• Journal of the Korean Professional Engineers Association
• /
• v.20 no.4
• /
• pp.42-44
• /
• 1987

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.585-588
• /
• 2004

In this study, Curve dependent wheel flange lubricator with grease spray type is investigated and estimated a point of view reducing wheel flange wear and noise in the curve through field test on korean rail. Advantage of curve dependent wheel flange lubricator with grease spray type is found on the basis of the result of field test in comparison with oil spray type lubricator and wheel without wheel flange lubricator on railroad in Korea.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.05a
• /
• pp.105-110
• /
• 2002

The use of microporous polymer lubricants (MPLs) can eliminate the storage, sealing, and pumping problems associated with liquid lubricants, This paper discusses the use of MPLs for a component as rolling-element bearings. An MPL composed of 40% HDPE and 60% ester oil was synthesized and the MPL was applied to a ball bearing. The MPL ball bearing, filled with the MPL instead of the usual grease pack, tested and compared with the usual grease sealed ball bearing. The MPL applied to a ball bearing showed lubricant properties as good as usual grease, and showed higher performance in bearing oil leakage test, rotating torque test and thermal test at high speed running than usual grease.

• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1273-1275
• /
• 1998

The main faults at cable joint are mainly originate from double layered structure, which is composed of different kinds of materials such as XLPE/EPDM laminatest. In this paper, to investigate the effect of interfacial condition and coagents on dielectric strength of XLPE/EPDM, we prepared XLPE/grease/EPDM, XLPE/grease + coagent/EPDM laminates. Dielectric strength of the XLPE/EPDM laminates pasted with the grease compounded crosslinking coagent (TMPTA, TMPTMA) is higher than that of the laminates paseted with the grease without coagent.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.05a
• /
• pp.540-543
• /
• 1999

In order to determine what indluences the interfacial breakdown in EPDM/XLPE laminates. We studied the interfacial breakdown phenomena at several interfacial conditions. Breakdown strength in laminates pasted with silicone oil was higher than that with silicone grease. As a function of heat treatment time in a vacuum, interfacial breakdown strength increased much in XLPE/EPDM laminates pasted with silicone grease but increased a little in that with silcone oil. FT-IR spectrum of silicone oil was similar to that is silicone grease. FT-lR spectrum of silicone oil was not changed by the heat treatment in a vacuum, but in silicone grease another peak appeared.

• Tribology and Lubricants
• /
• v.24 no.5
• /
• pp.234-240
• /
• 2008

It is well known that surface texturing improves the tribological properties of mechanical components for enhancing hydro-dynamic effect or serving as a micro reservoir. There are not, however, enough researches to reveal the effects of surface texturing on the tribological properties under grease lubrication which is used in lubricating many mechanical elements. In the present study, therefore, the effects of surface texturing on the tribological properties are investigated under grease lubrication based on an experimental approach. The results show that surface texturing decreases friction coefficient. It is found that the friction coefficient can be decreased by controlling the diameter and density of micro-dimple. The diameter of dimple is more effective under high load and low speed than otherwise. And, the density of dimple is effective under low load and high speed.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.9
• /
• pp.660-665
• /
• 2013

To find out the major cause of scale formation in digestion facility, a componential analysis of scale and a digestion experiment for food wastewater were conducted. The analysis indicated that grease in food wastewater was closely connected to the organic component of scale. It is also indicated that grease-removed food wastewater showed 58.9% level compared to unprocessed one in crystal generation quantity in this study. The experiment provided insight that grease is one of the important causes of scale formation. Additionally, pre-removal of grease from food wastewater did not show negative effect on digestion gas production, as 68.7 L-gas/kg-COD for grease-removed food wastewater and 67.7 L-gas/kg-COD for unprocessed one.

• Korean Journal of Materials Research
• /
• v.29 no.7
• /
• pp.443-450
• /
• 2019

Thermal management is a critical issue for the development of high-performance electronic devices. In this paper, thermal conductivity values of mild steel and stainless steel(STS) are measured by light flash analysis(LFA) and dynamic thermal interface material(DynTIM) Tester. The shapes of samples for thermal property measurement are disc type with a diameter of 12.6 mm. For samples with different thickness, the thermal diffusivity and thermal conductivity are measured by LFA. For identical samples, the thermal resistance($R_{th}$) and thermal conductivity are measured using a DynTIM Tester. The thermal conductivity of samples with different thicknesses, measured by LFA, show similar values in a range of 5 %. However, the thermal conductivity of samples measured by DynTIM Tester show widely scattered values according to the application of thermal grease. When we use the thermal grease to remove air gaps, the thermal conductivity of samples measured by DynTIM Tester is larger than that measured by LFA. But, when we did not use thermal grease, the thermal conductivity of samples measured by DynTIM Tester is smaller than that measured by LFA. For the DynTIM Tester results, we also find that the slope of the graph of thermal resistance vs. thickness is affected by the usage of thermal grease. From this, we are able to conclude that the wide scattering of thermal conductivity for samples measured with the DynTIM Tester is caused by the change of slope in the graph of thermal resistance-thickness.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.6_2
• /
• pp.917-926
• /
• 2020

Friction mechanisms is a very important role in the industrial machinery. However, many experiments have been conducted to reduce the loss of energy resources and parts used due to friction because the friction force adversely affects parts, efficiency, noise, and the like of the power unit. Therefore, in this study, the friction coefficient according to the characteristics of the lubricant was measured to find out which Grease Lubricant maintains the low friction coefficient without being most affected by external conditions. A total of five grease lubricants were tested in this study: GHP CAL 301, GHP EP 2, GHP KG 10, GHP HPG 2, and GHP HTG 2. And the friction coefficient was conducted by changing the load conditions (2, 4, 6, 8, 10N) and rotational speed (24, 48, 67, 86, 105, 124, 143, 162vrpm) using a pin-on-disk wear test system. Also, duty number were calculated. As a result, it was confirmed that in all grease lubricants, the speed did not significantly affect the friction coefficient, and it was confirmed that in all lubricants, the size of the friction coefficient decreased as the load increased from a small load to a large load. In addition, it was determined from the experimental results that GHP EP 2 is the most suitable as a grease lubricant and GHP CAL 301 is not the most suitable.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.1125-1128
• /
• 2004

This paper presents the temperature characteristics with structure of 18 kV lightning arresters for distribution. Three types of polymer arresters were fabricated and ceramic type arrester was also ready to investigate. Below $100^{\circ}C$, three types of polymer arresters exhibited almost the same leakage current value, but above $100^{\circ}C$, polymer arrester that arrester module was injected into polymer housing with grease exhibited the highest leakage current and the arrester with the lowest leakage current was the arrester that silicon rubber was directly injected to arrester module. The rising of leakage current of polymer arrester with grease was because of existing grease between FRP winding and silicon housing, and reducing the insulation characteristics of the grease. All polymer arresters exhibited the same temperature characteristics but ceramic typr arrester was slower than polymer arrester in heat emission despite lowest leakage current. It was thought that the air layer between ZnO varistor blocks and ceramic housing prevented the heat emission. However, in spite of the difference of the structure, the variation of the surface temperature of all arresters exhibited the same result.