• 제목/요약/키워드: 누설유량

검색결과 98건 처리시간 0.029초

탄소 주입 실리콘 산화 절연박막에서 전위장벽과 온도 변화에 대한 상관성 (Correlation between the Potential Barrier and Variation of Temperature on SiOC thin film)

  • 오데레사
    • 한국정보통신학회논문지
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    • 제12권12호
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    • pp.2247-2252
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    • 2008
  • 탄소 주입실리콘 산화막으로서 SiOC 박막은 화학적 증착 방법에 의해 성막되었으며, 박막의 분석기법으로 FTIR 분석기와 I-V 측정과 표면분석으로 전자현미경을 이용하였다. 증착된 샘플들은 유량비의 변화에 따라서 화학적 이동현상이 나타났으며, 표면에서의 그레인은 유기물 특성과 무기물 특성의 SiOC 박막샘플에서 나타났다. 그러나 하이브리드 특성의 박막에서는 그레인이 형성되지 않았다. 하이브리드 특성의 박막샘플에서 온도가 증가할수록 누설전류는 감소하였다. 누설전류는 온도가 증가함에 따라 감소하였는데 전위장벽이 증가하기 때문에 감소하는 것으로 나타났다.

로브 형상 변화가 루츠형 진공 펌프 성능에 미치는 영향 (Effects of Lobe Shapes on the Performance of Roots-Type Vacuum Pump)

  • 김현중;김윤제;황영규
    • 한국유체기계학회 논문집
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    • 제3권2호
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    • pp.50-56
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    • 2000
  • The effects of lobe shapes on the leak flow conductance of Roots-type vacuum pump are studied numerically and experimentally. The modelled lobe shape of Roots-type vacuum pump is two-lobe spur gear. The numerical analyses are performed on leak flows in Roots-type vacuum pump. It is numerically calculated using a 4th-order Runge-Kutta method and is compared with experimental results. Results show that for the case of involute lobe shape the total amount of the leak flow conductance is greater than that of cycloid and Cassini oval lobe shapes.

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씰리스 실린더의 특성 해석 및 실험 (An Experiments and Characterisics Analysis of the Sealless Cylinder)

  • 김영철;김동수;배상규;김성종
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.980-985
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    • 2004
  • This paper shows a performance analysis for conical type sealless cylinders and rod bearings. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the performance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a sealless cylinder are presented. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively. Leakage flow test is conducted to evaluate performance of piston and rod bearing in sealless cylinder.

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사판식 유압 피스톤 펌프의 슬리퍼 정압베어링면 형상에 관한 이론해석 (Theoretical Analysis of the Slipper Hydrostatic Bearing Shape in the Swash Plate Type Axial Piston Pump)

  • 조인성
    • 드라이브 ㆍ 컨트롤
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    • 제10권1호
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    • pp.14-20
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    • 2013
  • In the high rotational speed and pressure state, the leakage flow rate of the axial piston pump is one of the serious problems and make great reasons to decrease the volume efficiency. In this study, tribology characteristics is clarified for the hydrostatic slipper bearing in the swash plate type axial piston pump, by means of theoretical analysis for the different shape of the hydrostatic slipper bearing. It was analyzed by Mathcad software and used equal conditions at $0^{\circ}$ swash plate angle in each model. The results show that performance characteristics of the swash plate type axial piston pump are significantly influenced by the shape of the hydrostatic slipper bearing.

유압 피스톤모터용 Slipper Pad의 정압시험에 관한 연구 (A Study on the Hydrostatic Test of Slipper Pad for Hydraulic Piston Motor)

  • 함영복;김광영;김형의
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.645-649
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    • 1997
  • In case of swash plate type axial piston hydraulic motor, hydrostatic bearing used to achieve the lubrication effect on the mechanical sliding contact areas between the following parirs ; sliooer-pad and swash plate,piston and cylinder bore,valve plate and cylinder block, etc. This study discussed the basic charateristic for the hydrostatic slipper-pad bearings with the capillary or orifice restrictor under static load condition. And, we also development of hydrostatic bearing tester for hydrostatic balancing test of pistion & slipper-pad assembly, and some experimental data on supply pressure step responce are reported.

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공기압 서보 설린더 특성 해석 (Charncteristics Analysis of the Pneumatic Servo Cylinder)

  • 김동수;김강대;김명섭;허신
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1244-1249
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    • 2008
  • This paper shows a perfonnance analysis for pneumatic servo cylinder. The pistons without seal have partly cylindrical and conical shapes. 2 dimensional Reynolds equation and FD(finite differential) numerical techniques are utilized for the perfonnance analysis. The relationship among self-centering forces and leakage flows are investigated. Also, optimal design values for a servo cylinder are presented. A prototype of servo cylinder which had rod bearing with four pockets, five pockets, and six pockets was manufactured respectively.

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격납건물 국부누설률시험 표준절차 개발 (Development of Standard Procedures for Local Leakage Rate Testing of Containment Vessel)

  • 문용식;김창수
    • 한국압력기기공학회 논문집
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    • 제8권2호
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    • pp.42-47
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    • 2012
  • The containment local leakage rate testing in nuclear power plants is performed in accordance with ANSI/ANS 56.8-1994 in Korea. Two methods, the make-up flow rate and the pressure decay, are used for local leakage rate testing. Though ANSI/ANS 56.8-1994 does not define clearly the minimum test duration for the make-up flow rate method, it requires obtaining the data after reaching the stable condition. Thus the prerequisite stable condition for data acquisition and the testing time is differently applied to each NPPs. Therefore, this study presents a standardized test procedure for data stabilization and testing time through experiments to improve the test reliability.

충동형 초음속 터빈의 노즐-로터 축간극에 따른 성능변화 연구 (Numerical Study of The Nozzle-Rotor Axial Gap Effect on the Supersonic Turbine Performance)

  • 정수인;김귀순;정은환
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.160-163
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    • 2010
  • 부분흡입형 초음속 터빈의 노즐과 1단 로터 사이의 축방향 간극이 터빈의 단 성능과 유동장에 어떤 영향을 미치는지 알아보기 위해 터빈에 대한 3차원 유동해석을 수행하고 그 결과를 분석하였다. 상용 유동해석 프로그램 $FLUENT^{TM}$를 사용하였으며 다섯 가지 경우의 축간극에 대해 계산을 하였다. 노즐-로터 축간극이 팁 누설 유량의 증가와 로터 출구의 유동각에 영향을 주는 것을 확인하였다.

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고성능 씰리스 실린더의 해석 및 누설유량 시험 (An Analysis and Test for Leakage Flow of Sealless Cylinder)

  • 김성종;김동수;이승현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.961-966
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    • 2004
  • The cylinder without seal has a piston with air bearing which is partly cylindrical and conical shape. The description of system geometry is deviation by the flow rate equation. Then pressure distribution and bearing force equations are derived. Several non-dimensional parameters are suggested. The relationship among bearing force, leakage flow and geometry of the bearing is investigated by simulation. And determination method for optimal design of sealless cylinder is given. A prototype of sealless cylinder which had rod bearing with four pockets, five pockets, and six pockets was built respectively. As a result of leakage flow test, it is evaluation to air bearing in sealless cylinder.

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사판식 피스톤 모터의 정압베어링 윤활특성에 관한 연구 (A Study on Lubrication Characteristic of the Hydrostatic Bearing In Swash Plate Type Piston Motor)

  • 이용범;김광민
    • 동력기계공학회지
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    • 제15권5호
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    • pp.5-9
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    • 2011
  • The hydraulic piston using a hydrostatic bearing has been used widely due to its satisfying performance at very high pressurized circumstance and relative higher power density in comparison to conventional one. For high pressurization, enhanced efficiency and long durability of the hydraulic piston, the design of hydrostatic bearing is at issue, which is installed between piston shoe and swash plate. The performance of the hydrostatic bearing is influenced significantly by the assembly of the piston shoe consisting of circular land and recess. In this study, to estimate the performance of the hydrostatic bearing, the characteristics for lubrication of the assembly of the piston shoe were investigated by measuring a leakage rate of hydraulic fluid under an experimental condition, where a rotating velocity of the piston, hydraulic pressure and temperature of the hydraulic fluid were changed systematically. In addition, a film thickness of the hydraulic fluid on the piston shoe was measured and compared to theoretical one.