Study On Optimization Of Tooth Profile Surface Of Key Gear Pair Of Drive Axle For Vibration And Noise

With the rapid development of automobile industry and the continuous improvement of automobile performance and quality,people’s request for the performance of automobile NVH(Noise,Vibration,Harshness)is more and more high.Car for about a third of the performance problem is derived from the vibration and noise of the car,the car drive axle is one of the main vibration and noise in the automobile transmission system,is an important factor of restricting car product quality and performance,so how to reduce the noise of the automobile drive axle,improve the whole harshness(NVH)of vehicles performance has caused the wide attention of scholars and engineers.Automobile drive axle vibration noise is the main cause of the main reducer of the hypoid gear meshing gear meshing impact,the drive shaft,bearings and other components,to the drive axle casing,formed the incentive for drive axle casing,if the frequency of exciting force is located in the shell near the natural frequency,resonance is caused shell,which produce large noise;In addition,for the drive axle with helical gear,the poor meshing state of helical gear and uneven stress on the tooth profile surface of the drive axle in operation will also cause the resonance of the shell and produce noise.The above problems,the author of this paper put forward two kinds of drive axle vibration noise reduction scheme,two methods are from incentive flow noise,optimize the key drive axle gears tooth profile surface,the first one is on the surface of wheel hypoid gear tooth profile processing surface texture,the second is the microstructure parameters of the cylindrical bevel wheel has been optimized.In order to reduce the noise of the drive axle by machining the surface texture of the tooth profile of the hypoid gear big wheel,the three-dimensional model of the parameterized hypoid gear blank was established by MATLAB+CREO co-simulation.The helix equation of the hypoid gear and the involute equation of the equivalent gear corresponding to any point on the helix were derived.The program of calculating the coordinates of the discrete points on the tooth profile surface of the hypoid gear was designed in MATLAB.The discrete points of tooth profile calculated in MATLAB were imported into CREO to establish a three-dimensional parameterized tooth profile model of hypoid gears,which provided a model basis for the bearing contact analysis of gears using finite element method in the future.A set of laser equipment and fixtures for machining the tooth profile surface of hypoid gears were established,and the surface textures with different morphologies could be fabricated on the tooth profiles of hypoid gears of different sizes.For the optimization of the microscopic parameters of helical gear,an omni-directional modification method of tooth direction modification combined with tooth profile modification was proposed,and the modification effect was observed by using the simulation results of MASTA.