Shock Resistance of a Disk-Drive Assembly Using Piezoelectric Actuators With Passive Damping

Abstract

Current dual-stage actuator design uses piezoelectric patches only, without passive damping. In this paper, we propose a dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators. Because they incorporate passive damping, the proposed actuators will improve the existing dual-stage actuators, giving them higher precision and better shock resistance. We report finite-element analyses of different types of piezoelectric actuators in a disk arm assembly under external shock and vibration. We modeled the viscoelastic damping layers in the hybrid actuators with the Prony series, whose parameters we determined from the dynamic frequency data of a nomograph. In the analyses, a shock impulse (175 g, 1 ms half sine) and a vibration impulse (350 g and 1 ms full sine) are applied at one end of the base, while the other end of the base is fixed. We evaluated and compared the responses of the disk arm assembly with different configurations of the piezoelectric actuators. The simulation results show that the enhanced active-passive hybrid actuator design would reduce the residual in-plane vibration induced during the shock, resist liftoff motion, and reduce the impact damage when the head slaps.