PURPOSE: To ensure a rotation with high accuracy, by attaching rotatably a supporter of a rotary member to a fixed drum by means of a bearing and attaching detachably the rotary member to its supporter via an attaching means which decides the attaching position of the rotary member.
CONSTITUTION: A supporter 25 of a rotary member is attached rotatably to a lower fixed drum 22 by means of a roll bearing 33 provided between the counter faces 28 at the outer circumference side between the drum 22 and the supporter 25. Thus the axial size can be reduced with reduced thickness, and as a result, stable and highly accurate rotation is possible. At the same time, a rotary upper drum 21 is attached in a detachable way to the supporter 25 by means of an attaching means that decides the attaching positions of the drum 21 and the supporter 25 with an attachment screw 48. Thus the positioning control is possible for a magnetic head 49 before the drum 21 is attached to the supporter 25 to facilitate the control of a rotary head device.
NARASAWA TAKASHI
FUJIKI MAKOTO
EDAKUBO HIROO
