To provide a motor integrated magnetic bearing device constructed in a stably controllable manner even when high load operates on a motor to simplify the construction of a controller and reduce the length of a spindle to be rotated at a high speed.
The motor integrated magnetic bearing device comprises combined rolling bearings 15, 16. An axial gap motor 28 has a motor rotor 28a arranged on both end faces of a thrust plate 13a provided perpendicular to and coaxial with the spindle 13 and a motor stator 28b arranged so as to be opposed to the motor rotor 28a. A sensor 18 is provided for detecting force in the axial direction. In response to the output thereof, an adjuster 38 adjusts the phase of a driving current in the axial gap motor 28. A controller 29 controls the rotating speed of the axial gap motor 28. 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 motor part is set such that the former is greater than the latter.
MAKINO YUSUKE
SUZUKI KENICHI
Shuji Sugimoto