• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.3-42
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• 1997

A Development of Next Generation Gear Oils Is Very Complicated. Balancing Component Durability And Other Requirements (Fuel Economy, Etc.)Are Critical For A Successful Development Of The Next Generation Gear Oils.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.134-154
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• 2000

New engine design changes and ever increasing requirements make the design of gear oils challenging. Proper understanding of fundamental lubrication theory and formulation knowledge is necessary to develop new gear oils. This paper provides an overview on fundamentals of lubrication theory and functions of each additive. Also, key technical issues facing gear oils are discussed.

• Tribology and Lubricants
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• v.8 no.1
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• pp.24-29
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• 1992

Friction and wear characteristics of gear oils added load carrying aditives, JS and DBP have been invesitigated using Shell Four Ball Tester and Cygnus and also compared with commercial gear oil. The Gear oil added DBP among them showed excellent friction and wear performances, which is deduced by action mechanism of additives. The surface analysis of the worn balls was conducted using an optical microscope.

• Tribology and Lubricants
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• v.11 no.5
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• pp.136-143
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• 1995

The effect of additive chemistry on the serface fatigue of gears was investigated using the FZG gear tester and fluids based on an API GL-5 grade oil. Surface fatigue lives were determined as a function of load and additive chemistry. At 1.52 GPa, the removal of the primary extreme pressure additive (EP) from the fully formulated gear oil decreased the fatigue life of gears slightly (4%), however, the removal of the primary antiwear additive (AW) decreased the fatigue life of gears significantly (83%). At 1.86 GPa, the removal of the EP additive from the fully formulated gear oil decresed the gear fatigue life 27%, however, the removal of the primary AW additive decreased the fatigue life of gears significantly (75%). Micropitting was the dominant surface morphology in the dedendum of gears tested With two oils at load stage: one using the complete additive package, and a second where the EP additive has been removed. However, spalling is the primary failure mode of gears tested without an AW additive independent of whether an EP agent was present. Surface analysis of pinion gears showed the formation of a mixed phosphate/phosphite-oxide layer on the surface of gears tested with fluids containing an AW. Formation of this layer seems to be key to long fatigue life.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10a
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• pp.21-24
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• 2002

There is a trend with driveline lubricants toward improved thermal stability, vehicle component durability and fuel efficiency. These improvements can significantly reduce vehicle operating costs and improve customer satisfaction. Of these improvements, the fuel efficiency is getting a substantial attention due to recent focus on $CO_2$ emission control in Europe, Japan and $CAF{\'{E}}$ requirement in U.S.A. Lower viscosity axle oils and transmission fluids are currently being evaluated as potential solutions since these lubricants tend to reduce the churning losses and can improve the fuel efficiency. However, these lubricants should provide adequate gear and bearing protection, while increasing the overall efficiency of the driveline components. In this paper, the development of new fuel efficient axle was discussed with the focus on the effect of base oils, additives, and viscosity modifiers on the fuel efficiency of driveline components.

• Tribology and Lubricants
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• v.26 no.1
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• pp.61-67
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• 2010

The purpose of this paper is to study and analyze the failure examples on tribological characteristics of an automotive steering system. In this failure study, the grease leakage may stick leaked grease, dust, and wear particles between pinion and rack gears in mechanical steering system. In the case of seal failures such as a rod seal, o-ring and oil seals, the gear box and oil pump do not operate properly due to lack of oils. This means that oil pump does not supply a working fluid and produce a normal oil pressure of the steering system. This leads to leak a working fluid from the seals and produce a wear between pinion and rack gears. Especially, the leaked oil is usually mixed with internal wear particles and foreign dust/fine sands. Thus no leakage of working oils is very important design concepts, which is strongly related to the sealing components and smoothly operating of the mechanical friction parts of power steering system.

• Analytical Science and Technology
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• v.26 no.4
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• pp.276-286
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• 2013

This study was performed to investigate the contents characteristics of hazardous oil wastes and wastes of liquid fuels from different industrial process. In order to establish a hazardous waste list, samples of various industrial discharge have been analyzed for 16 non-regulated inorganic hazardous substances (i.e., Cu, Pb, Cd, CN, Hg, As, T-Cr, $Cr^{6+}$, Sb, Ni, F, V, Ba, Zn, Be, Se). In more detail, hazardous waste samples including waste hydraulic oils, waste engine, gear and lubricating oils, waste insulating and heat transmission oils, bilge oils, oil/water separator contents processing were collected from 37 workplaces and analyzed. We observed that the most of the inorganic substances exceeded the proposed criteria in many samples. Especially the concentration of Sb in heat transmission oil, bilge oil and gear & lubricating oils were ranged from 6 to 419 mg/kg whereas the proposed criteria is 50 mg/kg. The assessment result of hazardous waste in Korea according to the EWC showed that the out of 24 processes, 16 belongs to absolute entry and 8 belongs to mirror entry. In conclusion, we expect the outcome of this study to align the classification system of hazardous waste management in South Korea with international legislations, and consequently contribute to reduce environmental pollution as well as health risks by toxic wastes.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.311-312
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• 2002

Friction losses in complex tribo-technical system are revealed primarily through their effect on the operating temperature level. In order to assess the influence of the oil formulation on the temperature level comprehensive tests were run in a model test apparatus consisting of a special adapter for the 4-ball test rig. More than ten with different formulations (different base oils, additive packages and viscosity modifiers) were tested, The resulting temperature levels varied by nearly 25 %. The objective of this model testing is to assess the influence of the oil formulation on the operating temperature of vehicle manual transmission. The correlation to the real tribotechnical system was confirmed by a VW Polo transmission test.

• Clean Technology
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• v.19 no.2
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• pp.140-147
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• 2013

In this study, chemical demulsification and electrical treatment methods were investigated for improving the efficiency of water separation from a water/bitumen emulsion. Two types of motor oils (GS Caltex, Deluxe Gold V 7.5 W/30 and, Hyundai gear oil 85 W/140) were used as model oils in basic experiments to investigate the effects of a demulsifier on water/oil emulsion separation. Chemical demulsifiers showing good water separation performance were then used in asphalt emulsion and bitumen emulsion separation trials. Maleic anhydride and e-caprolactam were shown to be good oil soluble demulsifiers and 2-ethylhexyl acrylate and acrylic acid were effective as water soluble demulsifiers. Based on the results obtained in basic experiments, these four demulsifiers were used in further asphalt emulsion experiments. The oil soluble demulsifiers showed higher water separation efficiencies than the water soluble demulsifiers. To investigate the water separation efficiency using a combined chemical and electrical treatment method, the water/bitumen emulsion was separated with the electrical oil treatment apparatus after a chemical demulsifier had been added to it.

• Clean Technology
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• v.15 no.1
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• pp.54-59
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• 2009

In this study, the separation of water/bitumen emulsion was investigated by chemical demulsification method. Motor oils (GS Caltex Deluxe Gold V 7.5W/30, Hyundai gear oil 85W/140) and asphalt (AP-5, KS M 2201, Dongnam Petrochemical MFG. Co.) were used as model oils in the preliminary experiments to effectively remove water from water/bitumen emulsion. The bitumen extracted from Canadian oilsands was used in this study. The water/oil emulsion was not separated without demulsifiers, and Hyundai motor oil showed higher efficiency of water separation at a low concentration of demulsifier compared with that for GS Caltex motor oil. However, as the concentration increased, the efficiency did not rapidly increase compared with that of GS Caltex motor oil. It was highly speculated that the water phase of Hyundai motor oil was not dispersed well compared with that of GS Caltex motor oil because the viscosity of Hyundai motor oil was much higher than that of GS Caltex motor oil. The demulsifier of higher HLB (hydrophilic - lipophilic balance) value had high separation efficiencies in water/oil emulsion. The TWEEN 20 (polyoxyethylene sorbitan monolaurate solution) showed better separation efficiency than other demulsifiers.