Fluid Dynamic Bearing Groove Configuration
AssigneeHGST Netherlands B.V.
InventorChiaoping Ku
Life of this patent
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Abstract
A fluid dynamic bearing (FDB) includes a groove configuration that includes a pressure-generating groove pattern, and additionally includes a circumferential groove adjacent to the pressure-generating groove pattern and a pumping groove pattern adjacent to the circumferential groove. The circumferential groove may be deeper than the associated pumping and pressure-generating groove patterns and may extend for 360 degrees, and the pumping groove may be positioned at or near the entry to the bearing journal area to help maintain fluid flow direction and minimum pressure. Such an FDB groove configuration is likely to provide improved damping characteristics while maintaining relative stiffness, thereby improving vibration response characteristics.
Claims23
A fluid dynamic bearing comprising:
- a sleeve;
- a shaft disposed within said sleeve;
- a radial gap between said sleeve and said shaft;
- and
- a groove configuration positioned in said bearing radial gap, said groove configuration comprising:
- a pressure-generating groove pattern resembling a herringbone groove pattern,
- a circumferential groove adjacent said pressure-generating groove pattern, and
- a pumping groove pattern adjacent said circumferential groove and resembling an extension of said pressure-generating herringbone groove pattern;
- wherein the depth of said circumferential groove is greater than the depth of said pumping groove pattern and the depth of said pumping groove pattern is greater than the depth of said pressure-generating groove pattern.
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A hard disk drive comprising:
- a spindle motor comprising:
- a spindle on which a disk media is rotatably mounted, and
- a fluid dynamic bearing comprising:
- a sleeve,
- a shaft disposed within said sleeve,
- a radial gap between said sleeve and said shaft, said gap bounded by an inner surface of said sleeve and an outer surface of said shaft, and
- a groove configuration positioned in said bearing radial gap, said groove configuration comprising:
- a pressure-generating groove pattern resembling a herringbone groove pattern,
- a circumferential groove adjacent said pressure-generating groove pattern, and
- a pumping groove pattern adjacent said circumferential groove and resembling an extension of said pressure-generating herringbone groove pattern,
- wherein the depth of said circumferential groove is greater than the depth of said pumping groove pattern and the depth of said pumping groove pattern is greater than the depth of said pressure-generating groove pattern;
- a head slider comprising a read/write head configured to read from and to write to said disk media;
- and
- a voice coil actuator configured to move said head slider to access portions of said disk media.
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A method for damping a fluid dynamic journal bearing, the method comprising:
- on a shaft or a sleeve of said journal bearing, at a radial interface between said shaft and said sleeve,
- forming a pressure-generating groove pattern resembling a herringbone groove pattern;
- forming a circumferential groove adjacent said pressure-generating groove pattern and extending for 360 degrees;
- forming a pumping groove pattern positioned at or near an entry region of said journal bearing and resembling an extension of said pressure-generating herringbone groove pattern;
- wherein the depth of said pumping groove pattern is greater than the depth of said pressure-generating groove pattern and the depth of said circumferential groove is greater than the depth of said pumping groove pattern.
Dependencies are inferred from the claim text.