| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic bearing ball, a bearing and a disk drive device which can prevent a hard disk from irregular vibrations and is provided with high precision. SOLUTION: The ceramic bearing ball is characterized in that deviation from spherical form is 0.08μm or smaller, surface roughness Ra is 0.012μm or less and maximum size of void on surface is 5μm or smaller. COPYRIGHT: (C)2005,JPO&NCIPI
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