| 摘要 |
PURPOSE:To enable to vary a friction by providing a control coil and a coil for reducing the friction at a plunger provided outside a center pole, thereby simplifying a pneumatic bearing. CONSTITUTION:An outside stationary core 20 and a center pole 31 of a square- sectional columnar shape made of a ferromagnetic material are coupled by a magnetic terminal board 27. A drive coil bobbin 22 and a friction reducing coil bobbin 23 are provided at a plunger 25. Signals of oscillating frequency and amplitude of a level that the friction of a linear motor becomes lest are supplied to the friction reducing coil, and a positioning command current is supplied to the control coil. |
