DocumentCode :
856244
Title :
Characteristics of a permanent magnet type bearingless motor
Author :
Oshima, Masahide ; Miyazawa, Satoru ; Deido, Tazumi ; Chiba, Akira ; Nakamura, Fukuzo ; Fukao, Tadashi
Author_Institution :
Dept. of Electron. Eng., Sci. Univ. of Tokyo, Japan
Volume :
32
Issue :
2
fYear :
1996
Firstpage :
363
Lastpage :
370
Abstract :
Super high-speed and high-power electric machines are required for turbomolecular pumps and spindle drives. High rotational speed and high power drives can be achieved with bearingless motors. In this paper, a bearingless motor with the principles of permanent magnet type synchronous motors is proposed. High power factor and high efficiency can be expected in permanent magnet type bearingless motors. The proposed bearingless motor is a 4 pole permanent magnet synchronous motor, in which additional 2-pole windings are wound together with 4-pole motor windings in stator slots. With currents of 2-pole windings, radial magnetic forces are produced to support a rotor shaft. Principles of radial force production of surface-mounted permanent magnet bearingless motors are analyzed mathematically. It was found that radial forces are efficiently produced by employing thin permanent magnets on the surface of rotor iron core. A test machine was built in order to measure inductance functions as well as relationships between voltages and currents
Keywords :
machine testing; machine theory; permanent magnet motors; rotors; stators; synchronous motors; bearingless PM synchronous motors; efficiency; machine characteristics; mathematical modelling; power factor; radial force production; radial magnetic forces; rotor iron core; rotor shaft; spindle drives; stator slots; surface-mounted permanent magnets; testing; turbomolecular pumps; windings; Electric machines; Magnetic forces; Permanent magnet motors; Pumps; Reactive power; Rotors; Shafts; Stator windings; Synchronous motors; Wounds;
fLanguage :
English
Journal_Title :
Industry Applications, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-9994
Type :
jour
DOI :
10.1109/28.491485
Filename :
491485
Link To Document :
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