• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.279-282
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• 2000

진동가속도를 감지하는 힘평형 서보 가속도계의 성능특성을 결정하는 질량지지 장치를 4개의 팔로 구성된 형태로 설계하고 응답특성을 조사하였다. 스프링의 길이, 폭, 두께에 따른 질량지지 장치의 응답특성을 유한요소법을 이용하여 계산하고, 이를 바탕으로 힘평형 서보 가속도계의 감도, 사용주파수 범위 및 동적 범위를 예측하였다. 그리고 레이저 간섭계를 이용하여 힘평형 서보 가속도계의 각각의 진동 주파수 및 가속도의 크기에 따른 간섭무의 수의 변화와 이때의 응답전압간을 이용하여 가속도계의 응답특성을 측정하였으며, 수치해석을 통해 얻은 결과와 비교 분석하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.481-488
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• 2000

This paper presents a new passive gravity -compensating system for articulated robot manipulators. The system, which consists of linear zero- free -length springs, achieves exact counterbalancing o f the gravitational loads throughout the entire range of the manipulator workspace, A basic concept is to design springs such that the total potential energy of the system including the manipulator and the springs should be maintained constant. A prototype has been developed for a direct-drive five-bar manipulator and its performances have been investigated. Results show that the gravity-induced motor torques have been reduced to less than 5% of those of uncompensated robots. Also, the gravity-compensating system simplifies the position control algorithm while maintaining the trajectory-tracking errors in a satisfactory level. In conclusion, the proposed system efficiently improves the manipulator performances by reducing the driving motor size and the energy consumption as well as by simplifying the control systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.729-734
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• 2017

A safety relief valve is a device that relieves excessive pressure in piping lines or tanks and maintains pressure at the appropriate pressure level for use. The (pressure in the) safety valve is directly influenced by the change in the back pressure, depending on whether the vents in the spring bonnet are vented to the atmosphere or to the outlet. The back pressure is divided into the built-up back pressure and the superimposed back pressure, and the back pressure characteristics vary according to the usage conditions. The safety valve used in this study is a Conventional Safety Relief Valve. The blowdown of the safety valve is predicted by establishing the equilibrium equation between the opening force and spring force considering the back pressure characteristics. Its reliability is secured by using CFX17.1. In addition, the safety of the safety valve trim was examined through fluid-structure interaction analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.6
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• pp.669-675
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• 2011

A constant hanger is a device for supporting pipes in plants. It supplies a constant force to a supporting pipe even if the pipe moves because of thermal expansion. In this paper, we propose a method for designing the contour of a cam for a constant hanger. It has been shown that the contour of a cam must satisfy the geometrical relation of the cam, the force balance equation for the load tube, the relation between the side spring compression and the cam rotation angle, and the moment balance equation for the cam. A calculation procedure to solve these equations simultaneously is proposed, and a constant hanger is designed successfully.