| 摘要 |
A tubular element opposed to an inner peripheral surface of a brake drum of a guide tube is constituted of a weak-magnetic sheet to miniaturize and reduce in weight of apparatus and to enhance a brake performance. A permanent magnet type eddy current reduction apparatus comprising a brake drum 15 coupled to a rotational shaft, a guide tube B having a hollow portion which is rectangular in section one end of which is secured to a vehicle body side while the other end is projected into the brake drum 15, and a magnet supporting tube 9 axially movably supported on the hollow portion 20 of the guide tube B and having many magnets 8 coupled to an outer peripheral surface at certain intervals. A tubular element 14 opposed to an inner peripheral surface of the brake drum 15 of the guide tube B is constituted of a weak-magnetic sheet, and a permeability of a portion 14b covering a space 26 between the magnets of the tubular element 14 is the same as that of a portion 14a covering an outer surface of the magnet 8 or smaller than that of the portion 14a. |
