Table of Contents
ISRN Mechanical Engineering
Volume 2011, Article ID 896463, 4 pages
http://dx.doi.org/10.5402/2011/896463
Research Article

Applications of Permanent Maglev Bearing in Heart Pumps and Turbine Machine

1Institute of Biomedical Engineering, Jiangsu University, Zhenjiang 212013, China
2School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China

Received 16 January 2011; Accepted 26 February 2011

Academic Editor: D. Kalempa

Copyright © 2011 Kun-Xi Qian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Earnshaw's theorem (1839) stated that no stationary object made of magnets in a fixed configuration can be held in stable equilibrium by any combination of static magnetic or gravitational forces. What will happen by a moving body like a rotating passive magnetic levitator? Nobody has given an answer until now. The author applied a self-made passive magnetic bearing to radial pump and turbine machine and found that if the rotating speed could be higher than a critical value, 3250 rpm for a pump and 1800 rpm for a turbine, the rotors would be disaffiliated from stators and keep the rotation stable. It seems that the fast rotating levitator has a so-called “Gyroeffect” which makes the passive maglev rotator stable. These results have extended Earnshaw's theorem from static to dynamic equilibrium. In static state or by a speed lower than critical value, the passive maglev rotator cannot keep rotation stable; if the rotating speed is higher than critical speed, the passive magnetic levitator will have Gyroeffect and thereby stabilize its rotation.