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

Abstract

4bstruct -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 mixhanical 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 quasirigid body vibration mode is substantially suppressed and the primary resonance frequency is about 10 kHz in the novel actuator.h d e x Terms ---Moving-coil actuator, high-bandwidth, electromagnetic design, dynamics analysis, hard disk drive.

A suspension integrated with a piezoelectric microactuator for dual stage actuation

“…Mah developed a highbandwidth moving-coil actuator. The lateral vibration mode was substantially suppressed [4]. Z.W.…”

Fem and Experimental Analysis of the Actuator ‘Butterfly Mode’ in a Hard-Disk Drive

“…Another disadvantage is the higher manufacturing cost. The similar concept and design was proposed by Mah et al [5].…”

“…In the past, this assumption was used and accepted as long as the mass of the actuator was high [4,5,8,9]. However, with the shrinking form factor, the stiffness-to-mass ratio becomes higher rendering the rigid body assumption invalid, as both the bearing stiffness and the actuator stiffness are not infinite.…”

Modal Testing and Finite Element Modelling of Subsystem in Hard Disk Drive

“…Special excitation method and measurement instrument must be used for the HAA modal testing. For example, the voice coil motor has been used as a special exciter to obtain the frequency response functions of HAA in the lateral direction under the actual operating condition [3,4]. Furthermore, the measured time domain arrival profile can be used to show the HAA settling transient process.…”