Fluid bearing unit and spindle motor using the same
AssigneePanasonic Corporation
InventorsKatsushi Hirata, Takanori Shiraishi
Life of this patent
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Abstract
The present invention provides a fluid bearing unit capable of achieving lower torque and lower current consumption in comparison with a conventional bearing unit, and a spindle motor using the same. The present invention employs an ester derived from 1,5-pentanediol having one alkyl side chain and saturated monovalent fatty acid having 5 to 8 carbon atoms as a base oil of a lubricant with which a gap between a shaft and a sleeve is filled.
Claims6
A fluid bearing unit for a magnetic disc drive comprising:
- a sleeve,
- a shaft within said sleeve,
- dynamic pressure-generating grooves in at least one surface of said shaft or said sleeve, and
- a lubricant filled in a gap between the shaft and the sleeve, wherein
- the lubricant contains, as a base oil, an ester derived from 3-methyl-1,5-pentanediol and saturated monovalent fatty acid of a straight chain type having 5 to 8 carbon atoms, and
- the gap is a radial gap of 1 to 5 μm in diameter.
A fluid bearing unit for a magnetic disc drive comprising:
- a sleeve,
- a shaft within said sleeve,
- dynamic pressure-generating grooves in at least one of said shaft and said sleeve, and
- a lubricant filled in a gap between the shaft and the sleeve, wherein
- the lubricant contains, as a base oil, a mixture of at least two kinds of esters derived from 3-methyl-1,5-pentanediol and saturated monovalent fatty acid of a straight chain type having 5 to 8 carbon atoms.
A fluid bearing unit for a magnetic disc drive comprising:
- a sleeve,
- a shaft within said sleeve,
- dynamic pressure-generating grooves in at least one of said shaft and said sleeve, and
- a lubricant filled in a gap between the shaft and the sleeve, wherein
- the lubricant contains, as a base oil, a mixture of an ester derived from 3-methyl-1,5-pentanediol and saturated monovalent fatty acid of a straight chain type having 5 to 8 carbon atoms and at least one of polyolester and diester.
Dependencies are inferred from the claim text.