Vibration response simulation of a machine tool spindle system in non-stationary regime

Bearing and gear are one of the most important mechanical sources for vibration and noise generation in machine tool spindles. In this paper, we study the non-linear dynamic behavior of a machine tool spindle system in transient regime. Driving and driver rotors are, respectively, powered by a motor torque and loaded by the cutting force. They are supported by two identical Rolling Bearings (RBs). Gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiffness due to the variation of input rotational speed. The dynamic parameters of RBs are modeled by stiffness and damping matrices computed by the derivation of the bearing forces. The equations of motion are solved iteratively using Newmark time integration method. The numerical results of the dynamic responses of the system come to confirm the significant effect of the transient regime on the dynamic behavior of a gear set.