Study On Simulation Analysis Of Internal Gear Shifting Mechanism Of Transmission

Automatic mechanical transmission (AMT) is developed from manualtransmission (MT), only need to install automatically shift agencies basing on the MT,which not only has high efficiency of MT, but also has all the advantages of automatictransmission（AT）; at same time, China has extensive production capacity of MT.Therefore, with the production capacity to develop AMT is a convenient and feasiblemethod to improve shift quality and vehicle comfort.When change MT to AMT, the internal structures of MT shift mechanism aredifferent from AMT. Its designation depends on the traditional method"design-production-test-improved-and then test", witch westes much time and huge costs forfactory. Therefore, in this paper, during the development process of changing MT toAMT of a company, we provide a viable idea to improve the transmission shiftingmechanism, and to improve design efficiency and shorten the development cycle ofnew products. The main contents and conclusions are as follows:①Shifting process introduction and finite element model establishmentThrough the introduction of the shifting process, to understand the characteristicsof the shifting process; take reverse gear shift mechanism for instance, to build a finiteelement model of dynamic simulation; through analysising the issues of simulationresults, to modify the boundary conditions; through evaluating the modified modelresults, to find the right simulation model meeting analytical requirements.②Reverse gear mechanism motion simulation performance analysisAccording to the actual requirements of the movemention to establish dynamicsimulation finite element model of reverse gear mechanism; through simulating, to getparts stress distribution and contact force and displacement of each point on themechanism; through analysising, find that: the original reverse gear mechanism hasmany problems: lacking of strength; the force on the entire agencies is too large,it’s4.3times of the resistance on reverse gear; there is a serious distortion from fork assemblypart1to reverse gear engagement,which will affect the reverse gear shift fluency.③Reverse gear mechanism stress analysis and structural improvementsThrough stress analysis of the components, to found the structure of fork assembly2is unreasonable because it lets resistance magnified, so that the whole agencies’ stressare great; according to the force of all parts, establish static strength models; through static strength analysis, problem parts were strengthened, improved or optimized;finally get all parts meet the requirements of the static strength analysis.④Results analysis and evaluation of reverse gear mechanism after improvingAccording to the modified parts prior to re-establish a dynamic simulation model;through comparative analysising of the results of stress, force transmission,displacement transmission before and after improving showed that: the stress muchbetter than the original structure, and every part meets the strength requirements; forcetransmission, displacement transmission are more reasonable and more fluent than theoriginal structure, at the same time, the deformation of the entire organization is smallerthan before.In summary, this paper is based on the issue of internal shift mechanism motionsimulation and take reverse gear shift mechanism for instance, and take shifting motioncharacteristics, mechanical characteristics and structural characteristics of the nonlinearflexible into account, to establish finite element model and analyze the results of themodel, optimize the structure and verify the intensity of the problem components,comparative analysis of the performance of original model and modified model.,realized the forecasts ideas of predicting the performance of every componet,discovering and solving the problem of design shortage and strength issue, shorting thedesign cycles and accelerating its development process.