| 摘要 |
PURPOSE:To make it possible to grind a work with high surface-finishing accuracy by providing an exciting means for electrically controlling magnetic forces of electromagnets, thereby axially oscillating a rotor shaft of a magnetic bearing spindle. CONSTITUTION:When a grinder enters a range of spark-out, a command signal is inputted from a grinder controller 50 to an oscillator 51 of a thrust control unit 47, and an oscillation signal is added to a reference signal of the thrust control unit 47 by the oscillator 51 to be inputted to a comparator 53 as a control signal. On the other hand, an axial position detection signal of a rotor shaft 13 in a magnetic bearing spindle 11 is inputted from a position sensor 36 to the comparator 53 to excite and control of the rotor shaft 13, and axially oscillate the rotor shaft 13. A grinding wheel 41 provided on the end part of the rotor shaft 13 is thus oscillated, and a work surface can be ground with high finishing accuracy by the grinding wheel 41. |
