Hybrid modeling and time-varying analysis of vibration for a ball screw drive

In order to get the dynamic behavior of a ball screw drive, a hybrid modeling method was proposed here. The ball screw was considered as a distributed-parameter model, while the other more rigid components were considered as lumped-parameter models. The dynamic models for axial, torsional and flexural vibrations of the screw were built using the power balance and Ritz series method. The mass, stiffness and damping matrix of the system were deduced. The influences of parameters, such as, table mass and table position, on the structural dynamic behavior of the ball screw drive were discussed. The mode shapes of the screw for different table positions were obtained. The results revealed that the axial vibration of the ball screw drive is sensitive to table position and mass, while its torsional vibration is insensitive to table position and mass; table position has a large influence on the flexural vibration of the ball screw drive. Compared with the test results, it was shown that the proposed hybrid model can correctly predict the dynamic characteristics of a ball screw drive.