| 摘要 |
PROBLEM TO BE SOLVED: To increase braking with a small volume of magnet, and to reduce leakage flux at non-braking time by directing a magnet pole in a circumferential direction, at the same time, by forming the opposing magnetic poles of a magnet being adjacent in the circumferential direction at the same pole, and by arranging a ferromagnetic body opposite to the ferromagnetic plate of a guide cylinder between the magnets being arranged in the circumferential direction. SOLUTION: A number of magnets 6 are supported at even intervals in a circumferential direction for the outer-peripheral surface of a magnet support cylinder 16 consisting of a non-magnetic body, while a magnetic pole faces the circumferential direction and at the same time the opposing magnetic poles of adjacent magnet 6 are the same, and a wedge-shaped ferromagnetic body 15 is arranged between the magnets 6. The ferromagnetic body 15 projects toward the outside of a diameter from the magnet 6, and is allowed to approach an inner-peripheral surface 2b of a damping drum 2. On damping, when the magnet support cylinder 16 is pushed into the damping drum 2, a magnetic circuit (y) is generated between the magnet 6 and the damping drum 2, and damping force based on an eddy current is generated in the damping drum 2. Then, in non-damping, when the magnet support cylinder 16 is pulled to the outside of the damping drum 2, no magnetic field reaches the damping drum 2.
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