| 摘要 |
PROBLEM TO BE SOLVED: To increase a thrusting force while avoiding a large-sized formation of an active type vibration-proof device comprising a housing fixed to a vibration-proof object; a movable shaft enabled to be displaced in an axial direction and resiliently supported at the housing; a yoke having an umbrella-shaped part coaxially and cooperatively arranged at the movable shaft and a cylindrical part coaxially and cooperatively arranged at an outer periphery of the umbrella-shaped part; an annular coil fixed to the housing while being arranged between the movable shaft and the cylindrical part; and permanent magnets arranged at the yoke.SOLUTION: A yoke 9 has permanent magnets in which the first permanent magnets 11 are constituted in a smaller diameter annular form than that of a coil 10 and arranged inside the coil 10 in a radial direction and the second permanent magnets 12 are arranged outside in a radial direction of the coil 10 with their parts being faced against the inner peripheral surface of a cylindrical part 34 constituted in a larger diameter annular form than that of the coil 10.SELECTED DRAWING: Figure 1 |
