The structure includes cylindrical columnar and tubular bonded magnets. The columnar magnet has at least one pair of N and S poles that are alternately produced in the longitudinal direction. The tubular magnet surrounds the columnar magnet, and has at least one pair of N and S poles that are alternately produced in the longitudinal direction. Poles of the columnar and tubular magnets that are opposed to each other in the direction perpendicular to the axis of the columnar magnet as the propulsion force direction are of opposite magnetic polarity so that magnetic fields are produced in the direction perpendicular to the propulsion force direction. The surface magnetic flux density profile balance can be smoothed by adjusting higher and lower parts of the profiles of the columnar and tubular magnets.