Structural Synthesis And Analysis Of Multiple Speed Automatic Gear Transmission

Now 6-speed transmission mechanism is used on the automobile. It is necessary to constantly improve the gear number for improving people comfort and fuel efficiency, reducing the shift in the process of impact. Therefore, it has important social significance to synthesize automatic transmission gear.This paper focuses on the research of the classical mechanism, the number of members and the degree of freedom and aims at proposing a comprehensive method for the planetary gear transmission. In addition, this paper carries out research for the synthesized mechanisms.(1) Based on the topological graph atlas database of kinematic chains 9-link and 2 degrees of freedom (2-DOF) are synthesized. Considering the actual demand of topology and the requirements of gear transmission, this paper proposes "topological graph selection principle", "gear function diagram transformation principle". Therefore, the 6 speed transmissional mechanisms with 9-link and 2-DOF are synthesized.(2) Mulit-freedom planetary transmission scheme based on graph theory of topological synthesis is proposed.8 speed planetary gear transmission which should be the 12-link and 3-DOF kinematic chains are synthesized. Finally,8 speed transmission mechanism of automatic gearbox are obtained based on the extended level analogy. The specific location for the execution of components is determined.(3) The research for 8 speed transmission includes kinematics and dynamics analysis. The transmission line, transmission ration, each member speed analysis are carried out based on the different gear transmission. In addition, torque and efficiency are analysed in different gear locations. The specific value of themechanism is obtained by using the MATLAB software. And the result also compared with the classical mechanism.