A rotor includes four magnetic poles provided in a rotational direction at
intervals of 90 degrees. A stator includes a winding group for rotation
and a winding group for levitation. Each of the winding groups has
concentrated windings spaced at intervals of 30 degrees in a rotational
direction to provide induction conductive winding sections at twelve
locations. Each two of the induction conductive winding sections spaced at
an interval of 90 degrees among the twelve induction conductive winding
sections are connected to form one winding set such that six winding sets
are formed in total in each of the winding groups. Current for rotation
and current for levitation are conducted through the six winding sets in
the windings for rotation and levitation to perform rotation and
levitation controls of the rotor.