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US 4,907,897 AGranted
Bearing device
AssigneeKabushiki Kaisha Sankyo Seiki Seisakusho
InventorYozo Shirotori
Life of this patent
Estimating the term…
Abstract
An improved bearing device for use in a spindle motor for driving computer hard disks is disclosed. The device includes a shaft, bearings supporting the shaft, and a bearing holder for holding the bearings. The bearing holder is made of a magnetic material. The shaft, the bearings, and the bearing holder are made of materials having substantially the same thermal expansion coefficient.
Claims10
A bearing device comprising:
- a housing;
- a bearing holder having substantially the form of a cylindrical pipe, a lower end of said bearing holder being fitted in a central hole formed in said housing, said bearing holder being made of a magnetic material;
- a shaft;
- first and secod ball bearings fitted in said hearing holder and supporting said shaft;
- two yokes and a magnet held between said two yokes and fitted in an upper portion of said bearing holder;
- and a seal mechanism impregnated with magnetic fluid fitted between said shaft and inner peripheries of said yokes;
- said shaft, said bearings, and said bearing holder being made of materials which have substantially equal thermal expansion coefficients.
4 more elements
A bearing device comprising:
- a shaft;
- bearings supporting such shaft;
- a bearing holder adapted to hold said bearings, wherein said shaft, said bearings and said bearing holder are made of materials which have substantially equal thermal expansion coefficients;
- a hub rotated together with said shaft, said hub supporting magnetic disks;
- rotor magnets rotated together with said shaft;
- and
- a stator confronting said rotor magnets.
4 more elements
Dependencies are inferred from the claim text.