Study On The Parametric Design Of Tractor Transmission Based On SolidWorks

Transmission is an important part of vehicle,currently has been widely applied on cars,but the tractors still mainly use manual transmission shift, its poor power and smooth seriously hindered the tractor's long-term development. Dual clutch type transmission has simple structure and high transmission efficiency, tractors can realize the automatic transmission and load shift in the precondition of continuous dynamic, it meet the tractor's characteristics and operational requirements, which has very important significance in development of automatic shift and unmanned technology.Based on the manual transmission's design, combining the characteristics of double clutch, this text summarizes the tractor dual clutch type transmission's design steps, optimizes the empirical formula of center distance, established the mathematical model of the helical gear with hub, and optimized design scheme of gear-box's structure size has been put forwarded.Transmission box structure is complex, it can hardly be accurately analysis with traditional classical mechanics, so finite element analysis is adopted to carry on the structural strength analysis and modal analysis, the results showed that the cabinet design completely satisfy intensity and rigidity requirements, meanwhile, resonance and noise are not showed anymore, and personnel's ride comfort will not be affected .In the 3D modeling process of clutch type transmission, some nonstandard components' modeling process is relatively complex, such as helical gear with hub, helical gear connected by spline and gear-box. In order to reduce the workload and improve the design efficiency, parametric design is adopted for secondary development in SolidWorks.This text establishes the standard helical gears' evolvent tooth profile model which use alveoli centerline for Y coordinates, the design methods of parametric and automatic creating 2D engineering graphics are also expounded. Using the geometric constraint and engineering constraints between the components founded in structure design process, this text has compile and debug the entire program in the methods of recording macro, editing macro and VB language, illustrates API fuctions'significance and using methods detailedly. Whatsmore, this text has used Microsoft Visual Studio for secondary development of Solidworks, producing a plugin on main components'parametric design which is based on Solidworks. And the function that input the main parameter, output its three-dimensional structure and two-dimensional engineering graphics is realized.A double clutch type transmission has been designed for 36.75kW in engine power and 2000r/min in speed by the plugin, the transmission has finished parts of 3D modeling, assembly and 2D engineering graphics, it will be delivered to factory for trial and some experimental study.The results shows that the plug-in has many advantages, the interface and operation is simple, program operation is stable and reliable, 3d model has high precision. Using the plugin can reduce the design personnel's workload, improve the design efficiency and shortened product development cycle, provide solid foundation for clutch type transmission's standardization and serialization.