Effects of Rolling Friction of the Balancing Balls on the Automatic Ball Balancer for Optical Disk Drives

2005 ◽  
Vol 127 (4) ◽  
pp. 845-856 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Cheng-Kuo Sung ◽  
Hui-Chung Leu
Keyword(s):  
Steady State ◽  
Multiple Scales ◽  
Rolling Friction ◽  
Friction Model ◽  
Optical Disk ◽  
Contact Dynamics ◽  
Hertzian Contact ◽  
Disk Drives ◽  
Scaled Model ◽  
Stick Slip

This study is devoted to evaluating the performance of an automatic ball-type balance system (ABB) installed in optical disk drives (ODDs) with consideration of the rolling friction between the balancing balls and the ball-containing race of the ABB. Research has been conducted to study the performance of the ABB by investigating the nonlinear dynamics of the system; however, the model adopted to describe the rolling friction between the balancing balls and their race was a simple stick-slip type, which does not reflect the realistic contact dynamics, leading to an inaccuracy in predicting ABB performance. In this study, a complete dynamic model of the ABB including a detailed rolling friction model for the balls based on Hertzian contact mechanics and hysteresis loss is established. The method of multiple scales is then applied to formulate a scaled model to find all possible steady-state ball positions and analyze stabilities. It is found that possible steady-state residing positions of the ball inside the race are multiple and form continuous ranges. Numerical simulations and experiments are conducted to verify the theoretical findings, especially for the rolling friction model. The obtained results are used to predict the level of residual vibration, with which the guidelines on dimension design and material choices of the ABB are distilled to achieve desired performance.

Effects of Rolling Friction of the Balancing Balls on the Automatic Ball Balancer for Optical Disk Drives

2004 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Chi-Wei Chiu ◽  
Cheng-Kuo Sung ◽  
Hui-Chung Leu
Keyword(s):  
Steady State ◽  
Multiple Scales ◽  
Rolling Friction ◽  
Friction Model ◽  
Optical Disk ◽  
Contact Dynamics ◽  
Disk Drives ◽  
Scaled Model ◽  
Stick Slip ◽  
Balance System

This study is devoted to evaluate the performance of an automatic ball-type balance system (ABB) installed in optical disk drives (ODD) with consideration of the rolling friction between the balancing balls and the ball-containing race of the ABB. Researches have been conducted to study the performance of the ABB by investigating the nonlinear dynamics of the system; however, the rolling friction model adopted was a simple stick-slip type, which does not reflect the true contact dynamics between rolling balls and their races, leading to an inaccuracy in predicting ABB performance. In this study, a complete dynamic model of the ABB including a detailed rolling friction model based on contact mechanics is established. The method of multiple scales is then applied to formulate a scaled model to find all possible steady-state ball positions and analyze stabilities. It is found that possible steady-state residing positions of the ball inside the race are multiple and form continuous ranges. Numerical simulations and experiments are conducted to verify the validness of the theoretical findings. The obtained results are used to predict the level of residual vibration, with which the guidelines on dimension design and material choices of the ABB are distilled to achieve desired performance.

Dynamic Analysis of the Optical Disk Drives Equipped with an Automatic Ball Balancer with Consideration of Torsional Motions

2005 ◽  
Vol 72 (6) ◽  
pp. 826-842 ◽  
Author(s):  
Paul C. P. Chao ◽  
Cheng-Kuo Sung ◽  
Chun-Chieh Wang
Keyword(s):  
Multiple Scales ◽  
Spindle Motor ◽  
Optical Disk ◽  
Torsional Stiffness ◽  
Torsional Motion ◽  
Disk Drives ◽  
Scaled Model ◽  
Supporting Plate ◽  
Steady State Solutions ◽  
Balanced Solution

This study is dedicated to evaluate the performance of an automatic ball-type balancer system (ABS) installed in optical disk drives (ODDs) with consideration of the relative torsional motion between the ODD case and the spindle-disk-ABS-turntable system, noting that the turntable is the supporting plate structure for disk, pickup, and spindle motor inside the ODD. To this end, a complete dynamic model of the ABS considering the torsional motion is established with assuming finite torsional stiffness of the damping washers, which provides suspension of the spindle-disk-ABS-turntable system to the ODD case. Considering the benchmark case of a pair of balancing balls in an ABS, the method of multiple scales is then applied to formulate a scaled model for finding all possible steady-state solutions of ball positions and analyzing corresponding stabilities. The results are used to predict the levels of residual vibration, with which the performance of the ABS can then be reevaluated. Numerical simulations are conducted to verify theoretical results. It is deduced from both analytical and numerical results that the spindle speed of an ODD could be operated above both primary translational and secondary torsional resonances in order to guarantee stabilization of the desired balanced solution for a substantial vibration reduction.

Effects of Nonlinear Damping Washers on the Automatic Ball Balancer for Optical Disk Drives

2005 ◽  
Author(s):  
Cheng-Kuo Sung ◽  
Paul C. P. Chao ◽  
Ben-Cheng Yo
Keyword(s):  
Nonlinear Dynamics ◽  
Steady State ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Dynamic Performance ◽  
Nonlinear Damping ◽  
Disk Drives ◽  
Optical Disc ◽  
Scaled Model ◽  
Jump Phenomena

This study is devoted to explore the effect of nonlinear dynamics of damping washers on the dynamic performance of automatic ball balancer (ABB) system installed in optical disc drives. The ABB is generally used on rotational system to reduce vibration. Researches have been conducted to study the performance of the ABB by investigating the nonlinear dynamics of the system; however, the model adopted often consider the damping washer in a typical ABB suspension system as a linear one, which does not reflect the fact that the practical washers are inevitably exhibit nontrivial nonlinear dynamics at some range of operation, deviating the ABB performance away from the expecteds. In this study, a complete dynamic model of the ABB including a detailed nonlinear model of the damping washers based on experimental data for practical wahers is established. The method of multiple scales is then applied to formulate a scaled model to find all possible steady-state ball positions and analyze stabilities. It is found that with reasonable level of nonlinearity, the balancing balls of the ABB are still reside at the desired positions at steady state, rendering expected vibration reduction; however, jump phenomena also occurs as the spindle operated through natural frequency of the suspension, causing unwanted system vibrations. Numerical simulations and experiments are conducted to verify the theoretical findings. The obtained results are used to predict the level of residual vibration, with which the guidelines on choices of the nonlinear damping washers are distilled to achieve desired performance.

Dynamic Analysis of the Optical Disk Drive System Equipped With an Automatic Ball Balancer With Consideration of Torsional Motion

2003 ◽  
Author(s):  
Chun-Chieh Wang ◽  
Cheng-Kuo Sung ◽  
Paul C. P. Chao
Keyword(s):  
Steady State ◽  
Multiple Scales ◽  
Substantial Reduction ◽  
Disk Drive ◽  
Optical Disk ◽  
Balance System ◽  
Optical Disk Drive ◽  
The Stability ◽  
Steady State Solutions ◽  
Theoretical Results

This study is dedicated to evaluate the stability of an automatic ball-type balance system (ABS) installed in Optical Disk Drives (ODD). There have been researchers devoted to study the performance of ABS by investigating the dynamics of the system, but few consider the motions in torsional direction of ODD foundation. To solve this problem, a mathematical model including the foundation is established. The method of multiple scales is then utilized to find all possible steady-state solutions and perform related stability analysis. The obtained results are used to predict the level of residual vibrations and then the performance of the ABS can be evaluated. Numerical simulations are conducted to verify the theoretical results. It is obtained from both analytical and numerical results that the spindle speed of the motor ought to be operated above primary translational and secondary torsional resonances to stabilize the desired steady-state solutions for a substantial reduction in radial vibration.

Analysis of Friction-Induced Limit Cycling in an Experimental Drill-String System

2004 ◽  
Vol 126 (4) ◽  
pp. 709-720 ◽  
Author(s):  
N. Mihajlovic´ ◽  
A. A. van Veggel ◽  
N. van de Wouw ◽  
H. Nijmeijer
Keyword(s):  
Steady State ◽  
Oil And Gas ◽  
Static Friction ◽  
Friction Model ◽  
Drill String ◽  
Torsional Vibrations ◽  
State Behavior ◽  
Rotary Drilling ◽  
Stick Slip ◽  
Predictive Quality

In this paper, we aim for an improved understanding of the causes for torsional vibrations that appear in rotary drilling systems used for the exploration of oil and gas. For this purpose, an experimental drill-string setup is considered. In that system, torsional vibrations with and without stick-slip are observed in steady state. In order to obtain a predictive model, a discontinuous static friction model is proposed. The steady-state behavior of the drill-string system is analyzed both numerically and experimentally. A comparison of numerical and experimental bifurcation diagrams indicates the predictive quality of the model. Moreover, specific friction model characteristics can be linked to the existence of torsional vibrations with and without stick-slip.

Modeling of Piezo-Actuated Stick-Slip Micro-Drives: An Overview

2012 ◽  
Vol 81 ◽  
pp. 39-48 ◽  
Author(s):  
Ha Xuan Nguyen ◽  
Christoph Edeler ◽  
Sergej Fatikow
Keyword(s):  
Mechanical Model ◽  
Integrated Model ◽  
Friction Model ◽  
Fundamental Importance ◽  
Future Research ◽  
Stick Slip ◽  
Research Activities ◽  
Model Combining ◽  
Friction Models

This paper gives an overview about problems of modeling of piezo-actuated stick-slip micro-drives. It has been found that existing prototypes of such devices have been investigated empirically. There is only few research dealing with the theory behind this kind of drives. By analyzing the current research activities in this field, it is believed that the model of the drive depends strongly on the friction models, but in most cases neglecting any influences of the guilding system.These analyses are of fundamental importance for an integrated model combining friction model and mechanical model offering promising possibilities for future research.

Experimental Investigation of Power Umbilical Damping

2017 ◽  
Author(s):  
Torfinn Ottesen
Keyword(s):  
Steady State ◽  
Energy Input ◽  
State Energy ◽  
Seawater Temperature ◽  
Structural Damping ◽  
Stick Slip ◽  
Slip Regime ◽  
Free Decay ◽  
Vortex Induced Vibrations ◽  
Slip Transition

Ocean currents may cause vortex induced vibrations (VIV) of deep-water umbilicals and cables. Since the VIV response may give significant contributions to the total fatigue damage it is important to know the structural damping for relevant curvature levels. A laboratory test has been performed on a 12.5 m long test specimen to determine the damping for a range of curvature levels that are in the vicinity of the stick-slip transition region. The energy input to maintain steady state oscillations with curvature amplitudes in the range 0.0002–0.001 m−1 was measured. The steady state energy input is consistent with damping ratios obtained using the free decay method. The structural damping depends on construction temperature and curvature and is less for typically low seawater temperature and low curvatures. The transition between the stick- and the slip regime is seen for typical seawater temperature.

scholarly journals An Efficient Contact Model for the Simulation of Cargo Airdrop Extraction Phase

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Leiming Ning ◽  
Jichang Chen ◽  
Mingbo Tong
Keyword(s):  
Degrees Of Freedom ◽  
Friction Model ◽  
Rigid Bodies ◽  
Contact Dynamics ◽  
Moving Frame ◽  
Contact Friction ◽  
Practical Implementation ◽  
Contact Formulation ◽  
Efficient Code ◽  
Extraction Phase

A high-fidelity cargo airdrop simulation requires the accurate modeling of the contact dynamics between an aircraft and its cargo. This paper presents a general and efficient contact-friction model for the simulation of aircraft-cargo coupling dynamics during an airdrop extraction phase. The proposed approach has the same essence as the finite element node-to-segment contact formulation, which leads to a flexible, straightforward, and efficient code implementation. The formulation is developed under an arbitrary moving frame with both aircraft and cargo treated as general six degrees-of-freedom rigid bodies, thus eliminating the restrictions of lateral symmetric assumptions in most existing methods. Moreover, the aircraft-cargo coupling algorithm is discussed in detail, and some practical implementation details are presented. The accuracy and capability of the present method are demonstrated through four numerical examples with increasing complexity and fidelity.

Effect of Material and Geometric Parameters on the Steady-State Belt Stresses and Belt Slip for Flat Belt-Drives

2015 ◽  
Author(s):  
Cagkan Yildiz ◽  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Steady State ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Flexible Multibody Dynamics ◽  
Friction Model ◽  
Rigid Bodies ◽  
Geometric Parameters ◽  
Rubber Matrix ◽  
Axial Stiffness ◽  
Belt Drive

In order to accurately predict the fatigue life and wear life of a belt, the various stresses that the belt is subjected to and the belt slip over the pulleys must be accurately calculated. In this paper, the effect of material and geometric parameters on the steady-state stresses (including normal, tangential and axial stresses), average belt slip for a flat belt, and belt-drive energy efficiency is studied using a high-fidelity flexible multibody dynamics model of the belt-drive. The belt’s rubber matrix is modeled using three-dimensional brick elements and the belt’s reinforcements are modeled using one dimensional truss elements. Friction between the belt and the pulleys is modeled using an asperity-based Coulomb friction model. The pulleys are modeled as cylindrical rigid bodies. The equations of motion are integrated using a time-accurate explicit solution procedure. The material parameters studied are the belt-pulley friction coefficient and the belt axial stiffness and damping. The geometric parameters studied are the belt thickness and the pulleys’ centers distance.

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