| 摘要 |
PURPOSE:To provide a driving device, which can keep a disc away from dusts and a lubricant irrespective of the driving and interrupting operations, by making a construction in which the fluid resistances at the respective portions of a preset air passage are made to have a desired relationship by means of an air filter and a throttle. CONSTITUTION:The air having been supplied from a blower and having passed through an air supply filter 13 is quided through a clearance, which is divided into two halves by a spindle 4 and a cylindrical seal portion 12, and the one air flow is introduced into a magnetic disc chamber 3 whereas the other is discharged to the outside through an air filter 11 connected with a throttle 10 after having a passed through an air filter 5. According to this construction, the resistances R1 and R2 of the filters 13 and 5, the resistance R3 of the throttle 10 and the filter 11, and the resistance R4 of the seal portion 12 are set to satisfy the conditions of a formula I. As a result, when magnetic discs 1 and 7 are driven through the spindle 4, the lubricating oil spashing into a chamber 6 is discharged from the filter 11 to the outside by the centrifugal force of the disc 7, and the chamber 6 is evacuated more than the chamber 3 by the disc 7 having a larger diameter so that the dusts and lubricant can be prevented from stealing into the chamber 3. |
