Fluid bearing with non-uniform grooves

Patent metadata

Field	Value
Publication number	US-8926184-B2
Application number	US-201313787667-A
Country	US
Kind code	B2
Filing date	Mar 6, 2013
Priority date	Nov 22, 2012
Publication date	Jan 6, 2015
Grant date	Jan 6, 2015

Abstract

Provided herein is an apparatus, including a fluid dynamic bearing, wherein the fluid dynamic bearing includes a set of pressure-generating grooves, and wherein the set of pressure-generating grooves includes a plurality of chevron-shaped grooves, each chevron-shaped groove including at least two selected from a non-uniform depth, non-uniform angle, a non-uniform width, or a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the journal bearing during steady-state operation and during a shock event.

First claim

What is claimed is:

1. An apparatus, comprising:
a fluid dynamic bearing,
wherein the fluid dynamic bearing comprises a set of pressure-generating grooves, and
wherein the set of pressure-generating grooves comprises a plurality of chevron-shaped grooves, each chevron-shaped groove comprising at least two characteristics selected from a non-uniform depth, a non-uniform angle, a non-uniform width, or a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the fluid dynamic bearing during steady-state operation and during a shock event.

2. The apparatus of claim 1 , wherein the fluid dynamic bearing comprises
a journal bearing comprising a sleeve and a shaft configured for a fluid therebetween,
wherein the set of pressure-generating grooves comprises a set of upper journal bearing grooves and a set of lower journal bearing grooves.

3. The apparatus of claim 2 , wherein each chevron-shaped groove comprises an outside wall, the vertex of which points to an adjacent chevron-shaped groove, and an inside wall, the vertex of which points to the outside wall of the same chevron-shaped groove.

4. The apparatus of claim 3 , wherein the non-uniform depth comprises the outside wall of each chevron-shaped groove being deeper than the inside wall.

5. The apparatus of claim 3 , wherein the non-uniform depth comprises the inside wall of each chevron-shaped groove being deeper than the outside wall.

6. The apparatus of claim 3 , wherein the non-uniform depth comprises a center groove of each chevron-shaped groove being deeper than both the outside wall and the inside wall.

7. The apparatus of claim 3 , wherein the non-uniform angle comprises the vertex of the outside wall of each chevron-shaped groove being a narrower angle than the vertex of the inside wall.

8. The apparatus of claim 2 , wherein the set of upper journal bearing grooves and the set of lower journal bearing grooves are the same.

9. The apparatus of claim 2 , wherein the sleeve comprises both sets of journal bearing grooves.

10. The apparatus of claim 2 , wherein the shaft comprises both sets of journal bearing grooves.

11. The apparatus of claim 1 , wherein the fluid dynamic bearing comprises
a thrust bearing comprising a thrust surface and an opposing surface configured for a fluid therebetween,
wherein the set of pressure-generating grooves comprises a set of thrust bearing grooves.

12. The apparatus of claim 11 , wherein each chevron-shaped groove comprises an outside wall, the vertex of which points to an adjacent chevron-shaped groove, and an inside wall, the vertex of which points to the outside wall of the same chevron-shaped groove.

13. The apparatus of claim 12 , wherein each chevron-shaped groove comprises a symmetric depth profile selected to provide a predetermined spindle-motor stiffness during steady-state operation and during operation at a temperature higher than an optimum temperature range, wherein the symmetric depth profile comprises a center groove of each chevron-shaped groove of the set of thrust bearing grooves being deeper than both the inside wall and outside wall of the groove.

14. The apparatus of claim 13 , wherein the optimum temperature range is between about 35° C. and 45° C.

15. The apparatus of claim 13 , wherein the center comprises an angled bottom or a flat bottom.

16. The apparatus of claim 11 , wherein the thrust surface comprises the set of thrust bearing grooves.

17. The apparatus of claim 11 , wherein the opposing surface comprises the set of thrust bearing grooves.

18. The apparatus of claim 1 , wherein each chevron-shaped groove comprises a non-uniform depth and at least one characteristic selected from a non-uniform angle, a non-uniform width, or a non-uniform length.

19. The apparatus of claim 18 , wherein each chevron-shaped groove comprises a first segment, from the vertex of the chevron-shaped groove to a first terminus, oriented toward an end of the fluid dynamic bearing, and a second segment, from the vertex of the chevron-shaped groove to a second terminus, oriented toward the center of the fluid dynamic bearing, and wherein the non-uniform width comprises the first terminus of each chevron-shaped groove being narrower than the second terminus.

20. The apparatus of claim 18 , wherein each chevron-shaped groove comprises a first segment, from the vertex of the chevron-shaped groove to a first terminus, oriented toward an end of the fluid dynamic bearing, and a second segment, from the vertex of the chevron-shaped groove to a second terminus, oriented toward the center of the fluid dynamic bearing, and wherein the non-uniform length comprises the first segment of each chevron-shaped groove being longer than the second segment.

21. An apparatus, comprising:
a fluid dynamic bearing,
wherein the fluid dynamic bearing comprises a set of pressure-generating grooves, and
wherein the set of pressure-generating grooves comprises a plurality of chevron-shaped grooves, each chevron-shaped groove comprising at least two characteristics selected from the group consisting of a non-uniform depth, a non-uniform angle, a non-uniform width, and a non-uniform length, selected to provide a predetermined spindle-motor stiffness to the fluid dynamic bearing during steady-state operation and during a shock event.

22. The apparatus of claim 21 , wherein each chevron-shaped groove comprises a non-uniform depth and at least one characteristic selected from the group consisting of a non-uniform angle, a non-uniform width, and a non-uniform length, wherein each chevron-shaped groove comprises a first segment, from the vertex of the chevron-shaped groove to a first terminus, oriented toward an end of the fluid dynamic bearing, and a second segment, from the vertex of the chevron-shaped groove to a second terminus, oriented toward the center of the fluid dynamic bearing, and wherein the non-uniform width comprises the first terminus of each chevron-shaped groove being narrower than the second terminus.

Assignees

• Seagate Technology Llc

Inventors

• Flores Paco Gregor
• Le Lynn Bich-Quy

Classifications

• F16C2370/12

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• G11B19/2036

  Motors characterized by fluid-dynamic bearings · CPC title

• C12N15/85 Primary

  for animal cells · CPC title

• C12P21/00

  Preparation of peptides or proteins (single cell protein C12N1/00) · CPC title

• F16C17/107 Primary

  with at least one surface for radial load and at least one surface for axial load · CPC title