Experimental Study of Oil Supply Pressure Effects on Bearing Friction in Hydrodynamic Lubrication

2013 ◽  
Vol 315 ◽  
pp. 977-981 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce
Keyword(s):  
Friction Coefficient ◽  
Frictional Force ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Diameter Ratio ◽  
Pressure Effects ◽  
Oil Supply ◽  
Supply Pressure ◽  
Bearing System ◽  
Bearing Friction

Journal bearing is widely applied in most of rotating machineries for transmission of large loads at mean speed of rotation. Friction caused by the shearing condition between journal, bearing and lubricant contribute to power loses in journal bearing system. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on frictional force, friction coefficient and torque of a journal bearing. A journal diameter of 100 mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 MPa). Frictional force and friction coefficient results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the change in oil supply pressure has affected the fluid frictional force and friction coefficient to some extent.

The Effects of Oil Groove Position on Torque and Frictional Force in Hydrodynamic Journal Bearing

2013 ◽  
Vol 393 ◽  
pp. 907-912 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Mimi Azlina Abu Bakar
Keyword(s):  
Friction Coefficient ◽  
Experimental Work ◽  
Frictional Force ◽  
Power Loss ◽  
Journal Bearing ◽  
Diameter Ratio ◽  
Bearing Surface ◽  
Oil Supply ◽  
Supply Pressure ◽  
Hydrodynamic Journal Bearing

Axial groove is a common supply method of distributing lubricant within a journal bearing. Lubricant is generally fed at a specific supply pressure to ensure that the journal and the bearing surface are separated. Shearing action between lubricant and bearing parts creates frictions which contribute to power loss in journal bearing. In the present study, an experimental work was conducted to determine the effect of oil groove location on torque and frictional force in hydrodynamic journal bearing. A journal diameter of 100mm with a 12 length-to-diameter ratio was used. The oil supply pressure was set at 0.20 to 0.25 MPa. The groove was positioned at 3 different locations namely 00, +150and +300. Measurements of torque and frictional force were obtained for speed values of 300, 500 and 800 RPM at different radial loads. It was observed that the change in oil groove location has affected the fluid frictional force and friction coefficient to some extent.

The Effects of Oil Supply Pressure at different Groove Position on Temperature and Pressure Profile in Journal Bearing

2013 ◽  
Vol 66 (3) ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
R. S. Dwyer-Joyce ◽  
Aidah Jumahat
Keyword(s):  
Journal Bearing ◽  
Pressure Profile ◽  
Diameter Ratio ◽  
Radial Load ◽  
Oil Supply ◽  
Supply Pressure ◽  
Pressure Profiles ◽  
Hydrodynamic Journal Bearing ◽  
Temperature And Pressure ◽  
Length To Diameter Ratio

The effects of oil supply pressure on the temperature and pressure at different groove locations on a hydrodynamic journal bearing were investigated. A journal with a diameter of 100 mm and a ½ length-to-diameter ratio was used. The supply pressure was set to 0.2, 0.5, and 0.7 MPa at seven different groove locations, namely, -45°, -30°, -15°, 0°, +15°, +30°, and +45°. Temperature and pressure profiles were measured at speed values of 300, 500, and 800 rpm with 10 kN radial load. The results show that the change in oil supply pressure simultaneously reduced the temperature and increased the pressure profile.

The Effect of Oil Supply Pressure on the Circumferential Pressure Profile in Hydrodynamic Journal Bearing

2013 ◽  
Vol 315 ◽  
pp. 809-814 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Nik Rosli Abdullah
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Pressure Profile ◽  
Journal Bearings ◽  
Maximum Pressure ◽  
Oil Supply ◽  
Supply Pressure ◽  
Machine Elements ◽  
Hydrodynamic Journal Bearing ◽  
Circumferential Pressure

In hydrodynamic lubrication, the pressure condition of the fluid is critical to ensure good performance of the lubricated machine elements such as journal bearings. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on pressure profile around the circumference of a journal bearing. A journal diameter of 100mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 Mpa) and the circumferential pressure results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the maximum pressure values were affected by changes in oil supply pressure.

A Novel Friction Model Basing on Journal Bearing Theory for Reciprocating Compressor

2013 ◽  
Vol 456 ◽  
pp. 320-323 ◽  
Author(s):  
Le Wang ◽  
Bin Tang ◽  
Yuan Yang Zhao
Keyword(s):  
Friction Coefficient ◽  
Piston Ring ◽  
Sliding Friction ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Dynamic Change ◽  
Friction Model ◽  
Reciprocating Compressor ◽  
Oil Viscosity ◽  
Compressor Performance

The paper presents a comprehensive friction model of reciprocating compressor which is able to evaluate friction losses in moving parts. The model consists of crankshaft, connecting rod and piston all supported by bearings as well as the piston ring/cylinder interface viewed as sliding friction. Hydrodynamic lubrication theory reveals relationship between load and friction coefficient and was demonstrated to be helpful to give insight to the lubrication characteristics of journal bearing. The model gave the composition of friction losses, friction coefficient dynamic change with orbiting angle and effect of oil viscosity on compressor performance. The results showed that the friction losses of piston ring/cylinder interface and the rod big end bearing was most part of the friction losses and it was necessary to choose suitable oil viscosity to reach the optimum compressor performance.

An Experimental Investigation of Lubrication in Hydrostatic Extrusion Using Wax as a Model Material

1972 ◽  
Vol 94 (3) ◽  
pp. 913-919 ◽  
Author(s):  
A. Wuerscher ◽  
W. B. Rice
Keyword(s):  
Thin Film ◽  
Castor Oil ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Pressure Fluctuations ◽  
Model Material ◽  
Hydrostatic Extrusion ◽  
Strain Rates ◽  
The Coefficient Of Friction ◽  
Bearing Friction

This paper describes hydrostatic extrusion experiments in which paraffin wax was extruded, undertaken to test the validity of a theory proposed by Iyengar and Rice concerning the conditions necessary for hydrodynamic lubrication. Three fluids were used: castor oil, and two silicone fluids. Stress-strain curves obtained at several strain rates revealed that the particular wax behaves like many metals in that Y = Aεm. Strain-rates in the die are assessed, and corresponding values of Y are incorporated in the Hoffman and Sachs analysis of extrusion, which is then used to estimate the coefficient of friction from observed values of extrusion pressure. Analogy with journal bearing friction phenomena leads to the conclusion that at higher speeds hydrodynamic lubrication was attained with all three fluids, but that it was “thin-film” rather than “thick-film” predicted for similar billet speeds. Violent pressure fluctuations observed at higher speeds with castor oil, but not with the silicone fluids are attributed to smaller compressibility and viscosity of the castor oil.

Study on Dynamic Characteristics of a Hydrostatic and Hydrodynamic Journal Bearings for Small Diameter Grinding Spindle

2012 ◽  
Vol 497 ◽  
pp. 99-104 ◽  
Author(s):  
Zhi Quan Hou ◽  
Wan Li Xiong ◽  
Xue Bing Yang ◽  
Ju Long Yuan
Keyword(s):  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Small Diameter ◽  
Diameter Ratio ◽  
Design Parameters ◽  
Eccentricity Ratio ◽  
Dynamic Coefficients ◽  
Supply Pressure ◽  
Stiffness Coefficients ◽  
Direct Stiffness

The dynamic characteristics of a hydrostatic and hydrodynamic journal bearing with two arrays of eight holes have been investigated theoretically by the three-dimensional Computational Fluid Dynamics (CFD) models with respect to equilibrium position. The various dynamic coefficients for design parameters, such as orifice diameter, length to diameter ratio, eccentricity ratio, supply pressure, and rotational speed, are analyzed systematically under the action of displacement disturbance and velocity disturbance which are considered by the User Definition Function (UDF) programs. Results show that the dynamic coefficients greatly affected by design parameters. The cross stiffness coefficients increase rapidly more than direct stiffness with an increase of length to diameter ratio and rotational speed. Conversely, the direct stiffness coefficients are larger than cross stiffness with an increase of supply pressure and eccentricity ratio. It indicates that the journal bearing with two arrays of eight holes is suitable for their applications to small diameter grinding spindle by the means of optimizing the operating parameters and the structural parameters in order to obtain a better dynamic characteristic.

Oil Flow Through Journal Bearing

1973 ◽  
Vol 95 (4) ◽  
pp. 546-552 ◽  
Author(s):  
G. R. Kulkarni
Keyword(s):  
Significant Influence ◽  
Feed Rate ◽  
Journal Bearing ◽  
Great Influence ◽  
Operating Characteristics ◽  
Oil Supply ◽  
Supply Pressure ◽  
Attitude Angle ◽  
Oil Flow ◽  
Flow Through

Oil feed rate is an important parameter governing the operating characteristics of a journal bearing. In the present paper investigation is carried out to explore the effect of oil groove location and supply pressure on the oil feed rate to the bearing. These results are further used to get variation in Sommerfeld number and attitude angle for different oil groove locations and supply pressures. The results indicate that oil groove location has a great influence on oil feed rate to the bearing. It is also observed that oil supply arrangement does not have a significant influence on Sommerfeld number and attitude angle.

Research on shaft strength considering offsetting distribution of film pressure of journal bearing in shaft-bearing system

2007 ◽  
Vol 221 (1) ◽  
pp. 99-107 ◽  
Author(s):  
S Jun ◽  
G Changlin ◽  
W Jingfeng
Keyword(s):  
Stress Distribution ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Direct Interaction ◽  
Present Calculation ◽  
Design Calculation ◽  
Film Pressure ◽  
Lubrication Characteristics ◽  
Strength And Stiffness ◽  
Bearing System

There is a direct interaction between shaft and bearing in shaft-bearing system. The effect of lubrication status of bearing was not considered in the present calculation of shaft strength. In this paper, shaft-bearing system was taken as the study object. Hydrodynamic lubrication characteristics of a journal bearing considering misalignment caused by shaft deformation in shaft-bearing system were analysed. There are obvious offsetting distribution of film pressure and increase of the highest film pressure when journal misalignment takes place. Based on the lubrication analysis of bearing, the stress distribution of shaft was calculated when the film pressure calculated was used as boundary condition of load. The results show that there are obvious changes of stress distribution and great increase of stress near the area on shaft where it is acted upon the highest film pressure when considering the offsetting distribution of film pressure. The shaft strength is affected remarkably. Therefore, in order to accord with the tendency today for high precision in the design calculation, thus more reasonable design can be acquired, the coupling between the analysis of bearing tribology and the analysis of strength and stiffness of shaft must be studied in the design of shaft-bearing system.

Non-Linear Unstability Model and Analysis of the Engine Main Journal Bearing

2012 ◽  
Vol 246-247 ◽  
pp. 790-794
Author(s):  
Kang Shao ◽  
Chang Wen Liu ◽  
Feng Rong Bi ◽  
Xia Wang ◽  
Jian Zhang
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Main Bearing ◽  
Linear Effect ◽  
Non Linear ◽  
The Finite Difference Method ◽  
Engine Crankshaft ◽  
Bearing System ◽  
Oil Film Pressure

On the base of Reynolds equation, the dynamic load of an engine crankshaft main journal bearing system is studied. The oil film pressure is solved from the non-Newtonian Reynolds equation with non-linear model of a finite length journal bearing. The flexible crankshaft is coupling with hydrodynamic lubrication of bearing film. The elastohydrodynamic bearing is treated as non-linear bearing with the finite difference method when considered the unstability load that was acted on the main journal. This paper aims to identify the non-linear effect of engine main bearing in the case of unstability load.

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