Research On A Parameterized Cad System For The Vehicle Gear

With the rapid advance of the sixth large-scale speed-up of the railway, the railway department has higher requirements for the performance of the railway vehicles, especially the gear transmission system of the bogies for motor cars. Not only need it to meet the high-speed and precise transmission, but also need higher design efficiency to it. As the difference of operation conditions, restrict of manufacture and maintain, economic benefit and other specific factors, customers have different requirements on gear performance, structure, parameters and the process of materials. These gears can be drawn by the same set of parameters, easy to implement parametric. Therefore, with the development of the CAD technology, putting parametric technology into the design of the gears for vehicles has become an important part of the gear transmission system development.This study bases on database technology, modular technology, parametric technology and advanced assembly technology. Using COM component technology, parametric CAD system of vehicle cylindrical gears are developed in Visual C++programming and SolidWorks platform. It can not only improve the design quality and efficiency of the gears, but also can provide the necessary parameters and geometric solid model for the following structure design, strength and dynamic analysis. The content of this study is as follows:(1) Based on Visual C++, the gear-aided design system is developed. According to the working conditions and requirements of the load to transfer of gears, gear parameters are designed. Checking on the calculation of the tooth flanks contact strength and the tooth bending strength by "Calculation Method of Load-Carrying Ability to Cylindrical Gears". This can quickly identify the gear parameters which meet the working conditions.(2) Based on Visual C++and SolidWorks, the gears are drawn in parameter-driven method, and the spoke plates of the gears are drawn in procedural-driven method. This can quickly draw the gears with spoke plates.(3) According to "the Calculation and Design Rules to Interference Fit" and Visual C++, Computing software of interference fits to gear and gear shaft is developed. This can quickly compute the amount of interference of gears in different load conditions.(4) Based on SQL database theory, data needed for designing and designed data of the model parameters are managed by Microsoft Access. This can facilitate the sharing of the data.(5) Based on Visual C++and SolidWorks, gear transmission assembled system is developed. This system can realize fast and accurate assembly of the gears. (6) Based on ANSYS/LS-DYNA, dynamic stress of gear is analyzed. This can get the stress distribution of gear.The Models can be exported in Parasolid format by this system. They can be provided to gear dynamic stress analysis and other following analysis. This system has significantly reduced gear design cycle and improved the efficiency of product design. It has a certain value of engineering practicability.