Design of a high bandwidth moving-coil actuator with force couple actuation for HDDs]

This paper reports a novel high bandwidth moving-coil actuator. A special design in actuator construction leads to generation of pure torque in the actuator. With this special design the lateral quasi-rigid body vibration mode can be substantially suppressed. 2D FEA was carried out for the electromagnetic design to optimize the electromagnetic parameters and dimensions of the actuator. A 3D FEM solver was used to predict the characteristics of mechanical dynamics of the actuator. The electromagnetic characteristics, mechanical dynamics and performance of the actuator were measured. The results from simulation and experiment match quite well. The results show that the quasi-rigid body vibration mode is substantially suppressed and the primary resonance frequency is about 10 kHz in the novel actuator.