• Title/Summary/Keyword: Force transmission ratio

Search Result 80, Processing Time 0.022 seconds

An Experimental Study on the Estimate of Wind Force Coefficient of Transmission Tower Rectangular Frame (철탑 사각골조의 풍력 계수 산정에 관한 실험적 연구)

  • Shin, Koo-Yong;Lim, Jae-Seob;Hwang, Kyu-Seok;Kil, Yong-Sik
    • Journal of Korean Society of Steel Construction
    • /
    • v.23 no.1
    • /
    • pp.73-81
    • /
    • 2011
  • The wind force coefficient of a transmission tower frame shows several characteristics when the section shape, solidity ratio, and wind direction angle are changed. In this study, the wind force characteristics of a transmission tower frame with a basic structure were evaluated using different solidity ratios and wind direction angles in a wind tunnel test. According to the solidity ratio, the size of the structure and the rectangular-frame model of the transmission tower were changed by adding a two-dimensional (2D) or three-dimensional (3D) structure. The transmission tower's rectangular frame was tested by changing the wind direction angle of the 2D-type structure from 0 to $90^{\circ}$ and by changing the wind direction angle of the 3D-type structure from 0 to $45^{\circ}$ Based on the results that were obtained, it can be concluded that the wind force coefficient of a transmission tower frame can be used as preliminary data in deciding the transmission tower's wind load.

Power Transmission Characteristics and Speed Ratio-Torque Load-Axial Force Relationship for a Metal V-Belt CVT (금속 V-벨트 CVT의 동력전달 특성과 변속비-부하토크-축력 관계)

  • 김광원;김현수
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.2
    • /
    • pp.349-357
    • /
    • 1990
  • Power transmission characteristics and speed ratio-torque load-axial force relationship for a metal V-belt CVT were investigated theoretically and experimentally. In the metal V-belt CVT drive, it was found that the power was transmitted by thrust force and that band tension should be greater than compression force between the metal blocks. The experimental results for the speed ratio-torque load-axial force relationship showed good agreement with those predicted using equations developed from theoretical considerations.

A Geometrical Approach to the Characteristic Analysis of Parallel Mechanism for Planar Task (평면 작업용 병렬 메카니즘의 특성 해석을 위한 기하학적 접근)

  • Song, Nak-Yoon;Cho, Hwang
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.9
    • /
    • pp.158-166
    • /
    • 1998
  • This paper presents a geometrical approach to the characteristic analysis of parallel mechanism with free joints intended for use as a planar task robot. Solution of the forward and inverse kinematic problems are described. Because the mechanism has only three degree-of-freedom output, constraint equations must be generated to describe the inter-relationship between actuated joints and free joints so as to describe the position and orientation of the moving platform. Once these constraints are incorporated into the kinematics model, a constrained Jacobian matrix is obtained. and it is used for the solution of the forward kinematic equations by Newton-Raphson technique. Another Jacobian matrix was derived to describe the interrelationship between actuated joints and moving platform. The stiffness, velocity transmission ratio, force transmission ratio and dexterity of the mechanism are then determined based on this another Jacobian matrix. The geometrical construction of the mechanism for the best performance was investigated using the characteristic analysis.

  • PDF

Development of a five-bar finger with redundant actuation (여유구동을 이용한 5관절 휴먼핑거의 개발)

  • 이재훈;이병주;오상록;김병호
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.1613-1616
    • /
    • 1997
  • In order to develop a human hand mechanism, a 5-bar finger with redundant actuation is designed and implemented. an optimal set of acutator locations and link lengths for the case of one redundant actuator is obtained by employing a composite design index which simulataneously consider several performance indices such as workspace, isotropic index, and force transmission ratio. Each joing is driven by an compact actuator mechanism having ultrasonic motor and a gear set with poeneiometer an controlled by VME Bus-based control system.

  • PDF

An Experimental Study on the Shift Characteristics of a Metal Belt Type Continuously Variable Transmission (CVT) (금속벨트식 무단변속기(CVT)의 변속특성에 관한 실험적 연구)

  • 이충섭
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.5 no.6
    • /
    • pp.36-43
    • /
    • 1997
  • To cope with quest to improve the fuel economy and vehicle performance, Continuously Variable Transmission with Changing the speed ratio between minimum and maximum ratio by infinite step, is more efficient than conventional multi-ratio transmission. In this paper, to investigate a specific CVT shift ratio diagram and CVT shift characteristics, CVT vehicle was tested on the proving ground and chassis dynamometer. The test results are as follows; CVT can obtain the excellent vehicle performance and fuel economy changing the shift ratio by infinite step, without rapid change of engine revolution and driving force. And CVT can set up a special shift range that obtains not only the engine brake effect but also the maximum speed driving.

  • PDF

Improving Vehicle Driving Stability by Controlling CVT and Brake Force (CVT 및 BrakeForce 제어를 통한 차량 주행 안정성 향상)

  • 조현욱;이승종
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.305-308
    • /
    • 2002
  • The mechanics, electronics and manufacturing technology have been developed rapidly. Nowadays vehicle stability becomes more and more important then ABS (Anti-lo7k Brake System), ASR (Anti-Slip Regulator), TCS, (Traction Control System), ESP (Electronic Stability Program), and VDC (Vehicle Dynamic Control) which actively control the vehicle stability actively has been improved. In this study, instead of automatic transmission, CVT (Continuously Variable Transmission) is used because of the continuously gear ratio changes. It can effectively transfer the torque from engine to tire more than other gear transmission. The modeling is simplified assuming that there are no resistance parameters.

  • PDF

An Experimental Study on Suction Force of Plate Anchor Embedded in Bentonite (벤토나이트에 근입된 앵커의 흡입력에 관한 실험적 연구)

  • 이준대
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.2
    • /
    • pp.97-102
    • /
    • 2001
  • Anchors are often used in construction of foundations such as transmission towers to resist uplifting forces. When plate anchors are embedded in soft clay, they may undergo a deformation under the pressure of sustained load. In soft saturated clays, the suction force can be a large par of the ultimate uplift capacity. This study is to present recent laboratory model test results conducted to evaluate the nature of variation of the suction force for plate anchors with shear strength and embedment ratio. The ratio of F$_{s}$Q$_{n}$ versus H/D in bentonite decreases with the increase of the embedment ratio.o.o.

  • PDF

Modeling and Development of Human-Muscle Type Humanoid (인체근육 구조 인간형 로봇의 모델링 및 구현)

  • Oh, Ji-Heon;Yi, Byung-Ju
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.24 no.2 s.191
    • /
    • pp.64-72
    • /
    • 2007
  • Many human-body motions such as walking, running, jumping, etc. require a significant amount of power. To achieve a high power-to-weight ratio of the humanoid robot system, this paper proposes a new design of the bio-mimetic leg mechanism resembling musculoskeletal system of the human body. The hip joints of the system considered here are powered by 5 human-like bi-and mono-articular muscles, and the joints of knee and ankle are redundantly actuated by both bi-articular muscles and joint actuators. The kinematics for the leg mechanism is derived and a kinematic index to measure force transmission ratio is introduced. It is demonstrated through simulation that incorporation of redundant muscles into the leg mechanism enhances the power of the mechanism approximately 2 times of the minimum actuation.

Comparison of speed ratio-torque load-axial force characteristics and their performance for automotive rubber and metal V-belt CVT (차량용 고무 및 금속 V-벨트 CVT의 변속비-부하토크-축력특성과 성능비교)

  • 김현수;김광원
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.12 no.3
    • /
    • pp.9-20
    • /
    • 1990
  • The speed ratio-torque load-axial force characteristics of a rubber V-belt (RVB) and a metal V-belt (MVB) CVT are investigated and their performances are compared. It is found that power is transmitted by tension difference in RVB, and by thrust difference in MVB. The nondimensional equations for speed ratio-torque load-axial force of RVB are exactly same as those of MVB. However, actual characteristics of axial forces of RVB and MVB are different depending on their power transmission methods. The torque capacity of MVB is 5-6 times higher than that of RVB due to MVB's higher strength, even if the required axial force of MVB CVT control is 3-4 times higher than that of RVB.

  • PDF

Theoretical Analysis of Levers in a Precision Stage for Large Displacement (정밀 스테이지에서 출력변위 확대를 위한 레버의 해석)

  • 황은주;민경석;송신형;최우천
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2004.10a
    • /
    • pp.720-723
    • /
    • 2004
  • Lever mechanisms are usually employed to enlarge output displacement in precision stages. In this study, theoretical analysis of a lever is presented including bending effect and relation between dimension parameters and an objective function. The objective function is chosen as multiplication of magnification ratio and forcedisplacement transmission. Through theoretical analysis, this study presents optimal values for the parameters and the analysis is verified by finite element method.

  • PDF