Abstract: Digitized manufacturing is the kernel of advanced manufacturing technologies, and the realization of digitized and quantitative description of manufacturing process is the key to promoting the digitized manufacturing. Spindle assembly is one of the most important components of CNC equipment. Aiming at the bearings which are most vulnerable in the spindle system, a new time-frequency analysis method called S transform is studied, time-frequency distribution of vibration signals collected from spindle is obtained, and a singular value decomposition method is employed to condense the time-frequency matrix data so that the fault features can be extracted quantitatively. Simulation and experimental studies demonstrate that the proposed method can identify the running state of spindle bearing accurately. Thus a new idea for the evaluation of spindle service performance of digitized manufacturing equipments is provided.

Key words: Bearing, Digitized manufacturing, S transform, Spindle