• 제목/요약/키워드: Load-velocity Characteristics

검색결과 317건 처리시간 0.01초

다양한 링크구동 기계프레스에 대한 기구학적 분석 (Kinematic Analysis of Several Linkage Drives for Mechanical Presses)

  • 구형욱;황병복;임중연;이호용
    • 소성∙가공
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    • 제6권6호
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    • pp.471-481
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    • 1997
  • This paper is concerned with the kinematic analysis of several linkage drives for mechanical presses. Load and velocity characteristics of conventional presses are illustrated and a design of new drive for a mechanical press is represented. In this regard, a crank-slider mechanism with arc crank-pin guide is introduced and compared with other linkage drives. Kinematic performances are analyzed in respect of load capacity, slide velocity characteristics using a developed SS-Plot program. The new linkage drive turns out to be effective in terms of load and velocity characteristics, and productivity.

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MEASUREMENT OF TURBULENCE CHARACTERISTICS BY USING PARTICLE TRACKING VELOCIMETRY

  • Yoon, Byung-man;Yu, Kwon-kyu;Marian Muste
    • Water Engineering Research
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    • 제3권2호
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    • pp.135-142
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    • 2002
  • This study investigates the effects of sediment on the flow characteristics such as velocity distribution, friction velocity, turbulent intensities, Reynolds stress, etc. Particle tracking velocimetry (PTY) is used to measure the vertical flow field. Results show that flow over the high bed-load concentration region has larger values of mean velocity and friction velocity and smaller values of turbulence intensities, compared to those for flow over the low bed-load concentration region.

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밸런스빔을 이용한 미지부하 정속도 회전 (Constant Velocity Revolution of an Unknown Load Using a Balance Beam Controller)

  • 김용준;이건영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 D
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    • pp.2227-2229
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    • 2003
  • Using the gyro effect, Balance Beam Controller is developed with Samsung Corporation. Balance Beam Controller is possible to control the position of an object in air by controlling the attitude of inner gimbal. But in the unknown load inertia case, even a skilled worker it is not easy to operate a Balance Beam. That is caused by the difficulty to estimate the load inertia. If the amount of the gimbal operation is set excessively with a wrong load estimation, it can often cause accidents. To solve this problem, the control function which is revolving with velocity of the revolution has to be added to developed equipment. In this research, we analyze the characteristics of a Balance Beam(the smaller load inertia, the bigger force of restitution) using the angular velocity sensor, and present constant velocity revolving controller with estimating value of the load using this moving characteristics.

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고해부하가 지층 형성시 탈수특성에 미치는 영향 (Effect of Refining Load on the Drainage Characteristics of Pulp)

  • 김용식;원종명
    • 펄프종이기술
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    • 제32권4호
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    • pp.10-17
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    • 2000
  • The change of fiber length, freeness, initial forming drainage velocity, specific filtration resistance, final drainage time and wet web dryness were measured to investigate the effect of the refining load on the drainage characteristics of pulp. The arithmetic average fiber length after refining with higher refining load was shorter than that obtained with lower refining load. Higher refining load decreased initial forming drainage velocity, final drainage time and wet web dryness. The refining load also affected the relationship between freeness and specific filtration resistance, initial forming drainage velocity, final drainage time. It was found that the specific filtration resistance is better than freeness to predict the drainage characteristics of pulp and the wet dryness.

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이동하중과 축하중이 작용하는 유연한 기초위에 지지된 무한보의 동특성 (Dynamic characteristics of flexibly supported infinite beam subjected to an axial force and a moving load)

  • 홍동균;김광식
    • 오토저널
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    • 제4권3호
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    • pp.56-68
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    • 1982
  • This paper presents analytic solutions of defection and their resonance diagrams for a uniform beam of infinite length subjected to an constant axial force and moving transverse load simultaneously. Steady solutions are obtained by a time-independent coordinate moving with the load. The supporting foundation includes damping effects. The influences of the axial force, the damping coefficient and the load velocity on the beam response are studied. The limiting cases of no damping and critical damping are also investigate. The profiles of the deflection of the beam are shown graphically for several values of the load speed, the axial force and damping parameters. Form the results, following conclusions have been reached. 1. The critical velocity .THETA.cr decreases as the axial compressive force increases, but increases as the axial tensile force increase. 2. At the critical velocity .THETA.cr the deflection have a tendency to decrease as the axial tensile force increases and to increase gradually as the axial compressive force increases. 3. In case if relatively small dampings, the deflection increases suddenly as the velocity of the moving load approaches the critical velocity, and it reachs its maximum at the critical velocity, and it decreases and become greatly affected by the axial force as the velocity increases further. 4. in case of relatively large dampings, as the velocity increases the deflection decreases gradually and it is affected little by the axial load.

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50% 미만 부하조건에서의 3상 몰드변압기 진동 측정과 분석 (The vibration detection and analysis of 3-phase cast resin transformer in less than 50% load conditions)

  • 송길목;방선배;김종민;김영석;최명일
    • 전기학회논문지
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    • 제61권7호
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    • pp.992-997
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    • 2012
  • In this paper, we were analyzed the vibration characteristics of the three-phase cast resin transformer using less than 50% of load in the field. Most of the cast resin transformer is less than 50% in the domestic field is used for load conditions. Consisting of a solid insulator cast resin transformer is generating lots of noise and vibration. In addition, because it is affected by Joule 's heat is used in light load conditions. As a results, the transformer vibrations at frequencies below about from 200Hz to 500Hz were detected. Vibration velocity depends on the load variations were found. Load up to approximately 20-30% in most cases the vibration velocity was found at 4,000 ${\mu}m/s$ or less, 8,000 ${\mu}m/s$ or more. Vibration frequency at light load conditions were generated at the 120Hz, 240Hz, 360Hz and 480Hz. At the load condition of from 10% to 20%, vibration velocity is higher than another. Most of the vibration velocity were identified at the 1,000 ${\mu}m/s$ or less. Using the vibration frequency and velocity measurements data, the load on the cast resin transformer analyzed the correlation of the burden. Therefore, this data could be found in the vibration characteristics of the light-load conditions. If the field measurements using the data perform diagnostics on the transformer, it's expected to be very effective.

직선가이드프레스 구동부의 최적화 (Optimization of the Dirve for Lineaer-Guide Press)

  • 이영섭;황병복
    • 소성∙가공
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    • 제9권2호
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    • pp.171-178
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    • 2000
  • This paper is concerned with the optimization of the drive for linear-guide press which is one of mechanical presses. The design of linear-guide drive for a mechanical press is introduced and the drive for the linear-guide press is optimized for the improvement of load and velocity characteristics. As a result of optimization, the load capacity during stroke increases and the slide velocity decreases in working region, respectively. The new design could be suited to many applications in precision forming such as extrusion and the sheet metal-forming processes.

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풍력발전기의 풍하중특성에 관한 연구 (A study on wind load characteristics of wind turbines)

  • 김정수;박노길;김영덕;김수엽
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2010년도 추계학술대회 논문집
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    • pp.124-129
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    • 2010
  • Wind load characteristics is investigated for vibration analysis of wind turbine gearbox. A normal wind model assumed, of which the wind velocity is increased according to the height from ground. A blast wind model is assumed, of which the maximum velocity is located at the center and the velocity profile is normally distributed. The periodical torque and bending moments transmitted to the main shaft of wind turbine are investigated. The average values and the harmonic terms of the transmitted moments are studied on the wind direction of range $-45^{\circ}{\sim}45^{\circ}$ and the bending moment characteristics are examined, which is regarded as the main source of the misalignment of gear train.

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슬라이드의 하강속도특성을 개선한 기계프레스의 구동부 (Mechanical Pressure Drive with Enhanced Downward Velocity Characteristics)

  • 구형욱;최호준;황병복
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1996년도 춘계학술대회논문집
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    • pp.110-120
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    • 1996
  • A crank-slider mechanism is driven by the rotating disk with are crank-pin guide to be applied to the deep drawing and cold forging presses. Load characteristics for different presses are summarized to see the basics of deep drawing of sheet metal and forging in terms of load-stroke relationship. Several types of conventional deep drawing presses are also shown to be compared with the ratating disk-types press. Kinematic performances by thearc guide driving mechanism are anlayzed in terms of load capaicty, stroke, and slide velocity characteristics, and they are compared with those by conventional driving , e.g. Niagara-typepress and so on. Kinematically better performances is shown by arc guide drive than those by conventional ones. The new driving mechanism is also proven to be one of the best for mass production press in terms of short cycle time. Possible applications of the arc guide press to deep drawing and cold forging work are in terms of kinematics and load capacity.

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Random vibration of multispan Timoshenko frames due to a moving load

  • Wang, Rong-Tyai;Lin, Jin-Sheng
    • Structural Engineering and Mechanics
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    • 제6권6호
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    • pp.673-691
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    • 1998
  • In this paper, an analytic method to examine the random vibration of multispan Timoshenko frames due to a concentrated load traversing at a constant velocity is presented. A load's magnitude is a stationary process in time with a constant mean value and a variance. Two types of variances of this load are considered: white noise process and cosine process. The effects of both velocity and statistical characteristics of load and span number of the frame on both the mean value and variance of deflection and moment of the structure are investigated. Results obtained from a multispan Timoshenko frame are compared with those of a multispan Bernoulli-Euler frame.