A high-bandwidth moving-magnet actuator for hard disk drives

Abstract

This paper describes an experimental moving-magnet actuator (HBX) designed far a 3.5", 2-disk, hard drive. The specific design objective is to increase the small-signal bandwidth of the actuator without sacrificing good seek performance. The proposed actuator comprises a stiffened arm structure and an orthogonal drive, moving-magnet motor. The magnetics and mechanics of the motor are studied through finite element analysis (FEA). A prototype actuator is built and tested using static forces and modal analysis. These results agree with the FEA results and provide valuable insight into the design of moving magnet motors.