| 摘要 |
<p>A plurality of stators (16) of a linear induction motor are arranged at predetermined intervals, and guide rails (12a, 12b) are mounted on an upper portion of a track frame (11) having a U-shaped section. A levitated object (15) is magnetically levitated below the track frame (11) so as to freely travel along the guide rails (12a, 12b). Magnetic support units (31a, 31b, 31c, 31d) having electromagnets (55) for obtaining a levitating force, optical gap sensors (34a, 34b, 34c, 34d) for detecting gap lengths between the support units (31a SIMILAR 31d) and the guide rails (12a, 12b), i.e., deviations in a levitating direction, and optical gap sensors (46a, 46b, 46c, 46d) for detecting deviations in a guiding direction perpendicular to a traveling direction of the levitated (15) object are respectively arranged on the four corners of the upper surface of the levitated object (15). The length of each magnetic support unit (31a SIMILAR 31d) is larger than the width of each guide rail (12a, 12b). Each magnetic support unit (15) is disposed such that the inner ends of the unit (15) and the guide rail (12a, 12b) are aligned, and the outer end of the unit (15) extends outward from that of the guide rail (12a, 12b). A deviation between an output from each optical gap sensor (34a SIMILAR 34d, 46a SIMILAR 46d) and a corresponding reference value is fed back to a corresponding magnetic support unit (15), thereby controlling each electromagnet (55).</p> |
