| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor integrated magnetic bearing device constructed with combined rolling bearings in a stably controllable manner even when high load operates on a motor, to simplify the construction of a controller. SOLUTION: An electromagnet 17 as part of a magnetic bearing is mounted on a spindle housing 14 so as to be opposed in no contact to a flange-shaped thrust plate 13a of a ferromagnetic body provided in a spindle 13. A motor rotor 28a is fitted to the spindle 13 common with the thrust plate 13a and a motor stator 28b is arranged so as to be opposed to the motor rotor 28a for rotating the spindle 13 with Lorentz force operating therebetween, In response to the output of a sensor 18 which detects force in the axial direction, the electromagnet 17 is controlled. A relationship between a rigidity value for a combined spring formed by rolling bearings 15, 16 and their supporting system and a negative rigidity value for a combined spring formed by the electromagnet 17 and the motor 28 is set such that the former is greater than the latter. COPYRIGHT: (C)2007,JPO&INPIT
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