• International Journal of Precision Engineering and Manufacturing
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• v.9 no.1
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• pp.19-24
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• 2008

We propose a new miniature air-bearing stage with a moving-magnet slotless linear motor. This stage was developed to achieve the precise positioning required for submicron-level machining and miniaturization by introducing air bearings and a linear motor sufficient for mesoscale precision machine tools. The linear motor contained two permanent magnets and was designed to generate a preload force for the vertical air bearings and a thrust force for the stage movement. The characteristics of the air bearings, which used porous pads, were analyzed with numerical methods, and a magnetic circuit model was derived for the linear motor to calculate the required preload and thrust forces. A prototype of a single-axis miniature stage with dimensions of $120\;(W)\;{\times}\;120\;(L)\;{\times}\;50\;(H)\;mm$ was designed and fabricated, and its performance was examined, including its vertical stiffness, load capacity, thrust force, and positioning resolution.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.40-44
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• 2007

Light rail vehicle is optimized vehicle system for complex urban circumstance. LRT systems have many merits such as improve accuracy, speediness and safety. There are many LRT systems such as monorail, tram, automated guideway transit, linear induction motor propulsion and so on. These systems have operated in Japan and other advanced countries. In Korea, local government has many projects to apply the advanced LRT system. But there are no standardized specification, performance test specification, construction specification for monorail system, linear induction motor propulsion system, tram in Korea up to now. So, we need to establish of standardized to economical construction and safety. The linear induction motor system has been usually applied in Japan subway and ART(Advanced Rapid Transit) of Canada. In Korea, the linear induction motor system has been adopted for Yongin LRT and currently under construction. This paper covers the contents and technical base for main items of rolling stock, performance standard, carbody structure, bogie, electronic unit and brake equipment in order to implement linear induction motor LRT system according to local conditions.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.58-60
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• 2009

This paper deals with force characteristic analysis of linear switched reluctance motor using dynamic simulation. First, we calculated flux density of linear switched reluctance motor according to position. Second, analyzed normal force from flux density of linear switched reluctance motor according to position. Also, analysis result compares with data that is derived through a finite element analysis, and proved validity. However, linear switched reluctance motor has non linear characteristic, hence, analysis of propulsion force do not easy using analytical method. Therefore, we presented dynamic characteristic analysis model which is consisted at motor and sensor signal part, etc., and substitute circuit constant that get using magnetic equivalent circuit method, we confirmed propulsion force.

• Proceedings of the KIEE Conference
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• summer
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• pp.1223-1225
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• 2004

In difference with the rotary type electrical machinery, the linear induction motor(LIM) that generates the direct thrust directly, is widely used for the operation system of electrified railroad, elevation system, conveyer system, and so on. The operational principle of linear induction motor is constructively similar to the general rotary induction motor. It is difficult to realize the complicate linear induction motor which is applied SVPWM system, but widely used in vector motor control system or servo control system because of its high performance in current control. In this paper, we presented the dynamic characteristic analyzing methode, and calculated efficiently the end effect by using equivalent circuit methode in the operating linear induction motor control system for Maltlab simulink modeling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.177-180
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• 2000

In this paper, we studied efficiency improvement of linear ultrasonic motor using projection. The principle of ultrasonic motor is to use an elliptic motion generated at the side of the vibrator, and the elliptic motion of the ultrasonic motor was obtained by complex oscillation of L$_1$-B$_4$ mode. As the experimental results, the efficiency of linear ultrasonic motor without projection was 1.52[%] when applied voltage was 56[V] in resonance frequency 58.4[kHz]. The efficiency of linear ultrasonic motor using projection was 3.36[%] when applied voltage was 56[V] in resonance frequency 58.4[kHz]. The efficiency was improved by projection.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.20-25
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• 2000

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.305-308
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• 2005

Linear motor has been developed for linear motion of machine tools. Linear motor is useful to design the linear motion, high speed and high accuracy, because of the simple system not required the additional mechanical part such as coupling and ballscrew. This paper tested performance of linear motor such as velocity response, position tracing performance, subordinate Traction force change and positional accuracy.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.163-170
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• 2002

This paper presents some measures far the optimization of the thermal behavior of linear motors, which are used as a high speed feed mechanism in machine tools. Thermo-Sandwich-Construction using two cooling circuits and an insulation layer shows an effective cooling system for linear motors. Conducting sheet can be also used to reduce heat flow from linear motor to machine table. Cooling pipe is a simple and effective cooling system for the secondary part of synchronous linear motor. Through the combination of the Thermo-Sandwich-Construction, conducting sheet and cooling pipe the thermally optimized linear motor shows a well improved thermal behavior in comparison with the prototype motor.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.85-87
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• 1998

In the industrial field, the necessity for the linear motion is increasing. Because of the motion converting mechanism there exist many losses. So the application of linear machines instead of rotating machines is increasing. As compared with a mono-polar type linear DC motor, it is possible for a multi-polar type linear BC motor to have a longer stroke and more thrust with thin shape. However, there are thrust ripple on multi-polar type one. In this paper, a design to multi-polarize of the linear DC motor is discussed. In order to make a smoother thrust on multi-polar type linear BC motor. a method is proposed.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.174-181
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• 2004

Ultra precision positioning mechanism has widely been used on semiconductor manufacturing equipments, optical spectrum analyzer and cell manipulations. Ultra precision positioning mechanism is consisted of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design, analysis and manufacture all of the inchworm linear motor system, which is one of the equipments embodied in ultra precision positioning mechanism. Inchworm linear motor system is consisted of a controller system and an inchworm linear motor, and its driving form is similar to a motion of spanworm. A design and manufacture of inchworm linear motor, which is consisted of three PZT actuators, a rod, two columns and a guide plate, are performed. Minimizing the von-Mises stress of the hinge using Taguchi method and simulation by FEM software optimizes the structural design in a column of flexure hinge. The designed columns and guide plates are manufactured by a W-EDM and NC-milling. A controller system, which is an apparatus to drive inchworm linear motor, can easily adjust driving conditions by varying resonance frequency and input-output voltage of actuators and amplifiers. The performance of manufactured inchworm linear motor system is verified and valuated. In the future, inchworm linear motor system will be used to make a more precision positioning by reinforcing a sensor and feedback system.