Research On The Design And Calculating Method Of Heavy Vehicle’s Drive Axle Transmission System

Drive axle locates in the end of auto transmission system,as one of the maincomponents of heavy duty truck assembly,including lord reducer,differential,wheeledges reducer,wheel transmission device and drive axle housing,its basic function isto enlarge the torque from the drive shaft or transmission,and distribute the power tothe right and left drive wheels reasonably.The stress of the drive axle is very complexbeacause of the ever-changing road conditions in the course of driving,inheriting allkinds of vibration,impact and force from the roads and the car body,so the workingenvironment of the drive axle is very wicked.Therefore the drive axle performancecan make very big influence to the car, relating to the car’s transmission efficiency,vibration noise, durability, comfortableness,passability and vehicle smoothness,andthe design quality of the drive system that is the heart of drive axle influence theperformance of drive axle remarkablely. The traditional design is based on theProduction experience and according as formula, charts and manuals obtained byusing mechanics, mathematics and regression methods,the design methods has certainblindness and randomness naturally.At present,some enterprises and institutions usethe finite element method, compare with the traditional design methods the analysisprecision was proved and the product design cycle was shortened greatly,but theanalysis objects focus on the drive axle housing generally,and other important partslike main reducing gears were rarely analyzed.The design process and methods are the most key link influencing the productdesign and development of drive axle no matter which design methods wereused.Nodays some enterprises don’t have a set of systematic design process andmethods,for example, some manufacturers design drive axle refer to the foreignsimilar products,as a result the design cycle and cost would be increased inevitablilyand the enterprise benefit was influenced.So researching the design and calculationmethods of drive axle transmission system has important academic value and practicalvalue.According to the structure characteristics of the drive axle transmissionsystem,design order between the parts of drive axle transmission system of heavyduty truck were researched,and the design process of each of its components wereexpounded detailedly, meanwhile the calculating and selecting methods of each of itscomponents were researched and summarized based on the design order and process.Through the analysis of the matlab SQP optimization algorithm, the establishmethod of the main reducing gears mathematical model were researched with thetarget of volume minimize emphatically.After the optimizing the building method andstep of its finite element model was described detailedly then its dynamic meshingperformance like angular velocity,transmission error,tooth surface contact force,cont-act ratio and the dynamic strength were studied too.A set of drive axle transmission system was designed by using the design andcalculation method,then the system was analyzed comparing with a existing drive axiswhen meeting the same design requirements,the design results show that the designmethod can achieve the design of drive axle transmission system better.