• Title, Summary, Keyword: 유정압안내면

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Basic Characteristics of an Active Controlled Capillary for Compensating the Error Motion of Hydrostatic Guideways (유정압안내면 운동오차보정용 능동제어모세관의 기본특성)

  • 송영찬;박천홍;이후상;김수태
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.662-667
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    • 1996
  • For compensating the error motion of hydrostatic guideways, the structure and the theoretical design method of ACC(Active Controlled Capillary) are proposed. The maximum controllable range, micro step response and dynamic characteristics of ACC are analyzed experimentally for verifing the availability. The experimental results showed that by the use of ACC, the error motion within 2.7${\mu}{\textrm}{m}$ of a hydrostatic guideway can be compensated with the resolution of 27nm, 1/100 of uncontolled error, and the frequency band of 5.5Hz. From these results, it Is confirmed that the ACC is very effect to improve the moving accuracy of high or ultra precision hydrostatic guideways.

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Development of a Hydrostatic Guideway Driven by the Linear Motor (리니어모터를 이용한 초정밀 유정압안내면 개발)

  • 박천홍;황주호;오윤진;이찬홍
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.343-346
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    • 2003
  • In order to discuss the availability of the hydrostatic guideway driven by the coreless linear motor to ultra precision machine tools, a prototype of guideway is designed and tested in this research. A coreless linear DC motor with the continuous force of 156 N and a laser scale with the resulution of 10 nm are used as the feeding system. The experiments are performed on the static stiffness. motion accuracy, positioning accuracy. microstep response and variation of velocity. The guideway has the infinite axial stiffness within 50 N of applied load, and has 0.08 ${\mu}{\textrm}{m}$ of linear motion error and 0.1 arcsec of angular motion error. It also has 0.21 ${\mu}{\textrm}{m}$ of positioning error and 0.09 ${\mu}{\textrm}{m}$ of repeatability, and it shows the stable response against the 10 nm resolution step command. The velocity variation of feeding system is less than 5%. From these results, it is confirmed that the hydrostatic guideway driven by the coreless linear motor is very useful for the ultra precision machine tools.

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Basic Characteristics of an Active Controlled Capillary for Compensating the Error Motion of Hydrostatic Guideways (유정압안내면 운동오차보정용 능동제어모세관의 기본특성)

  • Song, Y.C.;Park, C.H.;Kim, S.T.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.8
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    • pp.130-136
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    • 1997
  • For compensating the error motion of hydrostatic guideways, we introduce a way that the clearance of table is actively controlled corresponding to the amount of error with the variable capillary. The structure and the theoretical design method of active controlled capillary using piezo actuator, named ACC, are proposed in this paper. Basic characteristics such as the maximum controllable range, micro step response and available dynamic bandwidth are tested for confirmation of structural suitability of ACC, and these characteristics are also tested on the table mounted with ACC for verifying the availability. The experimental result showed that by the use of ACC, the error motion within 2.7 .mu. m of a hydrostatic guideway can be compensated with the resolution of 2.7nm, 1/100 contollable range, and the frequency bandwidth of 5.5 Hz. From these results, it is confirmed that the ACC is very effective to improve the motion accuracy of high or ultra precision hydrostatic guideways.

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Development of a Hydrostatic Guideway Driven by the Linear Motor (리니어모터를 이용한 초정밀 유정압안내면 개발)

  • 박천홍;오윤진;황주호;이득우
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.6
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    • pp.139-144
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    • 2004
  • In order to discuss the availability of hydrostatic guideways driven by the coreless linear motor to ultra precision machine tools, a prototype of guideway is designed and tested in this research. A coreless linear DC motor with the continuous force of 156 N and a laser scale with the resolution of 0.01 ${\mu}{\textrm}{m}$ are used as the feeding system. The experiments are performed on the static stuffiness, motion accuracy, positioning accuracy, microstep response and variation of velocity. The guideway has the infinite axial stillness within 50 N of applied load, and by the motion error compensation method using the Active Controlled Capillary, 0.08 ${\mu}{\textrm}{m}$ of linear motion error and 0.1 arcsec of angular motion error are acquired. The guideway also has 0.21 ${\mu}{\textrm}{m}$ of positioning error and 0.09 ${\mu}{\textrm}{m}$ of repeatability, and it shows the stable response against the 0.01 ${\mu}{\textrm}{m}$ resolution step command. The velocity variation of feeding system is less than 0.6 %. From these results, it is confirmed that the hydrostatic guideway driven by the coreless linear motor is very useful fur the ultra precision machine tools.

Thermal Characteristics of Hydrostatic Guideway in Ultra Precision Positioning (초정밀위치결정을 위한 유정압안내면의 온도특성 분석)

  • 박천홍;오윤진;황주호;이득우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.37-41
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    • 2002
  • Thermal characteristics of hydrostatic guideway is largely depended on the temperature of supplied oil. For improving the positioning accuracy of hydrostatic guideway, relationship between setting temperature of oil cooler and thermal characteristics is analyzed, and influence of thermal characteristics on positioning accuracy is also analyzed experimental1y in this paper. Laser scale which has 0.01 $\mu\textrm{m}$ of resolution is used as feed-back unit. From the experimental results, it is confirmed that positioning error and repeatability is minimize upto 0.21 $\mu\textrm{m}$ and 0.18 $\mu\textrm{m}$ when the temperature of supplied oil is setting equal to temperature of atmosphere, and also confirmed that thermal deformation, which occurs by the temperature deviation between table and rail or scale supporter, works as limit of repeatability in long time operation.

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Structural Characteristic Analysis on the Hydrostatic Guide Way and Feeding System of a High-Precision Centerless Grinder for Machining Ferrules (페룰 가공용 초정밀 무심 연삭기의 유정압 안내면 및 이송계에 대한 구조 특성 해석)

  • Kim, Seok-Il;Park, Chun-Hong;Cho, Soon-Joo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.7
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    • pp.896-903
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    • 2004
  • This paper proposes the structural characteristic analysis and evaluation on the hydrostatic guide way and feeding system of a high-precision centerless grinder for machining ferrules. In order to realize the required accuracy of ferrules with sub-micron order, the axial stiffness and motion accuracy of feeding system have to become higher level than those of existing centerless grinders. Under these points of view, the physical prototype of feeding system composed of steel bed, hydrostatic guide way and ballscrew feeding mechanism is designed and manufactured for trial. Experimental results show that the axial and vertical stiffnesses of the physical prototype are very low as compared with those design values. In this paper, to reveal the cause of these stiffness difference, the structural deformations on the virtual prototype of feeding system are analyzed based on the finite element method under experimental conditions. The simulated results illustrate that the deformation of front ballscrew support-bearing bracket is the main cause of reduction in the axial stiffness of feeding system, and the deflection of bed structure and the bending deformation of hydrostatic guide rails are the main causes of reduction in the vertical stiffness of feeding system.

KSR-III 매니폴드의 추진제 분사균일성 해석

  • Cho, Won-Kook
    • Aerospace Engineering and Technology
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    • v.1 no.2
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    • pp.113-122
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    • 2002
  • A numerical analysis on the uniformity of propellant injection velocity of KSR-III has been carried out to give design improvements. Injector holes were approximated as porous media with the same pressure drop . The injection velocity is higher at the opposite side of the inlet for both LOX and fuel due to the static pressure rise in the stagnation region. Flow passages at the vertical circular plate in the LOX dome increase the uniformity of LOX injection. Little change was observed in the injection uniformity and pressure drop for the slanted LOX passage. Also provided were the O/ F ratio distributions from the oxidizer/ fuel injection velocity analysis.

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