Closed loop cooling system for disk file with heat exchanger integral with baseplate

Claim 1

In a disk file having an HDA comprising a baseplate, a plurality of magnetic disks which store information mounted on a spindle bearinged in said baseplate, a plurality of air bearing magnetic transducers, and means for positioning said transducers relative to said disks, an improved system for maintaining the operating temperature within the HDA enclosure substantially constant at a predetermined safe temperature and substantially free of contaminating particles which could adversely affect the normal air bearing relationship between any one of said transducers and an associated disk surface, said system comprising: (1) means for circulating air internally of said HDA in a substantially closed loop path which extends from the rotational axis of said stack of magnetic disks radially outward across the disk surfaces to the walls of said HDA and includes a return segment from said walls to the axis of said stack, said closed loop path involving first and second parallel branches, said first branch including a filter which creates a relatively high impedance, low volume path for said air in said first branch, said second branch including one side of a heat exchanger which creates a relatively low impedance, high volume path for said air in said second branch; and (2) means for circulating air externally of said HDA in an open loop path which extends through the cold side of said heat exchanger, said heat exchanger being integral with said baseplate whereby the temperature within said HDA is maintained substantially constant at a safe operating temperature by the relatively high volume of air being circulated in said closed loop path to permit a rapid removal of heat by said heat exchanger and any particles that are generated internally of said enclosure which might adversely affect said normal air bearing relationship are removed from said closed loop path by said filter.