Hydrodynamic bearing device, and spindle motor and magnetic disk device using the same
申请人:Hirata Katsushi
公开号:US20060045397A1
公开(公告)日:2006-03-02
The invention provides a hydrodynamic bearing device, comprising at least one of a shaft and a sleeve having a dynamic pressure-generating mechanism, and a lubricant present in a gap between the shaft and the sleeve; wherein the lubricant contains at least one compound selected from the group consisting of aliphatic ethers having a total carbon number of 24 to 32 as represented in Formula (1) or Formula (2)
R
1
—O—R
2
(1)
R
3
—O-A-O—R
4
(2)
and wherein R
1
represents a C16 or higher alkyl group having at least one side-chain, R
2
represents a C4 or higher alkyl group, the carbon number of R
1
is greater than the carbon number of R
2
, R
3
and R
4
represent C8 or higher alkyl groups, A represents a C5 or higher C
n
H
2n
group, and at least one of R
3
, R
4
, and A have a branched structure.