Abstract: A roller module includes a roller, a magnetic bearing, a permanent magnet, at least one pair of magnetic coring, and a plurality of gap sensors. The roller has a protrusion and has a cylindrical shape. The protrusion is formed at both outer surfaces of the roller with a stepped portion and has the cylindrical shape. The magnetic bearing is formed at the roller. The permanent magnet is formed at the roller. At least one pair of magnetic coring covers an outer circumference of the protrusion. The gap sensors are formed along an axial direction and a radial direction of the roller.