubrication performance was obtained by solving the mathematical equations with a multi-grid method. The results show that under the micro-dimple area density of 5%-40% the minimum oil film thickness increases and the dimensionless friction force decreases with the increasing of it. Under the dimple area density of 40%-60%, the minimum oil film thickness and the dimensionless friction force change slightly. Under various dimple area densities the optimum dimple depth at the given working condition in this paper is about 5µm.


Author(s):  
Yang Hu ◽  
Xianghui Meng ◽  
Youbai Xie ◽  
Jiazheng Fan

The cylinder liner surface finish, which is commonly produced using the honing technique, is an essential factor of engine performance. The characteristics of the texture features, including the cross-hatch angle, the plateau roughness and the groove depth, significantly affect the performance of the ring pack–cylinder liner system. However, due to the influence of the honed texture features, the surface roughness of the liner is not subject to Gaussian distribution. To simulate the mixed lubrication performance of the ring–liner system with non-Gaussian roughness, the combination of a two-scale homogenization technique and a deterministic asperities contact method is adopted. In this study, a one-dimensional homogenized mixed lubrication model is established to study the influence of groove parameters on the load-carrying capacity and the frictional performance of the piston ring–liner system. The ring profile, plateau roughness, and operating conditions are taken into consideration. The main findings are that for nonflat ring, shallow and wide groove textures are beneficial for friction reduction, and there exists an optimum groove density that makes the friction minimum; for flat ring, wide and sparse grooves help improving the tribological performance, and there exists an optimum groove depth that makes the friction minimum.


2019 ◽  
Vol 62 (6) ◽  
pp. 991-1006 ◽  
Author(s):  
Tongyang Li ◽  
Xiqun Lu ◽  
Xuan Ma ◽  
Hanzhang Xu ◽  
Bowen Jiao ◽  
...  

Author(s):  
S. I. Son ◽  
K. W. Kim

In this study, the effect of micro-grooves on hydrodynamic fabrication characteristics between a piston ring and a micro-grooved cylinder liner is analyzed numerically. Elrod’s universal equation satisfying JFO theory is adopted to predict the cavitation region properly and calculate the pressure distribution between a piston ring and a micro-grooved cylinder liner. The analysis is carried out by varying the shape, depth, length, width and location of micro-grooves during the full engine cycle. The results show that micro-grooves can make friction loss decrease in comparison with a non-textured cylinder liner.


2019 ◽  
Vol 72 (3) ◽  
pp. 465-471
Author(s):  
Chao Zhen Yang ◽  
Zhiwei Guo ◽  
Changkun Xu

Purpose Frictions in cylinder liner-piston ring often cause an inevitable loss of energy loss in the diesel engine. This study aims at evaluating the effect of depths in the cylinder liner groove texture on friction, wear and sealing performances. Design/methodology/approach Five depths of groove texture cylinder liners (50, 100, 150, 200, 250 µm) were fabricated, and experiments were carried out using a special-purpose diesel engine tester. Comparative analyses of cylinder liner contact resistances, piston ring wear losses and surface appearances were conducted with respect to different surface textures and applied loads. Findings Under no-load conditions, the cylinder liner with a 100 deep thread groove can significantly improve sealing and optimize its lubrication performance. On the other hand, the sealing is highly correlated with the depth of groove and the load within the cylinder liner. Under loaded conditions, the thread groove has less effect on the sealing performance. Originality/value The findings can provide feasible basis for the tribological design and production of diesel engines.


Author(s):  
Kishore Mistry ◽  
D. V. Bhatt ◽  
N. R. Sheth

Frictional losses in an IC engine are observed between 17–19% of total induced horsepower. 35–45% frictional losses observed due to piston ring assembly only from the above-referred total frictional loss. Lubrication system is for reducing the frictional losses and under the total hydrodynamic lubrication system, if made it feasible, above referred losses can be reduced considerably. Wear normally observed at TDC and BDC during the power stroke. Experimental set-up is prepared by using used piston-cylinder assembly of an engine. Experiment methodology is adopted based on certain assumption and simulated the entire system with an extra drive system by an electric motor with a provision of various speed availability. Various pockets on cylinder liner of 2mm diameter are located on the periphery of cylinder liner to offer lubrication to the system. Care was taken to control the rate of lubrication flow with the help of control knob. Seven different profiles on piston ring were generated and measured. Friction force is calculated by power consumption measurement under different dynamic condition with a variation of 5-speed, 3- lubricants and different 8- types of piston ring geometry are experimented under different combination and results are tabulated. Graphs are plotted for friction force v/s speed for different lubricants and piston ring profiles. Effect of lubricants (SAE30, 15W40& 2T) and ring geometry are compared.


Author(s):  
Lyu Xiuyi ◽  
Bowen Jiao ◽  
Yuechang Wang ◽  
Abdullah Azam ◽  
Xiqun Lu ◽  
...  

The prediction of lubrication performance is required to be the basement of friction optimization for marine engines. This paper simulates the lubrication performance of marine engines based on statistical models which have the advantages of fast, efficient, and macroscopic fault location. Boundary lubrication exists in the piston ring-cylinder liner (PRCL) of two-stroke marine engines because of the harsher load, lower speed, and larger structure. It has been proposed that there would be tribofilm under boundary lubrication which has a significant influence on the contact. To understand the boundary lubrication, it is necessary to study the lubrication regime transition. In this paper, firstly, the coefficient of friction curve combined with the thickness ratio embodies the lubrication regime transition process of two-stroke engines under work conditions. However, the phenomenon that the coefficients under boundary lubrication are smaller than that of other regimes shows the non-objectivity of this curve. Therefore, the Stribeck curve is introduced for objectively evaluating the transition. Then, the calculation of asperities contact pressure under boundary lubrication, which Wen proposed, is introduced into the classic Greenwood-Williamson model, the problem that the original model cannot reflect the boundary lubrication regime in the form of the Stribeck curve is improved. Finally, the results are compared before and after modifying the model to verify this study’s practicability. It provides more precise asperities contact pressure for the tribofilm growth calculation from the perspective of the Stribeck curve under the PRCL statistical model in future work.


2013 ◽  
Vol 871 ◽  
pp. 27-31
Author(s):  
Shi Feng Zhang ◽  
Shu Hua Cao ◽  
Jiu Jun Xu

This paper constructs a three-dimensional transient hydrodynamic lubrication model for cylinder liner-piston ring based on the three-dimensional transient average Reynolds equation and asperity contact model. A computer program was written with FORTRAN to calculate hydrodynamic lubrication, in which the surface roughness, the variable viscosity effect and the deformation of the circumferential direction of the cylinder liner are taken into account. The film pressure distribution in different crank angle during the stroke, minimum film thickness and friction are computed and analyzed with this program. This three-dimensional transient hydrodynamic lubrication model provides a design basis for the friction analysis of cylinder liner-piston ring.


2013 ◽  
Vol 842 ◽  
pp. 643-646
Author(s):  
Mei Peng Zhong ◽  
Ju Long Yuan ◽  
Wei Feng Yao ◽  
Xiang Chi

The method of the impacting to manufacture micro-pits is put forward in order to reduce friction between Piston ring and Cylinder liner, and improve the effective of air compressor. Method and principium of the impacting to manufacture micro-pits is recounted. The cylinder liner is set on principal axis of the rotating lathe. The tool can feed toward axis or radial direction. The micro-pits deepness is controlled by axis feeding, and distance between two micro-pits is controlled by radial feeding. The motor drives eccentricity wheel, so that the tool engender the low frequency vibration. The micro-pits are manufactured by the tools on low-frequency vibration. The effective of micro-pits processing is improved because the matrix tools were designed and manufactured. The depth of micro-pits can be controlled, so that it is even. The dynamic lubrication is built up between the cylinder and the piston, because the distributing regulation and the structural parameter can be controlled, and the micro-pits distribute evenly and independently. A theoretic model was presented to study the lubrication performance, The theory of dynamic lubrication of the honeycomb micro-pits was researched. The air compressor cylinder liners were manufactured. The tests of air compressors which cylinder liners have no micro-pits and air compressors which cylinder liners have micro-pits were done. The test result proves that friction between Piston ring and Cylinder liner is reduced, and the effective of air compressor is improved because of micro-pits.


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