Fluid dynamic pressure bearing device, spindle motor provided with the fluid dynamic pressure bearing device, and recording disk drive device with the fluid dynamic pressure bearing device

摘要

In a fluid dynamic pressure bearing device, a shaft member includes a shaft member-side annular member, and end surfaces of the shaft member and/or the shaft member-side annular member contact a base member of a motor. The shaft member is fixed to the base member. A bearing member is rotatably engaged with the shaft member, and a rotor hub of the motor is engaged with the bearing member. A bearing member-side annular member engaged with the rotor hub suppresses the bearing member from being pulled out in the direction of the base member. A capillary seal portion is formed by a micro gap between the shaft member-side annular member and the bearing member-side annular member. The capillary seal portion suppresses leakage of lubricant occupying the micro gap.