| 摘要 |
PURPOSE:To obtain a levitating type conveying apparatus which has small size, light weight and high energy-saving effect by flowing a positive rated current to an electromagnet when a levitating body places the maximum load amount, and flowing a negative rated current in case of no load. CONSTITUTION:An electromagnet 6 and a permanent magnet 7 are disposed at a levitating body side oppositely to the lower surfaces of guide rails 5 which are composed of a magnetic material at least at the lower surface. A block 17 calculates the difference DELTAR between an air gap length Z between the rails 5 from a gap sensor 16 and the electromagnet 6, and an instruction value Z0. A block 21 calculates the value of a current to be flowed to the coil 9 of the electromagnet 6 so that the length Z becomes the value Z0 on the basis of the signal DELTAR, the weight L of an article to be conveyed and the magnetomotive force Hmlm of the magnet 7. |
