• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.782-785
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• 2002

The goal of this research is to deduce the robust design of mold oscillator of the continuous casting machine. In the case of the system operated in the high temperature condition, the structural problems caused by the heat are dominant. Therefore, the thermal stress is considered with the connection of the thermal and structural analyses. The cooling ability of the water jacket was estimated and the robustness of mold oscillator was judged with the displacement and stress distributions obtained by the finite element method. The analytic results were compared with the real values of the iron mill.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.405-408
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• 2002

A high speed feeding type laser cutting UC is developed for the precise cutting of sheet metal. The M/C is a flying optics type one with specified functions of movability and strength in order to increase workability. The gantry frame should be moved with a certain velocity within a relatively short time for the proper cutting of object materials. The gantry is actuated by rack and pinion. In this paper, modal and structural analysis for a laser culling M/C, is carried out in development of the machine The machine is modeled by placing proper shell and solid finite elements and fictitious mass properties to represent the real one.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.21-23
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• 2007

It is well known that the characteristics of the induction machine depend on a great degree on the leakage reactance. And the leakage reactance is different according to a level of slant. So in this paper, we calculated the inductance per coil side. And the torque and speed characteristics are analyzed using a method base on the two-dimensional (2-D) finite element method (FEM) and on the circuits theory to model the rotor bar in a induction machine. The variable values of bar angle of slant are considered.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.138-140
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• 2007

These days, robot-industry development requires a new motor technology. Robot system is more complex than the other machine ones. They need the simplicity and light weight as robot systems. Moreover, They have to become a high energy efficiency machine. For these reasons, in this paper, the 3-degrees of freedom permanent-magnet spherical motor is proposed instead of existing ones. The proposed motor model is analyzed by using FEA(Finite Element Analysis), for comparing the results, torque of the motor is simulated by derived torque function.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2329-2334
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• 2018

This paper discusses the thermal effect of the number of permanent-magnet (PM) layers in an outer rotor machine. Depending on the number of axial-layer of PM, the operating temperature is compared analytically and experimentally. The electromagnetic analysis is performed using 3-dimensional time varying finite element method to get the heat sources depending on axial-layered PM models. Then thermal analysis is conducted using the lumped-parameter-thermal-network method for each case. Two outer rotor machines, which have the different number of axial-layer of PM, are manufactured and tested to validate the analysis results.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.190-195
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• 2001

The piercing and blanking of thin sheet metal working is specified division in press die design and making. In order to prevent the defects, the optimum design of the production part, strip process layout, die design, die making and try out etc. are necessary the analysis of effective factors. For example, theory and practice of metal shearing process and it's phenomena, die structure, machine tool working for die making, die materials and it's heat treatment, metal working in field, their know how etc. are included in those factors. In this study, we analyzed whole of data base, theoretical back ground of metal working process, and then performed the progressive die tryout with the screw press.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.836-840
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• 1995

Recently, the motor-integrated spindle spindle systems have been used to simplify the machine tool structure, to improve the motion flexibility of machine tool, and to perform the high-speed machining. In this study, a static and dynamic analysis system for motor-integrated high-speed spindle systems is developed based on Timoshenko theory, finite element method and windows programming techniques. Since the system has various analysis modules related to static deformation analysis, modal analysis, frequency response analysis, unbalance response analysis and so on, it is useful in performing systematically the design and evaluation processes of motor-integrated high-speed spindle systems under windows GUI encironment.

• Tribology and Lubricants
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• v.21 no.6
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• pp.289-295
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• 2005

Most machine element, such as gears and bearings, are operated in the mixed lubrication region. Contact between two asperities has an effect on machine life by increasing local pressure. To estimate fatigue life exactly, asperity contact should be considered as a factor of fatigue life because this happening produce friction, abrasion and make flash temperature. In this paper, asperity contact is considered as a result of film breakdown when lubricant pressure is not enough to separate two asperities. Contact pressure is calculated to asperity overlap region and added to lubricant pressure. For this model, numerical procedure is introduced and the result on surface roughness and velocity for wheel bearing is presented. Results of EHL analysis for wheel bearing show that asperity contact is occurred at the edge ofEHL conjunction where has a insufficient lubricant pressure to separate two surface.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1108-1114
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• 2013

This paper presents a new winding topology for MW class offshore wind generator having modular and dual 3-phase. Based on proposed simplified relationship between magnetic flux and phase current in the air gap, several new windings for modular and dual 3-phase are made. In case of one inverter operation or faulty operation, the proposed model can have balanced 3-phase induced voltage whereas the conventional generator with modular winding has unbalanced induced voltage, which can be important issue in offshore generator. The model was applied into 6MW prototype machine with dual 3-phase. Using finite element analysis, induced voltage, inductance were investigated. The results show that the proposed modular winding can be applicable to dual inverter system with electrically balanced voltage.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.765-771
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• 2017

This paper presents concurrent design methods of surface permanent magnet synchronous machines for saliency-tracking self-sensing position estimation. Magnetic saliency for the self-sensing is created by stator pole saturation due to the rotor zigzag leakage flux. The power conversion properties such as saliency ratio, torque ripple, and efficiency vary according to motor design. The property change due to design modification is analysed by using finite element analysis, and with the appropriate design modification, proper saliency is created while preserving their power conversion capabilities.