Near contact magnetic recording using a liquid lubricant bearing to separate media and transducer

• US 5,742,449 A
• Filed: 04/23/1991
• Issued: 04/21/1998
• Est. Priority Date: 10/31/1988
• Status: Expired due to Term

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Keller, Christopher Guild, Larson, Thomas Scott, Gregory, Thomas Allen
• Primary Examiner(s): Wolff, John H.
• Application Number:
  US07/689,671
• Time in Patent Office: 2,555 Days
• Field of Search: 360/102, 360/103, 360/97.02, 360/98.07
• US Class Current: 360/97.02
• CPC Class Codes: G11B 15/62 Maintaining desired spacing between record carrier and head
• CPC Class Codes: G11B 23/505 of disk carriers
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 33/1406 Reducing the influence of the temperature
• CPC Class Codes: G11B 33/148 Reducing friction, adhesion, drag
• CPC Class Codes: G11B 5/6005 Specially adapted for spacing from a rotating disc using a fluid cushion
• CPC Class Codes: H02J 13/00012 using an auxiliary transmission line

Abstract

A rotating magnetic storage device is shown wherein the transducer and media are separated during operation by a thin film of low viscosity liquid lubricant that is recirculated from a reservoir within the head-media enclosure. Lubricant recirculation can be effected by capillary action using a wick, mechanical pumping and metering or distillation techniques. As compared to devices using air bearing separation, the transducer carrying slider has very small bearing surfaces which may be in the form of narrow rails or small depending foot elements. This enables fly heights of 2 microinches using a film of one micron thickness.

Claims

1. A rotating magnetic memory device comprising

a rotating storage medium presenting a rotating magnetic data storage surface;

a magnetic transducer;

a head-disk enclosure surrounding said rotating storage medium and said magnetic transducer and substantially sealing said rotating storage medium from the surrounding ambient atmosphere;

means for maintaining a recirculating film of liquid lubricant on said magnetic data surface, including means for recirculating said liquid lubricant over said data surface;

said liquid lubricant being a low viscosity lubricant with said lubricant film being maintained as a substantially uniform thickness not exceeding 5 microns;

said magnetic transducer being supported above said rotating magnetic surface by said liquid film when writing data to or reading data from said rotating magnetic media data surface;

a reservoir in said head-disk enclosure and

a liquid lubricant distribution system associated with the rotating assembly which supports said disk and

wherein said means for maintaining a recirculating film of lubricant comprises a distillation system wherein said reservoir is maintained at a first temperature and a location on said enclosure positioned to deliver condensed liquid to said distribution system is maintained at a second temperature which is less than said first temperature.

2. The rotating magnetic memory device of claim 1 further comprising cooling fins on said enclosure exterior surface at said location on said enclosure.

3. The method of writing data to and reading data from a rotating magnetic disk data surface, which is provided with a recirculating supply of low viscosity liquid lubricant through wicking means, using a transducer carrying slider that presents bearing surfaces confronting said data surface comprising the steps of

recirculating liquid lubricant by capillary action through said wicking means to maintain a film of said liquid lubricant over said data recording surface and

flying said slider over said data recording surface by supporting said bearing surface on said recirculated liquid lubricant film.

4. The method of claim 3 further comprising the step of filtering said low viscosity liquid lubricant during said recirculating cycle.

5. A wet disk drive assembly, comprising:

a disk drive enclosure;

a disk and spindle mechanism, including a rigid disk mounted on a spindle, said spindle being rotatably mounted to said disk drive enclosure for rotating said disk in said drive enclosure;

means for rotating said spindle;

a liquid lubricating material;

a wicking material within said disk drive enclosure which provides a path for transporting said lubricating material by capillary action;

a wicking applicator for delivery of said liquid lubricating material to said surface, said wicking applicator providing a liquid conduction path between said wicking material and said disk surface; and

means for returning excess liquid lubricating material from said disk surface to said wicking material.

6. The wet disk drive assembly of claim 5 further comprising:

reservoir means formed in a lower portion of said disk drive enclosure for receiving said excess liquid lubricating material from said disk surface,

said wicking material extending into said reservoir means, whereby said liquid lubricating material is recirculated to said disk surface and particulate contaminants entrained in said excess lubricating material received from said disk surface are retained in said reservoir.

7. A wet disk drive assembly, comprising:

a casing enclosing a drive assembly space;

a circulating means in said drive assembly for circulating a liquid by capillary action within said casing;

a liquid lubricating material in said circulating means;

a disk drive mechanism in said drive assembly space, said disk drive mechanism including a rigid disk mounted on said disk drive assembly for rotation by said disk drive assembly; and

delivery means mounted in said drive assembly space and having a liquid-conductive connection to said circulating means for delivery of said liquid lubricating material to said rigid disk.

8. The wet disk drive assembly of claim 7 wherein said circulating means comprises:

a liquid reservoir for containing liquid lubricating material and receiving excess lubricant from said rigid disk; and

wick means extending from said reservoir,

said delivery means including a wicking applicator for delivery of liquid lubricating material to the surface of said rigid disk,

whereby liquid lubricant material is recirculated from said rigid disk by capillary action and particulate contaminants in said liquid lubricant material are retained in said reservoir.