• Journal of the korean Society of Automotive Engineers
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• v.5 no.1
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• pp.45-53
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• 1983

There exist many kinds of frictions in internal combustion engine such as piston ring and skirt, cam and tappet, bearing friction etc. Among them, the frictions between piston ring, skirt and cylinder are particular. These frictions for motoring test are differ from that of firing test even though the temperature of cooling water and lubricating oil keep identically. The frictions for firing test are increased due to combustion pressure and products. The precise calculation of the friction is difficult. But we can assume that the friction is governed by the viscosity of lubricating oil and gas pressure of cylinder. And the viscosity of lubricating oil is dependant on gas temperature of cylinder, so the piston friction may be governed by gas pressure and temperature of cylinder. In this treatise, we propose the method of evaluating piston friction under the condition of constant engine speed, and we analyzed the behaviours and influence of factors concerned with the piston friction for output correction when the inlet pressure and temperature were varied. The main results are as follows: 1) The behaviours on the inlet conditions for the contact force of the piston rings and the viscosity of the lubricating oil concerned with piston friction are found. 2) The essential point the these behaviours is dependant on the cyclic variation following to the inlet conditions. 3) According to our analysis, It was observed that the viscosity of lubricating oil is more effective than the contact force to the piston rings.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.244-247
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• 2001

Lubricanting characteristics in the warm forging have influence on forgeability of products. but Research on deformation characteristic of warm forging on the lubricant and lubricating method lack. This paper deform a bevel gear by warm forging and evaluate deformation loads and quality of products by each lubricants and lubricating method using oil-based lubricants(Soy, Oildag) and water-based lubricants(Deltaforge $\#31$, Renite S-26-X, Deltaglaze $\#151$). In conclusion, the less a deformation load by lubricants the more improvement a quality of product in manufacture of a bevel gear and water-based lubricants in the warm forging reduce a deformation load and improve a quality of products. Especially, Deltaforge $\31$ have excellent characteristic in the warm forging.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.30-37
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• 2002

Recently, there have been frequent environmental threats associated with the red tide. The discharge of bilge water and waste lubricating oil from fishing vessels is known to be the major cause of such problems. In oder to treat those wastes, post processing units at harbours are being considered, and an accurate prediction of the amount of such wastes is required. In this paper we have proposed a method to estimate the amount of bilge water and waste lubricating oil from fishing vessels. We identified the key parameters affecting the quantity of oily bilge water and waste lubricating oil, and proposed a prediction model. We applied the present model to estimate the quantity of oily bilge water and waste lubricating oil in the sample fishing port.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.130-136
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• 2004

Presence of water in the lubricating oils could be one of the first indicators of potentially expensive and possibly catastrophic failure of the machine as it may cause displace the oil films to prevent the lubrication function of the oil or chemically react with many oil additives resulting in the oil degradation. In order to detect water content quantitatively in lubricating oils many methods and sensors has been developed. Among these, capacitive sensors including sensitive layer, whose dielectric factor changes according to the water content absorbed in the layer, are proposed mainly in the market. But these sensors are not sensitive to a high water content. Besides, the absorbing layer soils in time. In this work, an evaporation of water moisture from oil into air volume above lubricant surface and condensation of water vapor at a cooling surface was used to measure water content quantitatively in an lubricating oil. Laboratory test results of a prototype sensor were presented. Test results showed that the proposed method could be avaliable to measure a low levels of oil moisture.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.285-286
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• 2002

The lubricating characteristics of negative pressure slider were performed by using divergence formulation method with the coordinate transformation method. This method makes it possible to deal with an arbitrary configuration of a lubricated surface. The pressure profile of the slider is calculated. These results are compared to that from direct numerical method. The steady-state, including minimum film thickness, pitching and rolling angle are calculated by multi-dimensional Newton-Rapson method. The stiffness and damping characteristics are also calculated.

• Journal of the Korean Applied Science and Technology
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• v.15 no.1
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• pp.1-7
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• 1998

Lubricating softner(SOS-2) for permanent press(PP) finish was prepared by blending water, beef tallow hardened oil for improving softness, and the emulsion which was synthesized from N-hexadecanoyl-N,N'-bis(2-hexadecamidoethyl)amine as a softening component and silicone oil KF-96 as a lubricating component. The prepared SOS-2 and the PP finishing resin were applied to PP finishing cotton broad cloth and P/C gingham samples using one bath method. The properties such as tear strength, crease recovery, bending resistance test were tested. The samples treated with SOS-2 and PP finishing resin have improved properties, compared with nontreated samples, those treated only with PP finishing resin, those treated with commercial PP finishing softners and PP finishing resin.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1063-1072
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• 2000

Kinetic tests on pyrolysis of the mixture of waste automobile lubricating oil and polystyrene were carried out with thermogravimetric technique at the heating rates of 0.5, 1.0, $2.0^{\circ}C/min$ in a stirred batch reactor. The activation energy and the reaction order were determined at conversions of 1 to 100% using differential method. The mixture of waste automobile lubricating oil and polystyrene was pyrolyzed at lower temperature rather than waste automobile lubricating oil and polystyrene. respectively. Also, the thermal decomposition took place in two broad reaction steps. The pyrolyzed oil of mixture represented high selectivity of styrene monomer and dimer like that of polystyrene pyrolyzed products.

• Tribology and Lubricants
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• v.10 no.4
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• pp.69-74
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• 1994

The space world under zero gravity and super vacuum where the space machine works has only friction and inertia. Inertia of acceleration and diceleration is accurately obtained by computing while friction is always in contact surface and unsteady. The sur soundings under super vacuum make surface friction more complicate. [1,2]. Therefore, method to lubricate stably the contact surface for long term in space machine is very important and friction for space machine proves to be true by several accident of space projects. In spite of that accident, method of lubrication and lubricants to keep stablity for long term in space machine have not been established so far. Lubrication for space machine is very important and under developings over the world. In this study we suggest a new lubricating technology, which improves powerful for space machine.

• Analytical Science and Technology
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• v.18 no.2
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• pp.168-172
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• 2005

A comparison study of XRF and $^{31}P$-NMR method for the analysis of phosphorous in lubricating oil has been described. Pure oil and water were used for the observation of matrices effect variation by different analytical methods. Quantitative analysis was carried out by XRF and $^{31}P$-NMR using real samples. Significant difference is observed from the slopes on the calibration curves by the XRF due to the matrices (water: 124.0, oil: 276.6). While the result obtained from XRF showed a large matrix effect, the slopes obtained from $^{31}P$-NMR results of two different matrices, however, are in good agreement ranged of ${\pm}9%$ (water: 4.9, oil: 5.3).

• Tribology and Lubricants
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• v.12 no.1
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• pp.15-21
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• 1996

Friction and wear properties of MoS$_2$ bonded films were studied using the Falex testing machine, and their properties were evaluated in terms of the life and the load carrying capacity of the films. MoS$_2$ bonded films were formulated from the mixtures of MoS$_2$ solid particles and epoxyphenol resin, and they were applied onto AISI 4130 steel surface by dipping method to form lubricating bonded films. The results of the life and the load carrying capacity of the films showed that films were mainly affected by the surface temperature arisen from the frictional heat at the contact surface. To obtain enhanced tribological properties of the films, various combinations of solid lubricants and additives with a basic polymer resin were attempted and evaluated. The effects of surface pretreatment, such as sand blast or Zn-phosphating, were also investigated.