| The gas turbines are widely used in modern industry,as the core component of gas turbines for power transmission and energy conversion,the dynamic characteristics of the rod-fastening rotor-bearing system directly determine the operational characteristics and stable operation of the gas turbines.Therefore,the core technology of the rod-fastening rotor-bearing system is one of the hot topics of related researchers.In this paper,the dynamic characteristics of the circumferential rod-fastening rotor-journal bearing system are studied as the object.The main contents are listed as follows:1.Considering the micro morphology features of the rough surface,the equivalent bending stiffness of the adjacent wheel disk of the rod-fastening rotor is studied based on the Greenwood-Williamson model.The calculation formulas are derived,on this basis,the variation law of the equivalent bending stiffness with the change of preload.Based on the finite element method and Timoshenko beam-axis unit,the motion equations of elastic axis section and rigid wheel disk are derived,and then the dynamic model of the rod-fastening rotor is established.On this basis,it is found that the numbers of rod-fastening are large,the preload force can be uniform distribution to ensure the stable operation of the rotor.2.The differential equations of motion of the circumferential rod-fastening rotor-journal bearing system are derived based on the D'Alembert principle,and the Wilson-? method is used to solve the differential equations of motion.In this thesis,the example results show that when the rotational speed of the rotor as the control parameter,the system response is periodic-1-periodic-2-quasiperiodic;when the eccentricity of the wheel disk as the control parameter,the system response is periodic-l-periodic-2-quasiperiodic;when the shaft stiffness as the control parameter,the system response is quasiperiodic-periodic-2-periodic-1.3.Considering the rubbing between the wheel disk and the stator,the dynamic model of the circumferential rod-fastening rotor-journal bearing system is established,the differential equations of motion of the system are derived and are solved by Wilson-? method.In this thesis,the example results show that when the rotational speed of the rotor as the control parameter,the system dynamic response is periodic-1-quasiperiodic-periodic-5-quasiperiodic;when the eccentricity of the wheel disk as the control parameter,the system dynamic response is quasiperiodic-periodic-l-periodic-5-quasiperiodic-periodic-2;when the radial stiffness of the stator as the control parameter,the system response is periodic-4-quasiperiodic-periodic-1.4.Based on the ANSYS Parametric Design Language,the modal of the rod-fastening rotor is analyzed to obtain the first ten natural frequencies with corresponding vibration mode cloud map,and the maximum amplitude position of the rod-fastening rotor.Then the structural strength of the rod-fastening rotor is analyzed,and the variation of the Von Mises equivalent stress of each wheel disk and rod-fastening rotor under different preload forces is studied.The transient motion law of the rod-fastening rotor is analyzed.It is found that the law of transient motion and the rotor bearing are similar with the comparison with two of them.The researches above is of great significance and provide a valuable theoretical reference for the study of the stability of the rod-fastening rotor-bearing system subsequently. |
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