摘要 |
A hydrodynamic bearing device is provided for a spindle motor used in a hard disk drive or the like with a good state of fastening and good fastening strength between a shaft and a fixed member. The hydrodynamic bearing device includes a shaft that has a cylindrical main shaft portion and a fixing portion provided at one end of the main shaft portion, a sleeve that has a bearing hole in which the main shaft portion is inserted in a rotatable state, and a fixed member that is fixed to the fixing portion of the shaft. A nitride layer is formed on the main shaft portion, and a nitride layer non-forming film is formed on the fixing portion.
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