• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.449-452
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• 2009

This paper was designed to fabricate the miniature spur gear with pitch circle of 1.8 by hot extrusion process of mechanically alloyed Zn-22wt%Al powder at various temperature. The mechanical alloying was preformed for ball milled times of 8h, 16h and 32h by the planetary ball milling. Mechanically alloyed powders were compacted cylindrical performs. Extrusions of the miniature spur gear using the alloyed powder were carried out at different extrusion temperatures. The extruded spur gear was sintered for 2h at $350^{\circ}C$ in argon atmosphere. The friction between the die and the powdered billet and the internally different density due to complex product shape cause the internal crack. To overcome the mentioned problems, high dimensional accuracy at cross section of the spur gear and uniform Vickers hardness could be obtained by graphite lubricant and controlling holding time.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.63-68
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• 2015

Recently, 3D printer technologies have been used in many research efforts for high precision manufacturing. In particular, the rapid prototyping technology has been developing rapidly, because it can be manufactured in a short time with a 3D designed shape. This paper relates to the production characteristics of the straight bevel gear designed using a 3D print using the PolyJet method. The characteristics of a 3D printed straight bevel gear were compared with a machined straight bevel gear. The accuracy of the produced straight bevel gear was evaluated by backlash, meshing pattern, face angle, root angle, and surface roughness.

• Design & Manufacturing
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• v.6 no.2
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1008-1012
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• 1997

This study is on a mathematical model of profile shifted involute gear, and this model is based on Camus's theory. Gear is general mechanical elements that used for power transmission between two shafts that interval is comparatively short. and it delivers bit power as accurate ratio of speed. The profile of Spur gear which is the most basic factor is divided into Trochoidal fillet curve and Involute curve. Involute curve is used a lot of a shape curve of machine parts such as a gear, a scroll compressor and a collar of centrifugal pump. However, It is poor to study the modeling of Trochoidal fillet curve and the three dimensions model shaped mathematical curve. So we draw three dimensions gear have accurate mathematical function using ADS(Automatic Drawing system), VisualLISP. To check accuracy and perfection, we make a program of checking Interference. and use for this study.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.95-101
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• 2012

An internal type roller ring gear(RRG) system composed of either a pin or a roller ring gear and its conjugated cam pinion can improve the gear endurance from that of a conventional gear system by reducing the sliding contact, while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection conditions obtained when the profile shift coefficient is introduced. Then, we investigated contact stresses and surface pitting life to fmd characteristics for surface fatigue by varying the shape design parameters. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1235-1242
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• 2018

When the wind speed changes rapidly, the wind turbine is stopped for the safety of the power system and the mechanical system. At that moment, the wind turbine gearbox is damaged and broken due to the contact load of the gearbox. In addition, the problems such as increasing frictional heat and deteriorate of the brake occur, because the power of the blades is transmitted directly to the brakes. This paper proposes a hybrid magnetic gear shape that solves the problem caused by the contact of the mechanical gear, which is the power transmission device of the wind power generation system, and the power cutoff system. The shape of the hybrid magnetic gearsuitable for the wind power generation system is derived through the torque and loss analysis according to the shape of the hybrid magnetic gear by using the two dimensional finite analysis method.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.127-138
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• 1991

A gear forming method by cold extrusion and an analytical method with its numerical solution program based on the upper bound method were developed. In the analysis the involute curve was 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(spur) gear were successfully calculated. These numerical solutions are in good agreement with experimental data. In the experiment, 4-6 class helical gear of KS standard for automobile transmission was successfully manufactured.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.13-18
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• 2011

This study deals with the effect of the honing in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by honing. Therein, the honing techniques are welcomed especially as one of the physical surface improvement methods. As a result, gear honing reduces vibration and noise, and will increase the life of gear. And gear honing also changes the surface of gear tooth in a short time and price, so it is a very important method in manufacturing industry. But nowadays, it is hard to find the detail information of gear honing. The test gear is a planetary gear which is used in the automotive industry. It is manufactured by the hobbing, shaving, carburizing and honing. This study investigates the effect of honing in surface shape of SCM420H planetary gears, including fatigue strength test and characteristics of honing of SCM420H planetary gears.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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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.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.1
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• pp.11-18
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• 1986

Schooling behavier to a fishing gear and estimation of the volume of fish school in set net have ~ been studied by making use of such techniques as visual observations, underwater cameras, under- water televison. However, all of these observation techniques are subject to restrictions caused by illumination, underwater visibility, underwater transparent and sea conditions. For the above mentioned reasoa, one of the most effective method by this time become generally known a method using fish finder. In this paper, in order to control the fishing ground of set net effectively and to develope the telemetric fish finder, the experiments for the target strength, underwater shape of fishing gear, schooling behavier and volume of fish school with fish finder were performed at Galgott fishing ground of set net located Keouje Island, 15th-24th July and 18th-20th October in 1985. The results of these experiment showed that a method using fish finder in fishing grOlllld of set net is available for estimating distribution and school size, fish behavier in relation to a fishing gear and underwater shape of fishing gears.