| 摘要 |
Magnets 20 are arranged, through ferromagnetic plates 21, opposedly of the inner peripheral surface of a brake drum 13 made of steel and secured to a rotational shaft 4. When the rotating brake drum 13 crosses magnetic fluxes from the magnets 20, the braking force caused by eddy current is generated in the brake drum 13. An annular body 41 formed of a good conductor such as copper is fastened to at least one end portion, not opposed to the ferromagnetic plate 21, in the inner peripheral surface of the brake drum 13. Annular body formed of a good conductor is connected to inner peripheral portion of the opposite ends of a brake drum to thereby increase a braking force and to prevent the annular body formed of a good conductor from being thermally deteriorated. <IMAGE> |
