Spindle device and bearing device therefor
AssigneeNsk Ltd.
InventorsKatsuhiko Tanaka, Hiromitsu Muraki, Ikunori Sakatani
Life of this patent
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Abstract
A bearing device includes a housing, a shaft arranged in an inner circumference of the housing, and a pair of bearings arranged between the shaft and the housing, and spaced from each other in an axial direction of the shaft, at least one of the bearings comprising a sleeve inserted in the housing and formed cylindrically. The sleeve has an outer layer portion including an outer cylindrical surface and an inner layer portion including an inner cylindrical surface, the outer layer portion being harder than the inner layer portion, the inner cylindrical surface having a groove for generating dynamic pressure. The sleeve is improved in working accuracy, and the dynamic pressure generating grooves can be formed with ease.
Claims4
A hearing device comprising:
- a housing;
- a shaft arranged in an inner circumference of the housing;
- and
- a pair of bearings arranged between the shaft and the housing, and spaced from each other in an axial direction of the shaft, at least one of the bearings comprising a sleeve inserted in the housing and formed cylindrically,
- the sleeve comprising an outer layer portion including an outer cylindrical surface and an inner layer portion including an inner cylindrical surface, the outer layer portion being harder than the inner layer portion, the inner cylindrical surface having a groove for generating dynamic pressure.
Dependencies are inferred from the claim text.