Research On Speed Governing Load Characteristic Of Electronic Mechnical Continuously Variable Transmission

Metal Pushing Belt Continuously Variable Transmission (CVT) has the advantage of simple structure, low cost, long life and easy for integrated control, can give full play of engine’s characteristic, can improve the gas efficiency, driving force, driving comfort and ride performance and so on. So CVT is always the respected transmission product. However, nowadays, CVT adopts hydraulic system to pressure on the cone-plate to control the speed ratio. But when CVT is used in practice there are three main problems:1. hydraulic system consumes more energy;2. the high cost of hydraulic system;3. low reliability of hydraulic system. The research object of this paper is EMCVT (Electronic Mechnical Continuously Variable Transmission) which is a latest developed product with completely independent intellectual property rights and governs speed of vehicle with low energy consumption of motor, gear, disc springs instead of the high energy consumption of the pump, valve, hydraulic torque converter. The thesis project is based on Liaoning province science and technology plan industrial research funded key projects, the project Numbers:2009220015, the name of this project is " the key technology research on experiment and control of Continuously Variable Transmission".The main work of this paper is:This paper understand speed governing device fully through field test and conduct the analysis of forces on speed governing device of EMCVT. Then the paper researchs the influence factors of load of speed governing and establishes the mathematical model of load of speed governing.This paper analyses mechanical properties of disc spring which is the core component in the speed governing device of EMCVT using ANSYS and analyses the influence of disc spring’s mechanical properties among different revolving speeds. The paper draws the conclusion that different revolving speeds in range of working conditions can do little impact on disc spring’s mechanical properties.This paper establishes the simulation model of the load of speed governing and draws the characteristic curve. The paper not only analyzes influence of the load of speed governing among different factors qualitatively and quantitatively but also provides some theoretical guidance to the following control strategy.This paper puts forward the optimization model of the load of speed governing, and optimizes the load of speed governing using complex method. Therefore the paper solves the parameters of the disc springs and the optimized results..This paper puts forward not only a new relationship between changing rate of speed ratio and the car’s acceleration in CVT but also a analytical approach between them. The paper puts forward a suspect between changing rate of speed ratio and the car’s acceleration in CVT on the basis of the existing research. The paper establishes the mathematical model of changing rate of speed ratio in the EMCVT, solve changing rate of speed ratio.There are some important conclusions through this paper:This paper draws the conclusion that different revolving speeds in range of working conditions can do little impact on disc spring’s mechanical properties. The characteristic curve of load of speed governing is unreasonable, so the paper puts forward a optimization model of the load of speed governing, and the optimization result is better than that before optimization and the optimization idea can be applied to EMCVT mechanism design. The relationship between changing rate of speed ratio and the car’s acceleration is more concise and more reasonable to the study of relationship between changing rate of speed ratio and the car’s acceleration. The suspect between changing rate of speed ratio and the car’s acceleration and mathematical model of changing rate of speed ratio can provide certain theoretical support to EMCVT control strategy for the change rate of speed ratio.