Numerical Analysis of Rotor Dynamics of Dredge Pump Shafting

The operating condition of dredge pump is highly complicated, a technical issue is the shaft vibration problems, which has great effects on the operation safety and stability of pumps. This paper introduces a mathematical model of rotor dynamics for the dredge pump, which is used to numerically investigate critical speeds and mode shapes of the pump shaft under different bearing stiffness and damping. The effects of bearing stiffness and damping on shafting vibration characteristics are considered. The results show that the stiffness has great effect on 1st and 3rd order critical speed and the damping effect can be ignored. The stiffness has little effect on shafting axial and torsional natural frequency, but has great effect on lateral natural frequency. The analysis method of rotor dynamics dealt with in this paper can provide a foundation for the design of dredge pump shafting.