• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.232-232
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• 2004

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.12a
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• pp.51-56
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• 1993

The conical bearing can be used to support the radial and thrust load simultaneously. Two circumferential grooves with discrete hole restrictions are made on the bearing surface in order to increase stiffness. In this paper, the dynamic characteristics of this type of bearings are calculated such as stiffness and champing coefficients. As a results of theoretical analysis, it is verified that there exist the groove depth and distance between two grooves which produce the maximum stiffness at the given bearing dimensions.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.217-224
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• 1997

Static characteristics of hemispherical aerodynamic bearing is studied theoretically. In this paper nonlinear equation of second order considering compressibility and slip effect of air is calculated by Newton-Raphson method. Results indicate that axial load capacity has maximum value when the inclination angle of groove is about 30$\circ$, the ratio of groove clearance to ridge clearance is two. We also present the design method of hemispherical Aerodynamic bearing based on it's load capacity taking into account manufacturing and assembling viewpoint.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1997.10a
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• pp.239-244
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• 1997

Recently, the high speed rotation and accuracy is needed in the field of electro-optic devices. But it is difficult for ball bearing to satisfy such conditions. So, we have developed the hemispherical type aerodynamic bearing for LSU(Laser Scanning Unit) motor. The hemispherical type aerodynamic bearing is able to support radial and axial load simultaneously. In this research, We have developed mass production method and tested the perromance of aerodynamic bearing in comparision with ball bearing at the speed of 23,000rpm. In the result, we proved that the properties of aerodynamic bearing is better than ball bearing's.

• Tribology and Lubricants
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• v.17 no.2
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• pp.116-123
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• 2001

A theoretical analysis has been undertaken to show the influence of bearing geometry on the steady state characteristics of air lubricated spherical tilting pad bearings. The geometry variations considered are the number of pads, the eccentricity ratio, the direction of load, and the preloading. Dynamic characteristic equations are derived with pad assembly method.

• Tribology and Lubricants
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• v.17 no.2
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• pp.97-108
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• 2001

This paper describes the development of performance analysis technique for a leaf-type gas lubricated fail bearing. Stiffness coefficient and frictional damping due to the slip between all contacts of leaves are evaluated for various leaf structures. The fluid film thickness and pressure distribution are computed but it is not considered the elastic deformation by film pressure. The analysis results include the effects that the curvature radius and the length of leaf and the friction coefficient have on the static and dynamic characteristics of the foil bearings.

• Tribology and Lubricants
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• v.10 no.1
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• pp.27-34
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• 1994

An analysis based on the narrow groove theory is not suitable for the case of insufficient number of grooves or of non-rectangular shaped grooves. In this study, we present the solution of the compressible Reynolds equation for the air-lubricated hydrodynamic herringbonegrooved journal bearing with circular shaped grooves. From the results calculated numerically, optimal design values are obtained for the herringbone-grooved journal bearing.

• Bulletin of Korea Environmental Preservation Association
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• v.28 s.361
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• pp.23-25
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• 2006

금년부터 수도권 공기질을 개선하기 위해 자동차 배출가스에 대한 규제가 강화되고, 대규모 개발사업 추진과정에서 발생하는 사회적 갈등을 미연에 방지하기 위한 전략환경평가제도가 도입되며, 생산자가 자신의 생산품중 일정비율을 의무적으로 수거해 재활용해야 하는 "생산자 책임 재활용제도"가 종전 윤활유, 휴대폰 등 18개 품목에서 프린트, 복사기, 팩시밀리까지 21개 품목으로 확대된다. 환경부에서 발표한 2006년부터 환경분야에서 달라지는 제도를 아래와 같이 분야별로 정리를 하였습니다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04b
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• pp.106-112
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• 1996

본 연구에서는 보다 향상된 정,동특성을 가지는 베어링을 구현하기 위하여 PZT 구동에 의해 가변 간극 형상을 갖도록 베어링 외경부를 강제로 변형시킨 중심 고정형 다이어프램을 생각하고, 우선적으로 이러한 가변 간극 형상의 외부가압기체 드러스트 베어링의 정특성을 해석 및 실험하여 그 개선된 성능을 알아보고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.1
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• pp.42-51
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• 1998

A 150 m$\^$3//hr, 30 kg/cm$\^$2/, air-cooled 3-stage reciprocating air compressor is designed to be used in starting large diesel engines of ships. A basic design procedure is presented to meet the targeted pressure and flow rate, and especially a volumetric efficiency of 80%. Temperature and stress analysis of the 1st stage cylinder are performed using axisymmetric FEM modelings. The dynamics of valve system is analyzed and stress at the 1st stage valve seat caused by valve impact is evaluated. To reduce friction loss and wear at the compressor engine system tribological design issues are reviewed and good design practices are suggested. Finally, forced-air pin-type interstage coolers are designed to dissipate generated compression heat at each stage.