Research On The Design And Performance Of Gear And Shaft Of Electric Vehicle Reducer Based On NVH And Wear

With the rapid development of economy,the amount of oil consumption and air pollution as well as the development of new technology,the popularity of electric vehicles is the trend of The Times,the motor replaces the engine as the new heart of the car.The motor has the characteristics of constant torque at low speed and constant power at high speed.However,because the speed of the motor is much greater than the engine speed,it is necessary to design a reasonable reducer to ensure sufficient driving torque and better economy of the car.Because the speed of the reducer is higher than the traditional transmission,the NVH(Noise,Vibration,Harshness)problem and gear wear is more obvious.Therefore,according to the needs of the manufacturer,in the design of a two-gear reducer process,NVH and wear problems are taken into account for the design and processing of the gear.First of all,the important macro parameters of reducer gear are analyzed according to customer input,then the factors that should be considered for each parameter are analyzed and determined.Based on the analysis of the parameters,the macro parameters of the gear are determined.On this basis,a model of the gear and shaft is built in MASTA software,and the layout of the gear and sahft is preliminarily determined.Secondly,in order to conduct an general analysis of the reducer,a threedimensional model of the reducer housing is built,and the mesh is divided in the finite element software.In order to be able to build the overall model of the reducer,the finite element model is extracted from the polycondensation stiffness matrix and imported into MASTA software to be connected with the previously established shaft and gear model.Based on the reducer integral model,the deformation of the shaft and gear was analyzed under different working conditions.Based on the results of deformation,the misallignment and transmission errors of the system under different stress conditions are analyzed.After that,the gear profile is modified for the transmission error and misallignment,and the misallignment and transmission error before and after the gear profile is compared through MASTA software simulation.Finally,in order to obtain better NVH performance and gear wear performance,the gear is processed by polishing grinding process.And the technology was verified by gear test.On the basis of the gear test,in order to comprehensively evaluate the design of the reducer,the operation test of the reducer was carried out on the AVL platform,and the NVH performance and durability performance of the reducer were obtained.