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.

Analysis of Oil Film Generation on the Main Journal Bearing Using a Thin-Film Sensor and Elasto-Hydrodynamic Lubrication (EHL) Model

2013 ◽  
Vol 6 (1) ◽  
pp. 119-125 ◽  
Author(s):  
Masatsugu Inui ◽  
Makoto Kobayashi ◽  
Kensaku Oowaki ◽  
Takayoshi Furukawa ◽  
Yuji Mihara ◽  
...  
Keyword(s):  
Thin Film ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Film Sensor ◽  
Thin Film Sensor ◽  
Oil Film

Hydrodynamic Lubrication of Hydrostatic Extrusion

1976 ◽  
Vol 98 (1) ◽  
pp. 27-31 ◽  
Author(s):  
W. R. D. Wilson ◽  
S. M. Mahdavian
Keyword(s):  
Film Thickness ◽  
Castor Oil ◽  
Hydrodynamic Lubrication ◽  
Film Formation ◽  
Hydrostatic Extrusion ◽  
Work Zone ◽  
Thickness Variation ◽  
Viscous Heating ◽  
Theoretical Predictions ◽  
Good Agreement

An analytical model for the hydrodynamic lubrication of hydrostatic extrusion is developed. This includes the effect of viscous heating on the film formation process and the effect of viscous and plastic heating on the friction and film thickness variation in the work zone. Theoretical predictions of film thickness and extrusion pressure show good agreement with experimental measurements for aluminum billets lubricated with castor oil.

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.

scholarly journals CFD Analysis of Thin Film Lubricated Journal Bearing

2013 ◽  
Vol 68 ◽  
pp. 56-62 ◽  
Author(s):  
B. Manshoor ◽  
M. Jaat ◽  
Zaman Izzuddin ◽  
Khalid Amir
Keyword(s):  
Thin Film ◽  
Journal Bearing ◽  
Cfd Analysis

Investigation of sustainability of lubricated journal bearing under relevant design parameters

2018 ◽  
Vol 70 (4) ◽  
pp. 789-804 ◽  
Author(s):  
M.M. Shahin ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Arefin Kowser ◽  
Uttam Kumar Debnath ◽  
M.H. Monir
Keyword(s):  
Aspect Ratio ◽  
Elastic Strain ◽  
Journal Bearing ◽  
Design Parameters ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Stress Formation ◽  
Bearing Design ◽  
The Stability ◽  
Bearing Friction

Purpose The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic strain, total deformation and stress formation. Design/methodology/approach A journal bearing test rig was used to determine the effect of the applied load on the bearing friction, film thickness, lubricant film pressure, etc. A steady-state analysis was performed to obtain the bearing performance. Findings An efficient aspect ratio (L/D) range was obtained to increase the durability or the stability of the bearing while the bearing is in the working condition by using SAE 5W-30 oil. The results from the study were compared with previous studies in which different types of oil and water, such as Newtonian fluid (NF), magnetorheological fluid (MRF) and nonmagnetorheological fluid (NMRF), were used as the lubricant. To ensure a preferable aspect ratio range (0.25-0.50), a computational fluid dynamics (CFD) analysis was conducted by ANSYS; the results show a lower elastic strain and deformation within the preferable aspect ratio (0.25-0.50) rather than a higher aspect ratio using the SAE 5W-30 oil. Originality/value It is expected that the findings of this study will contribute to the improvement of the bearing design and the bearing lubricating system.

Hydrodynamic Lubrication of Pocket Bearings and Effect of Contouring the Inner and Outer Regions, and Optimum Design Data

1989 ◽  
Author(s):  
C. Bagci ◽  
C. J. McClure ◽  
S. K. Rajavenkateswaran
Keyword(s):  
Optimum Design ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Load Flow ◽  
Temperature Dependent Viscosity ◽  
Design Data ◽  
Planar Surfaces ◽  
Friction Factors ◽  
The Coefficient Of Friction ◽  
Dependent Viscosity

Abstract The article investigates pocket bearings with contoured profiles of exponential forms on both surfaces inside and outside of the step boundary forming hydro-dynamic action surfaces, and develops optimum design data yielding efficient slider bearings with small pockets with higher load capacities than conventional pocket bearings. In the case of a pocket bearings, in addition to the Reynolds equation used for the regions inside and outside the pocket, the continuity equation along the pocket boundary is satisfied to form the complete model of the bearing. The optimum design data includes dimensionless load-, flow-, temperature rise-, power loss-, stiffness-, and the coefficient of friction factors. Incompressible lubricant with temperature dependent viscosity is considered. Detailed study of conventional pocket bearings with planar surfaces is included. Some optimum exponential pocket bearings yield up to 561 percent increase in load capacity as compared to the conventional tapered bearings.

Classification of journal bearing friction states based on acoustic emission signals

2018 ◽  
Vol 85 (6) ◽  
pp. 434-442 ◽  
Author(s):  
Noushin Mokhtari ◽  
Clemens Gühmann
Keyword(s):  
Acoustic Emission ◽  
Time Domain ◽  
Journal Bearing ◽  
Prediction Method ◽  
Support Vector ◽  
Mechatronic Systems ◽  
Prediction Time ◽  
Ae Signals ◽  
Bearing Friction

Abstract For diagnosis and predictive maintenance of mechatronic systems, monitoring of bearings is essential. An important building block for this is the determination of the bearing friction condition. This paper deals with the possibility of monitoring different journal bearing friction states, such as mixed and fluid friction, and examines a new approach to distinguish between different friction intensities under several speed and load combinations based on feature extraction and feature selection methods applied on acoustic emission (AE) signals. The aim of this work is to identify separation effective features of AE signals to subsequently classify the journal bearing friction states. Furthermore, the acquired features give information about the mixed friction intensity, which is significant for remaining useful lifetime (RUL) prediction. Time domain features as well as features in the frequency domain have been investigated in this work. To increase the sensitivity of the extracted features the AE signals were transformed to the frequency-time-domain using continuous wavelet transform (CWT). Significant frequency bands are determined to separate different friction states more effective. A support vector machine (SVM) is used to classify the signals into three different friction classes. In the end the idea for an RUL prediction method by using the already determined information is given and explained.

scholarly journals Влияние химического состава и локальной атомной упаковки твердосмазочных нанопокрытий MoS-=SUB=-x-=/SUB=- и MoSe-=SUB=-x-=/SUB=- на их трибологические свойства в осложненных условиях

2020 ◽  
Vol 46 (2) ◽  
pp. 36
Author(s):  
В.Ю. Фоминский ◽  
В.Н. Неволин ◽  
Д.В. Фоминский ◽  
Р.И. Романов ◽  
М.Д. Грицкевич
Keyword(s):  
Thin Film ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Friction And Wear ◽  
Pulsed Laser ◽  
Amorphous Structure ◽  
Laser Deposition ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
The Coefficient Of Friction

The results of a comparative study of the friction and wear of MoSx and MoSex thin film coatings that was carried out in an oxidizing medium (a mixture of argon and air) at a temperature of -100°C are presented. The films were obtained by pulsed laser deposition from MoS2, MoSe2, and Mo targets in vacuum and H2S. It was established that Se-containing coatings significantly exceeded the S-containing coatings in terms of wear resistance and provided a friction coefficient of ~ 0.09. The properties of MoSx films depended on the S concentration, which determines the local packing of atoms in the amorphous structure of the film. The coefficient of friction for MoS3 films after running-in turned out to be half as much as that for MoS2 films, and its value was 0.08.

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