A Medium-sized Passenger Car Drive Shaft Vibration Simulation Analysis

The power transmission system of the automobile is mainly composed of the clutch,the transmission,the drive shaft,the drive axle and the other components,and its function is to transfer the torque and the rotating speed.The drive shaft is an essential and important part in the power transmission system.The drive shaft rotates at a very high angular speed when the vehicle is running,so there will be the vibration due to the imbalance of the product itself,and then it will affect the vehicle’s running stability and the passengers’ comfort.The requirements for the technology are getting higher and higher in the continuous development of the automobile.Some design and calculation methods of the drive shaft is too old,and too much design time is needed,the error is big and it is inefficient,it will be replaced by the new design method.The new design method can meet the requirements of the products,and also can optimize the products,and then product reliability will be enhanced and the product development cost will be reduced.The driving shaft of a medium-sized bus is taken as the object of the study in this thesis.The virtual prototype and finite element analysis are used to analyze the main influencing factors to the vibration and modal of the drive shaft,and then the structure of the main functional parts will be optimize,and the entire drive shaft will be optimized in the design.The main contents of the thesis are as follows:(1)The analysis of a single drive shaft in the power transmission system.The threedimensional software CATIA was used to model the various parts of the drive shaft,and the components were actually expressed.The drive shaft model was introduced into the finite element software to divide the grid,and the corresponding model was established.The single shaft is analyzed and tested,and the results are compared to verify the correctness of the model.(2)The analyze the influencing factors of single drive shaft in running.The thickness of the driving shaft pipe wall and the length of the driving shaft pipe will be chosen as the studied subject to analyze its influence on the driving shaft vibration frequency and then the mathematical model is established to provide the theoretical basis for the analysis of the driving shaft structure.(3)The vibration analysis of a single shaft.The driving shaft coupling of the virtual prototype model is established in the kinematics simulation software to analyze the natural frequency of the driving shaft assembly,the input speed and the vibration of the drive shaft,so we can know more about the using conditions of the driving shaft.(4)The vibration analysis of the intermediate support driving shaft.The matching model of the drive shaft is established in the virtual prototype kinematics simulation software,and the basic vibration analysis is carried out.The influence factors of the transmission torque and the rotating speed of the driving shaft on the power transmission system are studied,and the running status of the transmission shaft is further analyzed.(5)The optimization design of intermediate support structure.The stiffness and damping of the intermediate support structure are taken as the design variables,and the angular velocity change rate of the intermediate pivot point of the drive shaft is taken as the studying object,and the influence parameters of the intermediate support are optimized.The influence of the parameters of the drive shaft on the function and performance will be clarified further through the above analysis.The service life of the driving shaft will be longer,and the vibration and noise of the vehicle will be reduced,and the vehicle comfort will be improved through the drive shaft structure’s optimization.