• 제목/요약/키워드: Thickness Error

검색결과 507건 처리시간 0.029초

링기어의 경계조건이 가공오차를 가지는 유성기어열의 정특성에 미치는 영향 (Influence of Ring Gear Boundary Conditions on the Static Characteristics of Epicyclic Gear Trains with Manufacturing Errors)

  • 천길정;오재국
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1775-1780
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    • 2003
  • A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of an epicyclic gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

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링기어의 경계조건이 가공오차를 가지는 유성기어열의 정특성에 미치는 영향 (Influence of Ring Gear Boundary Conditions on the Static Characteristics of Epicyclic Gear Trains with Manufacturing Errors)

  • 천길정
    • 대한기계학회논문집A
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    • 제27권11호
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    • pp.1949-1957
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    • 2003
  • A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of a planetary gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The minimum rim thickness limit should be determined considering not only the critical stress but also the load sharing. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

A simulation study on the variation of virtual NMR signals by winding, bobbin, spacer error of HTS magnet

  • Kim, Junseong;Lee, Woo Seung;Kim, Jinsub;Song, Seunghyun;Nam, Seokho;Jeon, Haeryong;Baek, Geonwoo;Ko, Tae Kuk
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권3호
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    • pp.21-24
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    • 2016
  • Recently, production technique and property of the High-Temperature Superconductor (HTS) tape have been improved. Thus, the study on applying an HTS magnet to the high magnetic field application is rapidly increased. A Nuclear Magnetic Resonance (NMR) spectrometer requires high magnitude and homogeneous of central magnetic field. However, the HTS magnet has fabrication errors because shape of HTS is tape and HTS magnet is manufactured by winding HTS tape to the bobbin. The fabrication errors are winding error, bobbin diameter error, spacer thickness error and so on. The winding error occurs when HTS tape is departed from the arranged position on the bobbin. The bobbin diameter and spacer thickness error occur since the diameter of bobbin and spacer are inaccurate. These errors lead magnitude and homogeneity of central magnetic field to be different from its ideal design. The purpose of this paper is to investigate the effect of winding error, bobbin diameter error and spacer thickness error on the central field and field homogeneity of HTS magnet using the virtual NMR signals in MATLAB simulation.

가공오차 및 조립오차가 유성기어열의 정특성에 미치는 영향 (Influence of Manufacturing and Assembly Errors on The Static Characteristics of Epicyclic Gear Trains)

  • 오재국;천길정
    • 대한기계학회논문집A
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    • 제27권9호
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    • pp.1597-1606
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    • 2003
  • Static analysis using hybrid finite element(FE) method has been applied to characterize the influence of position, runout and thickness errors of the sun, ring and planet on the bearing forces and critical tooth stress. Some guidelines for tolerance control to manage critical stress and bearing forces are deduced from the results. Carrier indexing error planet assembly and planet tooth thickness error are most critical to reduce planet bearing force and maximize load sharing as well as to reduce critical stresses. Sun and carrier bearing forces due to errors increase several times more than those of normal condition.

박용엔진 크랭크 핀 베어링의 형상오차가 최소유막두께에 미치는 영향 (Effect of Roundness Error of a Crank Pin Bearing for a Marine Engine on the Minimum Film Thickness)

  • 하양협;신인동;이상민;이승준;이득우
    • Tribology and Lubricants
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    • 제27권5호
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    • pp.256-263
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    • 2011
  • Bearings of marine engines are operated under severe conditions because of dynamic load and low sliding speed. This paper deals with lubrication analysis of a crank pin bearing for a marine diesel engine. Journal center locus and oil film thickness are compared of crank pin bearing. In the past researches, journal bearings have been studied only about the surface of bearing. In addition to this conventional research, this paper analyzes the effect of roundness error of a journal and a bearing on the minimum film thickness. Numerical analysis has been studied by using Reynolds equation and also Half-Sommerfeld condition is applied as boundary condition. Futhermore, this study investigates the effect of roundness error change on the minimum film thickness. The results demonstrate that the bigger amplitude of roundness error yields, the lower minimum oil film thickness is. In comparison to previous research considered a journal and a bearing individually, the results considering a journal and a bearing together show that amplitude of roundness error of journal has very little effect on the minimum oil film thickness.

정상 대학생의 눈 굴절이상, 안축장, 전방깊이, 수정체두께 그리고 각막두께의 연관성 (Correlation of Refractive Error, Axial Length, Chamber Depth, Lens Thickness and Corneal Thickness of Normal University Students)

  • 김창식;이학준
    • 한국안광학회지
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    • 제13권1호
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    • pp.89-94
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    • 2008
  • 목적: 안구크기의 생체 측정값과 눈 굴절이상 정도에 따른 상호 연관성을 비교 조사하고자 하였다. 방법: 평균연령이 22.85${\pm}$3.12세의 정상 대학생 68명(남 36, 여 32)을 대상으로 초음파(A-scan)를 이용하여 측정과 시력측정을 하였고, 그 결과를 SPSS 12.0 version을 이용해 통계학적 유의성을 조사하였다. 결과: 측정한 평균값은 안축장 24.31${\pm}$1.24 mm, 전방깊이 3.48${\pm}$0.28 mm, 렌즈두께 3.56${\pm}$0.26 mm 그리고 각막두께 0.55${\pm}$0.03 mm 이었다. 측정값의 안축장과 전방깊이는 남자가 크지만 렌즈두께는 여자가 두껍게 조사되었다. 렌즈두께는 굴절이상 적을수록 두꺼웠지만, 각막두께는 남, 여 모두 같았다. 좌 우안의 측정값은 차이가 없었으며 T-test 결과도 연관성이 없었다. 측정치의 Pearson Chi-Square 검정 결과는 안축장과 전방깊이, 안축장과 렌즈두께, 전방깊이와 렌즈두께 그리고 굴절이상과 렌즈두께는 p<0.01 수준에서 유의한 상관관계가 있었다. 굴절이상과 안축장은 선형회귀분석 검정결과 음(-) 선형관계를 나타내었다(r=-0.56). 결론: 눈 굴절이상은 안축장, 전방깊이, 렌즈두께에 의해 결정되지만, 좌 우안이나 성별의 차이와는 관계가 없었다.

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하부 실리콘 플레이트의 두께에 따른 FCP 표면 오차에 관한 연구 (A Study on the FCP Surface Error according to the Thickness of the Lower Silicone Plate)

  • 김지혜;정경태;이동훈
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.31-32
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    • 2023
  • Recently, with the digitalization of the construction industry, free-form building construction technology is developing. However, the technology for manufacturing free-form concrete panels is still insufficient. In this study, the surface error of the FCP according to the thickness of the lower silicon plate, which is a component of the existing lower multi-point press, was analyzed in order to manufacture a precise FCP. As a result of the analysis, it was found that the thinner the thickness, the larger the error value. These results can be used as a basis for existing research and are expected to be used for research on high-quality FCP manufacturing technology.

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추코트와 보퍼트 해에서 계측된 해빙 두께와 건현과의 관계 (Relation Between Measured Sea Ice Thickness and Freeboard on Chukchi and Beaufort Seas)

  • 정성엽;최경식;조성락;강국진;이춘주
    • 한국해양공학회지
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    • 제28권6호
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    • pp.527-532
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    • 2014
  • The thickness of Arctic sea ice is a particularly significant factor in Arctic shipping and other ice-related research areas such as scientific sea ice investigations and Arctic engineering. In this study, the relation between the measured sea ice thickness and freeboard on the Chukchi and Beaufort Seas during the 2010 and 2011 Arctic cruise of the icebreaking research vessel "Araon" were considered. An assumption of hydrostatic equilibrium was used to estimate the ice thickness as a function of the freeboard. Then, to examine the degree of error, a sensitivity analysis of the thickness estimation of the sea ice was conducted. The error in the density and depth of the snow and the error in the density of the seawater were subordinate parameters, but the density of the ice and the freeboard were the primary parameters in the error calculation. The presented relation formula showed fairly close agreement between the calculated and measured results at a freeboard of >0.24 m.

2날 엔드밀 슬롯 가공시 칩두께 모델의 개선 (Improvement of Chip Thickness Model in 2-flutes Slot End Milling)

  • 이동규;이기용;이근우;오원진;김정석
    • 한국정밀공학회지
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    • 제22권1호
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    • pp.32-38
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    • 2005
  • Generally, cutting force models use a sin function method to calculate chip thickness. In slot end milling, the error from a sin function method is much bigger than other machining because a tool rotation angle in cutting is much larger. Thus in this paper, a new method to calculate chip thickness was suggested and evaluated. In a new method, tool position data according to tool rotation are checked and stored so that it is possible correct chip thickness is calculated. Cutting force waveforms simulated from a sin function method and a new method and measured waveforms from experiments were compared and error percentages were obtained. Finally, a new method had good results for simulating cutting force in slot end milling.

배관감육 평가를 위한 UT 측정 신뢰도 분석 (Reliability Analysis of UT Measurement for Evaluating Pipe Wall Thinning in Nuclear Power Plants)

  • 윤훈;황경모
    • Corrosion Science and Technology
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    • 제11권4호
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    • pp.129-134
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    • 2012
  • UT(Ultrasonic Test), one of the non-destructive tests, is the most common thickness measurement method for evaluating the wear rate in NPPs(Nuclear Power Plants). UT is used widely because it is easy and safe for use. However some amount of error inevitably occurs in attempting to measure the thickness. The error, that could make the thickness data thicker or thinner, may affect estimation of wear rate in pipes. NPPs are composed of a lot of pipes and components. Some of them are tested to check the current status during RFO(Re-Fueling Outage). Reliability analysis of UT is essential for evaluating pipe wear rate and establishing the long-term management plan in NPPs. This paper reviewed the cause of error occurrence and presented the UT data reliability analysis method. Also, this paper shows the application result of reliability analysis to the UT data acquired in NPPs.