Robust torque optimization for BLDC spindle motors

A robust design for torque optimization of brushless de spindle motors appl ied in a hard disk drive, using the Taguchi method, is described and illust rated in this paper. The optimal design process takes into consideration no ises that arise in the manufacturing process, such as manufacturing toleran ces for the stator tooth shape and variation of the rotor magnet magnetizat ion distribution due to the magnetization fixture and process. The objectiv e of the optimal design using the combined Taguchi's design of experiment ( DOE) and finite-element analysis (FEA) approach is to ensure that the spind le motor torque performance is insensitive to the noise, with moderate comp utational effort. The optimization is realized by a simulation and analysis tool that integrates Taguchi's DOE with the FEA. In this paper, the design optimization process is described and the results are presented.