d a radial displacement sensor 42 for the electromagnet 41. The electromagnet 41 consists of four pairs of magnetic cores 41b and coils 41a wound around the magnetic cores 41b. The radial displacement sensor 42 consists of four pairs of magnetic cores 42b and coils 42a wound around the magnetic cores 42b. 
The stator column assembly 1 shown in FIG. 6 is fabricated as follows. First, into a cylindrical space within the cylindrical stator column 11 that has been heated at an appropriate temperature, the radial displacement sensor 32 of the first active radial magnetic bearing, a circular spacer member 30e, the electromagnet 31 of the first active radial magnetic bearing, a circular spacer member 30f, the stator coil 21, a circular spacer member 40e, the electromagnet 41 of the second active radial magnetic bearing, a circular spacer member 40f, and the radial displacement sensor 42 of the second active radial magnetic bearing are press-fitted in the order stated, fixing these parts at given positions. After completion of the press fitting, a columnar bushing is inserted therein from the opening 11b and the space is filled with a thermally curable epoxy resin material, coating those parts with the material and simultaneously forming an inner cylinder surface of resin mold inside the cylindrical stator column 11. When the molding work is finished, the inner cylinder surface of mold is subjected to cutting and scraping, to thereby expose the stator magnetic cores 21b, the electromagnet magnetic cores 31b, 41b, and the sensor magnetic cores 32b, 42b. The fabrication of the stator column assembly 1 is completed through, at least, three steps described above. Incidentally, reference symbol 10d denotes a mold portion.
The conventional stator column assembly 1 shown in FIG. 6 has some problems. The first of those problems is awkward fabrication work in constructing the stator column assembly, for the components are arranged in the cylindrical stator column 11 by using the circular spacers and by press-fitting the component