The Optimization Of The Gear Ratios On The Mechanical Automotive Transmission And The Analysis Of The Torsion Vibration Of The Transmission

The transmission is a key part in the driveline of the automobile. The quality of design will directly affect the actual function of use. Although there are many theories can consult about the design of transmission, but plenty of them are just experiential formula. There is not a good kind of calculation method for the distribution of concrete gear ratio. Traditional theories are generally according to experience or the same kind car type to decide the gear ratios of the transmission. Obviously there are its shortages: (1) The subjectivity factor compares greatly, (2) there is no a kind of valid evaluation index to confirm the quality of the design. By analyzing the merit and the shortage of the traditional method of the design of the gear ratios, In this passage we put out a new transmission's gear ratios allotting method, according to the different using rate to each gear of the transmission, We optimize the design by using it, the maximizes of the actual utilization rate of engines power ,as the target function Then we use an example's calculating result to prove that it is a kind of valid design method.The design of our country's transmission often copy the resemble type and use the static design. Using this method design will bring some problems on the performance, cost, use etc. In order to change the present condition of the design, the initial mission is to instead the static design with the dynamic design. The dynamic design has some purposes. (1) to cancel or minish the effects of the mechanical vibration, impingement and the noise. (2) to calm the running of the gears. (3) to prolong the service life of the transmission. (4) to enhance the efficiency of the transmission. (5) to reduce the pollution to the environment and the harm of the human bodies. This article analyzes the vibration of the gears, uses the Lagrange equation establish the vibration of the gears. It includes the torsion vibration, the landscape orientation vibration, the portrait vibration. The article also predigests the transmission's shaft and establishes the mathematics model of the gear trains, computes the parameters, seeks the inherence frequency and the swing of each vibration. The vibrations of the axles also have three orientations: the torsion vibration, the landscape orientationvibration, the portrait vibration. Finally this thesis also analyzes the dynamic response of the vibration of the gear trains. During the process of the torsion vibration, the article considers the effects of embranchment of the transmission, chooses the middle axes as the main chain, chooses the input axes and the output axes as the embranchment.In order to make the match of the transmission between the engine and the other parts of the power train more reasonable, the article designs the gearbox from the whole angle of the vehicle. This thesis has the leading meaning to design and choose the better transmission for some automotive factories. Based on the above objective, this thesis tries to find the best way to design the transmission.