Synthesis And Analysis Of Multi-speed AT Transmission Transmission Scheme

The multi-speed AT transmission has a significant share in the automatic transmission market share.For a long time,China's passenger car automatic transmission market and automatic transmission technology have been monopolized by foreign investors.Especially in the AT transmission,the planetary transmission mechanism transmission scheme is the core of the intellectual property of the foreign AT automatic transmission.For the development of the latest transmission scheme,it is regarded as the core secret of the new product.With the rapid development of China's automobile industry,the design of the transmission scheme of planetary shifting mechanism has become a hot topic in the research of automatic transmission theory.Based on the above background,this paper synthesizes and analyzes the transmission scheme of complex planetary shifting mechanism based on the lever method.This paper first analyzes the structure of two planetary rows in parallel,enumerates all possible connection methods,and analyzes the arrangement of the control elements on its structure.According to the one shift shifting principle,the transmission ratio is synthesized,and finally a reasonable transmission scheme of two planetary rows in parallel is obtained,which lays a foundation for the synthesis of the rear four planetary gear shifting mechanisms.Based on the analysis of the Lepelletier type structure,combined with its structural characteristics,based on the three-degree-of-freedom four-planetary row,three possible connection methods are analyzed,and an effective connection method is obtained after analysis.Control element placement and gear synthesis are performed on this structure.Then,the characteristics of the lever splitting are used to solve the available planetary connection methods,and the scheme judgment process of the plane graph method and the graph theory plane judgment is established,and finally 11 kinds of transmission schemes are obtained.Finally,the performance analysis of 11 kinds of schemes is carried out,and four kinds of 9-speed transmission schemes and 2 kinds of 8-speed transmission schemes are selected,and the efficiency calculation and analysis of the six schemes are carried out,and the transmission scheme with high transmission efficiency is obtained..