Modified structure for reduction of cavitation at fluid dynamic bearing of HDD spindle motor under non-operating axial vibration

A hard disk drive (HDD) is subjected to the axial vibration while it is transported long distance or stored in vibrating environments. The cavitation may occur in the lubricant film of the spindle thrust bearing due to the axial vibration. The cavitation bubble may push the lubricating oil out of the bearing clearance so that it may be resulted in system failure of the HDD. The formation of cavitation bubble is studied for a specially designed fluid dynamic thrust bearing (FDTB) for the HDD. A novel design method for the FDTB is proposed, which suppresses cavitation effectively.