• 한국생산제조학회지
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• 제26권2호
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• pp.199-204
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• 2017

In this study, analytical methods for designing a torque arm pin and elastomeric bushings of a conventional-type three-point-suspension gearbox of a wind turbine are investigated. The design loads for the torque arm were derived by considering the effects of the transmitted torque and self-weight of the gearbox. Based on the design loads, design methods for the torque arm pin and elastomeric bushings were introduced in the terms of material and size selection. Finally, a small-scale conventional-type gearbox was designed by applying the derived design methods. This study is an elementary and analytical study for the design of the torque arm pin and elastomeric bushings. It is necessary to verify and supplement the results further through extensive experimentation.

• 소음진동
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• 제9권5호
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• pp.1050-1057
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• 1999

The existence of clearance at the link joint of a machine is inevitable for assembly and mobility. During the cyclic operation of a machine, rapid changes of the direction and magnitude of connection forces cause momentary loss of contact between the pin and the bushing at the link joint. Contact loss at the clearance joint gives rise to undesirable impact. The impulsive force affects on the performance of the machine, and leads to excessive vibration, noise and faster wear in the connecitons. In this paper, experiment and theoretical analysis were carried out for the variation of crank speed and clearance size. The link mechanism employed in this investigation was newly designed to check the effects of parameter changes on the occurrence of contact loss and on the magnitude of the impact force. The contact loss and impact position were calculated with various driving conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.757-759
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• 1998

This paper proposes a new high-voltage measuring system that is able to provide current enough to charge a storage battery for a motor driving a load switch, and detect each phase voltage and phase angle in three phase distribution line accurately. In order to develop the reliable voltage measuring system we had designed and manufactured condenser-type bushing having good characteristics for temperature on account of using epoxy resin as dielectric material, and investigated the variation characteristics of capacitance via variation of applied voltage. The experiment results show that the proposed condenser has good characteristics to environmental changes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.38-42
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• 2001

This paper describes an application of the on line partial discharge measurement method in operating transformer. In the operating transformer, the partial discharge signal may be superimposed by radio intereference voltage(RIV) and pulse shaped noise signals generated by external corona. The partial discharge quantity showed about 3,800pC due to very high sinusoidal interferences at the measuring impedance terminal of the transformer bushing tap. In order to reject these noises, this paper applied RIV filter, band-pass filters and noise gating method. The resulting measuring sensitivity was improved from 3,800pC to 160pC.

• Structural Engineering and Mechanics
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• 제44권3호
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• pp.363-378
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• 2012

The stiffness of a suspension system is provided by the bushings and the stiffness of the wheel center controls the suspension's elasto-kinematic (e-k) specification. So the stiffness of the wheel center is very important, but the stiffness of the wheel center is very hard to measure. The paper give a new method that we can use the stiffness of the bushings to calculate the equivalent stiffness of the wheel center, which can quickly and widely be used in all kinds of suspension structure. This method can also be used to optimize and design the suspension system. In the example we use the method to calculate the equivalent stiffness of the wheel center which meets the symmetric and positive conditions of the stiffness matrix.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.338-343
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• 2007

We presented a special method of forging hollow shafts of hard-to-form material, which is composed of piercing with back pressing and hollow shaft extrusion. The presented method was applied to cold forging a bushing of an excavator. The finite element simulation technology was employed for developing the optimized process and the predictions were compared with the experiments. The method was also applied to an automotive part and was verified to be powerful for manufacturing the cold forged hollow shafts of the hard-to-form materials.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.187-190
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• 1999

To reduce the maintenance expence, and the possibility of electric outage and accident, accurate measurement should be carried. But the classical method has some problems in the aspect of man power, reliability, and expence. In this paper, we propose a new type apparatus, which could detect the degree of contamination on insulators on outdoor insulation system, such as transmission and distribution line insulator and bushing. The new type apparatus consists of Pelltier module, electrode system, and measuring part. At first leakage current detecting method was considered, then with the fault(oxidation of electrode) of that method we should propose a another method. We carried various test to prove the possiblity and reliability of the propoused apparatus. And we get some useful result with laboratory test.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.9-12
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• 2000

Insulators for high-voltage and large-power should be endured mechanically the weight of mold bushing itself and the force of pushed from contact with circuit breaker and conductor. But dielectric breakdown could be occurred result from the external circumstances and internal factors such as chemical reaction, partial discharge, change of temperature and the relation of temperature-time in process of casting. Therefore, to get rid of external and internal factors of dielectric breakdown. Furthermore, to prevent the internal cracks, void, cavity which resulted from the contraction originated on the interface between copper and epoxy resin, formed semi-conductive layer with partially carbon painted on copper bar. The PD properties and the insulation qualities of epoxy molded insulators were improved by roles of cushions for the direction of diameter and natural sliding effects as like separated from conductor for the direction of length.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.392-395
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• 2003

The study of electric field analyses has been conducted on two kinds of bushings for 17.5kV $SF_6$ gas insulated recloser. In this paper, two model bushings and input conditions for the analyses are described in detail. The results of the electric field analyses are presented and compared with to find out the better design in two bushings. Finally some suggestions are given for improving the insulation characteristics of the bushings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1618-1619
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• 2003

개방형 스페이서(barrier)가 적용된 가스 절연개폐장치(GIS)에 외장형 부분방전(PD) 센서를 적용 하고 센서장착부, 인근 스페이서 또는 부싱으로 유입되는 광대역 잡음신호의 투과율을 10 - 2000 MHz의 극초단파 영역에서 측정하였다. 또한 간단한 금속 차폐체에 의한 잡음신호의 감쇄효과도 측정 하였다. 스페이서 또는 부싱을 통하여 인근센서에 유입되는 잡음의 크기는 차폐시와 대비하여 약 25 dB 증가하였다.