Fluid Dynamic Bearing Groove Configuration

摘要

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.

主权项

1. 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, anda 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.