• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제31회 춘계학술대회
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• pp.194-200
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• 2000

The sealing performance of an elastomeric O-ring seal using NBR and FFKM has been analyzed for the contact stress behaviors that develop between the O-ring seal and the surfaces with which it comes into contact. The leakage of an O-ring seal will occur when the pressure differential across the seal just exceeds the initial (or static) peak contact stress. The contact stress behaviors that develop in compressed O-rings, in common case of restrained geometry(grooved), are investigated using the finite element method. The analysis includes material hyperelasticity and axisymmetry. The computed FEM results show that the contact stress behaviors are related to materials of NBR and FFKM and temperature of vaccum chamber.

• Tribology and Lubricants
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• 제19권1호
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• pp.9-14
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• 2003

The sealing performance of an elastomeric O-ring using the double layered material has been analyzed fer the contact stress behaviors that develop between the O-ring seal and the surfaces with which it comes into contact. The leakage of an O-ring will occur when the pressure differential across the seal Just exceeds the initial (or static) peak contact stress. The contact stress behaviors that develop in compressed O-rings, in common case of dovetail grooved geometry, are investigated using the finite element method. The FE analysis includes material hyperelasticity and axisymmetry. The computed FEM results show that the contact stress behaviors are related to the ratio of diameter between the inner ring and the outer ring, and the temperature of vacuum chamber.

• 항공우주기술
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• 제13권2호
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• pp.167-176
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• 2014

유로의 개폐를 위해 사용되는 파이로밸브는 가볍고 신뢰성이 높은 장점을 가진다. 미국에서는 하이드라진 추진제를 사용하는 일부 위성 유실의 원인을 착화기 연소 가스의 누설로 판단하였고, 블로우바이라 불리는 이러한 누설 문제를 방지하기 위하여 억지끼워맞춤을 하는 피스톤을 개발하고 추가적인 설계변경을 통하여 신뢰성을 향상하였다. 여기서는 미국에서 수행된 파이로밸브 연구에 대한 문헌조사를 AIAA Paper 위주로 수행하였다. 또한 파이로밸브의 일반적인 문제점과 개선방향, 성능비교평가 사례 등을 다루었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.374-377
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• 2005

Hyundai motor company has designed a above 50kW-class PEMFC stack for Fuelcell vehicle based on SUV. Hyundai increased the power density of the stack through the optimized flowfield of bipolar plate, manifold structure, and improvement of sealing, etc. Also, Gas to Gas humidifier was adopted in fuelcell system to reduce the system humidification load, it had been proven by short stack test. Components of stack, bilpolar plate, manifold, were analyzed through the computer simulation, so temperature and pressure distribution in the components and system were improved. This stack tested in Bread Board which was organized similar to real vehicle system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.951-955
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• 2007

Recently, drywall's demand is increasing by interest about spread of remodeling house and separated wall structure. This research evaluated panel's SRI and found out panel properties using material of small size. Conclusion of this research is as following. First, we confirmed the effectiveness of small-scale material. Measuring results appeared equally about 400 ${\sim}$ 500 Hz that is fc frequency. Second,, it is no big difference in SRI that use CRC or magnesium board that is used for protection of panel surface. Third, it is compared SRI by used junction to make wall that become disjointing assembly. By the result, sealed wall secures resemblant SRI performance almost with normal wall. Therefore, using joint materials and sealing junction became wall that is detached with high SRI.

• 한국소음진동공학회논문집
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• 제22권1호
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• pp.3-8
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• 2012

In an attempt to improve adhesion strength between glass and metal due to use of Pb-free solder as a sealant between glass and metal in the manufacturing process of vacuum insulation window glass to maintain the vacuum volume, ultrasonic energy is often applied during the process of Pb-free sealing. In this study, we propose an ultrasonic vibrator with a 4 mm end tip radius which performs resonance frequency of 60 kHz and 14 um or higher vibration displacement. A frequency variation due to applied pressure on piezo disks, which was excluded in the computer simulation, was verified experimentally, and we have demonstrated a 17 um vibration displacement at 50 V input through the performance test of a vibrator constructed with our specification.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.105-110
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• 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.

• 대한기계학회논문집
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• 제17권8호
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• pp.1940-1950
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• 1993

The theoretical investigation is done on the dynamic behavior of a crank shaft used in a scroll compressor. The compression performance of a scroll compressor is directly influenced by the sealing characteristics between fixed and orbiting scrolls, which is related with the dynamic behavior of a scroll compressor. Analyzing the constrained power transmitting system is came to be of importance, accordingly. The equations of motion and interacting forces of a scroll compressor are derived and solved numerically in this paper. The locus of the crank shaft is also obtained by employing the reaction force caused by the oil film of journal bearing. The results show that the crank shaft of a scroll compressor has considerably stable rotating locus.

• 한국초전도ㆍ저온공학회논문지
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• 제13권1호
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• pp.51-55
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• 2011

In this study, the liquid-vapor (L-V) separator equipped with liquid-level meter is developed. In the developed L-V separator, the flange is designed to be attachable so that the separator can be flexibly applied under any cases where the volumetric of L-V separator is varied by the system requirement. The leak-tightness between the attachable flange and the chamber is experimentally confirmed with the use of double groove indium wire sealing even under the high pressure up to 20 bar. In addition, the liquid-level meter is designed and fabricated to figure out the inner state of L-V separator. It consists with 19 carbon composition resistors in series. All resistors are separately calibrated in the temperature range from 77 K to 200 K. The performance of the L-V separator and the liquid-level meter is investigated with experimental tests, and the result is presented in this paper.

• 한국안전학회지
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• 제22권5호
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• pp.13-20
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• 2007

Elastomeric O-ring seals are widely used in static and dynamic applications. A compressed and highly pressurized O-ring seal inserted under laterally one-sided constrained condition has been analyzed experimentally and numerically. The deformed shape and extrusion length of the O-ring under high pressure has been measured by the computed tomography. Through the comparison of experimental and FE results, the numerical analysis technique has been verified. Using verified FE method, the contact stress profiles at sealing surfaces have been investigated and their relevance to the 0-ring performance evaluated based on stress-related and displacement-related parameters. It has been found that the contact stress profiles and deformation behaviors of the seal are affected by friction coefficient, gap clearance, and pressure considerably.