Study On The Influence Of Teeth Profile Of Synchronous Belt On Transmission Noise

The tooth profile of automobile synchronous belt directly affects the performance of vibration and noise performance in the process of synchronous belt transmission.With the continuous improvement of NVH performance requirements of automobile engine transmisson system,higher design requirements are put forward for the vibration and noise performance of timing transmission system.This paper in view of the same pitch ZA type straight synchronous belt and RU type arc-tooth synchronous belt are studied,through the process of meshing interference noise theory analysis,simulation analysis and the vibration noise test,the combination of system study the rule of tooth shape on the influence of the noise.Based on the analysis of noise mechanism of synchronous belt drive,the generation mechanism of meshing impact noise and transverse vibration noise in synchronous belt drive is analyzed.It's pointed out that meshing interference is the main factor leading to vibration and noise.Based on the coordinate transformation theory,the meshing interference is the main calculation model of automobile synchronous belt drive is established.The variation law of interference area under different meshing conditions is obtained,and the variation law of interference atea of straight tooth and circular arc tooth synchronous belt under different pitch difference is calculated by Matlab.Based on the combination of finite element method and boundary element method,the simulation model of two pulleys synchronous belt transmission noise prediction is established,and the noise distribution nephogtam and amplitude-frequency characteristic curve of the straight-tooth and circular arc-tooth synchronous belt are obtained with the speed and tension of the driving wheel.The meshing impact vibration at the meshing point of straight tooth and circular arc tooth synchronous belt is measured by Doppler laser displacement sensor on the two-wheel unloaded synchronous belt performance testing machine,and the variation law of meshing impact vibration of different tooth profiles is obtained,which provides a basis for the analysis of the influence of tooth profile on transmission noise.Based on the principle of acoustic array measurement,a synchronous belt noise source identification device is designed and built,and the noise performance of straight tooth and arc tooth synchronous belts is experimentally studied.Through experiments,the sound pressure distribution nephogram and noise time domain frequency domain curve of synchronous belts with different tooth profiles are obtained as a function of rotation speed and tension force.The test results are compared with the transmission noise simulation analysis results to verify the feasibility of the transmission noise prediction simulation model.The research results of this paper have certain theoretical significance and application value for improving the selection of synchronous belt for timing transmission system of automobile engine and improving the performance of NVH.