| The Continuously Variable Transmission(CVT) has good fuel economy, power transmission, driving ride, comfort, easy to manipulate, etc. the Chain drive has simple structure, high transmission efficiency, large speed range, and etc. Rocker-pin jointed CVT, which sets the advantages of the CVT and the chain in one, is the automotive powertrain with complex high-end products. Though Rocker-pin jointed CVT has been used in automotive driveline, but only a small numbers of foreign counties mastered the key technology of patent. Research on Rocker-pin jointed CVT transmission system is still in its infancy in domestic, and a systematic mature design and a analysis are not yet formed.The transmission characteristic on transmission will be improved, the fuel economy will be improved, the vibration and noise will be reduced, if assembly structures of chain pieces with different shapes, as well as arrangement and characteristics of vibration of chain pieces with different pitches in rocker-pin jointed CVT are optimized. Then, relied on strong industrial project of Industry and Information Department, the design method on rocker-pin jointed CVT transmission system is studied in this work, supported by enterprise project “the Development of Chain Simulation Technology, China(No. 2014220101000408)”. The main contents in this work are as follows:1. The working principle of CVT is introduced, and the kinematics equations of Rocker-pin jointed CVT transmission system are established, the composing form of Rocker-pin jointed CVT is described. The causes of chain whether or not assembled with different shapes are studied. The assembly rules of each shape and arrangements.2. On the basis of the kinetic theory of multiple-degree-of-freedom system, vibration discrete model of Rocker-pin jointed CVT transmission system is set up. Form the viewpoint of energy, non-conservative system Lagrange equations are listed, then the oscillatory differential equations of Rocker-pin jointed CVT transmission system is deduced. Analysis about Vibration characteristic of the Rocker-pin jointed CVT transmission system is done by means of MATLAB software and scientific computing software.3. Based on the theory of vibrating string on mechanical vibration, a numerical method for calculating the vibration mode of Rocker-pin jointed CVT transmission system is established. And the numerical method is used to study the vibration model of the entire hanging Rocker-pin jointed CVT and of the Rocker-pin jointed CVT.4. Using the proposed design method, a new Rocker-pin jointed CVT is designed, of which the vibration and kinetic characteristics are analyzed. The results show that, the requirements of use and design can be meet by this new Rocker-pin jointed CVT transmission system. Therefore, the reasonableness and correctness of the method proposed to design the Rocker-pin jointed CVT transmission system is further validated.In this work, a forward method to design Rocker-pin jointed CVT transmission system has been established, which includes the kinematics mathematical model, programming design and simulation analysis. Thus the theoretical support about design and analysis of the Rocker-pin jointed CVT transmission system is crucially provided. It has important theoretical and practical value for acceleration of development of domestic Rocker-pin jointed CVT transmission system and improvement of the ability to design the Rocker-pin jointed CVT transmission system with high performance and high reliability positively and independently. |
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