Research Of Dynamic Balancing Of Flexible Rotor And Rotor Dynamic Characteristic

Rotating components are widely applied in such machines as aeroengines,industrial compressors and electromotors. It plays an important role in such national economic fields as powe,aviation machine,chem,spin and so on. Because the vibration of the rotors bring so much expense which can be avoided. And rotor unbalancing is one of the main causes of vibration and noise, which affects work performance and fatigue life directly. So it is of significance to research Rotor Dynamics. There is research of rotor balancing of flexible rotor and rotor dynamic characteristic in the project background of compressor rotor.First, the paper introduces how to build the finite element model of compressor reasonably, how to get the mass properties by means of experiment and how to compute magnetic stiffness. On the base of them, the finite element model is the reasonable. Second, to validate the finite element model of rotor dynamic is to analyze and compute the model theoretically, to do some experiments on the Bently Rotor Experiment Table and to compute the finite element model employed by MSC.Nastran software. The finite element model is reliable by comparing the theoretical result, experiment one and finite element one done by MSC.Nastran. And it shows that the finite element method can be employed to research the rotor dynamic. Then, two methods of rotor balancing are presented:mode balancing method and influence coefficient method. And it is told that why the influence coefficient method is chosen in the paper. Last, the balancing procedure is based on a numerical approach using rotor dynamics theory coupled with the finite element and influence coefficient methods. The compressor machine is composed of a flexible rotating part (rotor) and a non-rotating part (stator). They are mounted on suspensions. The rotating part runs at a constant speed of rotation and mounted on bearing. Assuming that the unbalancing masses are relatively well defined, such as in the case of a crank-shaft, the excitation force is more exactly calculated. Moreover, the industrial application concerns a refrigerant rotary compressor whose experimental investigation permits validating the model. Assuming that the balancing planes are located on the rotor, it is shown that balancing on target planes of the rotor may reduce the vibration level of both rotor and stator. In the case of the rotary compressor, this avoids rotor-to-stator rubs and minimizes vibration transmission through pipes and grommets. The job is done on the base of rotor dynamic theory and finite element, and the results are still further validated by experiments. But the result provides the reference values for experiments and can be used in the industrial application directly.