Spindle apparatus
AssigneeSeiko Seiki Kabushiki Kaisha
InventorShigenori Ando
Life of this patent
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Abstract
A spindle apparatus comprises a rotary body and at least a pair of magnetic bearings for levitating the rotary body by magnetic forces. A combined motor and magnetic bearing device is disposed between the magnetic bearings for imparting a rotational torque to the rotary body and for positionally controlling the rotary body by magnetic forces. A control circuit outputs and exciting current to the magnetic bearings and the combined motor and magnetic bearing device and for makes an adjustment of the exciting current of the magnetic bearing and the combined motor and magnetic bearing device to hold the rotary body afloat in a predetermined position.
Claims16
A spindle apparatus comprising:
- a rotary shaft;
- magnetic bearing means for floatingly holding the rotary shaft by magnetic forces;
- and
- a combined motor and magnetic bearing device for imparting a rotational torque to the rotary shaft and for positionally controlling the rotary shaft by magnetic forces.
A spindle apparatus comprising:
- a rotary shaft having first and second ends;
- a first magnetic bearing for floatingly holding the first end of the rotary shaft by magnetic forces;
- a second magnetic bearing for floatingly holding the second end of the rotary shaft by magnetic forces;
- and
- a combined motor and magnetic bearing device interposed between the first magnetic bearing and the second magnetic bearing for imparting a rotational torque to the rotary shaft and for positionally controlling the rotary shaft by the magnetic forces.
A spindle apparatus, comprising:
- a rotary body;
- at least a pair of magnetic bearings for levitating the rotary body by magnetic forces;
- a combined motor and magnetic bearing device for rotating the rotary body and for controlling the position of the rotary body by magnetic forces;
- and
- a control circuit for outputting an exciting current to the magnetic bearings and the combined motor and magnetic bearing device and for making an adjustment of the exciting current of the magnetic bearing and the combined motor and magnetic bearing device to control the position of the rotary body to hold the rotary body afloat in a predetermined position.
Dependencies are inferred from the claim text.