| 摘要 |
PURPOSE:To change the head arm easily without lowering the rigidity of a bearing by forming an end of a rotation shaft and inside of the inner ring of the bearing to tapered form. CONSTITUTION:A rotation shaft 11 an end of which is formed to tapered shape is interposed between the inner ring of a bearing 4b and a rotation shaft 10, and is a ring having tapered at the inside. The ring 11 and inner ring of the bearing 4b, a housing 5 and the outer ring of the bearing 4b, and the rotation shaft 10 and inner ring of the bearing 4a are fixed tightly by bonding. Pressure is given to the outer ring of the bearing 4a by elastic pressing of springs 9 and 12 in the direction of thrust and radial directions. Bearings 4a, 4b, the rotation shaft 10 and housing 5 are assembled rigidly without play, and bearings of large outer diameter can be used. Accordingly, the arm 2 can be changed simply without lowering resonance frequency of the positioning mechanism. |
