| 摘要 |
PURPOSE:To facilitate assembling operation and to improve positioning precision, by providing a fixed member, rotary member supported rotatably on the fixed member, fixing means for fixing the fixed member near the rotating shaft of the rotary member, etc. CONSTITUTION:A magnetic head 14 is fitted to a rotary drum 21 via a base plate 14 and the drum 21 is fitted to an annular seat 23 with a screw 52. Then, the annular seat engages the shaft parts 22a and 22b of a stationary drum 22 by a small-diameter ball bearing 26 and a large-diameter ball bearing 27 and held rotatably to be fixed axially by a pre-loaded base 32. The pre-loaded base 32 is fixed to the shaft part 22a with a screw 53 so that adequate axial force is applied to two bearings 26 and 27. This constitution facilitates the assembling operation and provides the fixation with high positioning precision. |
