• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.627-628
• /
• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.11a
• /
• pp.141-142
• /
• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.199-200
• /
• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.93-93
• /
• 2010

We developed friction welded bimetallic sleeve for 220kV aluminum conductor XLPE cable. Not only friction welded bimetallic sleeve for Termination(EB-A, EB-G) but also friction welded sleeve for Joint of Al to Cu conductor was developed regardless of this project. Generally, friction welded sleeve used to connect Al conductor cable to Cu conductor cable and used for improvement of mechanical property of terminal by offer the copper side of friction welded bimetallic sleeve at the Termination. Connection method for Al-Cu conductor has mainly used friction welding at the solid state, because it is difficult to connect by using conventional welding method. this investigation introduces development of friction welded bimetallic sleeve by friction welding and test result of 220kV Al conductor XLPE cable and accessories using friction welded sleeve.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.521-522
• /
• 2010

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.3
• /
• pp.89-95
• /
• 2002

This paper describes a new identification method for friction in motion control systems, in which the friction model is not necessarily linear in parameters. The proposed method works well with any measurement data of velocity and input control force, as long as the initial and final velocities are identical. Most importantly, the proposed method does not require the information of acceleration for its implementation, in contrast with the previously known methods. This is due to the orthogonality property between acceleration and a function of velocity. In particular, if the parametric model is linear in parameters, its friction parameters can be identified in closed form without resorting to numerical search methods. To illuminate further the generality and practicality of the proposed friction identification method, we show good performance of the proposed method through some simulation results.

• Tribology and Lubricants
• /
• v.23 no.6
• /
• pp.306-311
• /
• 2007

This paper presents the friction characteristics of pb-fres pin bushing bearings for an automotive gasoline engine. The external load is 100 N to 600 N and the speed of the pin bushing bearing is 1000 rpm to 3000 rpm against the rubbing surfaces. And the contact modes of rubbing surfaces between a piston pin and a pb-free pin bushing specimen are a dry friction, an oil lubricated friction and a mixed friction that is starved by a lack of engine oil. Two influential factors of a contact rubbing modes and a material property are very important parameters on the tribological performance of a friction characteristic between a piston pin and a pb-free pin bushing. The experimental result shows that the pin bushing speed of 2000 rpm shows a typical oil film lubricated sliding contact mode in which means that as the applied load is increased, the friction loss is increasing. But other contact mode depending on the speed and the load may affect to the fiction coefficient without a regular and uniform trend. In summary, the oil lubricated rubbing surface definitely decreases a running-in period in short and increase oil film stiffness, and this may leads the reduction of a friction loss.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2002.05a
• /
• pp.226-234
• /
• 2002

A systematic study of the role of transfer films on friction properties was performed with various temperatures in the brake system. An NAO friction material specimens containing 9 ingredients were tested using a pad-on-disk type friction tester A new method of measuring the transfer film thickness was developed by considering the electrical resistance of the transfer film using a 4-point probe technique. The properties of transfer film such as surface morphology and film distribution vaied according to the relative amount of graphite and magnesium oxide. By using SEM, it was possible to obtain information about the chemical composition of the transfer film. Results showed that there detected a threshold value of the relative amount of a two active materials to maintain a certiain thickness of a transfer film. Results also showed that formation of friction layer generated on the friction surface was strongly affected by chemical action of two ingredients during sliding due to chemical reaction of solid lubricants at different interface temperature. The results suggested that no apparent relationship between transfer film thickness and the average friction coefficient was founded and friction characteristics were affected more by the property of the solid lubricant and abrasive in the material.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.11a
• /
• pp.515-518
• /
• 2006

This paper presents the friction and wear characteristics of contact type sealing unit for a water turbine of a small hydro-power generation, which Is to stop a leakage of a circulating water from a outside of an impeller to an inside of a rolling bearing. 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 Vickers hardness and the hardness of silicone carbide of SiC is 714.1 in Vickers 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 aye 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. 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

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7870-7877
• /
• 2015

In the case of CWR (Continuous welded rail) located on the railway bridge, the CWR has additional axial force due to interaction of bridge and track. Therefore, the CWR tracks located on the bridge have to secure the safety of running train and CWR track through mitigating influence for interaction of bridge and track. The railway design guide in Korea (KR C-08080) provides a certain value for property of longitudinal friction behavior of rail fastening system that is major parameter of interaction behavior by applying European codes. However, in order to apply to domestic railway, it is necessary to review property characteristics of the rail fastening system in actual use. In this paper, the experiment for longitudinal friction behavior of rail fastener applied to concrete track on the railway bridge in Korea was carried out, and statistical characteristic for property of the rail fastener was analyzed from the result of the experiment.