Piston Ring / Cylinder Bore Friction Under Flooded and Starved Lubrication Using Fresh and Aged Engine Oils

1998 ◽  
Author(s):  
John Glidewell ◽  
Stefan Korcek
Keyword(s):  
Piston Ring ◽  
Engine Oils ◽  
Starved Lubrication ◽  
Cylinder Bore

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.

Wear Model for Piston Ring and Cylinder Bore System

2005 ◽  
Author(s):  
Yunchao Qiu ◽  
Qian Zou ◽  
Gary C. Barber ◽  
Harold E. McCormick ◽  
Dequan Zou ◽  
...  
Keyword(s):  
Piston Ring ◽  
Thickness Distribution ◽  
Matrix Ring ◽  
Experimental Investigations ◽  
General Tendency ◽  
Wear Model ◽  
Wear Process ◽  
The Matrix ◽  
Surface Profiles ◽  
Cylinder Bore

A new wear model for piston ring and cylinder bore system has been developed to predict wear process with high accuracy and efficiency. It will save time and cost compared with experimental investigations. Surfaces of ring and bore were divided into small domains and assigned to corresponding elements in two-dimensional matrix. Fast Fourier Transform (FFT) and Conjugate Gradient Method (CGM) were applied to obtain pressure distribution on the computing domain. The pressure and film thickness distribution were provided by a previously developed ring/bore lubrication module. By changing the wear coefficients of the ring and bore with accumulated cycles, wear was calculated point by point in the matrix. Ring and bore surface profiles were modified when wear occurred. The results of ring and bore wear after 1 cycle, 10 cycles and 2 hours at 3600 rpm were calculated. They coincided well with the general tendency of wear in a ring and bore system.

A Study on Lubrication Characteristics between Piston Ring and Cylinder Bore of Bent-Axis Type Piston Pump

2009 ◽  
pp. 136-139
Author(s):  
Jae-Youn Jung ◽  
Ihn-Sung Cho ◽  
Il-Hyun Beak ◽  
Hyun-Il Shin ◽  
Jae-Cheon Jo ◽  
...  
Keyword(s):  
Piston Ring ◽  
Piston Pump ◽  
Lubrication Characteristics ◽  
Cylinder Bore

Piston Ring-Cylinder Bore Friction Modeling in Mixed Lubrication Regime: Part I—Analytical Results

1999 ◽  
Vol 123 (1) ◽  
pp. 211-218 ◽  
Author(s):  
Ozgen Akalin ◽  
Golam M. Newaz
Keyword(s):  
Boundary Conditions ◽  
Friction Force ◽  
Piston Ring ◽  
Cylinder Liner ◽  
Surface Flow ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Friction Modeling ◽  
Crank Angle ◽  
Cylinder Bore

An axi-symmetric, hydrodynamic, mixed lubrication model has been developed using the averaged Reynolds equation and asperity contact approach in order to simulate frictional performance of piston ring and cylinder liner contact. The friction force between piston ring and cylinder bore is predicted considering rupture location, surface flow factors, surface roughness and metal-to-metal contact loading. A fully flooded inlet boundary condition and Reynolds boundary conditions for cavitation outlet zone are assumed. Reynolds boundary conditions have been modified for non-cavitation zones. The pressure distribution along the ring thickness and the lubricant film thickness are determined for each crank angle degree. Predicted friction force is presented for the first compression ring of a typical diesel engine as a function of crank angle position.

Implementation of an Algorithm to Model the Starved Lubrication of a Piston Ring in Distorted Bores: Prediction of Oil Flow and Onset of Gas Blow-By

1996 ◽  
Vol 210 (1) ◽  
pp. 29-44 ◽  
Author(s):  
M-T Ma ◽  
I Sherrington ◽  
E H Smith
Keyword(s):  
Experimental Evidence ◽  
Internal Combustion Engines ◽  
Piston Ring ◽  
Operating Performance ◽  
Mass Conservation ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Single Ring ◽  
Oil Flow ◽  
Starved Lubrication

Experimental evidence suggests that piston rings in internal combustion engines normally experience 'starved' lubrication at some points along their stroke. To take account of lubricant starvation (and hence move towards a full ring pack analysis), a 'flow continuity algorithm' has been incorporated into a non-axisymmetric lubrication model of a single ring. The algorithm allows both inlet and cavitation boundaries of the full film to be located, making it possible to predict the occurrence of gas blow-by through the ring face, particularly for distorted bores. In addition, oil availability has been determined by applying the principle of mass conservation while considering lubricant accumulation. The computational scheme has been tested extensively and, in consequence, its credibility has been confirmed. Using this approach, a piston ring in a non-circular bore has been studied. The results show that, in general, the operating performance of the ring is influenced significantly by lubricant starvation. In particular, as starvation increases, the conditions that could lead to gas blow-by are greatly enhanced.

Frictional Characteristics of IF-WS2 Nanoparticles in Simulated Engine Conditions

2009 ◽  
Author(s):  
Burak Gullac ◽  
Ozgen Akalin
Keyword(s):  
Piston Ring ◽  
Normal Load ◽  
Mineral Oil ◽  
Test System ◽  
Mixed Lubrication ◽  
Bench Test ◽  
Inorganic Fullerene ◽  
Lubrication Regime ◽  
Mixed Lubrication Regime ◽  
Cylinder Bore

The effect of inorganic fullerene-like (IF) WS2 nanoparticles added to mineral oil which has a potential to reduce engine friction was investigated using a reciprocating piston ring - cylinder bore bench test system. The test system simulates actual engine conditions controlling oil temperature, speed, and normal load. Frictional characteristics of various IF-WS2 nanoparticle concentrations in mineral oil were experimentally analyzed. After a certain period of running in mixed lubrication regime, a significant reduction in friction coefficient was observed when the IF-WS2 formulated oil was used. This reduction remains to some extent with the reference mineral oil even after solvent cleaning. The results show that a thin tribofilm gradually forms on the piston ring and the cylinder bore surfaces that reduce the coefficient of friction in mixed lubrication regime. The effects of lubrication regime, load, speed, temperature and surface roughness on tribofilm formation were also discussed.

Study on the Abrasive Wear of Chromeplate Piston Ring and Cylinder Jacket Made by Different Materials

2012 ◽  
Vol 591-593 ◽  
pp. 927-930
Author(s):  
Wen Wei Gao ◽  
Zhi Zheng ◽  
Jian Ming Yang ◽  
Ya Qin An
Keyword(s):  
Abrasive Wear ◽  
Quartz Sand ◽  
Friction And Wear ◽  
Piston Ring ◽  
Positive Influence ◽  
Piston Rings ◽  
Cylinder Bore ◽  
Great Damage ◽  
Abrasive Ability

The abrasion of piston rings/tribomate pairs of cylinder jacket has great damage to engine, which can shorten the life of piston rings and cylinder bore, decrease the power of engine, enlarge the amount of oil, and release more pollution. Take a research of abrasive wear of piston ring and cylinder jacket made by different materials, will create a positive influence on extending the life of engine. This paper takes the SRV friction and wear tester, conducts the research on the abrasive ability of the three tribomate pairs (Cr plated piston ring and P-B, Cu-Cr-Ni-Mo and bainite cylinder bores) under the condition that there lies a certain amount of quartz sand in the lubricant and find that the hardness, intensity and tenacity of tribomate materials can have influence on its capability of resisting abrasion.

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