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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Tribologists and Lubrication Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Tribologists and Lubrication Engineers
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Volume & Issues
Volume 21, Issue 6 - Dec 2005
Volume 21, Issue 5 - Oct 2005
Volume 21, Issue 4 - Aug 2005
Volume 21, Issue 3 - Jun 2005
Volume 21, Issue 2 - Apr 2005
Volume 21, Issue 1 - Feb 2005
Selecting the target year
An Experimental Study on the Effect of Surface Roughness on Nanoscale Adhesion
Yang Seung Ho ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 1~7
Effect of Surface roughness on nanoscale adhesion was studied experimentally by using colloidal probe technique. Glass micro balls having the radius of
were glued at the end of AFM cantilevers to prepare colloidal probes. Adhesion force between the colloidal probe and Si-wafer was measured using pull-off force measuring method. Results showed that the measured adhesion forces are not the function of the radius of the glued balls because the ball surfaces are rough. It is also found that roughness parameters such as
do not have important role on nanoscale adhesion. In order to find the effect of surface roughness on nanoscale adhesion, the bearing areas were extracted from the measured topography of glued balls. After normalizing the measured adhesion force with the bearing area, it was found that the normalized adhesion force kept constant as function of the radius of glued ball.
Lubrication Performance Analysis of a Spiral Groove Dry Gas Seal for a High-Speed Flying Object
Lee An Sung ; Kim Jun Ho ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 8~15
In this study a general Galerkin FE lubrication analysis method is utilized to analyze the complex lubrication performance of a spiral groove seal, which is being designed and developed for a high-speed flying object application operating at a high-speed of over 50,000 rpm. As at the equilibrium seal clearance the axial stiffness of the seal is predicted to have almost such a constant high value of
regardless of a rotating speed, the seal is expected to maintain a stable thickness of lubrication film under a certain external excitation acting. Also, as even at an ultra high-speed of 80,000 rpm the axial damping of the seal is shown to have a rotatively high value of 5,775 N-s/m, the dynamic stability of the seal system at the axial degree of freedom is assured well enough.
Influence of Stick-Slip Behavior on the Friction Force under Fretting Conditions
Lee Young-Ze ; Jeong Sung-Hoon ; Yong Suk-Ju ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 16~20
Friction and wear characteristics between two steel surfaces under fretting condition are investigated experimentally. The fretting damage caused by low-amplitude oscillatory sliding can be classified into three regimes of gross-slip, mixed-slip and partial-slip due to stick-slip phenomenon. One of the most important characteristics of fretting wear is the transition from gross-slip to mixed-slip. This study was focused on getting the degree of stick-slip out of the friction transition under fretting condition. Fretting wear is divided into three conditions of gross-slip/mixed-slip/partial-slip. The criteria for the division are friction and displacement amplitude, wear scar morphology and dissipated energy. In this test, friction force and displacement were measured for detecting the transition from mixed-slip to gross-slip and qualitatively predicting the degree of the wear.
A Study on Characteristics of the Optimum Urea Ope Grease for Rolling Bearings
Han Jongdae ; Kim Sangkeun ; Park Changnam ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 21~26
Rolling bearings are assorted one of the most important machine elements. The various functions of bearings are greatly influenced by grease, and higher performance of rolling bearing greases is required to improve rolling bearing lubrication. The two conditions for optimum grease synthesis were selected by SSRED (Six Sigma Robust Engineering Design) program by using dropping points and OIT values respectively. And the optimized two urea/ether oil greases were synthesized to compare the performance. The typical physical properties of grease were investigated. And life test of these greases was conducted by rolling bearing grease life tester. The characteristics of the greases before and after life test were investigated using FTIR, microscope, SEM, TG/DSC, OIT and TAN meter. The optimized two greases showed longer life time than typical urea/ether oil grease. The optimized grease by means of OIT value showed higher performance such as long life time, low TAN value and high oil bleeding amount in comparison with the optimized grease using dropping point.
Performance Analysis of Pistons for Sealess Pneumatic Cylinders
Kim Young-Cheol ; Kim Dong-Soo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 27~32
This paper shows a performance analysis for step type and conical type sealess cylinders. 2 dimensional Reynolds equation and finite difference numerical techniques are utilized for the performance analysis and the piston design. Centering forces of conical pistons are higher than those of step ones. Also, leakage flows of conical pistons are lower than those of step ones. But, the step type piston is practically suggested to apply for sealess cylinders because it is difficult that conical portion is precisely manufactured.
Investigation of Wear Mechanisms of Tube Materials for Nuclear Steam Generators due to Stick-Slip Behavior under Fretting Conditions
Lee Young-Ze ; Jeong Sung-Hoon ; Park Chi-Yong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 33~38
Fretting is the oscillatory motion with very small amplitudes, which usually occurs between two solid surfaces in contact. Fretting wear is the removal of material from contacting surfaces through fretting action. Fretting wear of steam generator tubes in nuclear power plant becomes a serious problem in recent years. The materials for the tubes usually are Inconel 690 (I-690) and Inconel 600 (I-600). In this paper, fretting wear tests for I-690 and I-600 were performed under various applied loads in water at room temperature. Results showed that the fretting wear loss of I-690 and I-600 tubes was largely influenced by stick-slip. The fretting wear mechanisms were the abrasive wear in slip regime and the delamination wear in stick regime. Also, I-690 had somewhat better wear resistance than I-600.
Study on the Dynamic Behaviors of Engine Bearing with the Inertia Effect of Crank Pin Journal
Jang Siyoul ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 21, issue 1, 2005, Pages 39~45
Investigation of the mass effect on the journal traces in the clearance of engine bearing has been performed for better design of mass distribution of crank system components such as crank pin, piston, con-rod, balance weight, crank throw weight, etc. as well as for better oil reaction behaviors to the applied forces from the cylinder pressures on the bearing. In this preliminary study, crank pin traces in the engine bearing clearance are computed by varying the equivalent magnitude of crank pin mass that includes the masses of crank pin, piston, con-rod. etc.. while most previous studies regarding journal traces in the bearing clearance neglect the inertia effects of crank pin mass. Although the inertia effect of pill mass is negligibly small compared to viscous force by
theory, it is found that it gives a great amount of influences on the journal traces in full bearing computation
under the dynamic loading conditions.