Fluid dynamic bearing and pumping seal

摘要

A fluid dynamic bearing motor is provided having relatively rotatable facing surfaces that are reliably lubricated. A radial gap is defined between the relatively rotatable facing surfaces, wherein a first axial end of a fluid dynamic bearing has a larger radial gap as compared to a central region of the fluid dynamic bearing. In an aspect, a fluid recirculation passageway is established between the first axial end and the central region of the fluid dynamic bearing. In an aspect, a fluid reservoir is formed axially above the first axial end of the fluid dynamic bearing. Robustness of the FDB motor is increased, and sensitivity to external loads or mechanical shock events is reduced. Dry surface-to-surface contact of bearing surfaces and reduced performance or failure of the motor or disc drive components is averted. The use of diamond-like coating on relatively rotatable fluid bearing surfaces may also be reduced or eliminated.

主权项

1. An apparatus comprising:
an inner component; an outer component, wherein
said inner and outer components are positioned for relative rotation and positioned to form a pumping seal, andsaid outer component is a sleeve; a first gap formed by said inner and outer components; a second gap formed by said inner and outer components, wherein:
said first gap comprises a thickness in the range of approximately 10 microns to approximately 20 microns,said second gap comprises a thickness in the range of approximately 1 micron to approximately 6 microns,said first gap is adjacent an axial end of a fluid dynamic bearing and said second gap is defined at a central region of said fluid dynamic bearing, andsaid first and second gaps are radial gaps defined with respect to a surface of said inner component; and a radially extending passageway between said first and second gaps, wherein
said pumping seal is configured to pump fluid into said fluid dynamic bearing.