• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.63-70
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• 2011

This paper presents the design and operating characteristics of the novel cylindrical linear motor which is designed for the long stroke XY stage. In the long stroke structure, the air gap is changed by the distortion and bending effects, and it makes additional position error in the XY stage. In order to consider the distortion and bending effects of the long stroke, the field part of the cylindrical linear motor is designed as an open structure, and the stroke is supported by the bridge guide which is positioned in the open field part. The mechanical bridge guide can reduce the bending effects of the stroke and can keep a constant air gap. The detailed design process of the proposed cylindrical linear motor is presented in this paper. The proposed motor is analyzed by the 3D FEM technology. The practical XY stage which uses the proposed motor is tested to verify the propose novel cylindrical linear motor. The FEM and experimental results show the effectiveness of the proposed motor.

• Journal of KSNVE
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• v.7 no.6
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• pp.919-929
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• 1997

Induction motors are used in many areas to transform electrical energy to mechanical energy. In the design of an induction motor, not only energy efficiency but also noise becomes an important factor. To effectively address the noise problem, it will be convenient if one can see where and how noise is generated and propagated. In this study sound radiation by an induction motor is visualized using cylindrical acoustic holography. To minimize the bias error by window effect Minimum Error Window(MEW) is used. Its performance is verified by numerical simulations. Based on these theoretical understanding, sound pressure measurement with an induction motor are performed. Not only sound radiation are visualized but sound pressure level and sound power level are also estimated. Results show that the main source is located at nearly bottom part of the motor and the total sound pressure level is 49dB, which satisfies the guideline value suggested by the KS C 4202.

• Proceedings of the Korean Magnestics Society Conference
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• 1999.10a
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• pp.140-141
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• 1999

• Proceedings of the KIEE Conference
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• summer
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• pp.1034-1036
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• 2004

The most basic form of a direct-drive linear motor is the voice coil motor(VCM). The voice coil motor employs a stationary permanent magnet field assembly in conjunction with a moving coil winding assembly to produce a force proportional to the current applied to the coil. Voice coil motor provide motion capable of extremely fine position sensitivity, limited only by the feedback sensor used to close the control loop. This paper presents dual-servo voice coil motor for improvement of driving range and position resolution. The voice coil motor is a cylindrical shape to improve reliability of a nanoindenter.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.76-82
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• 2000

This paper describes the machining characteristics of cylindrical plunge grinding. The study investigates the process using the current signals of a spindle motor through a hall sensor. Grinding experiments were conducted under various conditions such as wheel speeds, workpiece speeds and infeed rates with a conventional vitrified bonded wheel. Analyzing the current signal of the spindle motor, a relationship between current signals and the metal removal rate in terms of the in(red rate is induced. It was also shown that a hall sensor has similar capabilities in evaluation of grinding behavior compared to the AE signals, which are useful far monitoring the grinding process.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.867-873
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• 2002

We have designed and fabricated the slidacs type automatic voltage regulator(SVR) that is able to control the output voltage continuously according to load variation. Especially, the frictions between the surface of contact of the slidacs coils and the output wire moving shaft arc reduced by modifying the mechanical configuration of surface of contact of slidacs from the conventional sliding one into the proposed rotary one composed of cylindrical bearing. Thus, SVR using cylindrical bearing proposed in this study has less noise than the conventional one owing to the reduction of friction, and its breakdown ratio caused by the abrasion of contact materials is reduced as well. We have designed U motor driving circuit for controlling the output wire moving shaft, and introduced the digital control method using the pulse width modulation(PWM) output for controlling DC motor.

• Proceedings of the KIEE Conference
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• summer
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• pp.1061-1063
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• 2004

This paper deals with the application of cylindrical Halbach array to a PM motor capable of producing pure rotary motion, pure linear motion, or helical motion, The proposed motor consists of an exterior polar Halbach array for a rotary motion and interior cylindrical Halbach array for a linear one. The two- dimensional space harmonic method is employed for predicting the electromagnetic characteristics, with reference to the following parameters as variables: magnetic field, torque/thrust and back emf.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1415-1423
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• 2013

The traveling wave ultra-sonic motor (TWUSM) is operated through the frictional force between the rotor and the stator. Hence, the contact mechanism should be analyzed to estimate the motor performance. However, the nonlinearity of the contact mechanism of the TWUSM makes it difficult to propose a proper contact model and a characteristic analysis method. To address these problems, a novel contact model is proposed and be termed the cylindrical dynamic contact model (CDCM) in this research. An estimation method of the motor performance is proposed using the CDCM, an analytical method, and a numerical method. The feasibility and usefulness of the proposed characteristic analysis are verified through experimental data.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.4
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• pp.179-187
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• 2003

In the machine tool industry, direct drive linear motor technology is of increasing interest as a means to achieve high acceleration and to increase reliability. This paper analyzes and compares the characteristics of the tubular linear actuator with the cylindrical Halbach and radial array, respectively. A tubular linear actuator with cylindrical Halbach array, consisting of parallel magnetized arc segments instead of ideal radial and axial magnetized rings, is manufactured. The magnetic field solutions due to the PMs and to the currents are established analytically in terms of vector potential, using the 2-D cylindrical coordinate system. Motor thrust, flux linkage and back emf are then derived. Thrust characteristics according to such design parameters as magnet height and air gap length are also given. The results are validated extensively by comparison with finite element analysis (FEA). Test results such as thrust measurements are also given to confirm the analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.11
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• pp.1541-1543
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• 2013

This paper presents a spherical motor which can control in multi-degree of freedom operation. The spherical motor has been researched by many types of structure. Thhis paper shows a spherical shaped airgap and surfaced permanent magnets. Especially, The motor consists of dual rotor cores. Unlike a cylindrical motor, the spherical motor design can be considered with azimuth direction on spherical coordinates. Therefore the permanent magnet surfaced on the rotor need to be designed optimally in order to generate a sinusoidal magnetic flux density in the airgap. This paper presents results of optimal design for reducing torque ripple of the multi-degree of freedom spherical motor.