| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydrodynamic pressure bearing assembly and a spindle motor with the same.SOLUTION: The hydrodynamic pressure bearing assembly comprises: a sleeve having a shaft hole formed therein; and a shaft rotatably inserted into the shaft hole, and constituting, together with the sleeve, a bearing clearance filled with lubrication fluid. At least one of an inner circumferential surface of the sleeve and an outer circumferential surface of the shaft includes upper and lower radial dynamic pressure grooves having a herringbone pattern formed therein to pump the lubrication fluid filled in the bearing clearance. The hydrodynamic pressure bearing assembly is characterized in that when an axial distance from an upper end of the upper radial dynamic pressure groove to a highest pressure generation portion is represented by a, an axial distance from a lower end of the upper radial dynamic pressure groove to the highest pressure generation portion is represented by b, an axial distance from an upper end of the lower radial dynamic pressure groove to a highest pressure generation portion is represented by c, and an axial distance from a lower end of the lower radial dynamic pressure groove to the highest pressure generation portion is represented by d, conditional expressions a+b>c+d and b-a>c-d>0 are satisfied. |
