Research On Noise Characteristics Of Multi-pulley Transmission Of Synchronous Belt

Synchronous belt is widely used in the timing drive system of automobile engines due to the advantages of low transmission noise,simple structure,no lubrication,low price and low quality.With the improvement of NVH performance of automobile engine,it is required to reduce vibration and noise of automobile engine.As the main source of engine noise,the synchronous belt transmission noise has important research value.In this paper,the noise generation mechanism of the multi-pulley drive system of the engine timing synchronous belt and the noise prediction method are studied in detail.A noise source identification device is designed based on the beamforming acoustic array measurement principle.The noise test of synchronous belt multi-pulley drive is carried out on the noise test bench.By comparing with the simulation results,the variation rule of three pulleys drive noise is obtained.Firstly,on the basis of summarizing the research on the transmission noise of the synchronous belt,the theoretical analysis of the three pulleys and one belt transmission noise is carried out.The transmission noise is decomposed into meshing impact noise,vibration noise,friction noise,air flow noise and noise caused by tension pulley.The structure and working principle of tensioning pulley are introduced systematically.The natural frequency of the tension pulley is measured.Then the noise simulation analysis method combining finite element and boundary element is proposed,and the noise simulation analysis model of three pulleys and one belt drive is established.The noise distribution cloud diagram and amplitude-frequency characteristic curve are obtained,and the influence of the installation position of tension pulley on the noise is simulated and analyzed.Finally,the vibration test of ZA type synchronous belt multi-pulley drive system is carried out by using doppler laser displacement sensor.Based on the beamforming acoustic array method,the noise of the three pulleys and one belt drive system is tested,and the correctness of the noise generation mechanism and the simulation analysis results are verified by experiments.The influence of speed,tension force,tension pulley installation position and other factors on the transverse vibration and noise of the automobile synchronous belt was studied.The results have important value for improving the noise characteristics of multi-pulley transmission system of synchronous belt and accelerating the development of vibration and noise technology of synchronous belt transmission system in China.It provides theoretical basis for reducing vibration and noise of synchronous belt multi-pulley transmission system and has certain practical significance.