• Title/Summary/Keyword: Damper cylinder

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A Performance Analysis and Experiment of Viscous Torsional Vibration Damper for High Speed Engine Shaft System (고속엔진축계용 점성 비틀림진동감쇠기의 성능해석 및 실험)

  • Yang, B.S.;Jeong, T.Y.;Kim, K.D.;Kim, D.J.
    • Journal of Power System Engineering
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    • v.1 no.1
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    • pp.98-105
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    • 1997
  • In general, crankshafts which are used in internal combustion reciprocating engines are subjects to high torsional vibration. Therefore, a damper is often used to minimize the torsional vibration in reciprocating engines. In this paper, in order to investigate damping performance of viscous damper, the real effective viscosity and complex damping coefficient of silicone oil, and the effective inertia moment of inertia ring are calculated considering the relative motion between damper casing and inertia ring. Based on these results multi-cylinder shaft is modeled into equivalent 2-degree of freedom system and optimum condition is estimated by calculating the amplification factor of viscous damper. Also the test damper was manufactured according to the result of theoretical investigation, the performance and durability was ascertained through experimental examination.

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Development of Improved Semi-Active Damper Using EMRF (EMRF를 이용한 개선된 Semi-Active Damper 개발)

  • Jeon, Seung gon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.26 no.4
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    • pp.149-156
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    • 2022
  • Magneto-Rheological Fluid (MRF) is a functional fluid in which flow characteristics change into magnetic force due to its magnetic particles. When the semi-active control device does not use MRF for a long time, precipitation of magnetic particles and abnormal control force occur. Thus, Electro Magneto-Rheological Fluid (EMRF), which improves the precipitation of magnetic particles for MRF and exhibits existing control performance, was developed in this study. First, the optimal mix proportion ratio was selected by conducting a precipitation experiment and a controlled force test by varying the content of grease based on the existing MRF components. Also, EMRF was applied to the shear-type damper to evaluate the control performance when applied to the control device. The cylinder-type damper was developed to apply to the structure, and control performance evaluation was conducted. The result confirmed that the precipitation of the magnetic particles was improved, while the damper using EMRF exhibited excellent control performance.

Modeling and Vibration Control of Small-sized Magneto-rheological Damper (소형 MR 댐퍼의 모델링 및 진동제어)

  • Lee, Jong-Woo;Seong, Min-Sang;Woo, Je-Kwan;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.344-349
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    • 2012
  • This paper presents a new small-sized damper featuring magneto-rheological (MR) fluid which can be applied to vibration control system. The proposed MR damper consists of cylinder, piston, a couple of bearings, oil-seals and magnetic circuit which has two coils. In this damper, approximately 5cc of MR fluid is used. The damping force of the MR damper is designed to be followed by linear shear-mode Bingham-plastic model. In order to verify the performance of the MR damper, an experimental apparatus is established. In the experimental test, the damping force of the MR damper is measured with respect to time, displacement and velocity. In addition, the time response of MR damper is measured when 1A of step current is applied. Finally, The proposed small MR damper is applied to vibration control. In this process, a simple 1-DOF system is modeled and controlled using PID controller.

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Modeling and Vibration Control of Small-sized Magneto-rheological Damper (소형 MR 댐퍼의 모델링 및 진동제어)

  • Lee, Jong-Woo;Seong, Min-Sang;Woo, Je-Kwan;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.11
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    • pp.1121-1127
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    • 2012
  • This paper presents a new small-sized damper featuring magneto-rheological(MR) fluid which can be applied to vibration control system. The proposed MR damper consists of cylinder, piston, a couple of bearings, oil-seals and magnetic circuit which has two coils. In this damper, approximately 5cc of MR fluid is used. The damping force of the MR damper is designed to be followed by linear shear-mode Bingham-plastic model. In order to verify the performance of the MR damper, an experimental apparatus is established. In the experimental test, the damping force of the MR damper is measured with respect to time, displacement and velocity. In addition, the time response of MR damper is measured when 1A of step current is applied. Finally, the proposed small MR damper is applied to vibration control. In this process, a simple 1-DOF system is modeled and controlled using PID controller.

Performance Evaluation of Small Dampers Using SMG Fluid (SMG 유체를 이용한 소형댐퍼의 성능평가)

  • Heo, Gwang Hee;Jeon, Seung Gon;Seo, Sang Gu;Kim, Dae Hyeok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.4
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    • pp.211-219
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    • 2019
  • In this study, SMG(Smart Material with Grease) was developed, which was improved the precipitation minute particle in grease during long term standstill. Also, small-sized cylinder damper equipped with an electromagnet in a piston was developed for using a performance evaluation of the damper with SMG and the dynamic load test, and damping force using Power model and Bingham model was derived in order to compare to the result of that of the damper. The data obtained from the dynamic load test were analyzed and plotted, and then a dynamic range was calculated to evaluate the usability of the damper with SMG. The performance of the damper with SMG was compared to the damping forse derived from the Power and Bingham model. The result of this evaluation shown that the usability of SMG damper was demonstrated by this test as a semi-active controlling equipment of small-sized damper.

Intelligence Control Characteristics of a Digital Damper (디지털 댐퍼의 지능제어 특성)

  • Song, Joon-Ho;Lee, Yuk-Hyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.3
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    • pp.5-10
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    • 2006
  • The objective of this paper is to investigate the Intelligence control characteristics of a digital damper. This paper deals with a two-degree-of-freedom suspension using the damper with ER fluid for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using passive and ANFIS control method. Computer simulation results show that the semi-active suspension with ER damper has good performances of ride quality.

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Development of a Stance and Swing Phase Control Transfemoral Prosthesis (입각기.유각기 동시제어식 대퇴의지의 개발)

  • Kim, Sin-Gi;Kim, Gyeong-Hun;Mun, Mu-Seong;Lee, Sun-Geol;Baek, Yeong-Nam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.4
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    • pp.685-694
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    • 2001
  • In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

Development of a Stance & Swing Phase Control Transfemoral Prosthesis (입각기와 유각기 제어 대퇴의지의 개발)

  • Kim, Shin-Ki;Kim, Jong-Gwon;Hong, Jeong-Hwa;Kim, Gyeong-Hun;Mun, Mu-Seong;Lee, Sun-Geol;Baek, Yeong-Nam
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.504-509
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    • 2000
  • In this study, a transfemoral prosthesis system of which stance phase and swing phase are controlled during walking has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics and behaviour of the knee damper which absorbs the impact energy generated at the heel contact was investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase was also studied for its mechanical characteristics. The prosthesis was subject to the clinical test ant the gait characteristics obtained were very close to those of normal. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

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A Study on Nonlinear Pneumatic System Characteristics (비선형 공기압시스템 특성연구)

  • 박재범;김동수;김형의;염만오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.826-830
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    • 1996
  • The pneumaic systems are widely applied to chemical factory of fire dangry and factory automation. by using compressed air, it is difficult to dynamics action analysis that the pneumatics system acts to nonlinear motion through orifices and valve flow. This paper was studied to a nonlinear chararistics of pneumaic spring, damper and absorber of pneumaic cushion cylinder.

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Experimental Study for Dynamic Characteristics of Eddy Current Shock Absorber (와전류 충격완충장치의 실험적 동특성 연구)

  • Kwag, Dong-Gi;Hwang, Jai-Hyuk;Bae, Jae-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.12
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    • pp.1089-1094
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    • 2007
  • This paper is concerned with a new concept for the damper without neither a coil spring nor fluid. The new damper concept consists of the permanent magnets and the cylinder of the conducting material. The opposite pole magnets produces the repulsive forces and this is substituted for the coil spring. The relative motion between the magnets and conducting cylinder produces eddy currents thus resulting in the electromagnetic force, which turns out to be the damping force and is substituted for a damping fluid. This damper is called the eddy current damper(ECD). The important advantage of the proposed ECD is that it does not require any damping fluid and any external power and is non-contacting and relatively insensitive to temperature. In the present study, the proposed ECD was constructed and the experiments were performed to investigate its dynamic characteristics. The experiments shows that the proposed ECD has the excellent damping ability.