The dynamics of motorized spindle of machine tool was analyzed based on transference matrix (TM), and the numerical calculation of a specific example was executed with MATLAB. The validity of this mathematic model was verified by experimental modal analysis (EMA). The results showed that the tolerance of the first set natural frequency is about 1.2%, but the tolerance of the second set is a little high, because TM is supposed to be the theory of lump mass and after the continuous model was dispersed, the tolerance of higher set natural frequency is considerable. Thus, this model is reliable for calculating the lower set modal parameters. Asymmetry details such as the screw holes and key slots are neglected during simplifying the model when using TM. The natural frequency obtained by TM is less than that by EMA, which means the symmetry modal shape can not be obtained.
