Finite Element Analysis on the Rod Fastening Rotor Bearing System

Modern large-scale gas turbine's rotor is the main form rod rotor. The contact friction between wheels, the pre-tightening force of the rod and bearing system have an effect on rotor dynamics. According to the structure characteristics of rod rotor, contacting model is established. In the rotor modal, contacting friction, the pre-tightening force of rod and bearing system is included to get natural frequency and mode shape. Through the analysis of rotor, with increasing the pre tightening force, the overall stiffness and natural frequency has increased. The natural frequency is increase fast when the pre-tightening force is small. With the increase of the pre-tightening force, speed of the natural frequency is slow. Bearing system with changes in speed, its oil film dynamic coefficients coefficient changes also have some impact on the inherent characteristics of the rotor.(1)