Study on vibro-acoustic characteristics of disks-spindle system of hard disk drives

An approach is present to predict vibro-acoustic dynamic characteristics of ball-bearing disks/spindle systems of hard disk drives (HDD) including flexible stationary structures, such as top cover, shaft and basement, etc. The discrete governing equations of motion for the system are derived through the use of Lagranigain equation. The flexible stationary part is examined and the noise predicting from the stationary part are calculated and analyzed based on finite element method. Some experiments were carried out to testify the approach. The results show that the noise level is determined by the motor forcing function, disks/spindle unbalance mode (0,0) and the amplification due to structural resonance of the stationary part.