• 유공압시스템학회논문집
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• 제6권3호
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• pp.23-31
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• 2009

Counter shaft transmission is a popular automatic transmission power train in construction vehicles such as wheel loader and forklift. The gear train layout of counter shaft transmission is a very basic and important development stage because it affects the most of components design including hydraulic system and shift control algorithm, etc. This paper presents a design methodology for the gear train layout from the analysis of power flow path and clutch hook-up of the existing counter shaft transmission that is adopted in commercialized construction vehicles. Also, independent constraints for the meshed gear ratios are derived in order to realize forward 4-speed and reverse 3-speed gear ratio. The layout design principle proposed here was applied to the new original counter shaft transmission that is underdevelopment.

• Design & Manufacturing
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• 제6권2호
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• pp.54-58
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• 2012

A counter shaft gear is an important part in the transmission system of vehicle. Its shape is relatively complicated and should meets high strength. Traditionally it has been manufactured as follows; the counter shaft gear has consisted of a clutch and helical body with teeth which are forged and machined for teeth respectively and then attached by frictional welding. In this study, a new hot forging process was proposed and designed so that the counter shaft gear is formed as one body without divide it into two parts. Furthermore, the precision forging process has been developed for the clutch teeth without additional grinding.

• Design & Manufacturing
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• 제6권2호
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• pp.6-11
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• 2012

A counter shaft gear is an important part in the transmission system of vehicle. Its shape is relatively complicated and should meets high strength. Traditionally the counter shaft gear has been manufactured as follows; a spline body is firstly machined for teeth and then attached to the main gear body by frictional welding, and finally is finished by grinding. Therefore it is necessary to develop a new manufacturing technology eliminating both frictional welding and grinding processes. In this study, a new hot forging process was proposed and designed so that the spline body with teeth and main gear body are formed as one body. Finite element simulations and experimental works were peformed for design of forging processes to get the quality final precision-forged product. Consequently the most suitable blocker process could be obtained.

• 한국융합학회논문지
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• 제8권8호
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• pp.197-202
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• 2017

본 연구는 미라 모발에 존재하는 멜라닌과립의 보존 상태와 모양을 규명하기 위해서 1250kV의 초고압전자현미경(high voltage electron microscope: HVEM)을 사용하여 3차 구조를 분석하였다. 미라 모발에서 피질에 분포하고 있는 멜라닌과립은 큐티클층에 인접한 바깥쪽 피질에 집중적으로 분포하고 있다. 이들 부위에는 다량의 멜라닌과립들이 무리를 지어 존재하고 있어서 현대인의 정상 모발에 있는 멜라닌과립의 분포양상과 뚜렷한 차이점을 나타내었다. 초고압전자현미경으로 ${\pm}60$도의 범위에서 1도 간격으로 촬영한 결과 멜라닌과립은 길쭉한 타원형의 형태로 크기가 다양하게 관찰되었다. 과립의 크기는 단축 직경이 $0.3-0.6{\mu}m$이고, 장축 직경은 $0.5-1{\mu}m$로 측정되었다. 결론적으로 초고압전자현미경은 일반 투과전자현미경보다 높은 해상도와 투과력을 가져서 두꺼운 절편의 생물 시료 구조분석에 용이하다.