A Correlation Between Engine Oil Rheology and Oil Film Thickness in Engine Journal Bearings

1986 ◽  
Author(s):  
Terence W. Bates ◽  
Brian Williamson ◽  
James A. Spearot ◽  
Chester K. Murphy
Keyword(s):  
Film Thickness ◽  
Journal Bearings ◽  
Engine Oil ◽  
Oil Film

Relationship Between Oil Film Thickness and Wear of Journal Bearings

1970 ◽  
Author(s):  
Andreas Gervé ◽  
Gustav Katzenmeier ◽  
Karl Kollmann
Keyword(s):  
Film Thickness ◽  
Journal Bearings ◽  
Oil Film

Experimental Investigation of Oil Accumulation in Second Land of Internal Combustion Engines

2005 ◽  
Vol 127 (1) ◽  
pp. 206-212
Author(s):  
T. Icoz ◽  
Z. Dursunkaya
Keyword(s):  
Film Thickness ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Engine Oil ◽  
Combustion Engines ◽  
Oil Consumption ◽  
Oil Accumulation ◽  
Oil Film ◽  
Piston Cylinder ◽  
Total Oil

Blowback of engine oil suspended in combustion gases, when the gas flows from the piston second land back into the combustion chamber, is believed to contribute to oil consumption and hydrocarbon emissions in internal combustion engines. Oil accumulation in the region between top and second compression rings is a factor that influences this phenomenon. The effects of individual parameters, such as oil film thickness and viscosity, however, have still not been understood. The present study was aimed at constructing an experimental setup to study the effect of oil film thickness on oil accumulation in the second land of internal combustion engines. Due to the inherent difficulties of experimentation on production engines, a modeled piston-cylinder assembly was constructed. Total oil accumulation in the modeled second land after a single piston stroke was measured and compared to oil consumption in operating engines.

Development of a Laser Fluorescence Technique For Measuring Piston Ring Oil Film Thickness

1980 ◽  
Vol 102 (2) ◽  
pp. 165-170 ◽  
Author(s):  
L. L. Ting
Keyword(s):  
Light Intensity ◽  
Film Thickness ◽  
Piston Ring ◽  
Laser Fluorescence ◽  
Engine Oil ◽  
Fluorescent Light ◽  
Fluorescence Technique ◽  
Thickness Change ◽  
Oil Film ◽  
Cylinder Sleeve

A single cylinder engine equipped with a transparent cylinder sleeve has been used to develop a technique to make visual investigations of piston ring lubrication behavior and engine oil loss mechanism. This paper describes this apparatus and the development of a laser excited oil fluorescence technique for measuring the oil film thickness change between the piston rings and the transparent cylinder sleeve wall. The amount of oil accumulated in the piston-cylinder clearance spaces above and below the ring pack, and those in the inter-ring spaces, can also be observed. Preliminary results showing oil fluorescence light intensity traces indicate that this technique works very well. Quantitative oil film thickness data should be readily obtainable from these traces once the fluorescent light intensity is calibrated.

A Study on Measurement of Conformability of the Piston Oil Ring on the Cylinder Bore Under Engine Operating Condition by LIF Method Using Optical Fiber

2013 ◽  
Author(s):  
Akemi Ito ◽  
Kazuya Mochiduki ◽  
Koji Kikuhara ◽  
Masatsugu Inui ◽  
Hirotaka Akamatsu
Keyword(s):  
Optical Fiber ◽  
Film Thickness ◽  
Engine Oil ◽  
Sliding Surface ◽  
Oil Consumption ◽  
Ring Groove ◽  
Operating Condition ◽  
Oil Film ◽  
Engine Operating Condition ◽  
Cylinder Bore

Engine oil consumption must be reduced for reducing exhaust gas emissions. It is well known that a cylinder bore shape under engine operating condition affects oil consumption. This study aimed clarifying the conformability of an oil ring against the distorted cylinder bore. Oil film thickness at the sliding surface of oil ring upper and lower rails was successfully measured by LIF method using optical fiber, which was embedded in the oil ring. The piston motion was also measured and compared with measured oil film thickness. It was found that the piston tilting motion affected oil film thickness hence its conformability. It was also found that thicker oil film was found at the following rail than that at former rail, and it was suggested that oil was supplied to the following rail from not only the sliding surface of the former ring but also somewhere, for example, the oil ring groove.

Report Paper 2: Approximate Short Bearing Analysis and Experimental Results Obtained Using Plastic Bearing Liners

1969 ◽  
Vol 184 (12) ◽  
pp. 190-196 ◽  
Author(s):  
J. P. O'Donoghue ◽  
P. R. Koch ◽  
C. J. Hooke
Keyword(s):  
Approximate Solution ◽  
Film Thickness ◽  
Journal Bearings ◽  
Experimental Results ◽  
Approximate Theory ◽  
Hydrodynamic Problem ◽  
Dynamic Conditions ◽  
Oil Film ◽  
Theoretical Predictions ◽  
Bearing Analysis

This paper outlines a new approximate theory for liquid lubricated plain journal bearings with elastic liners. This is a modified form of Ocvirk's theory and includes the effect of circumferential flow. The results of a series of tests on short plastic bearings are presented to compare with the theoretical predictions of the new theory. The authors conclude that for short bearings the theory gives reasonably good predictions of performance, but the elasticity assumptions cause major errors for length/diameter ratios greater than 0·5 due to the decrease in oil film thickness that occurs near the ends of the bearing. The approximate solution adopted for the hydrodynamic problem may be of use for considering dynamic conditions taking the Reynolds conditions for cavitation.

Effect of Scratches on a Tilting-Pad Journal Bearing

2020 ◽  
Author(s):  
Steven Chatterton ◽  
Paolo Pennacchi ◽  
Andrea Vania ◽  
Mohamed Amine Hassini ◽  
Antoine Kuczkowiak
Keyword(s):  
Film Thickness ◽  
Dynamic Performance ◽  
Journal Bearings ◽  
Hydrodynamic Performance ◽  
Axial Position ◽  
Steam Turbines ◽  
Local Pressure ◽  
Oil Film ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing

Abstract Many industrial rotating machines are equipped with hydrodynamic journal bearings, such as centrifugal compressors, steam turbines, pumps and motors. After some time from the installation, however, the surface of the bearings often presents imperfections and slight damages mainly caused by the presence of harder particles in the lubricant during start-ups and shut-downs, when the hydrodynamic mechanism is not well developed and the mixed lubrication can occur. The presence of scratches on a bearing can lead to variations of the oil film thickness which, in turn, causes significant degradation of the bearing hydrodynamic performance. For example, the reduction of the minimum oil-film thickness can lead to the increase in the local temperature, to local pressure peaks and, finally, to the failure of the bearing. Experimental data relating to scratches on journal bearings are extremely limited in the literature especially for tilting-pad journal bearings (TPJBs). An experimental activity was carried out to study the effect of artificial scratches on pads on the static and dynamic behaviors of a TPJB. The number of scratches, the depth and the axial position have been investigated and the dynamic coefficients have been estimated as well. The experimental results confirmed a degradation of the dynamic performance of the bearing in case of scratches, that it has has been also confirmed by means of numerical simulations.

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