The Design And Optimization Of Microcar Manual Transmission

As an important part of automobile transmission, gearbox not only has a direct impact on the vehicle's power and economy, also affects the operation reliability and ease, transmission stability and efficiency. Although the traditional mechanical manual transmission has many disadvantages, such as large shift shock, huge volume and complicated control, it is still widely used in modern cars for its advantages of high transmission efficiency, mature production technique and more importantly, low cost.With the rapid development of computer technology, the professional software on transmission study is more widely and increasingly used, such as MASTA and ROMAX, which are large-scale specialized software for selection, design, and manufacture. This article mainly focuses on the design, analysis and optimization of manual gearbox of micro cars with the help of MASTA. Meanwhile previous ideas on design and analysis are employed to enrich content of this thesis and improve the quality.This thesis firstly confirms the design plan of manual gearbox of micro car, basing on the comprehension and study on gearbox development process as well as relevant theories. The design plan includes the layout of gear and shaft, layout of gear shifting operation mechanism, etc. Secondly, based on the essential parameter of furnished engine and the required transmission ratio of the vehicle's power performance, the related parameters on main components of gearbox are worked out. Via analysis to design parameters, finds out the factors which take effects on the performance of manual gearbox. Based on the experimental method with MASTA to simulate practical loading condition of gearbox, this thesis completes the analysis of gear, shaft, bearing and other main spares as well as the synchronizing process of synchronizer. This analysis is also compared with theoretical analysis. It also establishes a good foundation for the research on vibration noise of gearbox by slightly modifying the gears designed with modification module provided in the software. Meanwhile, optimize the structure and performance of gearbox referring to the influencing factor and then take simulative experiment on the optimized model and at last evaluate the result of optimization. As there are so many structural parameters affecting the transmission performance, it is worthwhile to study how to take advantage of the software to analyze the influence exerted by various factors as well as how to meet structural optimization and how to realize optimal performance function. The study will provide a good guide to explore the use of specialized software for modeling and designing the manual transmission as well as the method of structure simulation and optimization for future development and application of new transmission.