Go to the main menu
Skip to content
Go to bottom
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
Editor in Chief :
Volume & Issues
Volume 17, Issue 6 - Dec 2001
Volume 17, Issue 5 - Oct 2001
Volume 17, Issue 4 - Aug 2001
Volume 17, Issue 3 - Jun 2001
Volume 17, Issue 2 - Apr 2001
Volume 17, Issue 1 - Feb 2001
Selecting the target year
Effect of Silver Particle Introduction on Rolling Friction
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 417~426
The effect of silver particle introduction on the rolling friction of AISI 52100 steel pairs has been investigated. Experiments ware performed in dry conditions using a thrust bearing-type rolling test rig at a load range of 12-960 N and a sliding velocity range of 8-785 mm/sec with pure (99.99%) silver particles. Results showed that introduced silver particles formed transfer layers, which protected the virgin bearing surfaces and resulted in the low lolling friction. By changing the quantity of silver particles, transitions in the rolling friction were found. Results also showed that the variations in normal load and rolling speed also affected the rolling friction behavior. Analyses of SEM and EPMA showed that the formation the transfer layer was mainly governed by the silver particle quantity, normal load and rolling speed, and this resulted in the different behavior of rolling friction. In this study, it was found that the low and stable rolling friction was resulted from the, shakedown phenomena occurred at the silver transfer layer.
Dynamic Behavior Analysis of a Crankshaft-Bearing System in Variable Speed Reciprocating Compressor
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 426~434
The hermetic reciprocating compressor driven by the BLDC motor rotating with variable speeds, is modelled and analyzed for dynamic characteristics. The governing equations of piston, connecting rod and crank-shaft of the reciprocating compression mechanism and characteristics of driving torque of the motor are obtained. Dynamic behavior of the crankshaft supported on 2 journal bearings is analyzed considering compression load and eccentric unbalance for the 4 rotating speeds of crankshaft. And. reaction forces generated from oil film in the journal bearings are analyzed under transient condition using Reynolds' equation. To take into account the dynamic characteristics depending on the variable rotating speeds, comparison on the dynamic behavior of crank-shaft is made for the 4 operating modes of the compressor. Results show that the magnitude of crankshaft locioperating on the lower rotating speeds is more larger than the higher ones due to reduction of inertia force of the reciprocating piston.
A Lubrication Analysis between the Piston and Cylinder in Hydraulic Piston Pumps Part II : The Effect of Piston Reciprocating Motion
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 435~440
A numerical analysis between the piston and cylinder in hydraulic piston pumps under reciprocating motion is presented. A finite difference method and the Newton-Raphson method are used simultaneously to solve the Reynolds equation in the clearance and the equation of motion for the piston. The tapered piston showed stable behaviors regardless of their initial eccentric positions in the clearance, and the reciprocating speed affect highly on the piston end trajectories. Therefore, the numerical methods and results of present study can be used in the lubrication study of other piston-cylinder type fluid machineries.
A Study on the Lift-off Characteristics of an Air-lubricated Bump Foil Journal Rearing
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 441~446
In this paper the effect of bump compliance, load, and the number of pad on the lift-off speed is studied. When the load is greater and bump compliance lower, the shaft is lifted off at higher rotating speed. And when the load is applied near the center of pad, lift-off speed is lower. When the number of pad increases, the lift-off speed is higher. The lift-off characteristics can be used to lengthen the lift time of the coating and design the rotating machinery supported by bump bearings.
A Study on the Aeration Mechanism in the Engine Lubrication System
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 447~452
In development process of engine lubrication system, many failure cases are related with aeration problem. Therefore, it is very important to clarify the aeration in the engine oil circuit system. As of today, many factors have been introduced as the major cause in the engine oil aeration. However, still many test data related with those are required to clearly understand it. In this paper the aeration measurement system and calculation method are introduced. And also using this system we measured engine oil aeration for various cases. From these results some conclusions are reduced.
Fretting Wear Mechanisms of TiN Coated Nuclear Fuel Rod Cladding Tube
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 453~458
The fretting wear of a nuclear fuel rod it a dangerous phenomenon. In this study, TiN coating was used to reduce the fretting wear of Zircaloy-4 tube, a nuclear fuel rod cladding material. TiN coating is probably one of the molt frequently and successfully used PVD coatings for the mitigation of fretting wear. The fretting tester was designed and manufactured for this experiment. The number of cycles, slip amplitude and normal load were selected as main factors of fretting wear. The results of this research showed that wear volume was improved 1.3∼3.2 times with TiN coating. The worn surfaces were observed by SEM. Wear mechanism at lower slip amplitude was the brittle cracks and rupture of TiN coating. However, adhesive and abrasive wear were mainly observed on most surfaces at higher slip amplitude.
The Effect of Oxide Layer Formed on TiN Coated Ball and Steel Disk on Friction Characteristics in Various Sliding Conditions
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 459~466
In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk on friction characteristics in various sliding conditions were investigated. AISI52100 steel ball was used for the substrate of coated ball specimens, which were prepared by depositing TiN coating with 1(m in coating thickness. AISI1045 steel was used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of two materials, the tests were performed both in air for forming oxide layer on the contact parts and in nitrogen environment to avoid oxidation. From the test results, the frictional characteristic between the two materials was predominated by iron oxide layer that formed on wear tract of counter-body and this layer caused friction transition and high friction. And the adhesive wear occurred from steel disk to TiN coated ball caused the formation of oxide layer on counter parts between the two materials.
Feasibility Study on Design of Thrust Bearing for Micro Gas Turbine Generator
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 467~475
Feasibility study of gas-lubricated bearing in micro gas turbine was performed. Based on Reynolds equation, finite difference method with coupled boundary was developed to analyze bearing characteristics, such as load capacity, mass flow rates and stiffness. By the bearing force and mass flow rates analysis with the variation of supply pressure, bearing clearance and capillary radius, acceptable range of design parameters were suggested in terms of load capacity and stiffness of bearings. Additionally, coupled boundary effect on pressure distribution was investigated and it is stated that coupling could reduce an excitation force due to narrow pressure distribution.
An Experimental Study on the Dynamic Coefficient According to the Source Positions in Externally Pressurized Air-lubricated Journal Bearing with Two Row Sources
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 476~481
This paper has been presented the hydrodynamic effect by the journal speed, eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from existed investigations in the side of pressure distribution of air film because of the high speed of journal and the wedge effects by the eccentricity. These optimal chooses of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high speed spindle. In this paper, The pressure behavior in theory of air film according to the eccentricity of journal and the source positions analyzed. The theoretical analysis have been identified by experiments. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high speed milling.
An Experimental Study on the Light Transmission Characteristics with Oil Contamination
Journal of the Korean Society of Tribologists and Lubrication Engineers, volume 17, issue 6, 2001, Pages 482~489
Changes in light transmission characteristics caused by various types of oil contaminations were experimentally measured with a built-in type wear monitoring device. Three kinds of iron powders of different size distribution, carbon duct, two kinds of solutions and grease were used for the test contaminants in this work. Light intensity of the transmitted light was measured with the contamination level. Results showed that the transmitted light intensity decreased linearly with the contamination concentration in the oil and the slope was affected by the size distribution. Light attenuation was also caused greatly by carbon dust, water contamination and poly-meric fibers in terms of the light absorption. As a result, it was proved that the optical measurement device could be applicable effectively for detecting any significant change in lubricating oils.