Research Of Micro-vehicle Transmission Shaft Dynamic Performance To Automobile's Vibration

Transmission shaft is the important part of automotive transmission, it plays a transfer vehicle movement and torque role. Due to the characteristics of transmission shaft itself structure, it inevitably exits vibration, and has an important effect on the vehicle ride comfort, easiness and power train component's life. Therefore, the research which transmission shaft's dynamic characteristics affect vehicle performance is very important. A company produces a new car which has bad comfort and big vibration of driveline. Take the transmission shaft of the new car as the research object, analyzes the vibration of transmission shaft assembly from the theoretical analysis, vibration test of vehicle driveline, dynamic simulation analysis and optimization design. The main contents are as follows:(1) Theoretical analysis. The kinematics and dynamics characteristics of Lardan University joint and the more universal shaft are analyzed, and the lateral load of the support of transmission shaft is analyzed, that offers gist to the dynamics analysis of transmission shaft assembly model.(2) The vibration test analysis of the vehicle driveline. Under the different speeds, according to the research models, contrast models and replace the intermediate support of the research models, use the vibration test software testing the intermediate support's vibration. From statistical analysis of test data, we can draw a conclusion that different stiffness and damp has a significant effect on the intermediate support's vibration.(3) Kinematics and dynamics analysis of the transmission shaft assembly. Based on the drawings'requirements, various parts of transmission shaft assembly are modeled and assembled by using the engineering design software UG, then import it into the mechanical dynamics analysis software ADAMS. Firstly defining material attribute of various parts, adding spring, constraint, drive, load according to actual motion, and then preliminary validation of the virtual prototyping model is made. Finally analyzing the virtual prototyping model's kinematics and dynamics characteristics, and comparing with the theoretical analysis and verifying the correctness of the virtual prototyping model.(4) Optimization design of the intermediate support's stiffness. Applying optimized design method, setting the stiffness as the design variables, the bearing's vibration amplitude as target value. Respectively at the transmission shaft speed 600r/min,1200r/min,1800r/min,2400r/min, optimized design for stiffness is made and then fit the optimization design curves of various speeds, the target values of different speeds are small when the stiffness is 450N/mm-600N/mm.(5) Summary. Form the vibration test of vehicle driveline and optimization design, a conclusion could be made that is reasonable design intermediate support's stiffness can effectively reduce the vibration of the transmission shaft assembly and improve the ride comfort.