Analysis of Vibration of Hard Disk Spindle Caused by Ball Bearing.

This paper describes theoretical and experimental analysis of radial vibration of hard disk spindle supported by two ball bearings with form errors. Assuming a small sinusoidal waviness of n-th order on the inner race, outer race and rotating balls, the displacement of the center of spindle while rotating is numerically calculated. The frequency and amplitude of the spindle vibration are analyzed by numerical FFT. It is found that the response of (0, 1) unbalance mode of disk/spindle system due to bearing form errors occur only when the position of balls in two bearings are different each other and that the calculated resonance characteristics qualitatively agree with experimental results.