| Rocker-pin joint chain continuously variable transmission (CVT) is complex high-levelproducts in modern automotive powertrain system. Due to its good practicality as well as ahuge market prospects, it has been quickly favored by domestic and foreign automobilemanufacturers. But the complexity of the transmission mechanism and manufacturingprocess, as well as transmission efficiency, dynamic characteristics, system matching andcontrolling technology is the key factors that restricting its development. Under theguidance of national energy saving strategy and the demand of the technology developmentin automotive industry, Chinese automotive industry must design the rocker-pin joint chainCVT innovatively and master the core technology of its transmission mechanism, designand analysis, only in these ways can we speedup the industrialization process of Chineserocker pin joint chain CVT.This paper is supported by Jilin University internal fund-science frontiers andinterdisciplinary innovation projects “Fundamental theory researching on transmissionmechanism and dynamic characteristics of the new rocker-pin joint chain continuouslyvariable transmission” and “Research on contact dynamic characteristics of the rocker-pinjoint chain in continuously variable transmission”. Based on systematically expounded ofthe researching status of the rocker-pin joint chain CVT in both domestic and foreigncounties, synthesizing with the working principle of the rocker-pin joint chain CVT, usingthe theory of the mechanical transmission and innovative design method, the contour of thecontact surfaces of the rocker pins were changed from arcs into involutes and cardioidswhich have better force transmitting performances. The new rocker-pin joint chain CVTwith Chinese independent intellectual property right was developed.The notion of equivalent teeth number was brought up for first time in this paper. Thevariable pitch characteristic of the new rocker-pin joint chain was studied and theharmonious relationship between chain pitch and adjacent chain link angle was analyzed.Based on the contact force analyzing of each component of the CVT, transmissionefficiency of the CVT was studied and the discipline of transmission efficiency changingwith the variation of the friction wedge angle was analyzed.Based on an overview of modern multibody dynamics, the virtual prototype model of the new rocker-pin joint chain CVT was established. Its dynamic characteristics under differenttransmission ratios were studied, and the moving trajectory curve of the link plate’scenterline was extracted. The fluctuation performance of the rocker pin joint chain wasevaluated by comparing the difference between the actual amount of fluctuation of therocker pin joint chain and the theoretical amount of fluctuation of the ordinary chain whichis caused by the polygonal action. The rotary stability of the rocker pin joint chain CVT wasstudied by analyzing the error rates of the transmission ratios.Based on finite element theory, the static tensile properties of the new rocker pin jointchain under the maximum tension were studied by using ANSYS software. The stress anddeformation contours of link plates and rocker pins were extracted. Observing andanalyzing the amount and the distribution of the stress and deformation, combining with thepermitted stress and deformation amount of the materials of the link plates and the rockerpins, the safety of the strength and the stiffness of the new rocker-pin joint chain waspredicted reasonably. The natural frequencies and mode shapes of the new rocker-pin jointchain were studied on the basis of the modal theory and the vibration characteristics of thesystem were analyzed by comparing the natural frequencies with the external excitationfrequencies.The research results in this paper lay an important theoretical foundation for the designand analysis of the rocker-pin joint chain CVT. It has important significance for speeding upthe industrialization process of Chinese rocker-pin joint chain CVT as well as improving thecapability of independent innovation of Chinese automotive industry. |
PDF Full Text Request