Ventilation system for computer disc drive hub assembly

摘要

A ventilation system for use with a computer disc drive is described which enables disc file data storage capacity to be increased for a given volume of chamber housing the discs and which provides increased disc-drive performance. A plurality of axially extending channels is provided in the hub of the drive and a breather filter is located axially, at one end of the hub, in the housing wall of the chamber. Rotation of the discs causes air to be thrown out to the periphery of the discs creating a high pressure zone thereat and a low pressure zone at the rotation axis. Air is drawn into the low pressure zone and is communicated to the inter disc spaces via the axially extending channels from where it is thrown out by centrifugal force during rotation. A substantially constant air density is provided adjacent the disc surfaces leaving the aerodynamic characteristics of the read/write heads substantially unaffected and facilitating the reduction of interdisc spacing. The breather filter location ensures that external air is drawn into the chamber opposite the zone of lowest pressure during switch-on and since this air is filtered it is clean. When the disc rotation stabilizes the pressure difference across the breather filter is zero.