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Vibration Characterization Of An Active Magnetic Bearing Supported Rotor
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Book Synopsis Vibration Characterization of an Active Magnetic Bearing Supported Rotor by : Jaco Bean
Download or read book Vibration Characterization of an Active Magnetic Bearing Supported Rotor written by Jaco Bean and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibration characterization -- Active magnetic bearings -- Natural frequencies -- Rotor dynamics.
Book Synopsis Magnetic Bearings by : Gerhard Schweitzer
Download or read book Magnetic Bearings written by Gerhard Schweitzer and published by Springer Science & Business Media. This book was released on 2009-06-10 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiling the expertise of nine pioneers of the field, Magnetic Bearings - Theory, Design, and Application to Rotating Machinery offers an encyclopedic study of this rapidly emerging field with a balanced blend of commercial and academic perspectives. Every element of the technology is examined in detail, beginning at the component level and proceeding through a thorough exposition of the design and performance of these systems. The book is organized in a logical fashion, starting with an overview of the technology and a survey of the range of applications. A background chapter then explains the central concepts of active magnetic bearings while avoiding a morass of technical details. From here, the reader continues to a meticulous, state-of-the-art exposition of the component technologies and the manner in which they are assembled to form the AMB/rotor system. These system models and performance objectives are then tied together through extensive discussions of control methods for both rigid and flexible rotors, including consideration of the problem of system dynamics identification. Supporting this, the issues of system reliability and fault management are discussed from several useful and complementary perspectives. At the end of the book, numerous special concepts and systems, including micro-scale bearings, self-bearing motors, and self-sensing bearings, are put forth as promising directions for new research and development. Newcomers to the field will find the material highly accessible while veteran practitioners will be impressed by the level of technical detail that emerges from a combination of sophisticated analysis and insights gleaned from many collective years of practical experience. An exhaustive, self-contained text on active magnetic bearing technology, this book should be a core reference for anyone seeking to understand or develop systems using magnetic bearings.
Book Synopsis Active Vibration Control of Flexible Rotors Using Magnetic Bearings by : Randall Allen Bartlett
Download or read book Active Vibration Control of Flexible Rotors Using Magnetic Bearings written by Randall Allen Bartlett and published by . This book was released on 1984 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Magnetic Bearings by : G. Schweitzer
Download or read book Magnetic Bearings written by G. Schweitzer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Bearings are bearings where the suspension forces are generated magnetically without any contact. The advantages to modern machinery are obvious: no mechanical wear, no lubrication, potential for high rotor speed, accuracy, and high dynamic performance, new constructional solutions to a classical problem in machine dynamics. The realization of such bearings is in rapid progress. Examples for application areas are turbomachinery, centrifuges, vacuum techniques, machine tool spindles, chemical industry, medical devices, robotics, high speed drives, spacecraft equipment, con tactless actuators, vibration isolation. The Symposium is demonstrating the current state of the art in this developing field of mechatronics, showing actual research efforts, reporting on applications in the various areas, and discussing open questions. The main purpose of the Symposium has been to establish a common information basis for people working on magnetic bearings. It will point to promising areas, and it will help to facilitate decisions on research and development projects, and on investments for applications.
Book Synopsis Nonlinear Vibration Control and Limit-cycle Analysis of Rotor/autobalancer Systems Equipped with Hydrodynamic and Active Magnetic Bearing Supports by : Daeyi Jung
Download or read book Nonlinear Vibration Control and Limit-cycle Analysis of Rotor/autobalancer Systems Equipped with Hydrodynamic and Active Magnetic Bearing Supports written by Daeyi Jung and published by . This book was released on 2012 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, there has been much interest in the use of automatic balancing devices (ABDs) in rotating machinery. Autobalancers consists of several freely moving eccentric balancing masses mounted on the rotor, which, at certain operating speeds, act to cancel rotor imbalance. This "automatic balancing" phenomena occurs as a result of nonlinear dynamic interactions between the balancer and rotor wherein the balancer masses naturally synchronize with the rotor with appropriate phase to cancel the imbalance. However, due to inherent nonlinearity of the autobalancer, the potential for other undesirable non-synchronous limit-cycle behavior exists. In such situations, the balancer masses do not reach their desired synchronous balanced positions resulting in increased rotor vibration. By recognizing this issues, this research explores this non-synchronous behavior for rotor-shaft system in the augmented with auto-balancer device(ABD) supported by various types of bearing and suggests methods to prevent this undesirable condition by searching for either desirable operating condition to avoid it or suppress it using active actuation. Specifically, an approximated harmonic solution for the limit-cycle is obtained and the limit-cycle stability is assessed via a perturbation and Floquet analysis and the coexistence of the stable balanced synchronous condition and undesired non-synchronous limit-cycle are studied. It is found that for certain combinations of bearing parameters and operating speeds, the non-synchronous limit-cycle can be made unstable thus guaranteeing global asymptotic stability of the synchronous balanced condition and the inherent nonlinear characteristic of the driving frequency induced by ball mass running on ABD track under limit cycle condition is revealed here. Finally the analysis is validated through numerical time and frequency domain simulation. The findings in this study yield important insights for researchers wishing to utilize automatic balancing devices in shaft/eccentric rotor system with various types of bearing. Additionally, a new adaptive active control algorithm for the rotor/bearing/ABD system supported by active magnetic bearing(AMB) is derived based on the Lyapunov approach which guarantees global asymptotic stability of the synchronous balanced condition. This approach enables the controller to cope with both the system nonlinearity introduced by the passive ABD and with the rotor imbalance uncertainty. Here, the controllability of system is established through an accessible distribution Lie bracket operational analysis. The simulation results demonstrate the advantages of the hybrid ABD/AMB. In particular, it is shown that the balanced equilibrium can be made globally attractive under the action of the adaptive bearing control law, and that the steady-state power levels are significantly reduced via the addition of the ABD. These findings are relevant to limited power applications such as in satellite reaction wheels or flywheel energy storage batteries.
Book Synopsis Active Magnetic Bearings by : Gerhard Schweitzer
Download or read book Active Magnetic Bearings written by Gerhard Schweitzer and published by . This book was released on 1994 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Magnetic Bearings by : Gerhard Schweitzer
Download or read book Magnetic Bearings written by Gerhard Schweitzer and published by Springer. This book was released on 2009-06-05 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiling the expertise of nine pioneers of the field, Magnetic Bearings - Theory, Design, and Application to Rotating Machinery offers an encyclopedic study of this rapidly emerging field with a balanced blend of commercial and academic perspectives. Every element of the technology is examined in detail, beginning at the component level and proceeding through a thorough exposition of the design and performance of these systems. The book is organized in a logical fashion, starting with an overview of the technology and a survey of the range of applications. A background chapter then explains the central concepts of active magnetic bearings while avoiding a morass of technical details. From here, the reader continues to a meticulous, state-of-the-art exposition of the component technologies and the manner in which they are assembled to form the AMB/rotor system. These system models and performance objectives are then tied together through extensive discussions of control methods for both rigid and flexible rotors, including consideration of the problem of system dynamics identification. Supporting this, the issues of system reliability and fault management are discussed from several useful and complementary perspectives. At the end of the book, numerous special concepts and systems, including micro-scale bearings, self-bearing motors, and self-sensing bearings, are put forth as promising directions for new research and development. Newcomers to the field will find the material highly accessible while veteran practitioners will be impressed by the level of technical detail that emerges from a combination of sophisticated analysis and insights gleaned from many collective years of practical experience. An exhaustive, self-contained text on active magnetic bearing technology, this book should be a core reference for anyone seeking to understand or develop systems using magnetic bearings.
Book Synopsis Proceedings of the 10th International Conference on Rotor Dynamics – IFToMM by : Katia Lucchesi Cavalca
Download or read book Proceedings of the 10th International Conference on Rotor Dynamics – IFToMM written by Katia Lucchesi Cavalca and published by Springer. This book was released on 2018-08-20 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: IFToMM conferences have a history of success due to the various advances achieved in the field of rotor dynamics over the past three decades. These meetings have since become a leading global event, bringing together specialists from industry and academia to promote the exchange of knowledge, ideas, and information on the latest developments in the dynamics of rotating machinery. The scope of the conference is broad, including e.g. active components and vibration control, balancing, bearings, condition monitoring, dynamic analysis and stability, wind turbines and generators, electromechanical interactions in rotor dynamics and turbochargers. The proceedings are divided into four volumes. This first volume covers the following main topics: Active Components and Vibration Control; Balancing; Bearings: Fluid Film Bearings, Magnetic Bearings, Rolling Bearings and Seals; and Blades, Bladed Systems and Impellers.
Author :National Aeronautics and Space Adm Nasa Publisher :Independently Published ISBN 13 :9781728915302 Total Pages :26 pages Book Rating :4.9/5 (153 download)
Book Synopsis Vibration and Control of Flexible Rotor Supported by Magnetic Bearings by : National Aeronautics and Space Adm Nasa
Download or read book Vibration and Control of Flexible Rotor Supported by Magnetic Bearings written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-18 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active vibration control of flexible rotors supported by magnetic bearings is discussed. Using a finite-element method for a mathematical model of the flexible rotor, the eigenvalue problem is formulated taking into account the interaction between a mechanical system of the flexible rotor and an electrical system of the magnetic bearings and the controller. However, for the sake of simplicity, gyroscopic effects are disregarded. It is possible to adapt this formulation to a general flexible rotor-magnetic bearing system. Controllability with and without collocation sensors and actuators located at the same distance along the rotor axis is discussed for the higher order flexible modes of the test rig. In conclusion, it is proposed that it is necessary to add new active control loops for the higher flexible modes even in the case of collocation. Then it is possible to stabilize for the case of uncollocation by means of this method. Nonami, Kenzou Glenn Research Center RTOP 505-63-1B
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781724707680 Total Pages :228 pages Book Rating :4.7/5 (76 download)
Book Synopsis Vibration Control in Turbomachinery Using Active Magnetic Journal Bearings by : National Aeronautics and Space Administration (NASA)
Download or read book Vibration Control in Turbomachinery Using Active Magnetic Journal Bearings written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-04 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effective use of active magnetic bearings for vibration control in turbomachinery depends on an understanding of the forces available from a magnetic bearing actuator. The purpose of this project was to characterize the forces as functions shaft position. Both numerical and experimental studies were done to determine the characteristics of the forces exerted on a stationary shaft by a magnetic bearing actuator. The numerical studies were based on finite element computations and included both linear and nonlinear magnetization functions. Measurements of the force versus position of a nonrotating shaft were made using two separate measurement rigs, one based on strain gage measurement of forces, the other based on deflections of a calibrated beam. The general trends of the measured principal forces agree with the predictions of the theory while the magnitudes of forces are somewhat smaller than those predicted. Other aspects of theory are not confirmed by the measurements. The measured forces in the normal direction are larger than those predicted by theory when the rotor has a normal eccentricity. Over the ranges of position examined, the data indicate an approximately linear relationship between the normal eccentricity of the shaft and the ratio of normal to principal force. The constant of proportionality seems to be larger at lower currents, but for all cases examined its value is between 0.14 and 0.17. The nonlinear theory predicts the existence of normal forces, but has not predicted such a large constant of proportionality for the ratio. The type of coupling illustrated by these measurements would not tend to cause whirl, because the coupling coefficients have the same sign, unlike the case of a fluid film bearing, where the normal stiffness coefficients often have opposite signs. They might, however, tend to cause other self-excited behavior. This possibility must be considered when designing magnetic bearings for flexible rotor applications, such as gas t...
Book Synopsis Vibration Analysis of Rotors by : Chong-Won Lee
Download or read book Vibration Analysis of Rotors written by Chong-Won Lee and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is intended for use as an advanced course in either rotordynamics or vibration at the graduate level. This text has mostly grown out of the research work in my laboratory and the lectures given to graduate students in the Mechanical Engineering Department, KAIST. The text contains a variety of topics not normally found in rotordynamics or vibration textbooks. The text emphasizes the analytical aspects and is thus quite different from conventional rotordynamics texts; potential readers are expected to have a firm background in elementary rotordynamics and vibration. In most previously published rotordynamics texts, the behavior of simple rotors has been of a primary concern, while more realistic, multi-degree-f-freedom or continuous systems are seldom treated in a rigorous way, mostly due to the difficulty of a mathematical treatment of such complicated systems. When one wanted to gain a deep insight into dynamic phenomena of complicated rotor systems, one has, in the past, either had to rely on computational techniques, such as the transfer matrix and finite element methods, or cautiously to extend ideas learned from simple rotors whose analytical solutions are readily available. The former methods are limited in the interpretation of results, since the calculations relate only to the simulated case, not to more general system behavior. Ideas learned from simple rotors can, fortunately, often be extended to many practical rotor systems, but there is of course no guarantee of their validity.
Book Synopsis Identification and Control of Flexible Structures Supported on Active Magnetic Bearings by :
Download or read book Identification and Control of Flexible Structures Supported on Active Magnetic Bearings written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis is the development and demonstration of adaptive control algorithms for Active Magnetic Bearings AMBs) that account for uncertainties associated with structural vibration modes. A flexible rotor AMB test rig is designed and modeled using Finite Element Analysis (FEA). The flexible modes and equations of motion are obtained using modal analysis techniques. Typically, such analyses accurately predict the low frequency modes, but accuracy at higher frequencies is greatly reduced. Adaptive control algorithms that account for parametric uncertainties and unmodeled dynamics are developed to levitate and control the flexible rotor. Model parameters for the system are identified using recursive least squares, and used to update a self-tuning pole-placement controller. This self-tuning approach dramatically improves the performance and robustness of the magnetic levitation system, as demonstrated through simulations and experimental demonstrations. The flexible rotor AMB test rig is fabricated to experimentally validate the identification and control algorithms. Results clearly demonstrate the performance and limitations of the adaptive control design.
Download or read book Rotor Systems written by Rajiv Tiwari and published by CRC Press. This book was released on 2017-11-22 with total page 1225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to give a basic understanding of rotor dynamics phenomena with the help of simple rotor models and subsequently, the modern analysis methods for real life rotor systems. This background will be helpful in the identification of rotor-bearing system parameters and its use in futuristic model-based condition monitoring and, fault diagnostics and prognostics. The book starts with introductory material for finite element methods and moves to linear and non-linear vibrations, continuous systems, vibration measurement techniques, signal processing and error analysis, general identification techniques in engineering systems, and MATLAB analysis of simple rotors. Key Features: • Covers both transfer matrix methods (TMM) and finite element methods (FEM) • Discusses transverse and torsional vibrations • Includes worked examples with simplicity of mathematical background and a modern numerical method approach • Explores the concepts of instability analysis and dynamic balancing • Provides a basic understanding of rotor dynamics phenomena with the help of simple rotor models including modern analysis methods for real life rotor systems.
Book Synopsis Vibrations of Rotating Machinery by : Osami Matsushita
Download or read book Vibrations of Rotating Machinery written by Osami Matsushita and published by Springer. This book was released on 2017-05-22 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book opens with an explanation of the vibrations of a single degree-of-freedom (dof) system for all beginners. Subsequently, vibration analysis of multi-dof systems is explained by modal analysis. Mode synthesis modeling is then introduced for system reduction, which aids understanding in a simplified manner of how complicated rotors behave. Rotor balancing techniques are offered for rigid and flexible rotors through several examples. Consideration of gyroscopic influences on the rotordynamics is then provided and vibration evaluation of a rotor-bearing system is emphasized in terms of forward and backward whirl rotor motions through eigenvalue (natural frequency and damping ratio) analysis. In addition to these rotordynamics concerning rotating shaft vibration measured in a stationary reference frame, blade vibrations are analyzed with Coriolis forces expressed in a rotating reference frame. Other phenomena that may be assessed in stationary and rotating reference frames include stability characteristics due to rotor internal damping and instabilities due to asymmetric shaft stiffness and thermal unbalance behavior.
Book Synopsis Vibrations of Rotating Machinery by : Osami Matsushita
Download or read book Vibrations of Rotating Machinery written by Osami Matsushita and published by Springer. This book was released on 2019-06-04 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the previous volume “Vibrations of Rotating Machinery - Volume 1. Basic Rotordynamics: Introduction to Practical Vibration Analysis,” this book is intended for all practical designers and maintenance experts who are responsible for the reliable manufacturing and operation of rotating machinery. It opens with the dynamics of oil film bearings and their influences on unbalance, vibration resonance and the stability of rotor whirl motion. Subsequently, the book introduces readers to vibration diagnosis techniques for traditional ball bearings and active vibration control from magnetic bearings. Case studies on vibration problems and troubleshooting in industrial turbo machines are then presented and explained, showing rotor designers how to eliminate instability and modify resonance characteristics. Torsional vibration and other coupled vibration phenomena are discussed, and vibration measurement techniques and related signal processing procedures for vibration diagnosis are provided. Our latest three topics are included, covering: (a) the importance of the modeling order reduction (MOR) technique; (b) the approximate evaluation for oil-wheel/whip instability; and (c) a systematic method for shafting-blading coupled vibration analyses. In closing, a 100-question trial test is supplied as an example of the certification of vibration experts based on the ISO standard.
Book Synopsis Proceedings of the 10th International Conference on Rotor Dynamics – IFToMM by : Katia Lucchesi Cavalca
Download or read book Proceedings of the 10th International Conference on Rotor Dynamics – IFToMM written by Katia Lucchesi Cavalca and published by Springer. This book was released on 2018-08-18 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: IFToMM conferences have a history of success due to the various advances achieved in the field of rotor dynamics over the past three decades. These meetings have since become a leading global event, bringing together specialists from industry and academia to promote the exchange of knowledge, ideas, and information on the latest developments in the dynamics of rotating machinery. The scope of the conference is broad, including e.g. active components and vibration control, balancing, bearings, condition monitoring, dynamic analysis and stability, wind turbines and generators, electromechanical interactions in rotor dynamics and turbochargers. The proceedings are divided into four volumes. This third volume covers the following main topics: dynamic analysis and stability; electromechanical interactions in rotordynamics; nonlinear phenomena in rotordynamics; rotordynamics of micro, nano and cryogenic machines; and fluid structure interactions in rotordynamics.
Book Synopsis Room Temperature Characterization of a Magnetic Bearing for Turbomachinery by :
Download or read book Room Temperature Characterization of a Magnetic Bearing for Turbomachinery written by and published by . This book was released on 2002 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open loop, experimental force and power measurements of a three-axis, radial, heteropolar magnetic bearing at room temperature for rotor speeds up to 20,000 RPM are presented in this paper. The bearing, NASA Glenn Research Center's and Texas A & M's third generation high temperature magnetic bearing, was designed to operate in a 1000 deg. F (540 deg. C) environment and was primarily optimized for maximum load capacity. The experimentally measured force produced by one C-core of this bearing was 630 lb. (2.8 kN) at 16 A, while a load of 650 lbs (2.89 kN) was predicted at 16 A using 1D circuit analysis. The maximum predicted radial load for one of the three axes is 1,440 lbs (6.41 kN) at room temperature. The maximum measured load of an axis was 1050 lbs. (4.73 kN). Results of test under rotating conditions showed that rotor speed has a negligible effect on the bearing's load capacity. A single C-core required approximately 70 W of power to generate 300 lb (1.34 kN) of magnetic force. The room temperature data presented was measured after three thermal cycles up to 1000 deg. F (540 deg. C), totaling six hours at elevated temperatures.
