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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Tribologists and Lubrication Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Tribologists and Lubrication Engineers
Editor in Chief :
Volume & Issues
Volume 25, Issue 6 - Dec 2009
Volume 25, Issue 5 - Oct 2009
Volume 25, Issue 4 - Aug 2009
Volume 25, Issue 3 - Jun 2009
Volume 25, Issue 2 - Apr 2009
Volume 25, Issue 1 - Feb 2009
Selecting the target year
Analytical Study on the Optimized Design of Engine Bearings for a Passenger Car
Kim, Chung-Kyun ; Kim, Han-Goo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 1~6
In this paper, the minimum oil film thickness and the maximum oil film pressure of engine bearings have been analyzed by using the elastohydrodynamic theory and Taguchi's design method as functions of the oil groove width, oil hole diameter, oil hole position, and oil supply pressure. The optimized design of the engine bearing f3r an automotive Diesel engine is very important for supporting a load-carrying capacity due to gas pres-sures from the engine combustion chamber and inertia forces of the piston. The optimized design data of engine bearings indicated that the optimized oil groove width and an oil diameter of a engine bearing are 8mm at the speed of 2,000 rpm for a given 4-cylinder Diesel engine. Thus, the oil groove oil groove and an oil hole for high performances of an engine bearing may be considered as major design parameters compared to other design factors, which are strongly related to the minimum oil film thickness and the maximum oil pressure distribution of the engine oil.
Analysis of Wear Properties for
Layer coated on Ferrous Materials by Diffusion Treatment after Combustion Synthesis at low Temperature
Lee, Han-Young ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 7~12
Coating brittle intermetallic compounds on metal can enlarge the range of their use. It is found that intermetallic compound coating layers made by only combustion synthesis in an electric furnace have porous multi-phase structures containing several intermediate phases, even though the coating layers show good wear resistance. In this study, dense
single phase layer corresponding to the initial composition of the mixed powder is coated on two different ferrous materials by the diffusing treatment after combustion synthesis. After- ward, sliding wear behaviors of the coating layer are evaluated in comparison with that of the coating layer with porous multi-phase structure made by only combustion synthesis. As a result, the wear properties of the coating layer composed of dense
single phase are considerably improved at the range of low sliding speed com- pared with that of the coating layer with porous multi-phase structure, particularly in the running-in wear region. This is attributed to the fact that wear of the coating layer is progressed by shearing as a sequence of adhesion, not by occurring of pitting on the worn surface due to having dense structure without pores.
Lubrication Analysis of Hydraulic Spool Valve with Groove Cross Sectional Shapes
Park, Tae-Jo ; Hwang, Yun-Geon ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 13~19
The spools in most hydraulic spool type control valve have several circumferential grooves to pre-vent well known hydraulic locking problems which result in high friction force and excessive wear. In this paper, a commercial computational fluid dynamics (CFD) code, FLUENT is used to investigate the flow and lubrication characteristics of grooved hydraulic spool valve. The stream lines and pressure distributions are obtained for various groove cross sectional shapes and film thicknesses. The stream lines are highly affected by groove cross sectional shape but pressure distributions mainly depend on the film shape and its magnitude. Therefore the numerical method adopted in this paper and results can be use in designing of various grooved spool valve.
Gas Reaction Time on Tribological Properties of TiC Derived Carbon Layer
Lim, Dae-Soon ; Bae, Heung-Taek ; Jeong, Ji-Hoon ; Na, Byung-Chul ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 20~24
TiC-derived carbon coatings have been synthesized at
temperature treatment with
mixture gases. From Raman spectroscopy measurements, the modified layer was covered with carbon and the thick-ness of the layer was increased with increasing reaction time. And
ratio was decreased with increasing reaction time. The superior tribological property was obtained from TiC reacted with
gas for 2 hrs. And the tribological property measurements indicate that TiC-derived carbon layer has
in wear coefficient and 0.13 in friction coefficient.
Tribological Characteristics in
Dimple Pattern for Hexagonal Array
Choi, Won-Sik ; Chae, Young-Hoon ; Umehara, Noritsugu ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 25~30
The Roles of Ingredients in Fade Resistance of Brake Friction Materials
Jang, Ho ; Cho, Keun-Hyung ; Han, Jae-Min ; Park, Sung-Bin ; Shin, Min-Wook ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 31~37
Optimization of the Gear Tooth Crowning Amount Considering Contact Subsurface Stress
Lee, Sang-Don ; Kim, Jong-Sung ; Cho, Yong-Joo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 38~42
Gear is an essential component of an automotive. Crowning is used for tooth modification of a gear. The basic concept of gear tooth crowning is to reduce the stress concentration in edge of contact area and appropriate profile modifications can help gears to resist scoring, pitting, and tooth breakage. In this study, a method to determinate spur gear tooth crowning amount to make smooth surface stress and subsurface stress distribution is proposed. This method is based on the contact analysis.
CFD Analysis of an Infinitely Long Slider Bearing with Two-Dimensional micro-Pockets
Park, Tae-Jo ; Hwang, Yun-Geon ; Sohn, Ja-Deok ; Chung, Ho-Gyeong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 43~48
It is reported by many researchers that the textured bearing surfaces, where many tiny micro-pockets or enclosed recesses were incorporated, can enhance the load support and reduce friction force. Recently, the basic lubrication mechanism of micro-pocketed parallel surfaces are explained in terms of "inlet suction" using continuity equation and simply cavitation condition. However, it is required that more actual cavitation condition in the pocket region should be applied to estimate exact bearing performance. In this paper, a commercial computational fluid dynamics (CFD) code, FLUENT is used to investigate the exact lubrication characteristics of infinitely long slider bearing with micro-pockets. The results show that the pressure distributions are highly affected by pocket depths, its positions and numbers. The numerical method adopted in this paper and results can be use in optimal design of textured sliding bearings.
The Effect of Abrasive Particles on the Frictional Properties of Automotive Brake Friction Materials
Jang, Ho ; Lee, Eun-Ju ; Cho, Keun-Hyung ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 49~55
The frictional properties of automotive brake pads with four different ceramic materials such as magnesia, hematite, alumina, and zircon were investigated. A Krauss type friction tester using gray iron disks was used to examine the friction coefficient, intensity of friction force oscillation, and the tribe-surfaces. Results showed that the friction coefficient increased as the hardness of abrasives increases. Friction oscillation was also increased with hardness of the abrasives. However, the friction materials containing less abrasive particles produced stable friction films on the sliding surface. The transition between two-body and three body abrasion during sliding also played a crucial role in destructing the friction film on the pad surface and in determining various frictional properties.
A Study on the Identification Method of Lubrication Characteristics for Journal Bearing
Kim, Myung-Hwan ; Lee, Sang-Don ; Cho, Yong-Joo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 56~60
A journal bearing is used in a hydrodynamic lubrication state, but it becomes a boundary lubrication state that asperity of a contact part touch each other when pressure is too high and an enough oil film is not formed by viscosity change due to lubricating oil temperature. At this time, abrasion due to contact between a journal and a bearing is unavoidable, and scuffing damage that the journal adheres to the bearing occurs if the process is repeated. Damage of the journal bearing is an important problem because it gives huge damage to a machine and can generate large accidents such as economic loss and human life damage. In this study, method for using the pull-up resistor concept was introduced as the monitoring technology. This monitoring system is important to enhance reliability of the engine.
Tribological Properties of Semi-metallic Brake Friction Materials Containing Different Solid Lubricants: Graphite,
Jang, Ho ; Shin, Min-Wook ; Kim, Yun-Cheol ; Chung, Dong-Yoon ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 61~65
Tribological properties of the semi-metallic friction materials containing different solid lubricants (graphite,
) were investigated. The friction materials were fabricated with an experimental formulation and tested with gray cast iron disks. Results showed that graphite contributed to stabilize the friction coefficient during run-in processes. Also, graphite provided better fade resistance than that of
. At intermediate temperature ranges, however, friction materials with
maintained higher friction effectiveness than that of graphite. On the other hand, friction materials containing
showed increased wear rates than that with graphite or
. Friction materials with proper combinations of two solid lubricants showed better friction and wear properties than that of the friction materials containing single solid lubricant.
Effect of MML on the Wear Behavior of Al/SiCp Composites
Kim, Yeong-Sik ; Kim, Kyun-Tak ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 25, issue 1, 2009, Pages 66~72
Al-based composites reinforced with SiC particulate were fabricated using a thermal spray process, and dry sliding wear behavior of the composites was investigated. Pre-mixed Al and SiC powders were sprayed on an A16061 substrate by flame spraying, and dry sliding wear test were performed under various sliding speed and applied load conditions against
ball. Wear behavior of the composites was studied by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). And build-up mechanism of MML on the worn surface of the composites was examined. It was revealed that these MML was formed of debris from the contact surface of the composites and effected to wear behavior of the composites protecting the contact surface of the composites.