Rotor Dynamic Analysis And Design Of 11MW High Speed Motor

With the speedy development of industry modernization,the demand for high speed motor is increasing.At present,there are several problems during the operation of high speed motor.Firstly,the noise of motor deteriorates the working environment.Secondly,the long-term reciprocating movement of motor accelerates parts failure.Thirdly,the rotor vibration leads to the generator outage and causes substantial economic loss.Therefore it's necessary to lucubrate the rotor system of motor.The thesis is based on the finite element method,which studies the dynamic characteristic of rotor system in 11 MW high speed motor.At first,the tilting-pad bearing mechanics model and rotor finite element model are established in this paper according to the structural characteristics and process feature of rotor system.Then,the dynamic characteristics of bearings are analyzed.The dynamic parameters of the bearing are imported into the rotor model to analyze the critical speed of rotor by the finite element method.Using the model to calculate the unbalance response of rotor system and check the unbalance response by API standard,analyzing the stability of rotor system with log decrement.At last,the modal frequency and the first critical speed in BODE plot of rotor is measured by model test,high speed dynamic balance test respectively,and the vibration test is used to verify the correctness of the finite element model and the finite element analysis.The first critical speed which is calculated by the finite element method have a great agreement with the result of the tests.There is a certain engineering value of this paper,which establishes the finite element model of rotor and analyzes the dynamic characteristics by the finite element method.The paper is also used to guide the engineering design of motor.