| 摘要 |
<p>PURPOSE:To keep a rotary part comprising a head and a rotor part, etc., constant in height by providing an attracting means for attracting a shaft with magnetic force to attract a fixed drum and a rotary drum to each other in the axial direction. CONSTITUTION:A surface 16a opposite to a tip part of the shaft 2 of a 2nd magnet 16 is treated with, for example, magnetization of a signle pole. Consequently, the 2nd magnet 16 and the tip part of the shaft 2 made of a magnetic material constitute a magnetic circuit. By this method, the shaft 2 is attracted by attracting force of the 2nd magnet 16 in its magnetic force, and also the height of the tip part of he shaft 2 is settled by press fitting, so that the whole of the head 6 and the rotor part 8 is maintained at a prescribed height. As a result, thrust force can be given in simple constitution.</p> |
