Estimation for bearing preload of machine tool spindle based on vibration signal

A significant source of noise and vibration in high speed machine tool spindle is bearing induced vibration, which is caused by geometrical characteristics and interactions between rolling members with surface irregularities. In this paper, analytical approach was proposed to calculate the bearing internal load distribution of spindle, with consideration of the operating conditions. The influences of operating conditions to internal load distribution, contact angles were analyzed. Furthermore, the estimation of power spectral density (PSD) method was used to analyze determination of bearing frequencies. The bearing preload of machine tool spindle was estimated according to the change of ball bearing frequencies. Experiments were carried out in a spindle bearing test rig to verify the validity of the presented analytical method. The method described in this paper can achieve the estimation for bearing preload of machine tool spindle.