Extraction of bearing coefficients of fluid-dynamic bearing spindle motors

In this digest, we report significant improvements over the method developed by Shen et al. [1] to extract bearing coefficients of a fluid-dynamic bearing (FDB) spindle motor in hard disk drives (HDD). An exact formulation is developed to extract bearing coefficients. Angular and radial displacements are measured to improve accuracy. Bearing coefficients are extracted successfully via three rounds of experiments.