• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.272-276
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• 2014

In this paper, cable drive mechanism is proposed to implement high reduction gear ratio. Cable drive mechanism has great advantages such as light weight, high degree of freedom about design aspect and zero backlashes. However, it is restrictively utilized for robotic applications because it is difficult to implement high reduction gear ratio more than 10 to 1. Proposed mechanism enables multi-level reductions by adopting seamless winding method (SWM) which links the previous output axis and the next input axis. Consequently, this reduces the mechanical complexity significantly and enables high reduction with only one single wire cable. 3D CAD design was provided and prototype was manufactured.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1059-1062
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• 2002

In this paper, after we make high speed gear requested high precision, we got data on the sound level is Max 60,000rpm for tooth modification. We make a decision about tooth modification after predicting exactly amount of tooth interference by FEM. The purpose of this research is that modified gear is to drive under stable sound level. To accomplish its, Beam elements are used to simulate the same condition as a real gear drive by FEM. From result of simulation and experiment, if it has holes to decrease whole weight of high speed gear, it is not good effect because it has much more deformation than not.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_1
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• pp.941-952
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• 2022

In this study, additive manufacturing technology was applied to restore a planner miller that was unusable due to aging. The drive spur gear of the planner miller was inoperable due to many defects in the teeth. The shape of the defective gear teeth was restored by deposition of the defective teeth using the DED method. However, as the location of the deposition head and the location of the set origin became farther, the deposition shape was different from the modeling shape. Nonetheless, since the modeling of the deposition part was designed to be larger than the tooth shape of the original gear, it was possible to completely restore all gear teeth through post-processing. The arrangement interval of the flow lines of the deposition part was narrower than that of the substrate. The hardness of the substrate was 172 HV, and that of the deposition part was 345 HV, which was twice as high as that of the substrate.

• Advances in Computational Design
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• v.8 no.3
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• pp.255-271
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• 2023

The gear drive of a combat aircraft engine is responsible for power transmission to the different accessories necessary for the engine's operation. Incorrect power transmission can occur due to the presence of failure modes in the gears like bending fatigue, pitting, adhesive wear, scuffing, abrasive wear and polished wear etc. Fault diagnosis of the gear drive is necessary to get an early indication of failure of the gears. The present research is to develop an algorithm using different vibration signal processing techniques on industrial vibration acquisition systems to establish gear fault diagnosis architecture. The signal processing techniques have been used to extract various feature vectors in the development of the fault diagnosis architecture. An open-source dataset of other gear fault conditions is used to validate the developed architecture. The results is a basis for development of artificial intelligence based expert systems for gear fault diagnosis of a combat aircraft engine.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.3
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• pp.96-102
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• 1997

Eigenvalue analysis of vibration mode and an analysis by frequency response among the methods of predicting gear noise are related with transmitting sound of vibration. In this study we intended to reduce the vibration noise of differential gear by reducing torque fluctuation of drive pinion shaft which causes vibration noise of differential gear in rear wheel drive vehicles. For this we developed multi-degree of freedom analysis model in which mass moment of inertia and torsional spring combined and we examined the influence of torsional vibration of driveline elements by performing forced vibration analysis of engine excitation torque. We studied the methods for reducing torsional vibration of driveline according to the design factor of propeller shaft and examined the effects reducing vibration in differential gear by applying flexible coupling.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.5-14
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• 2000

In the design of epicyclic gearing, the analysis of interference and mechanical efficiency is an important index. As an applied way, epicyclic gearing can be used for planetary gear drive and differential gear unit. In case that one of its components is fixed with intend, it is called planetary gear drive. On the contrary, in case that no component is fixed, it is called differential gear unit. In this paper, various design constraints and interferences are defined for 2K-H I type epicyclic gearing which is a basic arrangement of diverse epicyclic gearings. And various interferences are analyzed, and mechanical efficiency is calculated in case that 2K-H I epicyclic gearing is used for a differential gear unit as the change of gear ratio, cutter pressure angle, addendum modification coefficient. As that results, trend of mechanical efficiency is investigated in the ranges of addendum modification coefficients which would not lead to interferences, and the optimal range of addendum modification coefficient which can generate the maximum mechanical efficiency are presented. In order to prove results of theoretical efficiency analysis, experimental studies are performed.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.9-13
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• 2022

Electric wheelchairs, the output from the motor is mainly applied to a speed reducer using a power transmission device such as a belt or a chain. However, although a speed reducer using a belt or chain is a simple device, it occupies a lot of space and has a space limitation, so it is not suitable for an electric wheelchair driving part. However, since the speed reducer of the planetary gear type is decelerated on the same axis, the volume can be reduced, so the space constraint is less than that of the belt or chain type reducer. Therefore, in this study, a driving part that can obtain great propulsion with a speed reducer using a planetary gear type was developed through a study on the driving part of a wheelchair that can be switched between manual and electric. Accordingly, the tooth shape of the planetary gear applied to the reducer was designed using the Kisssoft program. In addition, the drive part was designed to be applicable to the existing wheelchair wheels, and the mechanism was optimized for the manual/electric switching principle and operation principle of the drive part. Based on the research contents, the final design and manufacture of the wheelchair reducer drive unit in the form of a planetary gear having one sun gear, two planetary gears and one ring gear was carried out.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.702-707
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• 2012

This paper considers two linear drive systems using roller gear mechanism(RGM), one is the RRP(roller rack pinion) system that consists of a roller rack and a cam pinion, the other is the CRP(cam rack pinion) system that consists of a cam rack and a roller pinion. Through the comparison of contact forces and load-stress factors between two linear drive systems, it reveals that the RRP system is superior to the CRP system in the aspect of the bending strength, while the CRP system has higher contact fatigue resistance than that of the RRP system.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.2
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• pp.3-7
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• 2006

We propose a new concept of transmission-tribology design based on the investigation of development and existing problems of the gear drive and tribology. The content of transmission-tribology and transmission-tribology design is probed. Some effective methods of transmission-tribology design is probed. Some effective methods of transmission-tribology design are put forward. Partial achievements in this research are introduced tersely. Mechanical transmission, which is represented by the gear drive, and tribology are two main branches of mechanical engineering. They have their own definite research field. In recent years, we have been doing our utmost to suggest combining mechanical transmission-tribology and transmission-tribology design. Partial achievements in this research area are obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.65-75
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• 2001

Modern vehicles require a high degree of refinement including good driveability. Vehicle driveability, which becomes a key decisive factor f3r marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. Therefore engine and drive train characteristics should be considered to achieve a well balanced vehicle response simultaneously. This paper describes experimental procedures which have been developed to measure engine torque and investigate shuffle characteristics. To analyze the vehicle dynamic behavior, fractional torques and inertia mass moment of engine, and drive train were measured. Shuffle characteristics during tip-in condition were investigated in an experimental vehicle at 2nd and 3rd gear stages. It was found that the shuffle characteristics were caused by sudden changes of engine torque and have a different vibration frequency with gear stage variation. Inertia mass moment of engine including flywheel rotation showed a key factor for the shuffle characteristics.