Browse Prior Art Database

Disk File with Reduced or Eliminated Air Effects

IP.com Disclosure Number: IPCOM000051665D
Original Publication Date: 1981-Feb-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Tietze, AR: AUTHOR

Abstract

To reduce the effects of heat generation and air turbulence in rotatin magnetic disk drives, the drive may be operated in a vacuum or at reduced air pressure, or in a gas other than ambient air.

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Disk File with Reduced or Eliminated Air Effects

To reduce the effects of heat generation and air turbulence in rotatin magnetic disk drives, the drive may be operated in a vacuum or at reduced air pressure, or in a gas other than ambient air.

In disk files rotating at 3600 rpm, heat generation and air-induced motor power requirements are of considerable concern. Higher rotational speeds in disk files is desirable because they reduce latency time, which is of special interest for fixed head disk files. However, heat generation, dynamic pack stability and air friction are drastically increased at such increased speeds.

In Fig. 1, a plurality of disks are held at the outside diameter with accessing from the inside diameter, and a vacuum or low pressure chamber is employed around the rotating disks. Heat generation by high surface speed does not exist in such a vacuum, and there is no gas turbulence, induced instability or friction by high surface speeds. As an alternate to the use of a vacuum, a low pressure of </- 100 torr could be employed to significantly reduce the undesired effects, and maintain a good thermal conductivity. It is known that gases down to 10-50 torr have a constant heat conductivity. In the range of 10-100 torr, a substantial improvement of the rotational stability and cooling can be expected.

Furthermore, the gas used between the shroud and the disk stack of Fig. 1 can be chosen for optimum performance, such as high conductivity and low load e...