# US 4,396,964 A · Recirculating air system for magnetic disk drive

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- Number: US 4,396,964 A
- Document ID: US4396964A
- Status: Granted
- Kind: A
- Application number: 06/165,255
- Filed: 1980-07-02
- Granted: 1983-08-02
- Earliest claimed: 1980-07-02
- Assignees: Storage Technology Corporation
- Inventors: James H. Morehouse; Mark A. Swenson
- Web page: https://patentgrep.com/patent/US4396964A

## CPC

- G11B 33/142: {by air cooling}
- G11B 33/1446: {Reducing contamination, e.g. by dust, debris}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

In a magnetic disk drive unit, air is pumped by the magnetic disks through a closed recirculating air path extending over and under the base plate. The air is pumped through a heat exchanger and an air filter to maintain uniform temperature and cleanliness of the recirculating air. A blower driven from the motor which drives the hub pumps air through the ambient side of the heat exchanger to effect a heat transfer from the enclosure.

## Claims

### Claim 1

A magnetic disk drive comprising:
a hollow rotating hub having air vents;
a base plate for mounting said hub for rotation thereon;
a frame on which said base plate is mounted;
an enclosure, said frame and enclosure defining a closed air path over and under said base plate, to the inside of said hub and through the vents therein;
a heat exchanger in said air path;
a centrifugal blower for circulating cooling air through said heat exchanger; and
a drive motor for driving both said blower and said hub.

### Claim 2 (depends on 1)

The magnetic disk drive recited in claim 1 further comprising:
vented spacer rings for mounting said magnetic disks on said hub.

### Claim 3 (depends on 1)

The magnetic disk drive recited in claim 1 wherein said frame is constructed of structural foam.

### Claim 4

A magnetic disk drive comprising:
a hollow rotating hub having air vents;
a base plate for mounting said hub for rotation thereon;
a frame on which said base plate is mounted;
an enclosure, said frame and enclosure defining a closed air path over and under said base plate, to the inside of said hub and through the vents therein;
a magnetic recording head assembly positioned in said closed air path;
a source of pressurized ambient air; and
an ambient filter, said pressurized ambient air being connected to said closed air path through said ambient filter so that leakage from said closed air path is replaced by clean ambient air.

### Claim 5 (depends on 4)

The disk drive recited in claim 4, further comprising:
a high efficiency air filter in said closed air path.

### Claim 6 (depends on 4)

The disk drive recited in claim 4, further comprising:
a heat exchanger in said air path.

### Claim 7 (depends on 6)

The magnetic disk drive recited in claim 6 further comprising:
means for circulating cooling air through said heat exchanger.

### Claim 8 (depends on 7)

The magnetic disk drive recited in claim 7 wherein said means for circulating comprises:
a centrifugal blower; and
a drive motor for driving both said blower and said hub.