DocumentCode :
1666382
Title :
Gyro-Effect and Earnshaw´s Theorem: Stable and Unstable Equilibrium for Rotary and Stationary Permanent Magnetic Levitators
Author :
Qian, K.X. ; Xu, H.X.
Author_Institution :
Inst. BME, Jiang-su Univ., Zhenjiang
fYear :
2008
Firstpage :
1323
Lastpage :
1325
Abstract :
Eamshsm\´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 happens 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, 3250rpm by a pump and 1800rpm by 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 "Gyro-effect" which makes the passive maglev rotator stable. These results have extended Earnshaw\´s theorem from static to dynamic equilibrium: In stationary state or by a speed lower than critical value, the permanent maglev rotator cannot keep rotation stable; if the rotating speed is higher than critical speed, the permanent maglev rotator will have Gyro-effect which stabilizes unstable levitator.
Keywords :
gyromagnetic effect; magnetic bearings; magnetic levitation; mechanical stability; permanent magnets; pumps; rotors; stators; turbomachinery; Earnshaw´s theorem; gyro-effect; passive maglev rotator; radial pump; rotary permanent magnetic levitators; rotating speed; rotors; self-made passive magnetic bearing; stable equilibrium state; stationary permanent magnetic levitators; stators; turbine machine; unstable equilibrium state; Dynamic equilibrium; Engine cylinders; Magnetic levitation; Magnetic separation; Magnets; Pumps; Rotors; Stability; Stators; Turbines;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Bioinformatics and Biomedical Engineering, 2008. ICBBE 2008. The 2nd International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1747-6
Electronic_ISBN :
978-1-4244-1748-3
Type :
conf
DOI :
10.1109/ICBBE.2008.659
Filename :
4535539
Link To Document :
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