Development of an HDD Spindle Motor With Increased Stiffness and Damping Coefficients by Utilizing a Stationary Permanent Magnet

This research proposes a novel design of a hard-disk-drive spindle motor with increased stiffness and damping coefficients. It has the permanent magnet in the sleeve, which generates the stationary attractive magnetic force. It results in the static eccentricity of the rotating spindle, which increases the stiffness and damping effect of fluid dynamic bearings. The performance of the proposed design is verified by the experiment, as well as by the numerical simulation. The experiment shows that the proposed design decreases the nonrepeatable vibration by 10% when the eccentricity increases by 0.2 mum in the given motor