| 摘要 |
PROBLEM TO BE SOLVED: To concentrate flux applied to a brake drum from a magnet in a medium revolving speed region of the brake drum to increase a flux density and increase an eddy current generated in the brake drum to increase a braking force. SOLUTION: A guide cylinder 10, which is made of nonmagnetic material and has an inside hollow part with a rectangular cross section is provided in a brake drum 7 connected to a rotary shaft 1. A number of ferromagnetic plates 15 are attached to an outer cylinder part 10a of the guide plate 10 in the circumferential direction with same intervals. Magnets 24 are connected to the outer circumferential surface of a magnet supporting cylinder 14, which is supported rotatably in the inside hollow part of the guide cylinder 10, so as to have one magnet 24 correspond to each ferromagnetic plate 15 individually and to have the polarities for ferromagnetic plates 15 changed alternately in the circumferential direction. The inclinations are provided from the center parts of front surfaces 15a of the ferromagnetic plates 15 toward the rear side of the rotating direction of the brake drum 7 and from the center parts of the rear surfaces 15b of the ferromagnetic plates 15 toward the front side of the rotating direction of the brake drum 7, to make the area of an outer surface 50a smaller than the area of an inner surface 50b. |
