Study On The Optimization Of Transmition Efficency Of Main Reducer In Driving Axle For Heavy Truck

The drive system of drive axle is located between the automobile engine and the driving wheel,and it can increase torque,reduce speed and realize power transmission.It is an important part of automobile transmission system.In the working process of drive axle,the mechanical transmission will inevitably cause a certain degree of power loss which determines the drive efficiency of the drive axle.It is an important technical index to evaluate the fuel economy of vehicle.With the enhancement of environmental awareness and the strong support of the national government,people are more interested in high efficiency,high performance high-end truck,and it has important practical significance to improve the transmission efficiency of truck drive axle.This paper takes the truck Q435 drive axle as the research object,analyzes the transmission torque path of the drive axle.Combining with the principle of gear meshing and the relevant knowledge of elastohydrodynamic lubrication,the power loss analysis of the main reducer of the main part of the power loss of the drive axle is carried out,and the power loss of the main reducer is mainly contained in the following three aspects: gear meshing power loss,bearing friction power loss,gear oil churning power loss.According to the empirical formula of power loss in each part,a theoretical model is established.The Q435 series drive axle is tested on the test bench of transmission system,and combining with the meshing efficiency of hypoid gears,the curves of the transmission efficiency of the drive axle are obtained.The test results under different input conditions are collected,and the theoretical model of transmission efficiency of the main drive of the drive axle is modified,and the transmission efficiency model with external conditions is obtained.Theoretical model of power loss of main reducer based on drive axle takes the volume of the main reducer,the efficiency of gear meshing loss and the power loss of the main reducer of the drive axle as the optimization objective,and the contact fatigue strength of gear tooth surface and the bending fatigue strength of tooth root as constraint conditions,and establishes the multi objective optimization model of the main reducer gear.Based on the genetic algorithm,the optimization model of the final reducer is solved by using the function of MATLAB global optimization toolbox,and KIMOS software is used to verify the strength of the optimization results and check the meshing characteristics.The results show that the gear meshing efficiency is improved by 3.5966% after the multi-objective optimization of the gear structure parameters of the main reducer.The analysis of power loss of main reducer and research on bench test and multi objective optimization of alignment parameters of double sided gear has a great effect on optimization of transmission efficiency of drive axle,improving transmission efficiency of drive axle and vehicle dynamic performance,and so on.