Research On The Dynamics Of Misaligned Rotor-bearing System With Rolling Bearing And Journal Bearing

It is unavoidable that misalignment appears in the rotor-bearing system because of some factors, such as manufacturing, installation and operational environment. The misaligned rotor can cause vibration and fatigue of bearings and twist of axles, etc; it is harm to work smoothly. Therefore dynamic analysis of misaligned rotor-bearing system (the static and dynamic characteristics of bearings, critical speed, stability and unbalance response) is very important in the theory and practical engineering.In this dissertation, the dynamic model of misaligned rotor-bearing system equipped with rolling bearing and journal bearing is developed by the method of lumped parameter. The dynamic behavior, such as the nature characteristics (critical speed, stability), unbalance response of the system, etc. is analyzed based on the theory of linear vibration. The main contributions and conclusions of the work are summarized as follows.Firstly, the load of every rolling unit of rolling bearing is calculated, the static and dynamic characteristics of the rolling bearings are analyzed. For the journal bearing, the film force is calculated based on the theory of linear vibration. On the base of narrow bearing theory and Campbell boundary condition, stiffness and damping coefficient expression is carried out.Then, after discussing the forces on the typical components of the system and their motions, the dynamic model of rotor-bearing system supported on rolling bearing and journal bearing is developed, in which the effects of the misalignment and unbalance of the rotor system are considered, and the dynamic characteristics of rotor-bearing system are simply investigated due to misalignment and unbalance. Additionally,the dynamics of the symmetric...