• Tribology and Lubricants
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• v.11 no.3
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• pp.48-53
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• 1995

In this paper, the friction characteristics of contact region between vane tip and camring is studied using a modeled experimental device. The contact region is under the influence of variable loads with the amplitude of hundreds of Newton and frequency of tens of Hz. The condition of lubrication between vane and disk is modeled after the actual condition between vane and camring. The coefficient of friction is obtained by measuring the frictional forces in the contact region between camring and vane. The friction characteristics of the actual oil hydraulic vane pump is estimated on the basis of coefficient of friction. The analysis of frictional characteristics shows us that the lubrication condition of vane tip is that of transition regime between hydrodynamic lubrication and mixed lubrication.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1990.06a
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• pp.32-44
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• 1990

유압 Vane pump는 carming, rotor, vane에 의하여 둘러싸인 공간체적이 rotor의 회전과 함께 변화하면서 pump 작용을 한다. 즉 공간체적이 증가하는 동안은 유압이 저압으로 되어 흡입구에서 유압유를 흡입하고 vane의 존환점 (vane이 가장 많이 출한 점)을 지나면 공간용적이 감소하여 유압류는 고압으로 될 수 있도록 되어있다. 이때 vane은 관성력과 점성력 그리고 유압류의 압력에 의한 힘으로 vane 선단이 캠링의 내면에 밀착되어 회전하도록 되어있다. 유압 vane pump 베인 선단부의 윤활문제와 관련된 지금까지의 연구로서는 Hibi 등에 의한 압력평형형 베인모터, W.D Beck, T.C Edwards에 의한 베인형 콤푸렛셔 Ujiie 등에 의한 베인형 진공펌프, Ueno 등에 의한 가변용량형 베인펌프의 마찰특성에 관한 연구 및 베인 이간 현상에 관한 실험적 연구가 있다. 그러나 이와 같은 연구들의 베인과 캠링 슬라이딩 부분에 관한 취급들은 베인선단 슬라이딩 부분에 가해지는 변동가중이 불명확했기 때문데, 단순히 슬라이딩 부분의 면적이 작다는 이유로 단성유체 윤활상태일 것이라는 확정을 하였을 뿐, 실제적으로 어느 정도의 윤활 상태를 파악하기 위하여 회전하는 vane의 가학적인 거동을 확실하게 규명하고자 함이 본 연구의 목적이다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.4
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• pp.351-358
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• 2006

This paper presents analytical results of a rotary vane compressor performance when the compressor is used for air supply from underwater. Compression characteristics such as pressure and temperature in a compression chamber are analyzed. Volumetric and adiabatic efficiencies are calculated. Vane dynamics are also performed to give reaction forces on the vane from the cylinder inner surface and from vane slots. Compressor efficiency is about 34.9%, and about 55% of the compressor loss is produced by the friction between the vane nose and the cylinder wall. Volumetric efficiency is about 79.5%, and indicated efficiency is about 77.1%, which are comparable to other displacement type compressors. When roller was introduced between housing inner wall and vane tips, mechanical efficiency could be improved by as much as 24.9%, depending on the roller friction.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.5
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• pp.974-982
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• 1992

The atomizations of CWM slurry and water are done by a wheel atomizer which is designed and manufactured for this experiment. The variables of the experiment are the angle of vane, aspect ratio, particle loading and the mean size of coal particle distribution. The main purposes of the experiment are to know how the angle of vane and aspect ratio of vane influence the size distribution of CWM droplets. The experimental results say there are no appreciable effects on the mean size of CWM droplets from the change of loading of coal prticles in slurry. The mean size of coal particle in slurry, however, influence quite strongly the mean size of CWM droplets. The mean size of CWM droplets is quite strongly affected by the angle of vane. The size distribution of CWM droplets is controllable by the change of aspect ratio.

• Plant Journal
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• v.6 no.2
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• pp.62-69
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• 2010

The stability of coal pulverizer in the 800 MW coal-fired plants is vital to maintain their performance. Thus, this study analyzed the uneven abrasion of the deflector and coal spillage due to the air velocity maldistribution in the vane wheel of a bowl-type pulverizer as it is a possible cause for problems of facility using pulverized coal. In addition, air flow in the underbowl of a bowl-type pulverizer was studied to check air velocity maldistribution in the vane wheel using numerical method. In an attempt to correct the maldistribution of air velocity, air flow of the modified duct vane was studied as enlarging the length of the duct vanes installed at the air inlet duct of the pulverizer and increasing the angle of inclination. It was found that modified duct vane make the velocity distribution at the vane wheel uniform. formed by the duct vanes installed at the air inlet duct of the pulverizer and swirling flow is the major factor in making the velocity distribution of vane wheel exit uniform. This can prevent the uneven abrasion of the deflector, which is one of the components inside the pulverizer and coal spillage.

• Tribology and Lubricants
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• v.6 no.1
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• pp.52-56
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• 1990

The Lubrication Mode of line contacts between the vane and camring in an oil hydraulic vane pump with intravanes has been investigated. Variations of the radial acting force of a vane were calculated from previously measured results of dynamic internal pressure in four chambers surrounding a vane, and variations of the lubrication mode were estimated in both the rotational speed range from 500 to 1500 rpm and in the delivery pressure range from 1 to14 Mpa. The results indicate the variations of the radial acting force. It is found that the regimes of lubrication in the vane tip contacts cover rigid-isoviscous to rigid-variable viscosities.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.385-386
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• 2002

The friction characteristics of contact region between vane tip and cam-ring is studied with an experimental device model. The radius of vane tip is less than 1 mm and sliding speed is lower than 10 m/s. The friction characteristics of the actual oil hydraulic vane pump is estimated on the basis of coefficient of friction. The coefficient of friction can be obtained by measuring the frictional forces in the contact region. The lubrication condition between vane and disk is modeled after the actual condition between the vane and cam-ring.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.3
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• pp.274-281
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• 2013

The variable demand on the energy market requires a great flexibility in operating hydro turbines. However, Francis turbine operated at off-design conditions poses technical challenges related to large unsteady forces given by residual swirl and angular momentum. In order to improve the performance of a Francis turbine, the paper presents a numerical investigation of the 3D flow in the turbine at off-design conditions and discusses the influence of variable guide vane openings on the internal flow of a Francis turbine with the help of computational fluid dynamics. First, the internal flow characteristics of Francis turbine operated by varied guide vane angle at off design condition are computed and the optimal guide vane angle is obtained. Secondly, the Francis turbine is operated with guide vane number varies at the optimal guide vane angle. Finally, pressure contours and velocity distributions in the distributor are discussed and compared.

• Tribology and Lubricants
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• v.5 no.2
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• pp.55-59
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• 1989

Measurement of the friction force of vane tip have been made to provide essential information for the study of the pump dynamics, the pump design and the analysis of triboligical problems in the sliding components. The influences of the radial load, rotating speed and frequency of vane on the friction forces of vane tip have been investigated. The results indicated that the friction coefficient of vane tip are affected by the rotating speed remarkably but the effect of acting load on the vane tip and frequency of load are very small. The stribecks diagram shows that the lubrication regime of the sliding point of vane tip is mixing lubrication.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.459-462
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• 2006

In this study, the characteristic of a vane pump of an automative power steering system is numerically analyzed. The vane pump changes the energy level of operation fluid by converting mechanical input power to hydraulic output. To simulate this mechanism, moving mesh technique is adopted. As a result, the flow rate and pressure are obtained by numerical analysis. The flow rate agrees well with the experimental data. Moreover, the variation and oscillation of the pressure around the rotating vane are confirmed. The difference of pressure appears in the vane tip as a result of the flow characteristics. Furthermore, the back flow into the rotor was observed.