| Continuously variable transmission(CVT) is a kind of advanced technology transmission products, compared with the traditional transmission,it has the advantages of simple structure, low cost,also can give full play to the dynamic characteristics of the engine, to realize the integrated control of the power transmission system. Considering with the two advantages of variable speed and good fuel economy, the market prospect of continuously variable transmission(CVT) is very broad. At present, the CVT mostly adopt the hydraulic control system of cone disc pressurization to realize variable speed drive control, on the basis of enterprise commissioned technology development project, it puts forward a mechanical transmission control mechanism. The mechanism through the spiral mechanism offer the pressure of cone disc, the servo motor is use to control the speed, compared with the traditional hydraulic control mechanism, it can significantly reduce the car’s fuel consumption, improve the transmission efficiency of the transmission system.It is through the contrast and analyze the different forms of transmission, integrating the mechanical CVT transmission control mechanism and research status at China and abroad, then it has a detailed explanation of the chain CVT transmission system of main components and transmission principle, consider with the mechanical model of the variable speed system for chain CVT, research and analyse the chain’s tension force of transmission system and the clamping force model of cone disc. Basic with the principle of continuously variable transmission system’s design requirements and electromechanical integration control, it propose the scheme that the joint control of the planetary gear train with screw mechanism. According to the transmission control mechanism design requirements, it design the transmission and drive control mechanism systematic, the gear in planetary gear train were designed by Parametric design methodBased on the Adams dynamics analysis software, establish the dynamic simulation model under the control of variable speed drive mechanism, on condition of the three typical ratios. study the dynamic characteristics of the transmission system under different driving conditions calculate the transmission ratio error of the transmission system, analyze the transmission efficiency of the system. According to the transmission tension force of the chain, the contact force between the rock pin and cone disc, analyze the stress condition of the variable speed system. According to the running track of the link in specific plane markers, analyze the link’s fluctuations in the process of transmission system.Utilizing ANASYS to analyze and calculate the the statics of planetary gear system for transmission control mechanism, study the meshing characteristics of the planetary gear train of the sun wheel and planetary gears, according to the stress and strain of the center wheel and the planet wheel under static load, analyze the stress and strain conditions., the calculation results show that the design of planetary gear system meet the strength and stiffness design requirements.The research results of this paper have laid an important theoretical foundation for the design and analysis of CVT transmission control system., its speed up the development of our country’s continuously variable transmission technology and the industrialization process as well as enhance the independent innovation capability of China’s auto products has an important engineering significance. |
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