1998 Fiscal Year Final Research Report Summary
Basic Study for Systematized Mechanism of Producing Radial Force and Rotational Torque of Bearingless Motors
| Project/Area Number |
09450108
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
FUKAO Tadashi Professor, Faculty of Engineering, Tokyo Institute of Technology, 工学部, 教授 (10016545)
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| Co-Investigator(Kenkyū-buntansha) |
CHIBA Akira Associate Professor, Faculty of Science and Technology, Science University of To, 理工学部, 助教授 (30207287)
ICHIKAWA Osamu Research Associate, Faculty of Engineering, Tokyo Institute of Technology, 工学部, 助手 (80302941)
TAKAHASHI Kouji Associate Professor, Faculty of Engineering, Tokyo Institute of Technology, 工学部, 助教授 (10179484)
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| Project Period (FY) |
1997 – 1998
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| Keywords | bearingless motor / magnetic bearing / magnetic levitation / radial force / torque / motor constant / inductance / magnetic circuit |
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| Research Abstract |
Bearingless Motors, combined motors with magnetic bearings, are free from maintenance, suitable for high speed and high power applications. Principles of bearingless motors can be applied for many types of motors. In this report, mechanism of producing radial force and rotational torque of bearingless motors are analyzed with test machines of reluctance type, induction type, homo-polar type etc. to systematize all types of bearingless motors. Consequences are as follows :
1. Induction type bearingless motors produce flux with both stator and rotor current. To control rotor positions, it is needed to maintain air gap flux.
2. Radial force of permanent magnet type bearingless motors can be expressed equations same as synchronous reluctance type's equations with equivalent current of permanent magnet instead of motor magnetizing current. Measurement method of motor constants in the equations is proposed.
3. Rotor and stator of homo-polar type bearingless motors are laminated in two units each, so path and distribution of flux are different from other motors. Analysis of torque and radial force show that dc component of motor flux doesn't generate rotational torque.
4. Position control current must be calculated in accordance with variation of motor flux in switched reluctance type bearingless motors. There are some limitation between radial force and rotational torque.
5. Axial gap bearingless motor controls rotor axial position, inclination and rotational torque. Though rotational torque of reluctance motor is limited by inclination torque and axial force, the maximum torque can be increased with axial force from load materials in use of fluid pump.
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