• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.331-333
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• 1998

This paper deals with the analysis of the magnetic circuit of a claw pole type step motor. The air gap flux equation is derived using Thevenin equivalent circuit. On the base of the magnetic circuit analysis, both static torque and the dynamic torque characteristics are presented.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.21-23
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• 2004

The claw-pole PM(Permanent Magnet) stepping motor has the advantage of the positioning machine because of a relatively little step angle, facility of control, and detent torque characteristics. Although the research about this motor has been progressed, it was difficult to analyze because of three-dimensional magnetic circuit. This paper performed analysis of the static and dynamic characteristics of the claw-pole PM stepping motor using 3D-FEM(Finite Element Method). We also manufactured the test products and practiced performance tests for verification of the analysis results.

• Proceedings of the KIEE Conference
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• summer
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• pp.911-913
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• 2004

This paper presents characteristic analysis of claw-pole type generator. The analysis is performed using 2D equivalent model by 2D FEM. 3D FEM is used to check whether 2D equivalent model reflects the magnetic characteristics of the actual machine. Initially, 2D equivalent model of the claw-pole type generator is designed only by 3D geometry. Using 2D equivalent model, back emf characteristics are estimated and compared to measurements. The analysis results agree with measurements well and take less time comparing to 3D FEM.

• Proceedings of the KIEE Conference
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• summer
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• pp.929-931
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• 2004

Recently, there are growing demands for permanent magnet(PM) type stepping motor that greater mechanical output, smaller size. Especially, the PM type stepping motor with claw-poles is preferred solution for many small electronics position determination devices since it is small in size, low cost. But, the design of the PM type stepping motor with claw-poles is very difficult because it has a magnetic 3-D shape. This paper deals with a study of the miniaturization of the PM type stepping motor with claw-poles. We investigate the characteristic of the actual model using the equivalent magnetic circuit method and 3-D FE analysis.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.118-121
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• 2005

The claw-pole PM(Permanent Magnet) stepping motor has the advantage of the positioning machine because of a relatively little step angle, facility of control, and detent torque characteristics. Although the research about this motor has been progressed, it was difficult to analyze because of three-dimensional magnetic circuit. This paper proposed a design method of the claw-pole PM stepping motor using 3D-FEA. We established design variables that have an important effect upon the characteristics of the motor, and then peformed analysis of the static and the dynamic characteristics. We also manufactured the test products and practiced the performance tests for verification of the analysis results.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.302-313
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• 1992

10-9Torr 정도의 압력에서 작동하는 반도체 공정 도구들을 펌프하기 위해 주로 사용되는 기술들을 살펴보고, 이 분야에서 진공을 만드는 기술적 방향에 대해 언급한다. 특히, Roots, Claw, Roots/claw 펌프의 작동원리와 자기 부양식 turbomolecular 펌프를 다루었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.269-270
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• 2014

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.369-374
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• 1999

One hundred forty cows that have claw disorder have been used to study the association between lameness and reproductive disorders. Weak estrus owing to ovarian hypoplasia (41.4%) followed by follicular cyst (39.3%) was more frequent than any other disorders. Two hundred ninety-four cows have been used to study the association between lameness and calving to first service and calving to conception intervals depending on lactations, claw disease and floor conditions. And a comparison of number of services per conception between cows with lameness and cows free from lameness was carried out. The calving to first service intervals were significantly increased from average 78 to 102.5 days and calving to conception intervals were significantly increased from 109.6 to 150.6 days in cows with lameness. The calving to first service and calving to conception intervals were not significant different between lactations in cows with lameness. In comparison of calving to first service and calving to conception intervals in cows with lameness depending on claw disease and floor conditions, there was no significant difference. The average number of services per conception was increased from 1.73 to 2.57 in cows with lameness. Service numbers were more frequent during second lactation (3.0 services) but there was no significant difference between lactations in cows with lameness. Therefore, it is likely that the management of lameness is important factor on proper health control of cows and the cows with lameness show decreased fertility.

• Journal of Power Electronics
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• v.11 no.4
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• pp.527-532
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• 2011

Due to the need for improved fuel consumption and the trend towards increasing the electrical content in automobiles, integrated starter generator (ISG) systems are being considered by the automotive industry. In this paper, in order to change the conventional generator of a vehicle, a belt driven integrated starter generator is considered. The overall ISG system, the design considerations for the claw pole type AC electric machine and a low voltage very high current power stage implementation are discussed. Test data on the low voltage claw pole type machine is presented, and a large current voltage source DC/AC inverter suitable for low voltage integrated starter generator operation is also presented. A metal based PCB (Printed Circuit Board) power unit to attach the 4-parallel MOS-FETs is used to achieve extremely high current capability. Furthermore, issues related to the torque assistance during vehicle acceleration and the generation/regeneration characteristics are discussed. A prototype with the capability of up to 1000 A and 27 V is designed and built to validate the kilo-amp inverter.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1005-1006
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• 2007

This paper analyzed the characteristics of the claw pole permanent magnet(PM) stepping motor by using 3D Finite element method(FEM). In this motor, magnetization is occurred along the z-axis, therefore it is necessary to apply 3D FEM for analysis of the claw pole motor. A phase difference of the two stacks's detent torque is 180 degrees. When the center of a permanent magnet is identical with the middle of a pole, small detent torque is produced in order to cancel each of detent torques. However, there are construction errors which are a discrepancy between one and the other phase section in the manufacturing process, thus the detent torque is increased. Moreover, it is confirmed that the proportion of the detent torque is considerably arisen according to the error. Analysis of the construction error is studied by changing the error $0^{\circ}$ to $3^{\circ}$.