• 제목/요약/키워드: friction drive

검색결과 215건 처리시간 0.028초

NC 선반에서 동시 3축을 이용한 구면 렌즈 가공 연구 (A Study on the Spherical Lens Manufacturing by Simultaneous 3-Axis for NC Lathe)

  • 이민기;이응석;안동율
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.956-961
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    • 2004
  • This paper proposes a study on the spherical lens manufacturing by simultaneous 3 axis for NC lathe. We use friction drive system for moving system in experimental diamond turing machine. The diamond turning machine use manufacturing for high quality lens, mirror and many optics products. Especially, the high tech industry require a lot of lens. For example, optical engineering. medical science, space engineering and material engineering etc. The friction drive system is very simple and quiet, compared to ball screw system. We find a problem at the simultaneous 3 axis and suggest a solution. Also, when we manufactured a micro lens. find a problem and solution.

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DSP를 이용한 직접 구동방식의 터보 압축기용 통합 제어기 개발 (The Development of DSP Based Multi Controller for Direct Drive Method Turbo Compressor)

  • 권정혁;변지섭;최중경;류한성
    • 한국정보통신학회논문지
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    • 제6권6호
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    • pp.885-890
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    • 2002
  • 터보 압축기는 구조적으로 임펠러를 고속회전 시켜야 한다. 범용전동기에 높은 기어비를 가진 기어박스를 이용하여 구현하였는데, 이는 관성 모멘트, 마찰손 및 압축기의 크기를 증가시켰다. 최근에 터보 압축기의 연구는 초고속 동기전동기를 장착하여 기어박스를 제거하여 크기와 마찰손을 최소화하는 방향으로 진행되고 있다. 본 연구에서는 150마력 70,000rpm 직접 구동방식의 터보 압축기를 개발하기 위하여 초고속 동기전동기용 인버터제어기, 공압제어기 및 MMI 기능을 통합한 단일 DSP에 근거한 통합제어기를 구현하였다. 이는 하드웨어적인 부분만 아니라 소프트웨어적인 측면에서도 통합 작업이 필요하였다. 이러한 소프트웨어 및 하드웨어 통합을 통하여 하드웨어적으로는 제어 시스템을 간략화 되었으며, 소프트웨어적으로는 동일한 개발환경에서 각 종 제어기가 구현되고 통합되었다. 이를 개발 및 제작하여 150마력70,000rpm 직접 구동방식의 터보 압축기에 적응하였다

A Dual-mode Pico-positioning System using Active Aerostatic Coupling

  • Mizumoto, Hiroshi;Yabuta, Yoshito;Arii, Shiro;Yabuya, Makoto;Tazoe, Yoichi
    • International Journal of Precision Engineering and Manufacturing
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    • 제8권2호
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    • pp.32-37
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    • 2007
  • This paper proposes a dual-mode ultra precision positioning system for machine tools and measuring machines. The objective was to position a machine table with a picometer order of resolution, i.e., pico-positioning. A twist-roller friction drive (TFD) was used in coarse-mode positioning. The TFD, which was driven by an AC servomotor, is a kind of lead screw in mechanical terms, and several centimeters of machine table movement was controlled with a nanometer order of positioning resolution. To eliminate lateral vibration caused by the TFD, an active aerostatic coupling driven by piezoelectric actuators was inserted between the TFD and the machine table. This active aerostatic coupling was also applied as a feed drive device for fine-mode positioning; in the fine mode, the positioning resolution was 50 pm. Factors influencing pico-positioning, such as how noise from displacement sensors and vibrations in the aerostatic guideway affect positioning resolution, are discussed.

A practical identification method for robot system dynamic parameters

  • Kim, Sung-wun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.705-710
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    • 1989
  • A practical method of identifying the inertial parameters, viscous friction and Coulomb friction of a robot is presented. The parameters in the dynamic equations of a robot are obtained from the measurements of the command voltage and the joint position of the robot. First, a dynamic model of the integrated motor and manipulator is derived. An off line parameter identification procedure is developed and applied to the University of Minnesota Direct Drive Robot. To evaluate the accuracy of the parameters the dynamic tracking of robot was tested. The trajectory errors were significantly reduced when the identified dynamic parameters were used.

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로보트시스템 동적 변수의 실용적인 추정 방법 (A Practical Identification Method for Robot System Dynamic Parameters)

  • Kim, Sungkwun
    • 대한전기학회논문지
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    • 제39권7호
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    • pp.765-772
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    • 1990
  • A practical method of identifying the inertial parameters, viscous friction and Coulomb friction of a robot is presented. The parameters in the dynamic equations of a robot are obtained from the measurements of the command voltage and the joint position of the robot. First, a dynamic model of the integrated system of the mainpulator and motor is derived. An off-line parameter identification procedure is developed and applied to the University of Minnesota Direct Drive Robot. To evaluate the accuracy of the parameters the dynamic tracking of the robot was tested. The trajectroy errors were significantly reduced when the identified dynamic parameters were used.

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스핀들 모터용 유체베어링의 마찰 및 마멸 특성 (Friction and Wear Characteristics of Fluid Bearing for Spindle Motors)

  • 정성훈;박동신;이영제;정광섭;정대현
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.372-377
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    • 2000
  • Recently, fluid bearing have been studied to apply to spindle motors for hard disk drive, printer and others. Since fluid bearing have excellent stiffness and good load carrying capacity, the bearing proved to be suitable for those devices related to computer industry. In this paper, the friction and wear characteristics of the bearing were studied. The bearing appears good performance at a high temperature and high wear resistance.

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초음파 진동을 이용한 마찰 및 음향부상에 의한 물체의 수송 (Friction-Based and Acoustically-Levitated Object Transport Using Ultrasonic Vibration)

  • Byoung-Gook Loh;Yong-Kuk Park
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권5호
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    • pp.590-599
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    • 2003
  • In this study. object transport method based on ultrasonic flexural vibration is presented. Ultrasonic vibration generates ultrasonic traveling waves on the surface of elastic medium. Objects are transported through the interaction with traveling waves propagating in medium. Two types of transport methods are studied: frictional drive and acoustic levitation. With frictional drive, objects are transported in contact with the beam in the opposite direction of wave propagation whereas with acoustic levitation, objects are acoustically levitated above the beam surface and transported in the wave propagation direction. Transport characteristics are experimentally investigated using objects of different shapes and sizes. The transition from acoustic levitation mode to frictional drive mode is also examined. and it is found to occur when the ratio of mass to area of an object exceeds the threshold ratio of mass to area. It is envisaged that this feasibility study will serve as a stepping-stone for ultrasonic vibration to become an effective industrial material handling device in the future.

이송계에서 이송중량이 동적정도에 미치는 영향

  • 홍성오;김홍배;조규재
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 춘계학술대회 논문집
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    • pp.528-535
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    • 2002
  • In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. However, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a feed drive systems. And also, the driving position is set near the center of the main slideway. From the results, it is confirmed that yaw error and straightness can be improved.

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볼스크류의 축-비틀림 복합강성을 고려한 이송계 모델링 (Modeling of Feed Drive System Considering Combined Stiffness with Longitudinal And Twist Direction)

  • 이찬홍;박천홍;노승국;이후상
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 춘계학술대회 논문집
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    • pp.387-390
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    • 2002
  • In machine tools, the stiffness of feed drive system is very important for high speed and accurate operation. The ball screw driven feed system has small friction, so the longitudinal and twist stiffness are connected directly and affected by each other. As the longitudinal and twist stiffness are participated in total stiffness of feeding system by about ratio of 4:1, the combined stiffness is necessary to compute when stiffness of feed system is estimated. In this paper, calculation of this combined stiffness is derived and applied for an actual ballscrew fled drive system. The static stiffness and 1 st natural frequency of the feed system is measured, and it is proved the difference between estimation and experiment result is less than 6%.

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