| Gears are extremely important basic components for the equipment manufacturing industry,precision machining and ultra-precision machining are the development direction of gear manufacturing industry.High precision gear machine tool is the first condition to realize the manufature of precision gears.The machining accuracy and performance are determined by the performance of precision transmission system in gear hobbing machine tool.However,the research on the key technology of precison gear transmission device design and manufacture,and precision theory of the precision transmission system in PRC is still in the bottleneck period.The mechanism of multi field coupling gear transmission is not fully revealed.Compared with foreign products,there is a wide gap between the performance of transmission parts and other important equipments produced by China and by advanced countries.Therefore,it is important to develop the research on the key technology and precision theory of the precision transmission system and improve the accuracy and performance of transmission system.In this paper,the influence of the manufacturing errors,the geometric error caused by the driving force and the electromechanical coupling on the precision of the transmission system is studied.The main research contents are as follows:(1)The influence of manufacturing errors on the linear error of transmission chain is studied,the mechanism of error transmission is revealed.A linear error model is established for the tool carrier transmission system of a type gear hobbing machine.The contribution of each transmission error to the transmission system error is analyzed.The precision of transmission chain is analyzed by considering the manufacturing errors,the force-induced geometric error and the effect of electromechanical coupling.A new precision model of transmission chain system is put forward.(2)The influence of the meshing stiffness,the torsional rigidity and the bearing stiffness on the mechanical stiffness of the transmission chain system is studied.The mechanical stiffness model of the transmission chain is established,and the stiffness matrix of the system is obtained.According to the characteristics of the worm,the mechanical stiffness model of the transmission chain is extended to the worm transmission chain.For a specific gear hobbing machine,the mechanical stiffness sensitivity of the tool carrier gear transmission chain system is simulated.Besides,the weak link of gear transmission chain system is found.The correctness of the theoretical model is verified by the mechanical stiffness experiment of transmission chain.(3)For the tool carrier gear transmission chain system of a specific gear hobbing machine,the electromechanical coupling model is established in terms of the whole electromechanical coupling.The relationship between the mechanical stiffness,the servo stiffness and the control parameters of the closed-loop system is analyzed.The coupling model of the system is simulated by Matlab/Simulink,the influence of the mechanical stiffness,the servo stiffness,the transmission error and the clearance of the transmission device on the dynamic performance of the system is analyzed.(4)For the tool carrier transmission system of a type of gear hobbing machine,the optimized model is established based on the electromechanical coupling simulation model and ITAE criterion.Genetic algorithm is applied to optimize the parameters of the regulator. |
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