Design Of Independent Final Drive And NVH Optimization Of Performance

With the rapid development of our country's economy,people have higher and higher requirements on the quality of cars,such as safety,comfort,quiet and so on.Independent main reducer can improve the handling stability and comfort,mainly used in the higher end of the rear drive or four-wheel drive vehicle.Independent main reducer is seldom used in domestic independent brands,and domestic independent research and development experience is also insufficient.However,independent main reducer needs a set of perfect design and development technology.In this paper,the independent main reducer design and NVH performance optimization are studied by combining theory and engineering development experience.The work is carried out from the aspects of structure selection,design verification,test verification,analysis and optimization,etc.The specific contents are as follows:First,according to the requirements of project development,the independent main reducer is selected and designed,such as the main reducer's deceleration form,gear type,differential type and support form.And in order to ensure that the main reducer has enough strength,the use of theoretical calculation method and CAE analysis method,calculate and check the main reducer unit tooth length on the circumference of force,tooth bending strength,tooth surface contact strength and analysis of shell strength.Secondly,the design requirements of stiffness are studied and analyzed,and the allowable dislocation quantity of the master-slave gear and the allowable maximum deviation angle of the inner and outer rings of the bearing are set.In addition,MASTA model is used to analyze the displacement of master slave gear and the deviation angle of the inner and outer rings of the main reducer bearing,so as to ensure that the main reduction gear meshing well,bearing running well,reducing the wear and noise of the gear and bearing,etc.,within the range of design requirements.Then,using the method of theoretical calculation,the main reducer of the bearing force analysis,calculate the bearing load,check the bearing static load and life,ensure the reliable work of the bearing.According to the working principle of lubricating oil circulation and the test method,the oil passage is optimized to make the gear and bearing lubricate well.Finally,in the performance test stage of the sample vehicle,aiming at the NVH problems of independent main reducer encountered by the project,such as the roar and squeal of the gear,the occurrence mechanism of them was found out through the real vehicle test and MASTA modeling and analysis method,and the structure of related parts was optimized anddesigned.These NVH problems have been effectively solved by real car verification.