| 摘要 |
PURPOSE:To remove clearance between a bearing and a rotary shaft and to highly accurately position the rotary shaft, by providing the external circumference of the rotary shaft including push metal and the internal circumference of the bearing with three contact points respectively in a cross section perpendicular to the shaft. CONSTITUTION:A head arm 3 provided with a magnetic head 4 is fitted to the rotary shaft 1, which is pivotary supported by the bearing 10. A semicircular notch part 7 or the like is formed on the rotary shaft 1 for a magnetic disc device and a member (press metal) 8 with which the notch part 7 is approximately filled is inserted and engaged into/with the notch part 7 with pressure to the bearing 10. A curved surface formed by the side of said press metal 8 opposed to the bearing 10 and the external circumference surface of the rotary shaft 1 is shaped so that the external circumferential of the rotary shaft including the press metal and the internal circumference of the bearing 10 have three contact points 15, 24, 25 in the cross section perpendicular to the shaft of the rotary shaft 1. |
