Active Vibration Control of a Flexible Rotor Using a Magnetic Bearing
Title | Active Vibration Control of a Flexible Rotor Using a Magnetic Bearing PDF eBook |
Author | David Rupert Laidig |
Publisher | |
Pages | 340 |
Release | 1985 |
Genre | Magnetic suspension |
ISBN |
Active Vibration Control of Flexible Rotors Using Magnetic Bearings
Title | Active Vibration Control of Flexible Rotors Using Magnetic Bearings PDF eBook |
Author | Randall Allen Bartlett |
Publisher | |
Pages | 342 |
Release | 1984 |
Genre | Rotors |
ISBN |
Vibration and Control of Flexible Rotor Supported by Magnetic Bearings
Title | Vibration and Control of Flexible Rotor Supported by Magnetic Bearings PDF eBook |
Author | National Aeronautics and Space Adm Nasa |
Publisher | Independently Published |
Pages | 26 |
Release | 2018-10-18 |
Genre | Science |
ISBN | 9781728915302 |
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
Vibration Control in Turbomachinery Using Active Magnetic Journal Bearings
Title | Vibration Control in Turbomachinery Using Active Magnetic Journal Bearings PDF eBook |
Author | National Aeronautics and Space Administration (NASA) |
Publisher | Createspace Independent Publishing Platform |
Pages | 228 |
Release | 2018-08-04 |
Genre | |
ISBN | 9781724707680 |
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...
Active Vibration Control Strategies for a Flexible Rotor-bearing System
Title | Active Vibration Control Strategies for a Flexible Rotor-bearing System PDF eBook |
Author | R. Tasaltin |
Publisher | |
Pages | |
Release | 1992 |
Genre | |
ISBN |
Active Vibration Control of a Rotor Bearing System by Means of an Active Journal Bearing with Flexible Sleeves
Title | Active Vibration Control of a Rotor Bearing System by Means of an Active Journal Bearing with Flexible Sleeves PDF eBook |
Author | Fei Chen |
Publisher | |
Pages | 244 |
Release | 2008 |
Genre | Journal bearings |
ISBN |
Magnetic Bearings
Title | Magnetic Bearings PDF eBook |
Author | G. Schweitzer |
Publisher | Springer Science & Business Media |
Pages | 387 |
Release | 2012-12-06 |
Genre | Technology & Engineering |
ISBN | 3642517242 |
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.