Effect of drive modes on the acoustic noise of fluid dynamic bearing spindle motors

The torque ripple is one of the major sources of acoustic noise in the fluid dynamic bearing (FDB) spindle motors. This paper analyzes the relationship between the acoustic noise frequency, harmonic current and harmonic field, and compares the acoustic noise produced in FDB motors driven by different modes. Results show the effect of drive mode on acoustic noise is significant in the FDB spindle motors.