Experimental analysis of HDD actuator for the improvement of shock reliability

The shock performance of a hard disk drive has been a serious issue with the use of mobile computer and AV application. Focusing on the motion of actuator, we investigated nonoperational shock mechanism and studied several parameters that affect the shock performance by experimental analysis. It was found that there are two important factors for the actuator to endure high shock level. One is shock transmissibility and the other is beating between the arm blade and the suspension. To generalize the shock transmissibility, the concept of shock response spectrum was introduced. A shock response spectrum of the actuator system was obtained experimentally and compared with that of an analytical single degree of freedom model. There was a good agreement, and the first bending natural frequency of arm blade was found to be the most important factor for the low shock transmissibility. By applying the shock response spectrum and avoiding the beating, we could design an actuator of high shock performance.