Abstract
This thesis mainly discusses the effect of misalignment on the rotor system, and also proposes a generative mechanism of the active balancing balancer. The content can be divided into three parts. In the beginning, we use Bernoulli-Euler beam theory as the foundation of the entire research to model the rotor system. After this, we discuss the difference on the dynamics of the rotor when the bearing supports are considered as the rigid or linear elastic. Besides, through the establishment of the theory, the result shows the effect of misalignment on the dynamic of the rotor is the additional static deflection when the stiffness of the bearing support is considered as linear elastic. This phenomenon also shows the effect of the misalignment on the rotor dynamic is mainly due to the nonlinear bearing stiffness and verifies the importance of the establishment of the nonlinear bearing stiffness model. The another discovery is that the whirling frequency of an continuous rotor on the linear bearing stiffness supports not only have the relation to the rotating speed of the rotor,but also the different parts of the rotor. It means the whirling frequency of the middle part of the rotor will be different from the end part under the same rotating speed. The secondary part is the modeling of the angular contact ball bearing and derivation of the stiffness matrix. In this part we use the method proposed by De Mul et al, using the Hertz contact theory to describe the contact phenomenon happening in the angular ball bearing. And find the stiffness matrix in all direction. It can be used as the input when we want to analyze dynamic of the rotor system equipped with the ball bearings as the supports in the future. In the last part, we introduce many kinds of the online active balancing system on the market, and propose a new concept of the online active balancing system adopt the supersonic motor as the driving mechanism.