The Study On The Control Technology About Noise Of Main Reducer Gear

With the rapid development of vehicle industry,vehicle has become an indispensable partner of mankind,vehicle has been integrated into people's daily life,and is closely related to everyone's work,study and life.In recent years,with the improvement of people's living standards,for consumers,vehicle is not simply a commodity,and the requirements for vehicle are constantly increasing.In addition to paying attention to appearance,price,power,economy,safety and so on,they also have their own psychological expectations for the comfort of vehicle.The purpose of vehicle comfort research is to reduce the vibration and noise in the car and improve the occupant's perception level.As one of the important assemblies of rear-drive or four-drive vehicles,the vibration and noise performance of driving axle is an important part of the vehicle's vibration and noise performance.The noise control of the main reducer gear of driving axle is very important to the vehicle's comfort.In this paper,the vibration and noise of driving axle is analyzed by finite element method,and the main reducer gear of passenger car driving axle is tested.Driving axle assembly mainly includes main reducer,differential,half-axle and axle housing.According to most research results,it is found that the fundamental cause of vibration and noise of driving axle is the meshing vibration of main reducer gears.Vibration is transmitted to driving axle housing through active gear bearing and differential bearing,which causes vibration on the surface of driving axle housing and radiates noise outward.The vibration and noise optimization measures of the bridge are mainly aimed at the main reducer gears.Because the differential does not work in the normal linear driving condition and has little contribution to the vibration and noise of the driving axle,the simplified model consisting of the main reducer gear,bearing,axle housing and half axle is not considered in the modeling.First,the HyperMesh software was used to pre-process the three-dimensional model of the driving axle,including geometric cleaning,mesh generation and mesh checking,material parameter definition and boundary conditions imposition.Then,the free modal analysis of the axle housing was carried out by Nastran software.Finally,Hyperview was used for post-processing,including checking the natural frequencies and modal shapes of each order,and analyzing whether the excitation generated by gear meshing of the main reducer would cause resonance of the axle housing.Then the radiated noise of the axle housing was calculated based on the modal method,and the modal-based response is calculated by the noise analysis software LMS Virtual.Lab.The radiated noise level and noise energy distribution of the axle housing at different frequencies were analyzed.The main position of the radiated noise energy was the starting point of reducing the noise of the driving axle.Finally,the vibration and noise bench test of the driving axle was carried out to verify the simplification of the finite element model and the application of boundary conditions.The spectrum analysis of the test results under the bench state was carried out to find out the vibration and noise characteristics of the driving axle and the main influencing factors.According to the test conclusion of driving axle bench,the optimization measures of main reducer gear were put forward and verified by bench test.