• Title/Summary/Keyword: 엔진윤활

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Size and Shape Optimization of the Oil Pump for Fuel Consuming Reduction (엔진 연비 향상을 위한 오일펌프 사이즈/형상 최적화)

  • Jo, Sok-Hyun;Nam, Kyung-Woo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.22-28
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    • 2008
  • Generally block imbedded type oil pump is adopted to make a small engine. In this paper 1D/3D numerical simulations were conducted to reduce energy consumption of the block imbedded type oil pump. At each stage of engine development we have estimated the oil flow rate and pressure to optimize oil pump sizes by using the 1D system analysis and then accomplished 3D CFD(Computational Fluid Dynamics) simulations to optimize oil pump shapes including inlet/outlet port. As a result, the energy consumption of oil pump has been reduced to nearly 27% and the engine fuel consumption to $1{\sim}1.5%$.

A Study on the Lubricational Characteristics with Compound Additives of Engine Oil (엔진오일의 혼합첨가제에 따른 윤활특성에 관한 연구)

  • 이봉구;오성모
    • Tribology and Lubricants
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    • v.11 no.1
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    • pp.50-57
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    • 1995
  • When engine oil is used under severe running condition, the Lubricational characteristics is very important. I have studied the Lubricational characteristics with Compound Additives of engine oil for the Falex wear test machine. Adding detergent (Ca-phenate) to engine oil, the seizure is more improved than in case of non-adding, and adding Zn-DTP (Zinc dialkyl dithio phosphate), the extreme pressure property is excellent at the high load. But when the PTFE (Polytetra Fluoro Ethylene) and MoS$_{2}$ (Molybdenum disulfide) are added, the temperature characteristics and the anti-wear property become excellent because the stability can be maintained in a high temperature. The result are as follows, it can be improved that when the compound of the Ca-phenate and Zn-DTP, MoS$_{2}$, PTFE, etc. was added to engine oil, the lubrication characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreame pressure properties and the heat stability.

Analysis of Journal Locus in a Connecting Rod Bearing (엔진 연결봉 베어링의 운동 궤적 해석)

  • 조명래;정진영;한동철
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.04a
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    • pp.183-189
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    • 1997
  • This paper presents the motion of dynamically loaded journal in the connecting rod bearing of reciprocating internal combustion engine. Journal motions in engine bearings have been composed of two components, which was rotational and translational motion. Early study of journal locus in engine bearing had been performed on each motion. This paper has been considered two motions simultaneously. Reynolds equation including the squeeze effect has been analyzed using the ADI method, and real engine bearing and crankshaft system has been considered to calculate the cyclic external force. The equations of journal motion have been derived and then the numerical integration of these equations performed by 4th order Runge-Kutta method. This paper gives various journal orbits in connecting rod bearing depending on cyclic external forces, rotating speeds, and bearing parameters.

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A Study of the Effects of Ceramic Tappet Shim Surface Roughness on the Friction Characteristics in the Valve Train System (세라믹 태핏심 표면 거칠기에 따른 엔진 밸브트레인계의 마찰 특성에 관한 연구)

  • 김승철;박형준;강경필;오대윤;최재권
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.115-123
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    • 1998
  • A $Si_3N_4$ tappet shim was devdoped in a direct OHC engine for the friction reduction of valve train system that contributes significantly to the engine friction in real driving condition. For commercializing $Si_3N_4$ tappet shim, it is important to reduce the machining cost. Therefore we analytically and experimentally figure out the optimum condition. Using ceramic tappet shims machined with different surface roughness, the effects of roughness on the friction loss were analyzed in view of the lubrication behavior. From this results it is shown that the friction torque of valve train system quickly drops at a certain surface roughness of ceramic tappet shim and its value remains constant despite further smoothing.

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Design of an air-cooled high-pressure 3-stage reciprocating air compressor, applied to the starting of diesel engines (디젤엔진 시동용 공냉식 고압 3단 왕복동 공기압축기의 설계)

  • 이안성;김영철;정영식;왕지석
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.1
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    • pp.42-51
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    • 1998
  • A 150 m$\^$3//hr, 30 kg/cm$\^$2/, air-cooled 3-stage reciprocating air compressor is designed to be used in starting large diesel engines of ships. A basic design procedure is presented to meet the targeted pressure and flow rate, and especially a volumetric efficiency of 80%. Temperature and stress analysis of the 1st stage cylinder are performed using axisymmetric FEM modelings. The dynamics of valve system is analyzed and stress at the 1st stage valve seat caused by valve impact is evaluated. To reduce friction loss and wear at the compressor engine system tribological design issues are reviewed and good design practices are suggested. Finally, forced-air pin-type interstage coolers are designed to dissipate generated compression heat at each stage.

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Analysis of Crosshead-pin Bearing with Various Oil Groove Shape for Marine Engine (박용엔진용 크로스헤드 핀 베어링의 급유 형사에 따른 윤활특성 해석)

  • 하양협;이득우;김창희;김정훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.578-583
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    • 1997
  • Abstract-Crosshead bearing in two-stroke marine diesel engine is operated under quite severe condition since the load on the bearing is sybject to the loading in a unidirectional and the sliding speed is very slow and oscillatory. So it is very difficult to form oil film and maintain the load. In this paper, two types of bearing are compared. One has large sized oil pocket and the seleted as multi-small oil grooves. Bearing clearance, oil inlet oressure and bearing types are selected as analysis parameters. Loci of journal center are presented to compare several cases. It is found that bearing clearance and shape affect to minimum film thickness.

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Evaluation of Oxidation Stability for Diesel Engine Oil by Hot-Tube Oxidation Test (Hot-Tube Oxidation Test에 의한 디젤엔진오일의 산화안정성 평가)

  • 정근우;조원오;김영운;서인옥;임수진
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.175-180
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    • 1998
  • This paper describes evaluation of oxidation stability for diesel engine oils by Hot-tube oxidation tester at high temperature. Evaluation was rated by visual inspection of lacquer in capillary glass tube and TAN determination of used oil. Air, NO$_2$-air and SO$_2$-air mixed gases were used as oxidizing gas. One oil which has low oxidation stability is selected and reformulated by addition of some additives such as antioxidant, detergent and disperant to improve oxidation stability. As a results of reformulation, antioxidant and detergent was effective for improvement of high temperture oxidation stability on diesel engine oil.

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Evaluation of Engine Lubrication System for Adapting Variable Cam Timing System (VCT탑재를 위한 엔진윤활시스템 평가)

  • Yun Jeong-Eui
    • Tribology and Lubricants
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    • v.22 no.1
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    • pp.14-19
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    • 2006
  • VCT(Variable Cam Timing) system is one of very useful engine components to improve fuel economy and overcome emission regulation etc. In order to adapt the VCT to a base engine, many design mod ifications in the mechanical and lubrication fields are required. Especially, because the VCT performance itself depends on supplied oil flow rate and pressure, it is very important to evaluate the engine lubrication system in a viewpoint of supplied oil flow rate and pressure. In this paper, unsteady transient flow network analysis on the engine oil circuit system was carried out to do this.

고속 회전축-베어링계의 스퀴즈-필름 댐퍼에 관한 연구

  • 한동철;윤석철
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1989.06b
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    • pp.48-59
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    • 1989
  • 최근 터어보 샤프트, 터어보 팬, 터어보 쳇트 엔진, 가스 터어빈, 공작기계의 주축, 그리고 섬유기계 섬유봉등의 회전기계류 설계에서 단위 무게당 출력의 비율을 높이기 위해서 회전속도의 고속화가 요구되고 있다. 이러한 경우 회전축계의 진동특성에 크게 영향을 미치는 감쇠특성을 부각시키기 위하여 베어링의 외부에 스퀴즈-필름 댐퍼 (Squeeze-film Damper)를 부가하고 회전축계를 유연하게 지지하여 줌으로써 진동문제를 간단히 해결하며 회전속도의 고속화를 가능하게 할 수 있다. 적합하게 설계된 스퀴즈-필름 댐퍼의 잇점은 다음과 같다. (a) 회전축의 위험속도를 작은 공진쪽으로서 통과하는 것이 가능. (b) 베어링과 지지구조물에 전달되는 하중이 감소 (c) 장기간 사용중, 마모 및 브레이드 파손에 의해 진폭이 증가된 불평형 강제진동에서도 안정된 운전이 가능 (d) 미끄럼 저어널 베어링에 지지된 회전축계의 고속회전에서 불안정한 자려진동이 나타나는 안정 한계속도를 높히는 것이 가능

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A Feasibility Study for Application of On-Line Wear Condition Monitoring Technique to the High-powered Diesel Engine (고출력 디젤 엔진의 On-Line 마모상태진단 기술 적용을 위한 기초연구)

  • 윤민호;정동윤;공호성
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.10a
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    • pp.59-65
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    • 1997
  • The calibration of O.M.D is carried out experimentally and is analysed theoretically. O.M.D experimentally measures the change in optical density of artificially contaminated oil which contains Fe powder of 5, 10, 20, 30, 40, 50, 70, 100, 200 ppm. The change in optical density, D$_1$ means the logarithmic transmittance of I$_0$ over $I_1 D_2$ denotes the logarithmic transmittance I$_2$ over I$_1$ on electromagnetic force which arranges the ferrous particles along the line of magnetic force. The theoretical D$_1$ which increases linearly as increasing Fe concentrations, is analysed by light attenuation theory. The difference between theoretical D$_1$ and experimental D$_1$ is due to the attenuation of micro bubbles and the agglomeration of fine particles in the sample oil. The calibrated O.M.D is applied to the sample oil from the high-powered diesel engine. Also the results are compared with those out of the off-line techniques such as JOAP and ICP.

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