A Study On Power Flow Transmission Characteristics Of Roots Blower With Multi-Excitation Sources

With the development of science and technology, modern machine is developing toward the trends of complication, low quality, heavy load and high speed, this brings the issue of structural vibration and structural noise on the mechanical equipments becoming more and more serious. As a typical transport equipment for gas, Roots blower brings serious vibration and noise which badly affects it's mechanical performance. This dissertation uses power flow as the estimation methods, establishes Roots blower spatial flexible couple dynamics model, studies the transmission rule of vibratory energy in Roots blower structure and further discusses it's dynamical characteristics. The study has great meaning for realizing vibratory noise analysis and control of complicated coupling structure, estimating and improving mechanical dynamical characteristics in theory and engineering fields. The main contents and contributions in the dissertation are as follows:The dynamics model of double floating raft vibration isolation system is established, power flow transmission function of the system is derived, the effects of structural parameters on power flow transmission are studied.Roots blower spatial flexible couple dynamics model is established. These methods of component transmission matrix, four-pole parameters and component dynamic function are used to derive the expression of power flow. The effects of gas dynamics parameters and structural parameters on dynamics characteristics are studied, the credible theory for reducing blower vibratory noise is provided.The finite element models of rotor system, blower box are respectively established, the preliminary limited rank modal frequencies and deformations are studied by ANSYS software.At last, an introduction of Experiment modal method is given.