• Journal of Mechanical Science and Technology
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• v.18 no.8
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• pp.1319-1326
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• 2004

Transient 3-dimensional elasto-hydrodynamic lubrication (EHL) analysis is performed on the contacting teeth surfaces of involute spur gears. Kinematics of the gear and the pinion are taken into account to get accurate geometric clearance around the EHL region of the contacting teeth. The surface pressure and film thickness distribution for the whole contact faces in a lubricated condition at several time steps are obtained through the analysis. Besides the pressure spike at the outlet region, a representative phenomenon in EHL regime, the pressure at the inlet region is slightly higher than that of the center region. The film thickness of transient condition is thicker than that of steady condition.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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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.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.200-206
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• 2002

Pressure and film thickness of contacting surfaces between teeth of the involute spur gear in lubricated condition were studied by a numerical method. Dynamics of the gear and pinion was considered to gel ail accurate initial clearance between gear teeth. The 3-dimensional non-steady elastohydrodanamic lubrication analysis on the gear teeth showed a slight higher pressure at the inlet region of the contacting face as well as pressure spike at the outlet region and a more thick film thickness than that of steady condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.633-637
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• 1995

Numerical calculation tool for forging of gear-like components based on kinematically admissible velocity fields for upper bound method applicable to various deformation features of workpiece in forging processes were suggested. Each one of them deals with unidirectional flow of metal on dies, such as external involute spur gear, sequare spline, internal serrations. A complex calcuation tool of gear-like component forging process was built up by combining these kinematically velocity fields. In this paper, the workpiece with both external and internal teeth is divided into two parts. The deformation of each part is analyzed simultaneously using numerical calculation tool form combined kinematically admissible velocity field. The experimental set-up was installed in a 200 ton hydraulic press. As a result, each kinematically admissible velocity field could be combined with other and the calculated solution are useful to predict the capacity of forging equipment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.25-30
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• 2002

To reduce the vibration of a gear driving system, the modification of gear tooth from the orignal involute gear profile is usually done in gear manufacturers. The quantity of tooth modification has been decided on the basis of the interference between two gear teeth during gear meshing and the elastic deformation due to loading. However, the dynamic characteristics with tooth modification has to be investigated to avoid the instability to the variation of gear meshing stiffness and the nonlinearity due to gear backlash which results in sub- or super-harmonics in its responses. This research shows the dynamic characteristics with various tooth modifications in its type and quantity.

• Tribology and Lubricants
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• v.19 no.2
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• pp.65-71
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• 2003

An elastohydrodynamic lubrication analysis was performed on the contacting teeth surfaces of involute spur gears. Kinematics of the gear and the pinion were taken into account to get accurate geometric clearances around the elastohydrodynamic lubrication region of the contacting teeth. Pressure and film thickness distribution for the whole contacting faces in lubricated condition at several time steps were obtained through the analysis. Besides the pressure spike at the outlet region, a representative phenomenon in elastohydrodynamic lubrication regime, the pressure at the inlet region was slightly higher than that of the center region. The film thickness of transient condition was thicker than that of steady condition.