Antti Kärkkäinen Dynamic Simulations of Rotors during Drop on Retainer Bearings Lappeenranta, 2007 91 p. Acta Universitatis Lappeenrantaensis 279 Diss. Lappeenranta University of Technology ISBN 978-952-214-444-7; ISBN 978-952-214-445-4 (PDF) ISSN 1456-4491 The active magnetic bearings have recently been intensively developed because of noncontact support having several advantages compared to c...

The paper has described the different components of a hybrid magnetic bearing model which is used as an integrated platform for teaching and learning. The main purpose is to encourage the students to utilise their knowledge learnt through the lecture to solve a complex engineering problem. The magnetic bearing as an integrated platform provides an environment for innovation, verification of the...

Active magnetic bearings (AMBs) are a mature bearing technology that is being applied to many new turbomachines. They have become the bearing of choice for most new turboexpander applications. They are seen as a key enabling technology for compact, high speed, high power density direct-drive generators and turbomachinery. As more and more units are fielded, it will become important that end-use...

Magnetic bearings are often designed using magnetic circuit theory. When these bearings are built, however, effects not included in the usual circuit theory formulation have a significant influence on bearing performance. Two significant sources of error in the circuit theory approach are the neglect of leakage and fringing effects and the neglect of eddy current effects. This work formulates a...

Inherent in every Active Magnetic Bearing (AMB) are differences between the expected geometric axes and the actual magnetic axes due to a combination of discrepancies, including physical variation from manufacturing tolerances and misalignment from mechanical assembly, fringing and leakage effects, as well as variations in magnetic material properties within a single AMB. A method is presented ...

Abstract: In this paper, the nonlinear dynamical behaviors of an active magnetic bearing-rotor system are investigated using numerical simulation. Firstly, the nonlinear magnetic force is obtained by Taylor series. Secondly, the primary-internal resonance of an AMBRS(active magnetic bearing) -rotor system is studied with the help of LungKutta method. To analyze the motion characters of system, ...

The contactless nature of active magnetic bearings brings about many advantages over the conventional bearing while industrial real-time applications are often limited by the significant complexity of control algorithms. This paper presents the application of an LQ controller to an active magnetic bearing system (AMB). Two control strategies are presented and compared: local and global. In the ...

High-speed and high-power-density drives are attracting much interest in today’s industry, e.g. for applications with mesoscale gas turbine generator systems or turbocompressors for fuel cells. In all high-speed machinery the bearing is a key component. Therefore, this paper presents the analysis of an active magnetic bearing suitable for a permanent magnet machine, being part of a high-speed e...

– This report presents some improvements to the radial stiffness of a magnetic suspension in a new ventricular assist device (VAD) that has been jointly developed by Dante Pazzanese Cardiology Institute (IDPC) and Escola Politecnica of São Paulo University. This VAD has a novel architecture that distinguishes it from other known VADs. In this, the rotor that impels and pressurizes the blood has...

The use of magnetic bearing in industrial applications has increased due to their unique properties. Nowadays efficiency and predictability in handling rotors on magnetic bearings is asked with the same standard as conventional rotors on oil or roller bearings. First of all one must be aware of the special technical properties of magnetic bearing designs. The dynamic behaviour of the rotor comb...