• 한국해안·해양공학회논문집
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• 제28권2호
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• pp.73-80
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• 2016

파의 왕복운동을 지속적인 일방향 회전운동으로 유도하여 발전기의 가동에 있어 기계적인 손실 에너지를 감소시켜 발전효율을 극대화시킬 수 있는 파의 수평왕복운동을 직접 이용하는 가동물체형 파력발전장치가 개발되었다. 그리고 실제 전력생산에 관한 수리실험이 수행되었고 그 결과가 토의되었다. 수리실험에서 부력 탱크의 형상에 따른 발전장치의 발전효율은 파력판의 무게를 충분히 지탱하는 직경 9 cm의 고정식 부력 탱크가 평균발전효율 14.6%로 좋은 결과를 보였으며 효율이 좋을 것으로 기대되었던 부력 탱크가 자유로이 승강하는 경우는 발전효율이 8.5%로 좋지 못한 결과를 보였다. 그리고 여러 파랑조건에 따른 직경 9 cm의 고정식 부력 탱크형 발전모형의 평균발전 효율이 수심 90 cm에서 기어비 2단 3.9%, 3단 4.9%, 4단 4.9%, 5단 12%, 6단 10.0%, 7단 3.1%, 그리고 8단 3.0%를 나타냈으며, 수심 80 cm의 기어비 5단에서 15%의 발전효율이 계측되었다. 따라서 이 파력발전장치는 수심 80~90 cm의 기어비 5단에서 비교적 높은 13.5%의 평균발전효율을 얻을 수 있었다.

• 한국정밀공학회지
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• 제18권3호
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• pp.205-215
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• 2001

Continuously variable transmission(CVT) mechanisms considered here combine the functions of a 2K-H I type differential gear unit and a V-belt continuously variable unit(CVU). One shaft of the V-belt CVU is connected directly to the differential gear unit and remaining shaft of it is linked to the output shaft. These mechanisms have many advantage which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range, and the generation of geared neutral. In this paper six different mechanisms of output coupled type CVT are proposed. Some useful theoretical formula related to speed ratio, power flow and efficiency are derived and analyzed, and theoretical analysis are proven by various experiments.

• 대한기계학회논문집B
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• 제38권1호
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• pp.95-101
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• 2014

본 연구는 고속 회전형(~10,000 rpm) 기어펌프의 질량유량과 효율을 예측하기 위해서 2 차원 immersed solid method(ISM)를 이용한 수치해석을 수행하였다. 기어펌프와 하우징의 순환유동을 고려하기 위하여 유체 유동을 난류 유동으로 가정하였고, 기어 펌프의 입 출구의 일정 압력 조건하에 기어펌프의 회전 속도를 부가하였다. 기어펌프의 다양한 회전 속도 및 기어 끝 단과 하우징 사의의 서로 다른 간극에 대한 질량유량 및 효율을 검토하였다. 해석 결과로서, 회전 속도가 증가할수록 평균 질량유량 및 효율은 증가하였고, 기어펌프와 하우징의 간격이 증가할수록 평균 질량유량 및 효율은 감소하였다. 간격이 없는 조건하의 6,000 rpm, 8,000 rpm, 10,000 rpm 회전속도에의 효율은 각각 85.11 %, 90.94 %, 93.62 % 를 얻었고, 간격이 0 m, 0.00001 m, 0.00003 m 에 대해서 효율은 각각 93.62 %, 93.29 %, 92.74 % 를 얻었다.

• 유공압시스템학회논문집
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• 제2권4호
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• pp.23-29
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• 2005

In order to improve the efficiency of hydraulic gear pumps or motors especially for high operating pressure, power losses due to viscous friction and leak flow through gear teeth end-gaps are considered in this paper. Optimal gaps minimizing the power loss for pumps and motors with uniform heights of gaps are analysed first. And the effect of the shapes of gaps with unequal heights on the power loss are studied and discussed by simulation. Considering that the outer shell lacing gear teeth may expand due to high internal pressure or thermal stress, the results drawn in this paper can be used for the design of high efficiency pumps and motors.

• 한국환경보건학회지
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• 제27권3호
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• pp.27-34
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• 2001

This paper discussed the shape effect of ceramic support carrier in order to facilitate biomass immobilization. The shape of ceramic support carrier was modified hollow pipe type into hollow gear type. After seeding, microorganisms were attached in crevices where protection from shear forces or surfaces where easy to contact with support carrier surface. In case of hollow gear type carrier, initial attachment rate was faster than that of hollow pipe type and obtained thick biofilm. Synthetic wastewater(COD:75~880 mg/L, organic loading rate:0.36~4.22 kgCOD/㎥.d) was treated aerobic fixed bed biofilm reactor where 100% of the volume was filled with the ceramic carrier. COD removal efficiency of reactor filled with gear type support carrier was a little high withing 70 days, and then showed similar removal efficiency. It was found that highly loaded operation with up to 4.22 kgCOD/㎥.d was possible in both reactor. Total biomass amounts of pipe type was higher than gear type, however, attached biomass of gear type was higher than that of pipe type.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.316-323
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• 2003

The gear system is commonly applied in the marine propulsion shafting system using the diesel engine with the power take off/in system and it also is necessary to reduce propeller revolution increasing the propulsion efficiency. The diesel engine has the advantage more than other thermal engines in high thermal efficiency and mobility. But the large vibratory torque which induced by higher combustion pressure is transmitted to these gears. In this paper, the surface durability and bending stress of gear system considering vibratory and transient torque is evaluated by ISO and AGMA regulation. And the influence of these in gear design is investigated with the theoretical analysis and onboard measurement result of torsional vibration.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.99-106
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• 1999

Because many light rail transit systems are mainly operated in the downtown areas of a large cities and the congestion areas, there are many steep gradients and sharp radius sections in that lines. As that reasons above, light rail vehicles are equipped with differential gear units between traction motors and final reduction gear units. In this paper, the configurations and the interferences of 2K-H I type Planetary gear train, which is applicable for light rail vehicles and based on various differential gear units, are studied. The ranges of addendum modification coefficients which would not lead to interferences is analyzed, and optimal addendum modification coefficients among these ranges are presented, which generate the maximum efficiency of planetary gear drives and differential gear unit as pressure angles, speed ratios,

• 한국항공우주학회지
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• 제35권7호
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• pp.612-618
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• 2007

본 연구에서는 KT-1 계열 항공기 전륜착륙장치의 동적거동을 분석하고 충격흡수효율을 향상시키기 위한 완충기의 최적설계가 수행되었다. 전륜착륙장치는 ADAMS를 이용하여 2자유도계로 모델링하였으며 운영/환경 조건을 고려한 해석결과는 낙하실험결과와 잘 일치하였다. 또한 최적설계변수를 선정하기 위해 오일밀도, 오리피스 단면적과 같은 완충기 파라미터를 변화시켜 동적거동 및 충격흡수효율에 미치는 영향을 분석하였으며, 해석 결과 완충기 파라미터가 다른 파라미터들보다 큰 영향을 미쳤다. 유용방향탐색법을 사용하여 최적설계를 진행하였고, 최대효율을 나타낼 때 설계변수의 값을 산출하였다. 이러한 방법으로 전륜착륙장치의 최적설계를 통해 충격흡수효율과 동적거동능력을 향상시킬 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.347-348
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• 2006

Among various gear system, planetary gear system has the best characteristics in high efficiency, excellent strength capacity, easy convertible speed control, and compact design aspect. Strength of gear is considered as the most important design factor. We have studied tooth form and the planetary gear system that have high reduction gear ratio is created by using the involute curve.

• 한국기계가공학회지
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• 제17권1호
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• pp.1-7
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• 2018

We aimed to develop a high quality 3.5 ton class swing reducer by studying the efficiency improvement of the reducer through the optimum design and performance evaluation of the assembled, high efficiency, lightweight 3.5 ton swing reducer. Based on the optimal design of the worm and worm wheel, the optimal manufacturing method of the worm wheel, the optimized casing design, and the optimum design of the output pinion, Respectively. Therefore, in this paper, to improve the efficiency of the worm gear reducer system, we will develop the manufacturing technology and verify the mass production by combining the manufacturing process design, processing and assembling technology according to the optimization design. We have conducted research to realize mass production by product verification such as product efficiency, reliability and durability according to optimal design of worm gear reducer.