Key Problem Research For Heave Duty Truck Twin-countershaft Structure 13 Speed Transmissions

This paper discusses three key issues closely related to the ultimate performance of transmission based on the design of 13 speed manual dual intermediate shafts transmission. The paper begins with the introduction of the whole process of how the design of the new transmission is determined, then puts forward three key issues closely related to the realization of final design that need to be resolved. These three issues are the strength checking of high-gear, optimization of shift control system, and development issues of a new synchronizer.In the study of high-gear, the paper compares the stress characteristics of normal gear and high-gear and establishes a simple and reliable high-gear stress calculation mathematical model by carefully analyzing gear meshing process and the whole situation of the force load. By giving an example the paper describes a very practical method of high-gear strength checking, which is quite helpful for future analysis of the high-gear.In the study of shift control system, a new design of auxiliary case pneumatic control system is proposed, which can achieve the design goals. And especially by using an error-proof valve in shift control system, the error operation of rear PTO which has troubled us for a long time is to be avoided.In the study of the new synchronizer, a new floating-type synchronizer has been developed to adapt to the characteristics of dual intermediate shaft transmission. At the same time the paper focuses on the research on the base material and friction material of friction ring, which is the core component of synchronizer.The topics of this paper are as follows: how to improve the overall performance of new transmission, how to prevent repeating defects of similar product and how to remain competitive in future market. Through the research on the possibility of some key technologies, the paper attempts to find out the difficulties impeding the use of key technologies and to seek solution. The ultimate objective of this paper is to provide a theoretical basis for the feasibility of the design.