• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.551-558
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• 2011

To analyze the effect of wear of wheel profile on the running stability of rolling-stock, theoretical and experimental studies were conducted on the profiles used in conventional lines. In experiment using 1/5 scale model to verify the results of the theoretical analysis, the test results of the critical speed for worn wheel profile samples show similar trend. In case of the conical type wheel profile(Profile 40), the equivalent conicity is increased with flange wear. But in case of the arc type wheel profile(Profile 20h), the equivalent conicity is decreased with flange wear. And the critical speed of the bogie was inverse proportion to the equivalent conicity. It is shown that the variation of the critical speed with the wheel wear could be changed according to the design concept and wear pattern of wheel profile. Results of the theoretical and experimental studies are discussed here.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.433-434
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• 2006

The limited slip differential(LSD) is a device which enables the driving force to be transmitted from one slipping wheel to another wheel in such case that the car is stuck in clay or snow. When the unwanted slipping occurs on one wheel, the LSD temporarily restraints the differential motion to transmit the driving force in the other wheel. So far, many types of LSD were developed such as mechanical lock type, disk clutch type, viscous coupling type, torsion type and multiple clutch type. we designed a new type of the hydraulic LSD which uses the principle of trochoid gear pump.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.720-725
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• 2004

We proposed new arc-type wheel profiles to improve severe flange wear of conventional wheel profile coned 1:40. We designed many candidate wheel profiles and analyzed the geometric characteristics, dynamic performance and stress at contact points to draw out the final profiles. From the analysis result, we chose two cases of profiles and applied to wheels of test train. Tests carried out in service line to analyze the dynamic performance and verify the wear reduction for two cases of profiles. Test results shows the equal level of dynamic performance and the improvement of wheel flange wear compared with the conventional wheel profile.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.27-33
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• 2005

This study deals with the truing of diamond wheel fur the manufacture of micro v-shaped grooves with fine sharp edges in the grinding. Fine micro v-shaped grooves are key components to fabricate LGP(light guide plate), optical fiber connector and so on. Conventional v-shaped groove methods such as etching and lithography are difficult to make grooves with accuracy and cutting by lathe is difficult to select target materials. Therefore, as a preliminary stage to developing the grinding technology that will be expected fabrications for micro 3-dimensional structure of high effectivity and accuracy and freed up the restrictions of machinability to the materials for micro v-shaped grooves, truing is carried out with resin bond diamond wheel and electroforming diamond wheel using a cup-type truer. From the experimental results, it is found that the effects according to working direction of the cup-type truer and the restrainable methods of plastic deformation that is generated at wheel edge are examined. As a result, fine micro v-shaped diamond wheel was obtained, which are applicable to micro grinding for optical devices.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.38-42
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• 1995

In this paper, a theoretical analysis is presented on the mechanics for the side-cut grinding by electrodeposited CBN wheel of a hemispheric type. Each of the grinding force components is calculated by using the geometrical model. It is also presented that experimental results show grinding forces for grinding variable such as wheel speed, feed speed,depth of cut, and grinding wheel positions. The experimental results are found to be in good agreement with those predicted by the analytcal calculation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.567-573
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• 2012

Outer rotor type in-wheel Blushless DC Motor(BLDCM) for three-wheeled electric vehicle is researched. In-wheel system is to drive the electric vehicle without mechanical transmission, shaft, differential gears or other mechanical system. The motor is designed considering the performance requirements and drive modes of the vehicle. The determined dimensions as well as the slot and rotor pole are simulated by magnetic and thermal finite element analysis and ansys workbench to analyze the performance and heating of the motor. In order to verify the performance characteristics of the proposed motor, the experiment tests are executed and satisfy well the requirements.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.153-158
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• 1998

In this paper, a theoretical analysis is presented on the mechanics of the grinding by hemispheric type electroplated CBN wheel. The grinding forces acting on a single grain were calculated from its geometry by assuming the abrasive grain is spherical. Then. the total grinding forces were obtained by estimating the number of acting abrasive grains and the area of contact. The model includes the grinding variables such as wheel speed. feed speed. depth of cut, and grinding wheel positions. Experiments were also carried out to compare with the analytical results. The experimental results were found to be in good agreement with the analytical ones.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.309-314
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• 2011

Outer rotor type in-wheel switched reluctance motor for Welfare neighborhood electric vehicle is researched. In-wheel system is to drive the electric vehicle without mechanical transmission, shaft, differential gears or other mechanical system. To calculate drive power for each wheels, the elder's and disable's safety driving conditions are considered. The designed outer rotor SRM has a 6-stator and 8-rotor pole. The determined dimensions as well as the stator and rotor pole arc are simulated and tested with CAD and finite element analysis to verify the performance of the proposed motor.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.73-79
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• 1998

For the design and development of the wheel type excavator, the dynamic effects of travelling on the performance of the equipment should be first analyzed and conside- red in the initial design stage. In order to test the durability of the equipment in a short period, th travelling test should be performed over accelerated durability test tracks. which is more severe than general field roads such as city road, paved road, unpaved road and rough road. In this paper, a parametric study is performed in order to determine important design parameters of durability test track of a wheel type excavator. A rigid body model is developed using DADS and dynamic analysis is performed for the equipment travelling over several test roads with different severity. A comparison of test and analysis results is also presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.463-467
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• 2003

The traveling system of wheel type excavator, that is applied to drive method by friction of transmission, has many problems about transmisson. It need to settle the problem which is occurred at wheel type excavator and to study continuously variable transmisson which is used with only travel motor. This paper base on mathmetical modeling for travel motor and travel motor of wheel type excavator is designed continuously variable transmisson system without transmisson by direct control method.