• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.109-112
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• 2006

In the recent studies, various types of multi mode electric variable transmission for hybrid electric vehicle have been proposed. Multi mode electric variable transmission consists of two or more different type planetary gear hybrid powertrain system(PGHP), which can change its power flow type by means of clutches for improving transmission efficiencies. Generally the power flows can be classified into three different types such as Input split, output split nd compound split. In This paper, we present velocity and torque equations of the input-split powertrain and analyze its optimal Performances. There are six combinations of the input-split powertrain, each combination has various lever length. We find optimal planetary gear ratios for fuel economy and acceleration performance, and compare performances of each combination.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.59-66
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• 2011

This study was carried out the experimental and the analysis for process of carburizing and quenching, evaluated the reliability of mock-up. Carburizing of comer of rock gear was higher than body regardless of condition of eight processes, and the end of gear tooth was more highly distributed than root. Hardness of surface shows the maximum value and was decreased linear to depth direction. The result of analysis wasn't nearly the heat deformation. In mock-up, tooth flank increased 0.096%, thickness of tooth decreased 0.11% and body increased 0.11%. It had no trouble with assembly and operation like this. The mock-up of recliner for automobile was secured stability by four types of test.

• Tribology and Lubricants
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• v.34 no.5
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• pp.169-174
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• 2018

A multi-stage compressor (MSC) is comprised of several impellers installed in the pinion gear shaft driven by a main bull gear. In the pinion shaft, a thrust collar (TC) is installed to support the thrust load. The TC makes the lubrication system simpler in the MSC; therefore, it is widely used in similar kinds of machinery. Typically, TCs are installed on both sides of the bull gear and pressure is developed in the lubricated area by creating a taper angle on the TC and bull gear surface. In the current study, we developed a numerical analysis model to evaluate the performance of the TC considering its design parameters. We sloved the Reynolds equation using the finite element method and applied the half Sommerfeld condition to consider cavitation. Based on the pressure calculated in the lubricated area, we calculated the power loss and minimum film thickness. In addition, we calculated stiffness and damping using perturbation method. We performed parametric studies using the developed model. The results of the analysis show that the maximum pressure presents in the center area of the TC and it increases with the taper angle. The area over which pressure is developed decreases with the taper angle. The results also show that there is an optimum taper angle providing minimum power loss and maximum film thickness. Additionally, the stiffness and damping decrease with the taper angle. As the applied load increases, the power loss increases and the minimum film thickness decreases. However, the stiffness and damping increase with the applied load.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.288-294
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• 2009

The purpose of this study is manufacturing of monolithic housing for modularization of steering gear. Monolithic housing is difficult to weld with only rotation and linear motion. It is for this reason that housing of joining parts have a slope of 76.3 degrees. For this reason, welding trajectory was measured by the cooperative controled robot system, and then allowing for measured results, we developed the dedicated system. The developed system can be welded by using only 3 axises in contrast with robot system using 8 axises in housing welding. In addition, we applied CMT and laser welding device to dedicated system and as a result of experiment, sound bead and excellent roundness could be obtained.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.316-321
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• 1997

The purpose of this study is 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, the validity of the simulation model was checked by the field test 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 differential gear by applying flexible coupling.

• 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 Machine Tool Engineers Conference
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• 2003.04a
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• pp.33-38
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• 2003

There have been continuous efforts for developing the automatic mechanical design system to increase the efficiency of the tedious design process. However, these efforts have been concentrated on single platform application. Hence, the developed systems have been available only in a designated place and time and have been difficult to modify. It is proposed in this study that a web-based design system is developed to offer more reliability and convenience without any restriction of tine and place. The developed system is programed based on Java, and architecture of the system has object-oriented features of Servlet and JSP and is independent on any operating systems. The developed system has been applied to the initial design of multi-stage gear dirves but however as the framework of the developed system is quite versatile, its application to automatic design of any mechanical system or evaluation can be easily expected.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.118-126
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• 2008

A new approach to the critical speed calculation of general multi-mesh gear chain system included bevel gear is presented. A transfer matrix mode! based on Hibner's branch method is developed and the natural properties of the branched rotor system are calculated with using the ${\lambda}$-matrix formulation. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors, misalignment and the transmitted errors of the gearing are considered, shows that, at the neighborhood of the operating speed, there are the two critical speeds amplifying the first mode and the eighth mode.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.2
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• pp.54-60
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• 2004

There have been continuous efforts for developing the automatic mechanical design system to increase the efficiency of the tedious design process. However, these efforts have been concentrated on single platform application. Hence, the developed systems have been available only in a designated place and time and have been difficult to modify. In this study a web-based design system is developed to offer more reliability and convenience without my restriction of time and place. The developed system is programmed based on Java, and the architecture of the system has object-oriented features of Servlet and JSP and is independent on my operating systems. The developed system has been applied to the initial design of multi-stage gear drives, but as the framework of the developed system is however quite versatile, its application to automatic design of my mechanical system or evaluation can be easily expected.

• Transactions of Materials Processing
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• v.6 no.4
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• pp.291-299
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• 1997

This paper is concerned with the design of process sequence to form the inner skin of landing gear. The inner skin of landing gear is a part of airplane which is known to be difficult to form its shape. Our study investigates the production method of inner skin and examines the design criteria by three dimensional elastic-plastic finite element method. Based on the results of simulation, design strategy for improving the process sequence is developed using stretch forming process. The final product of inner skin is produced in multi-stage operations with annealing treatment to meet the required capacity of press. The numerical results show that the newly designed process can produce the required part successfully within the design criteria.