Analysis of Tribological Performance of Piston Ring Lubrication

2011 ◽  
Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Power Loss ◽  
Piston Ring ◽  
Design Parameters ◽  
Oil Film ◽  
Starved Lubrication ◽  
Piston Ring Lubrication ◽  
Cylinder Bore ◽  
Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

Numerical Simulation on the Lubrication Performance of Surface Textured Piston Rings

2011 ◽  
Vol 199-200 ◽  
pp. 734-738 ◽  
Author(s):  
Qiu Ying Chang ◽  
Xian Liang Zheng ◽  
Qing Liu
Keyword(s):  
Numerical Simulation ◽  
Film Thickness ◽  
Friction Force ◽  
Friction And Wear ◽  
Piston Ring ◽  
Hydrodynamic Lubrication ◽  
Cylinder Liner ◽  
Area Density ◽  
Oil Film ◽  
Lubrication Performance

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.

Piston ring–cylinder liner lubrication analysis in a CO2 refrigeration reciprocating compressor

2011 ◽  
Vol 225 (11) ◽  
pp. 2638-2648 ◽  
Author(s):  
B Yang ◽  
Y Zhao
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Piston Ring ◽  
Leading Edge ◽  
Cylinder Liner ◽  
Stress Factors ◽  
Maximum Magnitude ◽  
Reciprocating Compressor ◽  
Oil Film ◽  
Effect Of Surface

A simulation model is developed for the piston ring–cylinder liner lubrication problem in a CO2 refrigeration reciprocating compressor. Patir and Cheng’s modified Reynolds equation including pressure flow factors, shear flow factors, and shear stress factors is used to consider the effect of surface roughness on lubrication. The piston ring is assumed to be fully flooded at the leading edge, and both the cavitation case and fully flooded case are considered at the trailing edge. Modified Reynolds boundary condition is employed. The simulation results show that, the minimum oil film thickness has a maximum magnitude in the middle stroke region for downward stroke and upward stroke. In the vicinity of the dead centres, the magnitude of the friction force is much higher than that in the middle stroke region. The oil film pressure distribution along the piston ring thickness at different specified crank angles is indicated. The effects of ring thickness, crown height on minimum oil film thickness, and friction force are also investigated.

A Study on the Distribution of Oil Film Thickness in the Circumferential Direction of Oil Ring in a Gasoline Engine

2019 ◽  
Author(s):  
Akemi Ito ◽  
Tadatsugu Hakkaku ◽  
Kazuya Mochiduki ◽  
Keita Tomotsune ◽  
Masatsugu Inui ◽  
...  
Keyword(s):  
Film Thickness ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Axial Direction ◽  
Circumferential Direction ◽  
Sliding Surface ◽  
Oil Consumption ◽  
Measuring Point ◽  
Oil Film ◽  
Cylinder Bore

Abstract Oil traveling upward through the sliding surface of a piston ring causes oil consumption of an engine. Piston rings are designed considering conformability to deformed cylinder bore. However, cylinder deformation sometimes affects strongly oil consumption. It suggests that a piston ring cannot conform dynamically to the cylinder bore. In this study, distribution of oil film thickness of an oil ring was measured for investigating the dynamic conformability. An optical fiber has embedded in the sliding surface of the lower rail of the oil ring, and oil film thickness was measured by laser induced fluorescence method. The measuring point was rotated in the circumferential direction, so the distribution in both the circumferential and the axial direction could be measured. Thick oil films partially were found and it was found that the oil ring did not conformed to the deformed cylinder bore dynamically. Furthermore, such oil film showed thicker value than those expected theoretically. It was showed that dynamic conformability must be considered for piston ring design for reducing oil consumption.

Piston Ring Lubrication and Cylinder Bore Wear Analyses, Part II—Theory Verification

1974 ◽  
Vol 96 (2) ◽  
pp. 258-266 ◽  
Author(s):  
L. L. Ting ◽  
J. E. Mayer
Keyword(s):  
Wear Rate ◽  
Analytical Method ◽  
Piston Ring ◽  
Rankine Cycle ◽  
Wear Factor ◽  
Factor Data ◽  
Piston Ring Lubrication ◽  
Engine Components ◽  
Cylinder Bore ◽  
Lubrication Conditions

Based on the analytical method presented in the previous paper (Part I), comparisons of predicted wear curves along the major and minor side-thrust sides of the cylinder bore are made with the measured ones obtained from several truck engines for various vehicle mileages. The agreement was found to be good. This indicates the analytical model developed in Part I is relevant and suitable for predicting the severity of piston-ring bore contact for varying engine operating and lubrication conditions. From this, the necessary parameter changes may be found such that the wear rate of the cylinder bore may be reduced. Wear factor data, however, must be available in order to make quantitative predictions of wear. The model ultimately may be useful also in the design optimization of engine components. Since the method is general, it also can be applied to other reciprocating piston devices, such as gas compressor, Rankine cycle engine, or Stirling engine.

Two-dimensional lubrication study of the piston ring pack

1998 ◽  
Vol 212 (3) ◽  
pp. 215-220 ◽  
Author(s):  
K Liu ◽  
Y. B. Xie ◽  
C. L. Gui
Keyword(s):  
Film Thickness ◽  
Piston Ring ◽  
Cylinder Wall ◽  
Asperity Contact ◽  
Two Dimensional ◽  
Oil Film ◽  
Secondary Motion ◽  
Piston Ring Pack ◽  
Ring Pack ◽  
Piston Ring Lubrication

Based on the two-dimensional average flow model and asperity contact model, a theoretical model for the non-axisymmetrical analysis of piston ring lubrication has been suggested in this paper. The two-dimensional distribution of oil-film thickness between the piston rings and cylinder wall is obtained. Results show that the oil-film thickness along the circumference is non-uniform. Starvation is also considered in the model. The effect of secondary motion of piston assemblies on the lubrication property of the piston ring pack has also been studied.

Mixed Lubrication and Friction Power Loss of Piston Ring Pack

2014 ◽  
Vol 668-669 ◽  
pp. 205-208
Author(s):  
Xiao Ri Liu ◽  
Guo Xiang Li ◽  
Shu Zhan Bai ◽  
Yu Ping Hu
Keyword(s):  
Diesel Engine ◽  
Film Thickness ◽  
Power Loss ◽  
Piston Ring ◽  
Asperity Contact ◽  
Simultaneous Solution ◽  
Oil Film ◽  
Friction Power ◽  
Piston Ring Pack ◽  
Ring Pack

With consideration of asperity contact, the minimum oil film thickness and friction power loss are calculated by simultaneous solution of the dynamics, blow-by and lubrication of piston ring pack. Take the piston ring pack in the first cylinder from the free end of a six-cylinder diesel engine for example, results show that the asperity contact takes place at all of the compression rings and oil ring; the minimum oil film thickness is 1.04μm at the top ring; the total friction loss power is 0.94kW, the top ring accounts for 37.2%, the second ring accounts for 33.0%, the oil ring accounts for 29.8%.

Characterization of Friction Condition Transition by Phase Space Trajectories

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Yan Shen ◽  
Mei Jin ◽  
Ye Liu ◽  
Feng Zhu
Keyword(s):  
Phase Space ◽  
Friction Force ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Friction Condition ◽  
Space Trajectories ◽  
Starved Lubrication ◽  
Lubrication Conditions ◽  
Phase Space Trajectories

A starved lubrication experiment and analytical model have been developed to investigate the friction condition transition (FCT) at the interface between a piston ring and a cylinder liner with the piston ring reciprocating liner test rig. To obtain a solution for the friction condition transition, phase space trajectories are used to extract the transient features of the friction force. The trajectories have three typical patterns for starved lubrication conditions. The irregular friction force of different strokes is classified based on the trajectories. When the projection of the trajectories in the phase space enters into the third pattern variation, this indicates the onset and progression of scuffing. The autocorrelation analysis of the wear surface topography at the stroke end validates the characterization method.

Lubrication Phenomena in Spur Gears: Capacity, Film Thickness Variation, and Efficiency

1965 ◽  
Vol 87 (3) ◽  
pp. 655-663 ◽  
Author(s):  
R. Wayne Adkins ◽  
E. I. Radzimovsky
Keyword(s):  
Shear Stress ◽  
Film Thickness ◽  
Pressure Distribution ◽  
Power Loss ◽  
Hydrodynamic Lubrication ◽  
Thickness Variation ◽  
Spur Gears ◽  
Oil Film ◽  
Lubrication Conditions ◽  
Lubricant Viscosity

In this paper the oil film separating the mating surfaces of involute spur gears operating under hydrodynamic lubrication conditions is analyzed. This analysis surpasses previous analyses in as much as the actual motion of the involute profiles (rolling, sliding, and squeezing motion) and the total number of teeth engaged at any one time are considered. Expressions are derived for the pressure distribution, shear stress, and power loss in the oil film at any phase of tooth engagement. A method is developed by which these expressions can be applied to determine the film thickness at any instant and the power loss for a given load, speed, and lubricant viscosity.

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