FLUID DYNAMIC PRESSURE BEARING ASSEMBLY, MOTOR INCLUDING THE FLUID DYNAMIC PRESSURE BEARING ASSEMBLY, AND RECORDING DISK DRIVING APPARATUS MOUNTED WITH THE MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a fluid dynamic pressure bearing assembly to compensate for a dynamic pressure of a motor where the height of levitation is reduced due to temperature rise and the rigidity of a bearing falls, a motor including the fluid dynamic pressure bearing assembly, and a recording disk driving apparatus mounted with the motor.SOLUTION: The fluid dynamic pressure bearing assembly includes a sleeve provided with a shaft hole into which a shaft is inserted, a radial dynamic pressure part formed on at least one of the outer diameter of the shaft and the inner diameter of the sleeve, and a sub radial dynamic pressure part formed on at least one of the outer diameter of the shaft and the inner diameter of the sleeve at the top in a shaft direction of the radial dynamic pressure part. In the fluid dynamic pressure bearing assembly, an oil interface formed in the shaft hole between the radial dynamic pressure part and the sub radial dynamic pressure part can be raised in the direction of the sub radial dynamic pressure part due to an increase in temperature by motor drive.