Hybrid modeling and analysis of structural dynamic of a ball screw feed drive system

In order to get the complete structural dynamic of the ball screw drive this paper proposes a hybrid modeling method. The dynamic characteristic of a ball screw is analyzed by a continuous beam approach having axial, torsional and flexural dynamics. The dynamic equation of a rotating screw subjected to the axially moving load with general boundary conditions are obtained through Lagrangian approach. Compared with the experimental results, the model can accurately capture the structural dynamics of the ball screw drive. Influences of parameters, such as table mass, screw pitch, table position and preload on the structural dynamic of the ball screw drive are discussed. Finally, the hybrid model is integrated into a servo control system, which makes an integrated design of the servo-mechanisms possible.