Dynamic Analysis And Research On Certain Transmission Of Commercial Vehicle

Transmission is critical component of powertrain, its performance mainlyinfluences the safety of vehicle, the comfort of driver and passenger and the energyconsumption of vehicle. According to the actual need of product development, a certaintransmission of commercial vehicle was set as object of study in this dissertation. Loadsand frequency of gear pair meshes, interference of middle shaft, synchronizer and casecomponents were mainly researched in this dissertation by virtual prototype.The performance of products can be found in initial design process by virtualprototype, it has important significance for the product development of transmission.Improvements design could be easily realized by virtual prototype in improve developmentprocess of transmission. In lightweight, energy-saving improvements and noise reduction,virtual prototyping technology also has obvious technical advantages. Based on reviewinga large number of references, studying on the research progress of transmission in domesticand international, the following five aspect works were focused in this dissertation.1. The virtual prototype of transmission was built. Transmission3D models werebuilt in UG software and the main points of modeling and assemblage were summarized.2. Research on loads and frequency of constant gear pair meshes. After thedynamic analysis model was built, based on Hertz contact theory the loads and frequencyof constant gear pair meshes were obtained, and loads parameters were set as inputparameters in interference analysis.3. The interference of middle shaft was analysed. The loads of constant gear pairmeshes was set as load boundary condition in finite element analysis of the interference of middle shaft, the results show influential factors includ value of interference, frictioncoefficient between contact surfaces and the powertrain loads.4. Research on Synchronizer. Firstly, mathematical model about shifting time andforce was established, then, dynamic analysis model was established in ADAMS software,the results show influential factors includ the moment of inertia, the friction coefficient ofcontact cone ring, the cone angle of combine gear and the engine speed.5. Case components were analysed in dynamic loads by finite element analysis(FEA). Firstly, dynamic models of shift-I was established, the loads of bearing of all shaftswere obtained, then the case component finite element analysis (FEA) model wasestablished in UG software advanced simulation module, the front and the back casecomponents were connected by multiple points constrain (MPC). Finally, the weakstructures of case component were found and the improved suggestions were provided. Byusing new materials and re-analysis of the FEA model, the mass of case component wasreduced by62.8﹪, the results have good effects for the transmission lightweight design.