Study On The Radiating Noise Prediction Of Rollers Driving Mechanism

Rollers driving mechanism is widely used in industrial production.However,the mechanism will produce great vibration noise pollution during the work process,which not only lead to serious influence to the physical and mental health of the workers and their motivation,but also restrict the improvement of social productivity.Test and simulation were collaborated for predicting the noise of the rollers driving mechanism.Finally,a believable method for noise prediction was established.The following research is conducted in this paper.First of all,with reference to the national standard,a proposal for vibration noise test of the rollers driving mechanism was formulated.At the same time,measured positions of vibration and noise signals were determined.Vibration and noise signals were captured under the different working conditions of rollers driving mechanism during the test.Then study on its vibration and noise response by analyzing vibration and noise signals in a piece of analysis software.Secondly,the force in vertical direction was found to be a main reason for the vibration response of the rollers driving mechanism according to force analysis between rollers.So a vertical structural mechanical model of rollers driving mechanism was established through the use of lumped parameter method,and vibration differential equations were established according to the mechanical model.The all of the lumped mass,stiffness and damping parameters were determined according to measured sizes of the mechanism and searching for the material parameters.Finally,the vibration velocity responses were obtained according to solving the differential equations in which the only unknown parameter is excitation force.In addition,a structural model of this rollers driving mechanism was established in CATIA software according to the measured size of the mechanism,and a structural finite element model of the rollers driving mechanism was established in Hypermesh software.Then the finite element model was imported into a piece of finite element analysis software for modal analysis.The next step is that the finite element model of the rollers driving mechanism and the vibration spectrum from test was imported into the finite element software.According to the technology of inverse excitation force identification,equivalent excitation load spectrum at rollers’ contact positions was calculated.The equivalent excitation load spectrum was imported into vibration velocity responses which was figured out before to calculate the vibration velocity response of each lumped mass.Finally,a noise radiation model of the rollers driving mechanism was established based on points sources and a line source.The noise radiation of the rollers driving mechanism was regarded as a radiating noise superposition of a line source and 20 points sources.The values of sound pressure levels of related measured points in the rollers driving mechanism were calculated by importing the calculated vibration velocity and the related structure size data into the noise radiation model.Comparing the simulated values and the test values to modify the noise radiation model for a better simulation results.At last,a more accurate radiating noise prediction method is established.