• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.8-11
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• 2002

In this study, Automatic design program creates 3D solid models and constructs them. The method of making assembly model is two. One assembles the element made in automatic design program with hand, the other develops the automatic design program for creating assembly model. Automatic design program improves the convenience of user. In creating gears, involute ewe and Trochoidal fillet curve are made by mathematical development.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.28-31
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• 2002

In this study, we develop automatic design program, which create 3D model of spur gear and helical gear used VisuaILISP and create helical gear in the CATIA using 2D profile of gear. This model become the standard model, which give not only in itself mold information but also computer processed product with measuring date. Spur gear require mathematical examination of involute curve and trocoidal fillet curve. Automatic design program, which have a mathematical development create the profile of spur gear.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.591-594
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• 2002

In this study, we develop automatic design program, which create 3D model of spur gear and helical gear used VisualLISP and create helical gear in the CATIA using 2D profile of gear. This model become the standard models which give not only in itself mold information but also compare processed product with measuring date. Spur gear require mathematical examination of involute curve and trocoidal fillet curve. Automatic design program, which have a mathematical development create the profile of spur gear.

• 소성∙가공
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• 제5권2호
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• pp.105-114
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• 1996

Recently, precision forging techniques are applied to manufacture spur gears. Compared to conventional machining, they produce parts of better mechanical properties and less residual stresses with a much higher production rate. In the present investigation a rigid-plastic three dimensional finite element method was applied to analyze hot forging and cold sizing of a spur gear by closed dies. The involute curve of a tooth profile was approximated by a circle close to the curve. Results of the analyses make it possible to predict local strengths of the gear die failure and an appropriate preform for cold sizing. It was found that the preform for cold sizing. It was found that the preform for the cold sizing is the most important because it determines whether the gears especially teeth can be successfully formed.

• 소성∙가공
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• 제21권1호
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• pp.67-74
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• 2012

Although high productivity is possible, cold forged helical gears have not been widely used due to difficulty in achieving mechanical properties as well as dimensional accuracy of the product. Confidence in the gear characteristics also is very important in heavy-duty gear applications. Therefore, the properties of forged gears must be compared to the properties of conventional machined gears. The properties might be different due to the different fabrication processes. In this study, machined and forged products both before and after heat-treated have been compared by measuring the residual stress and involute curve of the tooth. Characteristics of hardness and microstructure were also compared. Additionally, tooth fracture strength was compared for the heat-treated products. Moreover, the tooth strength and the fracture pattern were compared between the machined and forged gears. The forged gear showed decreased changes in residual stress and decreased changes in dimensions when compared to the machined gear before and after heat treatment. The forged gear was over 10% better than the machined gear in tooth strength.

• 대한기계학회논문집
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• 제15권1호
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• pp.127-138
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• 1991

본 연구에서는 인벌류트 치형을 갖는 헬리컬 기어압출에 있어서 실제 치형형 상인 인벌류트 곡선을 다이의 형상으로 하여 비대칭 형상의 다이를 몇 개의 대칭영역 으로 분할하고 각 영역에 대하여 각각의 동적가용 속도장을 구한 후 전체 형상으로 확 장시켜 상계해석 하였다. 해석결과의 계산은 위의 동적가용속도장으로 헬리컬 또는 평기어 압출을 해석하는 수치해석 프로그램을 개발하여 수행하였다. 상계해석에서는 기초원 이하의 필렛부분과 이 뿌리 틈새등은 그 형상이 매우 복잡하므로 해석의 간략 화를 위하여 기초원까지만 변형되는 것으로 가정하였으나 실제의 기어압출실험에서는 기어의 모든 조건이 고려되었다. 압출실험은 전기동으로 전극봉을 제조하고, 전극설 계시에 금형과 소재의 탄성변형량, 방전가공시의 과방전량 그리고 래핑 가공여유등을 고려하여 설계한 후 호빙 및 셰이빙가공하여 실제 제조하려는 기어와 유사하게 기어전 극을 제조한 후, 이를 금현본체와 조립하여 3축제어 방전가공기로 금형을 제작하였다.

• 한국유체기계학회 논문집
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• 제3권2호
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• pp.50-56
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• 2000

The effects of lobe shapes on the leak flow conductance of Roots-type vacuum pump are studied numerically and experimentally. The modelled lobe shape of Roots-type vacuum pump is two-lobe spur gear. The numerical analyses are performed on leak flows in Roots-type vacuum pump. It is numerically calculated using a 4th-order Runge-Kutta method and is compared with experimental results. Results show that for the case of involute lobe shape the total amount of the leak flow conductance is greater than that of cycloid and Cassini oval lobe shapes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.460-463
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• 2005

Gear is an important machine element to be used transmission in case short between axis. We drew gear using automatic design program to solve problem when it draw gear. We manufactured gears that it have different pressure angles using W-EDM. And we got a 2D profile of manufactured gear using reverse engineering. So we got to manufacturing error in comparison with CAD data and measured data. In result we could manufacture precise gear through improvement of manufacturing processes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.224-230
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• 1993

Closed-die forging of spur gears with hollow cylindrical billet has been analysed by using the upper-bound method. A kinematically admiccible velocity field has been developed. wherein, an involute curve has been introduced to represent the forging die profile. In the analysis, the deformation regions have been divided into nine zones. A constant frictional stress has been assumed on the contacting surfaces. Utilizing the formulated velocity field, numerical calcuations have been carried out to investigate the effects of various parameters, such as module, number of teeth and friction factor,on the forging of spur gears.

• 한국정밀공학회지
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• 제9권3호
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• pp.12-28
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• 1992

A new helical gear extrusion process was proposed and its numerical solution program based on the upper bound method was developed. In the analysis the involute curve was used as a shape of die and the upper bound method was used to calculate energy dissipation rate. By this method the power requirement and optimum conditions necessary for extruding helical gear were successfully calculated. These numerical solutions were in good agreement with experimental data. In the experiment, die life was greatly improved compared with that of Samanta process and 4 .approx. 5 class helical gear of KS standard for automobile transmission was successfully manufactured.