The Design Of An Adjustable Frequency Vibration Absorber

Roots blower has a very wide applications in the industry, but the noise of roots blower is very big, the influences the staffs physical and mental health seriously and also greatly polluted the surrounding environment.The noise of Roots blower is mainly includes the aerodynamic noise and mechanical vibration. In order to effectively reduce the noise generated by roots blower at Purification workshop of aluminum electrolytic factory, an adjustable frequency vibration absorber was designed in this article.The study of theoretical basis in this paper includes the theory of mechanical vibration, the damping principle of dynamic vibration absorber and evaluation methods of damping effect for vibration. Based on these theories and the energy of the system, the principle of vibration absorber is analyzed. Base on the structure, principle, application scope and mode of action of active vibration absorber, a kind of design scheme of vibration absorber is proposed. The absorber adopts the electromagnetic driving way, which is used to make transmission process has good flexibility, and reduces the influence of vibration on the absorber. A continuous beam structure is applied on the elastic to realize the natural frequency of vibration be continuous adjustable within a certain range. An electromagnetic damping device is designed; it can transfer the vibration energy which is absorbing by the absorber into electricity in a timely manner, and consume it through the circuit resistance. According to the plan, completing the design based on the electromagnetic driving structural parameters of the cantilever beam of vibration absorber.A dynamic model of the absorber was established and the principle of vibration absorber was analyzed.And the structure parameters of vibration Absorber are optimized. Based on the dynamic model, presenting a method which can optimize the size parameter of the absorber, and getting the geometric size of the beam of optimal absorber vibration absorption performance.In order to simplify the calculation, the flat plate structure which has the same natural frequency of roots blower was used as the main system of vibration. Base on the finite element methods, the damping effects before and after optimization of dynamic vibration absorber is analyzed. The performance of vibration absorber of cantilever beam type driven by electromagnetic was analyzed, and presenting the adjustable range of the absorber, and also analyze the damping effect of the absorber after frequency shift and damping effect of absorber.through the analysis of influence on the vibration reduction of vibration absorber by installation position. This is used to provide the basis on choosing the installation position of vibration absorber. Based on the simulation, the achievement can be described as follows:through optimizing the size parameters of the vibration absorbing device, which can make its damping effect better; Based on the cantilever beam of electromagnetic drive frequency shift characteristics of isolator has good absorption, within the adjustable scope,which can effectively reduce the vibration for the main system; Installation position has little influence on the damping effect of the vibration absorber which is used to find an appropriate installation position on the main system of vibration absorber.