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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 22, Issue 6 - Dec 2006
Volume 22, Issue 5 - Oct 2006
Volume 22, Issue 4 - Aug 2006
Volume 22, Issue 3 - Jun 2006
Volume 22, Issue 2 - Apr 2006
Volume 22, Issue 1 - Feb 2006
Selecting the target year
The Effect of Pressure on Viscosity in Grooved Hydraulic Spool Valves
Park, Tae-Jo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 307~313
In this paper, a theoretical analysis is carried out to study the effect of viscosity variation with pressure in multiply grooved moving hydraulic spool valves. Analytical expressions for pressure distribution in the clearance and leakage flowrate are obtained solving one-dimensional Reynolds. For constant viscosity, an analytical expression for lateral force is also presented. The results showed that variation of viscosity with pressure affect highly on pressure distribution, leakage flowrate and lateral forces in hydraulic spool valves. Therefore additional intensive studies, including numerical analysis for two-dimensional Reynolds, should be required to investigate detailed lubrication characteristics of spool valves for high pressure.
A Study on the Friction and Wear Characteristics of Contact Sealing Units for a Small Hydro-power Turbine Under Various Rubbing Conditions
Kim, Chung-Kyun ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 314~319
In this paper, the friction and wear characteristics of contact type sealing unit far a water turbine have been presented. The sealing unit for a small hydropower generation is to stop a leakage of circulating water from an outside of an impeller to an inside of a rolling bearing. The friction heating between a seal ring and a seal seat may radically increase a surface temperature in which increase a power loss and wear on the rubbing surface. The surface wear strongly affect to the seal life of a mechanical face seal. In this study, the hardness of a stainless steel in which is a heat-treated is 892.8 in Victors hardness and the hardness of silicone carbide of SiC is 714.1 in Victors hardness. The surface hardness of a heat-treated stainless steel is 25% high compared with that of a ceramic material of SiC. The contact modes of rubbing surfaces are a dry friction, a water film friction and a mixed friction that is contaminated by a dust, silt, and moistures, etc. These two factors of a contact rubbing modes and a material property are very important parameters on the tribological performance such as a friction and wear between a seal ring and a seal seat in primary sealing unit. The experimental result shows that the surface hardness of a seal material is very important on the friction coefficient and a wear volume. Thus, the results recommend higher hardness of a seal material, which may reduce a friction loss and increase a wear life of primary seal components.
Contact Fatigue Life Prediction under Elliptical Elastohydrodynamic Lubrication
Kim, Tae-Wan ; Lee, Sang-Don ; Koo, Young-Pil ; Cho, Yang-Joo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 320~328
In this study, the simulation of rolling contact fatigue based on stress analysis is conducted under Elastohydrodynamic Lubrication state. To predict a crack initiation life accurately, it is necessary to calculate contact stress and subsurface stresses accurately. Contact stresses are obtained by contact analysis of a semi-infinile solid based on the use of influence functions and the subsurface stress field is obtained using rectangular patch solutions. And a numerical algorithm using Newton-Rapson method was constructed to calculate the Elastohydrodynamic lubrication pressure. Based on these stress values, several multiaxial high-cycle fatigue criteria are used and the critical loads corresponding to fatigue limits are calculated.
Analysis of Check Valve Seal for CNG Vehicle Fuel Supply Line
Yoo, Jae-Chan ; Yeo, Kyeong-Mo ; Kang, Byeong-Roo ; Park, Tae-Jo ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 329~334
In CNG (Compressed natural gas) fuel supply line, whose main components are receptacle and check valve are used to charge high pressure gas to the tank of NGV (Natural gas vehicle). It is reported that the seal is separated occasionally form valve seat and results in blockage of gas flow. In this paper, MARC is used to investigate the reasons of seal separation and suggest design improvements. The static gas pressure distributions acting on the seal which calculated using FLUENT are considered to investigate accurate seal deformation behaviors. Deformed seal shapes are obtained for various amounts of seal interference and its location, gas pressure distributions and Young's modulus of the rubber used. The results showed that the reasons of seal separation problems are verified theoretically, and suggested examples of new design method. Therefore the present numerical methods can be applied in designing and performance analysis of rubber seals adopted in high pressure fluid machineries.
Wear Characteristics of
Coating Materials by Plasma Spray
Kim, Sung-Ig ; Kim, Hee-Gon ; Lee, Bong-Gil ; Kim, Gui-Shik ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 335~341
This paper reports the wear characteristics of two types of coating materials, which are
, by coated plasma thermal spray method. The wear test was carried out under air, grease, and bearing fluid conditions. The wear testing machine of a pin-on disk type were used to measure friction forces, friction coefficients and the weight losses of the coating specimens on the various sliding velocity and loading condition. The wear surface of specimens were observed by scanning electron microscope (SEM) photographs.
Analysis of the Dynamic Behavior and Characteristics of the CNG Compressor Considering Bearing Characteristics
Kim, Tae-Jong ;
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 22, issue 6, 2006, Pages 342~349
In this study, a dynamic behavior of rotor-bearing system used in CNG compressor has been investigated using the combined methodologies of finite elements and transfer matrices. The finite element is formulated including the field element for a shaft section and the point element for roller bearings. The Houbolt method is used to consider the time march for the integration of the system equations. The transient whirl response of rotating shaft supported on roller bearings is obtained, considering compression forces and unbalance forces at eccentric crank-pin part. And, the steady state displacements of the rotor are compared with a variation in stiffness coefficient of roller bearings. Results show that the loci of crankshaft considering unbalance forces and external compression forces are more severe in whirl motion than with only unbalance forces.