• 한국가스학회지
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• 제25권4호
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• pp.27-35
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• 2021

최근 "전력 예비율" 급감에 대한 해결책으로 양방향 송배전이 가능한 마이크로 그리드로 전환되고 있다. 마이크로 그리드는 소규모 분산전원과 부하로 구성되는데, 분산전원의 대표적인 기술로 가정·건물에 적용하는 소형 열병합 발전시스템이 있다. 본 연구에서 가스 소비량 232.6kW(20만 kcal/h) 이내의 소형 가스엔진 발전시스템의 안전기준을 도출하고 발전 시스템, 냉각시스템, 윤활 시스템, 배기 시스템으로 구분하여 안전기준(안)을 개발하였다. 발전시스템의 경우 필터를 설치하고 가스 누출 및 엔진 회전수나 출력에 이상이 발생할 경우 이를 감지하여 시스템이 정지하도록 하였고, 냉각시스템은 냉각수 부족이나 과열이 발생할 경우 시스템이 정지하도록 규정하였다. 윤활 시스템은 윤활유의 압력과 온도를 모니터링 하고 이상이 발생할 경우 시스템을 정지하도록 하고, 배기 시스템은 국내·외 기준과 부합하여 배기가스 배출 농도 규제 값을 지정하였다. 본 연구 결과를 통해 가스엔진 발전시스템의 안전성을 향상시키고 제품 확산·보급에 이바지할 수 있다고 판단한다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.455-456
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• 2002

Wear is one of the main factors causing breakdown and fault of machine, so ferrography technique analyzing wear particles can be an effective way for condition monitoring and fault diagnosis. On the base of the forward multilayer neural network, a nodes self-deleting neural network model is provided in this paper. This network can itself deletes the nodes to optimize its construction. On the basis of the nodes self-deleting neural network, an intelligent ferrography diagnosis expert system (IFDES) for wear particles recognition and wear diagnosis is described. This intelligent expert system can automatically slim lip knowledge by learning from samples and realize basically the entirely automatic processing from wear particles recognition to wear diagnosis.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.383-384
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• 2002

Frictional sound is observed in great many practical systems, but its generation mechanism is still unknown Model systems are best suited for research on the fundamental mechanisms, but results cannot be easily applied to real systems, because each system has different sound radiation properties. At present, there is no easy method for evaluation of these properties. We propose to describe the sound radiation property of a tribo-system by the relationship between friction-induced sound power and the friction-induced vibration velocity of the contact element. It was found that the sound power of a tribo-system is linearly proportional to the mean-square velocity of the sliding element by a constant coefficient having the dimension of mass flow rate (kg/s).

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.245-246
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• 2002

The objective of this study is to evaluate corrosive wear resistance of metals used for bearings and gears in seawater. Sliding wear test of ferrous and copper materials against $Al_2O_3$ were carried out in artificial seawater using an electrochemical potentiostat. As the results, the wear rate and the coefficient of friction of the copper materials are lower than those of the ferrous materials. The corrosive wear of stainless steel is remarkably affected by normal load and sliding speed in view of tribological characteristics including adhesion and corrosion products.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.421-422
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• 2002

The purpose of this paper is to investigate the leakage characteristics of the valve stem in the gasoline engines. Especially, three factors affecting oil leakage are the power cylinder, engine head system, and the positive crankcase ventilation system. Which is the most variables, analysis difficulty is the valve stem seal characteristics. The testing system is used with oil motoring system. The leakage of an engine is analyzed for the cylinder temperature, atmosphere pressure, positive pressure, negative pressure, revolution of the camshaft and the surface roughness of the valve stem.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.283-284
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• 2002

Ball bearings (BB) are generally used in spindle of‘ disk drives at present, but they have been known that BB generate high frequency vibration. Fluid dynamic bearings (FDB) having high-rotational accuracy and small vibration characteristics have been developed as next generation spindles. Especially. a ferro fluid bearing (FFB) spindle has the advantage to prevent leakage and dispersion of lubricating oil using a ferro seal. In this study, we measured damping characteristics and frequency characteristics of these bearing spindles using a high-frequency vibration base. High frequency excitation was added to these bearing spindles mounted on the vibration base, and we proved that FFB and FDB spindles have effective damping.

• 대한기계학회논문집A
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• 제33권6호
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• pp.614-619
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• 2009

An engine for marine propulsion and power generation consists of several cylinder liner-piston sets. And the oil groove is on the cylinder liner inside wall for the lubrication between a piston and cylinder. The machining process of oil groove has been carried by manual work so far, because of the diversity of the shape. Recently, we developed an automatic grinding robot system for oil groove machining of engine cylinder liners. It can covers various types of oil grooves and adjust its position by itself. The grinding robot system consists of a robot, a machining tool head, sensors and a control system. The robot automatically recognizes the cylinder liner's inside configuration by using a laser displacement sensor and a vision sensor after the cylinder liner is placed on a set-up equipment.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.237-242
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• 2001

This paper presents the thermal characteristics analysis of a high-speed HMC spindle system with angular contact ball bearings, built-in motor, oil-jet lubrication method, oil jacket cooling method, and so on. The spindle system is composed of the main spindle and sub-spindle which are mechanically connected by a flexible coupling. The spindles are supported by two front and rear bearings, and the built-in motor is located between the front and rear bearings of the sub-spindle. The thermal analysis model of spindle system is constructed by the finite element method, and the thermal characteristics in the design stage are estimated based on temperature distribution, heat flow and thermal deformation under the various testing conditions related to material of bearing ball, spindle speed and coolant temperature.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.198-205
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• 1998

Recently, according as the supply of power steering system has been diffused, for the comfortable driving condition, the problem to reduce the noise and vibration of this system suddenly appeared. This system can be classified two systems of the pipe line and the pump. In this paper, it is described about the noise characteristic with the camring profile of the hydraulic vane pump. As a result, when it excesses tolerance, the noise is increased. Moreover, in the case of the same of cam-ring, the effect of the rotating speed is larger than the discharge pressure.

• 한국기계가공학회지
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• 제10권5호
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• pp.31-37
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• 2011

For the domestic glasses industry to procure competitiveness in the world CA(Cellulose Acetate) frame of spectacles market, CNC machining system for CA frame including high-value added CA cutting technologies should be developed with new materials for the rim based on Cellulose and sheet manufacturing base. The spindle system of glasses frame equipment that is the core to the quality of CA frame is the key technologies to realize high-speed, high-precision so its importance is remarkably emerging. In the study, at the structural design of the high spindle system of the private equipment for CA glasses frame embedded a motor of 40,000rpm, the stability of design was analyzed and investigated through selecting lubrication structure and thermal characteristics of the spindle system.