Method and apparatus for spindle stiffness and/or damping in a fluid dynamic bearing spindle motor used in a hard disk drive

摘要

A test stand is disclosed for estimating the dynamics of a Fluid Dynamic Bearing (FDB) coupling a spindle motor to a rotating hub. The hub includes an air target and displacement plate. At least one air jet strikes the air target, and at least one displacement sensor engages the displacement plate to create a displacement reading. The displacement reading(s) are analyzed to estimate the dynamics of the FDB. The estimates may include but is not limited to the stiffness and/or damping of the FDB.