The dynamic performance affected by the axial magnetic force for a DVD spindle motor

The axial magnetic force induced by rotor and stator is an important perfor mance index to affect the dynamic characteristic on a high-precision DVD sp indle motor design. In this research, the axial magnetic forces are calcula ted at varying relative heights between rotor and stator by 3D finite eleme nt method (FEM), and compared with the experimental data. Based on the resu lts of simulation and measurement of the axial magnetic forces, the dynamic vibration could be apparently improved and decreased from 76.7 to 3.85 mg at 6000 rpm with disc by a variation of relative height on a DVD spindle mo tor. The torque constant and running current are also applied as performanc e indices to evaluate dynamic performance in the paper. (C) 2000 Elsevier S cience B.V. All rights reserved.