Original scientific paper
IMPACT OF OIL VISCOSITY ON FUNCTIONAL PARAMETERS OF JOURNAL BEARINGS IN INTERNAL COMBUSTION ENGINES
Ivan Filipović
; Faculty of Mechanical Engineering Sarajevo
Dževad Bibić
; Faculty of Mechanical Engineering Sarajevo
Abstract
The IC engine crnakshaft bearings, especially at the crankpin journals, are very loaded elements. For their proper functioning it is necessary to define carefully the working conditions, where the quality of oil is one of the most important factors. From the aspect of the working conditions of journal bearings it is important to ensure a minimum change in oil viscosity in a wide IC engine operating range. Selection of lubricating oil from the standpoint of physical characteristics, primarily the appropriate viscosity, has an important place in the area of reducing friction losses in journal bearings and increasing IC engine efficiency.
This paper deals with the impact of lubricating oil viscosity on the working conditions of vehicle turbocharged diesel engine crankpin journals. Analyzed parameters are: an oil temperature in the bearing, a change of the maximum value of the average pressure in the oil, the minimum carrying oil layer and the share of mixed friction, all in the function of oil viscosity at the bearing inlet, with different clearances between bearing and crankpin journal. Results were obtained using the model and own developed software to simulate the working conditions of journal bearings with an experimental verification.
Keywords
hydrodynamic plain bearing; functional performance and design viewpoint; iterative mathematical model; supercharged diesel engine; engine operating temperature and load; engine oil rheologic properties; lubricating film strength
Hrčak ID:
61932
URI
Publication date:
15.12.2010.
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