Thermal Structural Coupling Characteristics And Thermal Failure Analysis Of Synchronizer

Synchronizer is the core component in the shift process of the transmission system,and its working characteristics directly affect the shift process.Therefore,the in-depth research and analysis of the synchronizer can not only improve the shift efficiency of the synchronizer,but also help to improve and improve the performance of the transmission system.From synchronizer friction performance of friction pair,thermal analysis and thermal structure coupling simulation of synchronizer summarizes research status at home and abroad,by studying the synchronizer friction pair contact behavior,the frictional contact calculation model was established,combining with synchronizer three-dimensional finite element model of friction pair,the mechanics response characteristics as the boundary conditions of finite element simulation,set up the multifactor synchronizer of interaction of hot structure coupling finite element analysis model,and analysis of typical working conditions using the thermal structure coupling analysis synchronizer friction pair temperature characteristic and thermal failure modes.In chapter 1,starting from the application and research status of synchronizer,elaborated the research significance and the background,introduces in detail the structure of single taper lock ring synchronizer,shifting principle,and the thermal characteristics of synchronizer friction pair,the friction performance and thermal failure summarizes research status at home and abroad,the research contents and technical route is determined.In chapter 2,the heat generation mechanism and heat transfer mechanism of the friction pair in the synchronization process of the synchronizer are studied,and the thermal boundary conditions such as convection heat transfer model,heat transfer model and heat flux model in the actual operation process of the synchronizer are determined.In chapter 3,the synchronization process of the synchronizer is divided into three stages:oil film shear,mixed friction and contact friction.According to the detailed friction principle of each stage,the friction-contact pressure model,the bearing capacity model of the synchronous ring and the solution model of the synchronous moment are established by using the relevant theories of fluid mechanics and the calculation formula of friction.In chapter 4,according to the working principle of the synchronizer shift process,the dynamics co-simulation model of the synchronizer is established by using AMESim and Matlab/Simulink modules.And according to the working conditions of typical research synchronizer mechanical response characteristics of working condition of each index,friction contact model combined with synchronizer friction pair,the comprehensive plan into synchronizer friction contact force,the condition of input output speed change and cooling lubrication state,using the related theory of transform it into finite element analysis of boundary conditions,imported into the synchronizer in the 3 d model is set to the boundary input,set up multi-factor synchronizer of interaction of hot-structure coupling finite element analysis model.And the simulation model is verified by using the self-developed synchronizer shift performance test bench.In chapter 5,by using finite element simulation software,the thermal structure coupling finite element analysis model of the synchronous lock with multi-factor interaction is simulated and analyzed,and the distribution law of temperature field and stress and strain field on the friction surface of the synchronous lock is obtained.At the same time,the influence of different operating parameters,elastic modulus,thermal conductivity coefficient and thermal expansion coefficient on the temperature field,stress and strain field of the friction cone of synchronous locking ring was analyzed.Finally,the cause of the local high temperature phenomenon on the surface of the friction pair is analyzed,and the concrete manifestation of the thermal failure of the synchronous locking ring is analyzed based on the actual engineering situation.In chapter 6,The author summarizes the research results and content of the whole paper,and looks forward to the next stage of research.