Spacer ring reservoir for magnetic recording disk lubricant

• US 5,381,284 A
• Filed: 06/17/1994
• Issued: 01/10/1995
• Est. Priority Date: 05/18/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gregory, Thomas A., Keller, Christopher G.
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): DITMYER, PAUL JOSEPH
• Application Number:
  US08/261,654
• Time in Patent Office: 207 Days
• Field of Search: 360/97.01, 360/97.02, 360/97.03, 360/102, 360/103
• US Class Current: 360/97.02
• CPC Class Codes: G11B 23/505 of disk carriers
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 33/148 Reducing friction, adhesion, drag

Abstract

A lubricant reservoir system for a magnetic disk near contact data storage device, which rotates in unison with the disk assembly to replace lubricant depleted from the disk surface over the life of the device, includes reservoir chambers in disk spacers with lubricant metering provided by restricted passages or textured surfaces extending radially outward from the reservoir chamber while replacement air passages extend radially inward to replace dispensed lubricant. The metered lubricant is delivered to the disk surface at a location where the surface confronting the disk is made compliant with the disk surface and the adjoining surface is beveled to form an angle of more than 90 degrees with the disk surface thereby preventing migration of lubricant away from the disk. Nonwettable surfaces may be used in metering passages, air passages, and on some beveled surfaces to further control lubricant metering. In operation, the high G forces induced by rotation cause lubricant to be metered to the disk while the same small metering passages function as a barrier when the disk assembly is not rotating.

Claims

1. A magnetic disk data storage device comprising:

a disk assembly including at least one magnetic data storage disk with an inner diameter and an outer diameter including a liquid lubricant film overlying a disk data storage surface, said disk having a plurality of data storage tracks for recording data on said data storage surface;

a lubricant reservoir system adjacent the disk inner diameter and radially inward of the data storage tracks on said data storage surface;

said reservoir system including a lubricant reservoir and a metering means for releasing lubricant from said reservoir during device operation at a rate substantially equal to a rate of lubricant film depletion caused by disk rotation, said metering means being located radially outward from said lubricant reservoir and comprising a compliant element urged against the disk surface, wherein metering is provided by surface irregularities in at least one of the confronting surfaces of said disk and said compliant element; and

means for delivering lubricant metered from said reservoir to the disk data storage surface.

2. The magnetic disk data storage device of claim 1 wherein said reservoir system is formed as a part of a disk spacer assembly.

3. The magnetic disk data storage device of claim 1 wherein said surface irregularities comprise disk surface texturing with longitudinal depressions forming the textured surface having a radial component.

4. The magnetic disk data storage device of claim 1 wherein said compliant element includes an annular compliant surface.

5. The magnetic disk data storage device of claim 4 wherein said compliant element is a metal ring and further comprising biasing means urging the compliant metal surface against the confronting surface of the disk.

6. A magnetic disk data storage device comprising:

a disk assembly including at least one magnetic data storage disk with an inner diameter and an outer diameter including a liquid lubricant film overlying a disk data storage surface, said disk having a plurality of data storage tracks for recording data on said data storage surface;

a lubricant reservoir system adjacent the disk inner diameter and radially inward of the data storage tracks on said data storage surface;

said reservoir system including a lubricant reservoir and a metering means for releasing lubricant from said reservoir during device operation at a rate substantially equal to a rate of lubricant film depletion caused by disk rotation, said metering means being located radially outward from said lubricant reservoir, said metering means comprising at least one spacer ring having a surface abutting a portion of the surface of said disk, at least one of said disk surface and said spacer ring surface abutting the disk surface having controlled roughness to form metering passages between said disk surface and the surface of the spacer ring abutting the disk surface; and

means for delivering lubricant metered from said reservoir to the disk data storage surface.

7. A magnetic disk data storage device comprising:

a disk assembly including at least one magnetic data storage disk with an inner diameter and an outer diameter including a liquid lubricant film overlying a disk data storage surface, said disk having a plurality of data storage tracks for recording data on said data storage surface;

a lubricant reservoir system adjacent the disk inner diameter and radially inward of the data storage tracks on said data storage surface;

said reservoir system including a lubricant reservoir and a metering means for releasing lubricant from said reservoir during device operation at a rate substantially equal to a rate of lubricant film depletion caused by disk rotation, said metering means being located radially outward from said lubricant reservoir, wherein said lubricant reservoir system is foraged of a plurality of parts and said metering means comprises abutting surfaces of said plurality of parts, said abutting surfaces including a controlled roughness and extending radially outward from the lubricant reservoir;

means for delivering lubricant metered from said reservoir to the disk data storage surface; and

a compliant member that is biased to compliance with the surface of said disk at a radially outward edge of said compliant member and provides a lubricant passage that is less restrictive than said metering means.

8. The magnetic disk data storage device of claim 7 further comprising a dike positioned to direct lubricant released from said metering means to said lubricant passage provided by said compliant member.

9. A magnetic disk data storage device comprising:

a disk assembly including at least one magnetic disk with an inner diameter and an outer diameter and including a lubricant film on the recording surface that has a viscosity greater than one centipoise, said disk having a plurality of data storage tracks for recording data on the recording surface;

a lubricant reservoir that forms a part of the disk assembly is positioned radially inward of the data storage tracks on a confronting surface of said disk, rotates in unison with said disk assembly, and contains a supply of said lubricant; and

metering means for effecting the controlled release of lubricant from said reservoir to supplement said lubricant film and replace lubricant depleted from said film by disk assembly rotation, said metering means comprising passage means extending from the outer diameter of said lubricant reservoir to a disk surface adjacent an outer diameter of said metering means, wherein said metering means presents a compliant annular interface surface radially extending from said lubricant reservoir and metering is provided by a controlled roughness of at least one confronting surface of said disk and said annular interface.

10. The magnetic disk data storage device of claim 9 further comprising a disk spacer adjoining an inner diameter of the confronting surface of said disk and wherein said lubricant reservoir is formed as an annular space in said spacer.

11. The magnetic disk data storage device of claim 10 wherein said disk spacer is formed as a disk spacer assembly of multiple parts that form an annular lubricant reservoir cavity and includes a spacer interface between disk spacer assembly parts that extend from the outer diameter of the annular lubricant reservoir to an outer peripheral surface of said disk spacer, said metering means being effected by the controlled roughness of the spacer interface surface.

12. The magnetic disk data storage device of claim 11 wherein the outer peripheral surface of said disk spacer assembly includes a beveled surface extending from an outer termination of said spacer interface and the disk surface causing a greater than 90 degree angle between said beveled surface and said disk surface whereby lubricant emerging from the termination of said spacer interface travels along said beveled surface to said disk surface rather than being spun off the peripheral surface of said spacer assembly as droplets as a result of disk assembly rotation.

13. The magnetic disk data storage device of claim 12 wherein said beveled surface is coated with a material that is nonwettable by said lubricant.

14. The magnetic disk data storage device of claim 11 wherein a second spacer interface between spacer assembly parts extends from said annular lubricant reservoir to an inner diameter of said disk spacer which provides restricted air passage means, whereby air is permitted to enter said reservoir to replace lubricant metered from said reservoir or compensate for thermal changes.

15. The magnetic disk data storage device of claim 10 further comprising restricted air passage means extending from said lubricant reservoir to an inner diameter of said disk spacer whereby air is permitted to enter said reservoir to replace lubricant metered from said reservoir or compensate for thermal or barometric changes.

16. The magnetic disk data storage device of claim 10 wherein at a termination of the annular interface at an outer diameter of said disk spacer, the spacer peripheral surface adjoining the disk surface is beveled to provide an angle greater than 90 degrees with the disk surface, whereby lubricant metered from said interface termination does not travel along an spacer peripheral surface away from the disk.

17. The magnetic disk data storage device of claim 16 wherein said compliant annular interface surface extends to said beveled surface whereby lubricant metered from the termination of said annular interface becomes part of the lubricant film on the surface of said disk rather than being released into the atmosphere as droplets induced by disk rotation.

18. The magnetic disk data storage device of claim 9 wherein the controlled roughness comprises disk texturing at said annular interface, grooves forming the textured surface having a radial component.

19. The magnetic disk data storage device of claim 9 wherein said controlled roughness comprises a controlled roughness surface on said annular interface surface.

20. The magnetic disk data storage device of claim 9 wherein said lubricant reservoir comprises an annular cavity and said metering means comprises passage means extending radially outward from said annular cavity.

21. The magnetic disk data storage device of claim 20 wherein said passage means is treated with a coating that is nonwettable by said lubricant.

22. The magnetic disk data storage device of claim 21 further including an air passage leading from the reservoir annular cavity radially inward, said air passage being treated with a coating which is nonwettable by said liquid.

23. The magnetic disk data storage device of claim 22 further comprising an absorbent matrix material disposed in said annular cavity which retains the lubricant.