Dynamic Modeling Analysis And Experimental Study Of Synchronizer

Synchronizer is one of the core components of MT/DCT/AMT/EMT and other kinds of transmission,which has an important impact on transmission shift performance.A thorough study of synchronizer is not only conducive to improving shift performance of synchronizer,but also can shorten design and development cycle of transmission.By summing up research status of synchronizer at home and abroad,this paper analyzes the eight stages of synchronizer work.For synchronization process of synchronizer,the corresponding mathematical model is established,and the model is tested and validated on the self-developed synchronizer monomer test bench.The influence of synchronizer parameters on synchronous performance is studied by using the model.According to the established mathematical model and the actual shift situation of synchronizer in transmission,the AMESim/Simulink co-simulation model is established.After testing and verifying the co-simulation model,the influence of various parameters about transmission shift performance is studied.In Chapter 1,the research background and significance of synchronizer are introduced,and the research status of synchronizer at home and abroad is discussed.The eight main working stages of synchronizer are analyzed,including pick-up,slip,pre-synchronization,synchronization,turning the synchronizer ring,second bump,turning the gear and gear meshing.The research content and technical path of the subject are established.In Chapter 2,basing on the average Reynolds equation and the friction principle of asperity,four mathematical models of oil film pressure,asperity contact pressure,synchronous ring bearing capacity and cone torque are established.The oil film thickness and speed difference are solved numerically by 4-Runge-Kutta method,and the oil in synchronous process of synchronizer is analyzed.The variation of film thickness,rotational speed difference,viscous shear torque,rough friction torque and total torque was tested and verified by self-developed synchronizer monomer test bench.In Chapter 3,the influences of synchronizer structure parameters,working conditions parameters and material performance parameters on synchronization process are studied by using the numerical analysis model.The effects of synchronous ring width,synchronous ring radius,friction cone angle,friction material thickness,input moment of inertia,speed difference,shift force,lubricant viscosity,friction material permeability,surface roughness of friction pair,equivalent elastic modulus of friction pair and friction coefficient on oil in synchronization process of synchronizer are analyzed.The effects of film thickness,rotational speed,viscous torque and frictional torque on the asperity are investigated.In Chapter 4,according to the gearshift process of transmission,AMESim is used to build physical models such as input of manual model,shift rod and shift cable model,shift tower model,self-locking device model,synchronizer model,synchronizer input equivalent model,main reducer and vehicle model,and MATLAB/Simulink is used to build oil film shearing and friction of asperity model.The simulation of shift process is carried out by using the co-simulation model,and the simulation results are analyzed.In Chapter 5,basing on the actual requirements of transmission design and development,the mechanical system and software system of transmission shift performance test-bed are designed and developed.The model is tested by test rig that it is independently developed.The shifting force,shifting displacement,cone torque and input speed of the test and simulation results are extracted and compared.Through the comparison and analysis of simulation and test results,it can be seen that the transmission shift model can accurately characterize the working mechanism of its shift process.In Chapter 6,because of needing shift performance evaluation of transmission,four objective evaluation indexes that are synchronous impulse,shift work,secondary impact and shift time are put forward.Using the established co-simulation model,transmission performance under different self-locking spring stiffness,shift rod ratio,input moment of inertia,friction coefficient of synchronous ring and lock angle parameters are studied in depth.The objective evaluation index is used to quantitatively analyze the influence of each parameter on transmission shift performance.In Chapter 7,summarizes the main research contents and achievements of the thesis,and prospects the future research directions.