Title:
MAGNETIC BEARING PROTECTION DEVICE AND TURBO MOLECULAR PUMP
Document Type and Number:
Japanese Patent JP3215842
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a magnetic bearing protection device and a turbo molecular pump free to stably control against excessive deflection of a rotor and vibration from outside.
SOLUTION: A magnetic bearing is protected by stopping the magnetic bearing in the case where an electric current value flowing in electromagnets 3A, 3B for radial direction positional control and an electromagnet 5 for axial direction positional control keeps reaching a specified value for a constant period of time. At this time, vibration, etc., of a rotor vane 1 is converged at an early stage as no regulation is provided for the electric current value flowing to the electromagnet 3A for radial direction positional control, etc. Consequently, burden to be given to protective bearings 13, 15 is also reduced.
Inventors:
Miyako Kagotani
Application Number:
JP8537099A
Publication Date:
October 09, 2001
Filing Date:
March 29, 1999
Export Citation:
Assignee:
Seiko Instruments Inc.
International Classes:
F04D19/04; F04D29/04; F04D29/058; F16C32/04; F16C39/06; (IPC1-7): F16C32/04; F04D19/04
Domestic Patent References:
| JP7151146A | ||||
| JP109266A |
Attorney, Agent or Firm:
Masatoshi Shiina