Optimization Analysis Of Vehicle Rotary Vane Electric Vacuum Pump Noise

With the consumption of energy and the increase of environmental pressure in China,the state puts forward new requirements for the development of automobile industry.Small emissions and new energy vehicles have become the trend of development in the future.The rotary vane electric vacuum pump is widely used in the vacuum assisted braking system of small displacement and new energy vehicle because of its good performance,but the vibration and noise of the pump is very serious.With the improvement of automobile comfort requirements,it is necessary to study and control the vibration and noise of motor vehicle rotary vane electric vacuum pump.In this paper,the vibration and noise of motor vehicle rotary vane electric vacuum pump are studied.First of all,the working principle,basic structure and performance test are deeply studied,and the sound generating mechanism and noise reduction methods of the main noise sources are analyzed.In this paper,the aerodynamic noise and the mechanical noise in the working chamber are optimized.Then,the hydrodynamic software ANSYS Fluent and acoustic simulation software Virtual.Lab Acoustics are used to jointly simulate the aerodynamic noise in the exhaust process.The large eddy simulation method and acoustic boundary element method are used to carry out the numerical calculation,and the fluid simulation is obtained by using the method of large eddy simulation and the acoustic boundary element method.Results and acoustic simulation results,using the noise control method,fluid simulation results and acoustic simulation results to optimize the structure of the silencer cover;The results of fluid and acoustic simulation before and after the optimization of the silencing cover show that the gas flow direction is constrained and the sound pressure value of the noise is obviously reduced after the optimization.Then,the mechanical noise of the working chamber is studied,and the dynamic simulation of the working chamber is carried out by using the virtual prototype software ADAMS,and the simulation results such as the motion curve of the rotating disc and the contact force between the components are obtained.Through the analysis of the simulation results,it is found that the contact force between the rotating plate and the stator is the most important factor affecting the mechanical noise.According to the analysis results,the simulation results before and after the optimization show that the contact force between the rotating plate and the stator is obviously reduced,thus reducing the production of mechanical noise.Finally,the experiment is carried out in the semi-silencing chamber.First,the clearance between rotor and stator,which affects the mechanical noise,is tested and compared.The result shows that the gap between the rotor and stator is 0.03 mm,which can guarantee the basic performance of the noise at the same time.Then the simulation results of aerodynamic noise and mechanical noise are verified by experimental comparison.Using all the noise reduction measures,the maximum sound pressure level of electric vacuum pump noise is measured to reduce 3?5dB(A).