Effect of tilting angle on the dynamics of tilting table driven by worm and worm wheel

The dynamics of tilting table behaves differently during five-axis machining due to the constant changes of the position of its center of mass which leads to different forces acting on parts of the transmission system. In this research, the lumped parameter method is used to model the dynamics of tilting table driven by worm and worm wheel in the tilting direction, where the varying stiffness of the transmission system at different tilting angles is considered. The impact testing experiments of tilting table system with tilting angles from 0° to 90° are also performed to verify the analytical model. The results from sensitivity analysis show that the three stiffnesses have a great effect on the variation of system natural frequency in the tilting direction, including the equivalent tangential meshing stiffness of worm and worm wheel, the torsional stiffness of worm wheel shaft, and the axial stiffness of worm supporting bearings. Moreover, the variations of system natural frequency with the three stiffnesses at different tilting angles are further investigated.