• Title/Summary/Keyword: Generated axial force

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Analytic Study on the Axial Forces of a Double Offset Constant Velocity Joints in Consideration of Friction Effect (마찰을 고려한 이중 오프셋 등속조인트의 축력 해석에 관한 연구)

  • Bae, Byoung-Chul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.2
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    • pp.120-127
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    • 2008
  • The constant velocity joint(CVJ) used for transmitting torque to the front wheels is an important part in automotive drive system. There are several types of constant velocity joints. Typically, they are classified by fixed and plunging constant velocity joints. The axial force generated in plunging constant velocity joints influences significantly the noise, vibration and harshness. For heaps of time, many constant velocity joint markers have been studying and developing a valid method to reduce the axial force and extensive tests have been carried out on rigs. This paper presents the analysis method to predict the axial force of a double offset constant velocity joint(DOJ), a kind of plunging constant velocity joint, and the influence of ball-cage dimension tolerance on the axial force.

Development of Rotary Actuator Including Function of Axial Bearing (축방향 베어링 통합 회전 구동기의 개발)

  • 허진혁;정광석;백윤수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1083-1086
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    • 2003
  • Recently, the study on bearingless motors which integrate both motor and magnetic bearing function in one stator is very active, as many machines have high rotational speed, high precision, smaller size and lighter weight. In this paper, we propose a novel rotary actuator including function of axial bearing using Lorentz force as a preceding research for development of a bearingless motor. As using Lorentz force, this type has some merits such as the linearity of control force, freedom from flux saturation and high efficiency unlike conventional rotary actuators using a reluctance force. This type is cotrolled independently in levitation and rotational directions respectively. It shows by mathematical expression of levitation force and torque in the proposed rotary actuator. And also, the levitation force is generated by magnetic interaction between the magnetic materials and the rotational torque is generated by Lorentz force. Finally. for verification of this proposed system, a prototype is made and some experiments will be performed in the near future.

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Development and Verification of Measuring Tester for Generated Axial Force at Constant Velocity Joints (등속조인트에서 발생하는 축력 측정장치 개발 및 검증)

  • Lee, Kwang-Hee;Lee, Deuk-Won;Lee, Chul-Hee;Yun, Hyuk-Chae;Cho, Won-Oh
    • Tribology and Lubricants
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    • v.28 no.6
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    • pp.328-332
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    • 2012
  • Generated Axial Force (GAF) due to internal friction at Constant Velocity (CV) joints is one of the causes generating vibration problems such as shudder in vehicle. In this study, the GAF measuring tester is developed to precisely measure GAF caused by internal friction in CV joints. As the developed tester can control temperature at joint, driving torque, angle of rotation and joint angles, actual driving conditions such as sudden acceleration can be applied to the machine. GAFs are measured and compared by using different types of grease in tripod housing. Also GAFs are measured for both new and used CV joints to be compared and analyzed. The test result shows the repeatability and consistency of the tester in terms of the different test conditions. By using the developed CV joint tester, friction performance of the joint can be evaluated by proposing the best CV joints as well as greases generating the lowest GAF.

Estimation of Axial Nail Force Considering Cracks and Creeps of Grout (그라우트의 균열 및 Creep 현상을 고려한 쏘일네일의 축인장력 산정)

  • 임유진;황상기
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.159-166
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    • 2000
  • A new method of estimating axial nail force is proposed. An instrumented soil nail wall is selected to investigate the effectiveness of the new proposed method. The new method includes effect of creep and age of cement grout surrounding the steel bar, The new method also considers cracks in the grout generated during and after the end of the wall construction. It is found from this study that a reduced grout stiffness due to creep with age and crack of the grout must be considered for estimating correct axial nail forces. The reduced grout stiffness is considered also providing significant part of axial nail load compared to that of steel bar.

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A study on the axial force on the CWR of the suport rotation (열차하중에 따른 교량 신축부 장대레인 축력 연구)

  • Park, Jun-O;Kim, Jong-Min;Kim, Woo-Jin
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.460-469
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    • 2006
  • It is widely known that the temperature variation introduces the axial force along a CWR(Continuous Welded Rail) in the railway bridges. Additional axial forces are generated due to many other reasons. These includes the interaction between the bridge girder and the CWR; acceleration or deceleration of the vehicles; support rotation (or deflection) of the girder. Among aforementioned reasons, this study investigates the influence of the support rotation on additional axial forces throughout the numerical study and the field test. Several strains gauges are installed along the CWR and the strains are measured under passing trains. It is expected that the elaborated estimation of the axial force on CWR will be beneficial for future railway maintenance.

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The Axial Vibration of Internal Combustion Engine Crankshaft (Part II. Resonant Amplitudes Calculation of the Crankshaft Axial Vibration) (내연기관 크랭크축계 종진동에 관한 연구 (제2보 : 크랭크축계 종진동의 공진진폭계산))

  • 김영주;고장권;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.6 no.2
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    • pp.69-91
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    • 1982
  • The major factors which affect the crankshaft axial vibration are such items as the axial stiffness and mass of crankshaft, the thrust block stiffness, the propeller's entrained water and the exciting and damping forces of engine, propeller and shafting. Among above mentioned items, the axial stiffness and mass of crankshaft, thrust block stiffness and propeller's entrained water were treated in detail in part I, and so in this paper, the rest of above items will be studied. The exciting forces of crankshaft axial vibration are generated mainly from the gas explosion pressure of cylinder, the thrust fluctuation of propeller, and sometimes the torsional vibration of crankshaft induces the crankshaft axial vibration. As for the propeller thrust fluctuation, its harmonic components can be fairly exactly calculated from the experimental results of propeller in the towing tank, but as the calculation process is rather tedious and laborious, the empirical values are ordinarily used. On the other hand, the table of harmonic components of gas pressure has been already published by major slow speed diesel engine makers, but the axial thrust conversion factor of radial force is not unknown yet, and as its estimated value is unreliable, the axial vibration force of gas pressure is uncertain. As the calculation of damping force is very complicated and it includes some uncertain factors, the thoretically estimated amplitudes of axial vibration are much more incorrect in comparison with those of torsional vibrations. Authors have paid special attentions to deriving the theoretical calculation formula of axial conversion factor of radial force and damping force of crankshaft axial vibration and developed a computer program to calculate resonance amplitudes and additional stresses of crankshaft axial vibrations. Also, to check the reliability of the developed computer program, the axial vibrations of three ships' propulsion shaftings were analyzed and their results were compared with those of measured values and makers' results.

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Feasibility Study on the New Structure of a Spindle Motor for Hard Disk Drive

  • Kim, Tae-Woo;Chang, Jung-Hwan
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.3
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    • pp.295-299
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    • 2013
  • This paper presents the new structure of a spindle motor for hard disk drive (HDD). It can produce axial force as well as torque without a pulling plate or a pulling magnet required for the normal operation of a hydrodynamic bearing in rotating-shaft structure. The proposed models have different air gap length along the axial direction by changing the thickness of permanent magnet (PM). One has a single slope and the other has double slopes on the surface of PM. For the design of the proposed models, variables are defined and its effects on the motor performances are investigated by 3-demensional finite element analysis (FEA). The equi-performance curves are investigated for the main characteristics of the spindle motor such as generated torque, axial force and torque ripple ratio. The validity of the proposed models is verified by the feasibility study and performance evaluation.

Design of Combined Radial and Axial 4-pole Electromagnetic Bearing (I) - with Uncoupled Bias Flux - (반경방향-축방향 일체형 4극 전자기 베어링의 설계 (I) - 바이어스 자속 독립형 -)

  • Kim Ha-Yong;Kim Seung-Jong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.12 s.243
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    • pp.1561-1566
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    • 2005
  • In this paper, a new compact active magnetic bearing(AMB) is proposed in which radial and axial bearings are integrated in one bearing unit. It consists of four U-shaped cores circumferentially connected by yokes and two-layer coils for radial and axial controls. For the radial control action, it has the same principle as conventional homopolar AMBs, while for the axial control, it uses the Lorentz force generated by the interaction of the bias flux for radial control and the axial control flux. The proposed structure makes it easy to design a compact AMB because it has no disk for axial control. This paper introduces the proposed structure, principle, and design process based on the magnetic flux analysis. By using a control algorithm with feedforward action to compensate the coupled flux effect, the feasibility of the proposed AMB is experimentally verified.

Multi-body Dynamic Analysis for Tripod Constant Velocity Joint (트라이포드 타입 등속조인트의 다물체 동역학 해석)

  • Song, Myung-Eui;Lim, Young-Hun;Cho, Hui-Je;Bae, Dae-Sung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.1
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    • pp.1-7
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    • 2010
  • The paper proposes a multi-body dynamic simulation to numerically evaluate the generated axial force(G.A.F) and plunging resistant force(P.R.F) practically related to the shudder and idling vibration of an automobile. A numerical analysis of two plunging types of CV joints, tripod joint(TJ) and very low axial tripod joint(VTJ), is conducted using the commercial program DAFUL. User-defined subroutines of a friction model illustrating the contacted parts of the outboard and inboard joint are subsequently developed to overcome the numerical instability and improve the solution performance. The Coulomb friction effect is applied to describe the contact models of the lubricated parts in the rolling and sliding mechanisms. The numerical results, in accordance with the joint articulation angle variation, are validated with experimentation. The offset between spider and tulip housing is demonstrated to be the critical role in producing the 3rd order component of the axial force that potentially causes the noise and vibration in vehicle. The VTJ shows an excellent behavior for the shudder when compared with TJ. In addition, a flexible nonlinear contact analysis coupled with rigid multi-body dynamics is also performed to show the dynamic strength characteristics of the rollers, housing, and spider.

Design of Combined Radial and Axial 4-pole Electromagnetic Bearing (II) - with Coupled Bias Flux - (반경방향-축방향 일체형 4극 전자기 베어링의 설계 (II) - 바이어스 자속 공유형 -)

  • Kim Ha-Yong;Kim Seung-Jong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.12 s.243
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    • pp.1567-1573
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    • 2005
  • This paper introduces a new active magnetic bearing(AMB) that can provide both radial and axial control functions in one bearing unit without axial disk. It has a structure of double four-pole AMB or a four-pole AMB where each core is split into two axially. The cores have two kinds of coil winding; they independently generate fluxes on the planes perpendicular or parallel to the shaft. For the radial control action, it works just like a conventional four-pole AMB. Meanwhile, for the axial control, it uses the Lorentz force generated by the interaction of the bias flux for radial control and the axial control flux. In this paper, the proposed structure, principle, and design process based on magnetic flux analysis are introduced, and its feasibility is experimentally verified by using a simple PD control algorithm with a feedforward loop to compensate the coupled flux effect.