• 제목/요약/키워드: commercial lubricants

검색결과 79건 처리시간 0.029초

국부가열을 이용한 박판의 사각통 디이프 드로잉 성형에 관한 연구 (A Study on the Drawability of Rectangular Deep Drawing of Sheet Metal using Local Heating)

  • 박동환;김창호;강성수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 춘계학술대회 논문집
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    • pp.209-214
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    • 1995
  • This paper describes that the effects of punch speed and temperatures of the die and the blank holder on the drawability are examined. Up to now, multi-stage of dies sets have been used generally at room temperature in deep drawing of rectangular shaped components. But using local heating, it is shown that one stage of die set was capable of deep drawing and the drawability was increased and sheet thickness of component was drawn somewhat uniformly. Rectangular deep drawing experiments on two kinds of stainless steel STS316L, STS430 of 1.0 mm thickness have been conducted using local heating. The limiting drawing height can be increased by heating the die and the blank holder up to 100 .deg. C at STS316L. Commercial lubricants hadn't an effect on drawability in rectangular deep drawing, but vinyl and teflon film had an effect on it.

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전용제어회로를 적용한 딥스틱게이지형 소형 엔진열화감지센서 개발 (Development of Dipstick-Gage-Type Small Sensor Equipped with Individual Control Circuit for Detecting Engine Oil Deterioration)

  • 전상명
    • Tribology and Lubricants
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    • 제29권3호
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    • pp.143-148
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    • 2013
  • In this study, several sensor parts used to obtain better signal stability are designed, a separate control circuit for the sensor is developed, and the results obtained using this control circuit are analyzed. The capacitances of the whole sensor system are measured using the control circuit connected to an improved flexible printed circuit board and an asymmetric dual sensor coated with a ceramic material. To realize good discrimination for a small change in the measured capacitance as the engine oil deteriorates, a commercial application-specific integrated circuit is installed on the control circuit as a capacitance-to-digital converter. The absolute error of a measured signal is found to be approximately ${\pm}4fF$.

로프 브레이크 시스템에서 마찰 특성을 고려한 설계 변수특성 연구 (Design Parameters Considering Friction Characteristics for Rope Brake System of Elevator)

  • 장주섭
    • Tribology and Lubricants
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    • 제29권3호
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    • pp.171-179
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    • 2013
  • In this study, hydraulic systems of the rope brake system of an elevator are modeled to evaluate design parameters that consider friction characteristics such as cylinder pressure, piston displacement, and flow rate. Hydraulic systems of the rope brake system are analyzed using the commercial program AMESim. Analysis modeling data are compared with data obtained from experiments, and the analysis modeling results are found to be reliable. The analysis results will be used to design hydraulic systems of the rope brake system of elevators.

CFD를 사용한 복잡한 형상을 갖는 래버린스 실의 누설량 예측 (Prediction of Combination-Type-Staggered-Labyrinth Seal Leakage Using CFD)

  • 하태웅
    • Tribology and Lubricants
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    • 제22권2호
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    • pp.66-72
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    • 2006
  • Leakage reduction through annular type labyrinth seals of steam turbine is necessary for enhancing their efficiency and the precise prediction method of seal leakage is needed. In this study, numerical analysis for leakage prediction of the combination-type-staggered-labyrinth seal has been carried out using FLUENT 6 which is commercial CFD (Computational Fluid Dynamics) code based on FVM (Finite Volume Method) and SIMPLE algorism. The present CFD results are verified with the theoretical analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage. Comparing with the result of Bulk-flow model analysis, the leakage result of CFD analysis shows good agreement within 7.1% error.

Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제3보 - 딤플 수의 영향 (Lubrication Characteristics of Laser Textured Parallel Thrust Bearing : Part 3 - Effect of Number of Dimples)

  • 박태조
    • Tribology and Lubricants
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    • 제27권6호
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    • pp.302-307
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    • 2011
  • Laser surface texturing (LST) methods are widely applied recently to reduce friction and improve reliability of machine components such as thrust bearings, mechanical face seals and piston rings, etc. In this paper, numerical analysis is carried out to investigate the effect of number of dimples on the lubrication characteristics of parallel thrust bearing using a commercial computational fluid dynamics (CFD) code, FLUENT. Pressure distributions of present analysis are physically consistent than those obtained from numerical analysis of Reynolds equation. The overall lubrication characteristics are highly affected by number of dimples and their locations. The results can be use in design of optimum dimple characteristics to improve thrust bearing performance and further researches are required.

Laser Texturing한 평행 스러스트 베어링의 윤활특성 : 제4보 - 딤플 형상의 영향 (Lubrication Characteristics of Laser Textured Parallel Thrust Bearing : Part 4 - Effect of Dimple Shape)

  • 박태조
    • Tribology and Lubricants
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    • 제27권6호
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    • pp.338-343
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    • 2011
  • Laser surface texturing (LST) methods are widely applied now to reduce friction and improve reliability of machine components such as thrust bearings, mechanical face seals and piston rings, etc. In this paper, the effect of dimple shapes on the lubrication characteristics of parallel thrust bearing are studied using a commercial computational fluid dynamics (CFD) code, FLUENT. Pressure and streamline distributions, variations of supporting load, leakage flow rate and friction force, are compared for three different dimple sectional shapes such as circle, pyramid and rectangle type. The lubrication characteristics are highly affected by dimple shapes and number of dimples. The pyramid type dimple shape can support the highest load while the rectangle type is the best in friction reduction.

Groove 단면형상에 따른 유압 Spool Valve의 윤활해석 (Lubrication Analysis of Hydraulic Spool Valve with Groove Cross Sectional Shapes)

  • 박태조;황윤건
    • Tribology and Lubricants
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    • 제25권1호
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    • pp.13-19
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    • 2009
  • The spools in most hydraulic spool type control valve have several circumferential grooves to pre-vent well known hydraulic locking problems which result in high friction force and excessive wear. In this paper, a commercial computational fluid dynamics (CFD) code, FLUENT is used to investigate the flow and lubrication characteristics of grooved hydraulic spool valve. The stream lines and pressure distributions are obtained for various groove cross sectional shapes and film thicknesses. The stream lines are highly affected by groove cross sectional shape but pressure distributions mainly depend on the film shape and its magnitude. Therefore the numerical method adopted in this paper and results can be use in designing of various grooved spool valve.

화학공정용 전동기에 사용된 3D 프린팅 플라스틱 볼베어링의 내화학성 평가 및 현장적용 연구 (Chemical Resistance and Field Trial of 3D-Printed Plastic Ball Bearing Used in Electric Motors for Chemical Processes)

  • 권영준;노명규
    • Tribology and Lubricants
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    • 제39권1호
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    • pp.1-7
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    • 2023
  • Fluid pumps in chemical processes are typically driven by electric motors. Even if the motor is separated from the pump with seals, wear resulting from friction and misalignment can lead to leakage of chemical fluid, causing corrosion in the bearing supporting the motor, and, eventually, failure of the motor. It is thus a standard procedure to replace bearings at regular intervals. In this article, we propose 3D-printed plastic ball bearings for use as an alternative to commercial stainless-steel ball bearings. The plastic bearings are easy to manufacture, require less time to replace, and are chemically resistant. To validate the applicability of the plastic bearings, we first conducted chemical resistance tests. Bearings were immersed in 30 caustic acid and 30 nitric acid for 30 min and 24 h, respectively. The test results showed no corrosive damage to the bearings. A test rig was set up to compare the performance of the plastic bearings with that of the commercially equivalent deep-groove ball bearings. Loading test results showed that the plastic bearings performed as well as the commercial bearing in terms of vibration level and load-handling capability. Finally, a plastic bearing was subjected to a clean-in-place process for three months. It actually outperformed the commercial bearing in terms of chemical resistance. Thus, 3D-printed plastic bearings are a viable alternative to stainless-steel ball bearings.

냉간단조용 수용성 윤활제의 평가 및 윤활 처리 공정의 최적화 (Evaluation of water-Soluble Lubricant for Cold Forging and Optimization of Coating Process)

  • 임우진;이인수;제진수;고대철;김병민
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 춘계학술대회 논문집
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    • pp.149-154
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    • 2007
  • The zinc prosphate film treatments used to lubricating treatment of mostly cold forging processes. But there are several problems happened to lubricating treatment process such as happening harmful environment on person, complex lubrication processing occurring in energy and time consumption, eco-destructive and chemical by-product generation, the needs of waste disposal etc. As a result, a water-soluble lubricant was developed to replace the perfect or some of the zinc prosphate film in the world. In order to solve these problems, this study evaluated the performance of the typical water-soluble. In this study, for these requirement inquiry of two part. First, about possibility of replace zinc phosphate lubricant, quantitatively evaluation developed of water-soluble lubricant for cold forging vs zinc phosphate lubricant. Second, About optimization of coating Process use to equipment with practicable automatic coating Process. The performance evaluation of these lubricants was conducted using the double cup extrusion test and spike forging test. With the use of the commercial FE code DEFORM, friction factor calibration curves, i.e. cup height ratio vs. punch stroke and spike height vs. punch stroke, were established for different friction factor values. By matching the cup height ratio and the punch stroke and spike height vs. punch stroke from experiment to that obtained from FE simulations, the friction factor of the lubricants was determined. Survey of comparative analysis use to SEM that sprayed lubricant surface structure of grain shape and characteristic of lubricant performance based on grain shape and deformed lubricant surface expansion. As a result, developed lubricant were found to perform comparable to or better than zinc phosphate. And thought this result, innovatively cope with generated problem of existing lubrication process.

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베어링의 열전도율이 평행 슬라이더 베어링의 윤활성능에 미치는 영향 (Effect of Thermal Conductivity of Bearing on the Lubrication Performance of Parallel Slider Bearing)

  • 박태조;이원석;박지빈
    • Tribology and Lubricants
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    • 제34권6호
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    • pp.247-253
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    • 2018
  • Temperature rise due to viscous shear of the lubricating oil generates hydrodynamic pressure, even if the lubricating surfaces are parallel. This effect, known as the thermal wedge effect, varies significantly with film-temperature boundary conditions. The bearing conducts a part of the heat generated; hence, the oil temperature varies with the thermal conductivity of the bearing. In this study, we analyze the effect of thermal conductivity on the thermohydrodynamic (THD) lubrication of parallel slider bearings. We numerically analyze the continuity equation, Navier-Stokes equation, energy equation including the temperature-viscosity and temperature-density relations for lubricants, and the heat conduction equation for bearing by creating a 2D model of the micro-bearing using the commercial computational fluid dynamics (CFD) code FLUENT. We then compare the variation in temperature, viscosity, and pressure distributions with the thermal conductivity. The results demonstrate that the thermal conductivity has a significant influence on THD lubrication characteristics of parallel slider bearings. The lower the thermal conductivity, the greater the pressure generation due to the thermal wedge effect resulting in a higher load-carrying capacity and smaller frictional force. The present results can function as the basic data for optimum bearing design; however, the applicability requires further studies on various operating conditions.