| 摘要 |
PURPOSE:To enhance abrasion resistance and magnetic permeability, by forming a fulcrum by contacting an armature and a yoke, and providing an impregnated body impregnated with a magnetic fluid in the vicinity of said fulcrum. CONSTITUTION:A step part 15 is formed to the bank part 3 of a yoke 2 and holds a ring shaped impregnated body 16 impregnated with a magnetic fluid comprising an oil medium having a magnetic powder dispersed therein. The magnetic fluid of the impregnated body 16 gathers the contact part (fulcrum 6) of the bank part 3 of the yoke 2 and an armature 7 and the abrasion resistance of the part of the fulcrum 6 is enhanced while the armature 7 is directly contacted with the yoke 2 to enhance magnetic permeability and large attraction force can be obtained by small magnetomotive force. |
