Optimization And Simulation Analysis Of Two-speed Automatic Transmission Shift Mechanism

The optimized design of the shifting mechanism is one of the key technologies to improve the shifting quality of the automatic transmission.In this paper,a developed two-speed automatic transmission was carried coordinated shift test.According to the experimental data,found that the shift time is too long,so we focus on the gear stage.Through the optimized design of the shifting mechanism,the shifting time at this stage is shortened,and the shifting quality of the gearbox is improved.This article mainly carried out the following work:Firstly,the coordinated shift test of the two-speed gearbox was carried out.The experimental data showed that the time taken to switch the gear to the first gear and the second gear was 0.82 s and 0.68 s respectively,while the time spent in the gear shift phase was 0.41 s and 0.25 s respectively.And the time of the gear shift accounted for 50% and 36.8% of the entire shift time respectively,so the gear shift phase was selected as the key research phase in the shifting process.Secondly,the performance of the shifting mechanism determines the time of movement during the gearing phase.The shifting mechanism is taken as the research object,and the dynamics analysis is carried out during the synchronization phase of the gearshift process and the various stages of the shifting process.By analyzing the key parameter of the shifting mechanism,the shifting force,matching the shifting motor required to check the shifting mechanism,which lays the foundation for the subsequent synchronizer simulation.Thirdly,the influencing factors of the time of each stage of shifting are analyzed,and the virtual prototype of the working process of the synchronizer is established.The accuracy of the model is verified by comparing with the stage of the test.Based on this,the synchronizer is simulated and analyzed on performance related parameters.Fourth,the shifting mechanism is optimized from both the cam stroke and the synchronizer parameter optimization.The cam stroke is shortened by 68.54° cam angle compared with the original design parameters.After optimizing the parameters of the synchronizer,the simulation results of MATLAB and ADAMS show that the synchronization time is shortened by 24%,which verifies the effectiveness of the optimization method and improves the synchronous operation performance of the shifting mechanism.