| 摘要 |
PURPOSE:To lessen the inertia mass of a driven member greatly by installing a driven member through No.1 gap and No.2 gap, which are to be filled with a magnetic powder and a high lubricative magnetic powder, respectively, when an excitor coil is energized, in such an arrangement as interposed between the driving member and a yoke. CONSTITUTION:Between a driving member 8 and a yoke 30 with excitor coil 38, a driven member is installed equipped with a cylindrical part 24 with small wall thickness, and a No.1 gap 18 is provided between said driving member 8 and cylindrical part 24 while a No.2 gap 27 between this part 24 and the yoke 30. When the excitor coil 38 is supplied with power, No.1 gap shall be filled with No.1 magnetic powder while No.2 gap 27 with No.2 magnetic powder having high lubricating performance. Accordingly, when the excitor coil 38 is energized, a magnetic circuit is formed in such an arrangement that the flux is oriented to penetrate No.1 gap 18, cylindrical part 24 and No.2 gap 27, so that the driven member can be designed with small wall thickness to serve lessening of the intertia mass greatly. |
