The Matching And Optimization For Transmission Shaft Of Heavy Duty Truck

The drive shaft is one of the important parts of the automobile site structure,whose main function is to transfer the car engine torque and speed.Because of its low natural frequency and cardan joint additional force,the resonance phenomenon is easy to appear in the car when driving,which is not conducive to the comfort of the members.So the study has important significance on the transmission shaft to reduce vibration and noise in the vehicle and improve occupant comfort.Due to long design period and other reasons traditional design method of propeller shaft does not apply to now fast manufacturing system,which can not meet the development requirements of modern market.The modern design method is to shorten the design cycle and improve precision,which can greatly enhance the transmission shaft of the competition ability of the enterprise.This paper regard a heavy truck transmission shaft as the research object,using finite element technology and virtual prototype technology to invest the modal influence of transmission shaft and optimize the design of the key parts of the drive shaft assembly.Its main contents are as follows:1.Single shaft design and verification.It mainly includes the calculation of the maximum torque of the drive shaft and the selection of the transmission shaft series,the critical speed of the transmission shaft,the check of the equivalent included angle and the strength check of some key parts of the drive shaft.Through the verification and analysis of the shaft,the appropriate drive shaft which meet the requirements of the vehicle transmission output parameters is selected.The chosen drive shaft will have a good balance between the performance and the cost.2.Vibration analysis of the drive shaft.Mainly including the establishment of a number of modules,the number of modules into the finite element software to establish the finite element model,using the finite element solver for the model of the model to solve the modal.The transmission performance is optimized by drive shaft modes and the attitude angle.So the vehicle vibration and comfort performance can be improved.3.Study factors affecting single shaft modal parameters.The reason of the vehicle vibration is analyzed by both simulation and test.The result shows that the first modal frequency of the drive shaft is too low.The effective ways to improve thedesign is explored by analyzing the actual failure cases,comparing the simulated results and the test results,and verifying the actual vehicle conditions.4.Drive shaft design optimization.Taking the length of drive shaft and the tube thickness as the design variables,the first order mode is used as the constraint function,and the quality of the drive shaft is optimized as the objective function.5.Test verification.Shaft test specification and drive shaft modal analysis specification are built by summarizing the test procedure.And the accuracy of the simulated model is verifying by comparing the results of the analysis and the test.