• 한국정밀공학회지
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• 제13권1호
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• pp.69-77
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• 1996

To design high-effective profile in screw rotor profile using in screw compressor, we design the symmetric type changing the number of lobes and the non-symmetric type changing the neighbourhood of the top point of lobe. Then, we calculated the performance value of profile according to the scale of these non-symmetric's wrap angle. We had the results as follows. 1. About the non-symmetric case, the larger a wrap angle is the shorter seal line is and the smaller blow hole is, thus we know what the large wrap angle profile is better than the small one. 2. We know what the non-symmetric profile is better than the symmetric profile in the result of the compare of seal line's length, blow hole's area, volume curve. 3. About the non-symmetric case, the deformation of the neighbourhood of lobe's top point of the rotor profile has a large effect upon the increase of performance because the length of seal line became short and the area of blow hole is small.

• 한국기계가공학회지
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• 제11권6호
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• pp.195-200
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• 2012

In this study, parameters and requirements of an 120kW class monorail planetary gearbox was analysed and the adaptive planetary gearbox design was selected. The specification of the sun gear, planetary gear and carrier was set and the profile & lead was optimized. The mechanical efficiency of the optimized one and the original one was observed. Dynamo-tester system was used to observe the mechanical efficiency of the planetary gearbox. A dynamo unit was connected with the planetary gearbox which straightened through the motor by a coupling. The standard tooth shape planetary gearbox and modified tooth shape planetary gearbox were used as test pieces and the rotation speed was set from 600 to 6000rpm with 600rpm, 2.5min one step. In order to check the mechanical efficiency of the planetary gearbox, the tests were done as follows. 1) The power loss between driving motor and dynamo tester. 2) Temperature variation by different rotation speeds. 3) Noise variation by different rotation speeds.

• 한국기계가공학회지
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• 제16권5호
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• pp.1-6
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• 2017

Gear tooth micro-geometry modifications include the intentional removal of material from the gear teeth flanks, so that the shape is no longer a perfect involute. If the gear shapes are perfect, then the gear tooth meshing is better, therefore the gears will transmit input torque in a more efficient manner without the generation of high frequency engine fluctuation noise. In this paper, we study tooth micro-geometry optimization of rear gear set in 2 speed planetary gear reducers. Analysis revealed problems which are need of modification. Based on the results, tooth micro-geometry was used to deal with load distributions on the rear gear set.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제45차 학술발표회
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• pp.49-49
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• 2011

GNP 증가 등의 요인으로 생활수준이 향상되면서 사람들의 고급스럽고 아름다운 공간에 대한 선호도가 점점 증가하고 있으며 따라서 실내 인테리어 산업에 대한 관심이 높아지고 있다. 인테리어 산업에서 주로 사용되는 무늬목은 나무 모양이 나게 무늬를 새겨 넣어, 외양을 장식하는 얇은 합판으로 나무의 고급스러움과 아름다움으로 인해 고부가가치 상품으로 자리잡고 있으며 주로 실내인테리어장식 및 가구, 마루바닥, 건축내장재, 제재목 등의 건축 자제의 용도로 사용되고 있다. 또한 천연목재를 이용한 다양한 가공법으로 아름다운 무늬의 재현 등을 실제 이루고 있으며, 천연 목재의 색감 외 표백/염색/가공을 통한 염색무늬목 제조도 이루어지고 있는 실정이다. 무늬목 염색가공에 대한 기술이 보편화되지 않은 실정에서 고부가가치형 기술로 자리 매김 하기 위해서는 제조공정 시 보다 안정적인 작업성과 최소한의 작업 변수를 확보하는 것이 무엇보다도 중요하다. 이에 본 연구에서는 고부가가치형 무늬목의 생산성을 향상하고, 불량률의 최소화를 궁극적 목적으로 하며, 실제 침염목의 건조공정 중 최적의 함수율을 확보할 수 있는 예비건조 시스템을 개발 적용하여 시간과 에너지 절감 효과를 확보하였다. 생산 중 최대의 불량현상으로 갈라짐(건조로 발생한 응력에 의해 목리방향으로 갈라지는현상:checks)과 건조공정의 지연으로 발생하는 부패현상도 개선하였다.

• 한국기계가공학회지
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• 제21권9호
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• pp.21-27
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• 2022

The rotorcraft engine gearbox transmits the power generated by the turboshaft engine to the rotor by reducing the rotational speed and increasing the torque. The core of the rotorcraft engine gearbox is lightweight performance, which requires maximum weight reduction within the range that meets various requirements and constraints. Therefore, lightweight design through gear macro geometry optimization is necessary. In this study, gear macro geometry optimization was performed to reduce the weight of a rotorcraft engine gearbox. NSGA-III was used for the optimization, resulting in a combination of the gear ratio and macro geometry that minimizes the weight of the total gear. In addition, the safety factor of the gears satisfied the given conditions.

• 한국정밀공학회지
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• 제13권4호
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• pp.129-135
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• 1996

The area of gear vibration and noise, has recently been the focus of many studies. The proper kinematic and geometric design of gears, the mathematical modeling of gear system are essential for a good design. This work present a gear disign for reducing noise, and practical approaches used for machinery noise reduction slong with the summary of methods available for predicting gear noise in terms of the transmis- sion error, and show a comparative study with other methods. A new tooth profile modification is proposed for reducing vibration and noise of involute gears. The method is based on the use of cubic spline curves. The tooth profile is constrained to assume an involute shape during the loaded operation. Thus the new gear profile assures conjugate motion at all points along the line of action. The new profile is found to result in a more uniform static transmission error compared to not only standard involute profile but also modificated profile therby contributing to the improvement of vibration and noise characteristics of the gear.

• 치위생과학회지
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• 제12권6호
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• pp.566-571
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• 2012

제한된 조건 하에서 수행된 본 연구에서는 다음과 같은 결론을 얻었다. 1. 치형과 고정성 보철물을 근 원심 방향의 단면에 8지점을 선정한 후 서로 다른 두 가지 방식으로 적합도를 측정하여 비교한 결과 8지점 모두에서 유의한 차이를 보이지 않았다(p<0.05). 2. 8지점을 변연부, 경사부, 축벽부, 교합면으로 분류하여 비교한 결과에서도 역시 두 측정 방법 간에 유의한 차이를 보이지 않았다(p<0.05). 이와 같은 결과를 바탕으로 실리콘 복제본 기술을 이용하여 적합도를 측정하는 것이 치형과 고정성 보철물을 직접 절단하여 단면을 측정하는 것만큼 정확하다는 결론을 얻었다. 따라서 고정성 보철물의 적합도 측정 시 비 파괴적인 방법인 실리콘 복제본 기술을 이용한다면 치형과 고정성 보철물 모두 파괴하지 않고 측정이 가능할 것으로 사료된다.

• 한국산업융합학회 논문집
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• 제9권4호
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• pp.269-276
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• 2006

Strength Design method for involute spur gears is developed. The developed gear strength design system can design the optimized gear that minimize the number of pinion teeth with face tooth. Method of optimization is matrix form which is developed from this study. Design variables are transmitted power, gear volume, gear ratio, allowable contact stress and allowable bending stress, etc. Gear design method developed this study can be apply to the gears of plants, machine tools, automobiles.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.249-250
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.901-902
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• 2010