Characterization of NRRO in a HDD spindle system due to ball bearing excitation

This research characterizes the source of NRRO by analyzing NRRO of the outer-race rotating spindle and the inner-race rotating spindle, respectively. It also characterizes the transmission of NRRO from the ball bearing to the disk by investigating NRRO and the frequency response function before and after mounting the disks on the spindle, respectively. Finally, it investigates the effect of the visco-elastic damping material to reduce NRRO by inserting it in the transmission path of NRRO. This research shows that visco-elastic damping material reduces NRRO by damping out ball bearing excitation, and it improves the frequency response function in the frequency region where the loss factor of the damping material is effective.