Study On The Simulation And Experiments Of Involute Gear Generated Rolling Process

The processing method of gear generated rolling as one of the nearly net gear forming methods, whose formed parts have better precision and strength, have better processing efficiency and better use ratio of materials. In the processing of gear rolling, the load of equipment will be lower and materials will reasonable flow to fill the molds. In recent years, the studies on gearing rolling especially on thread rolling is insufficient. Also the systemic analysis on forming procedure and microscope of material in gear rolling process is few, which hugely restrict the application of gear rolling method. To solve these problems, this passage will study on following aspects:(1) According to the characteristic of involute gear tooth profile, the general machining parameters such as blank, rolling wheel parameters and the rolling reduction of the involute gear are summarized. Based on the theory of gearing, the tooth shape according to the relative motion between the rolling wheel and the billet is forecasted.(2) The process of radial and axial direction gearing rolling is simulated with the help of Deform software. The difference on distribution of strain and stress and equipment load between different processing method is compared. The material flowing behavior is discussed with the help of flowing net simulations. The result of simulation is used to compared with the theoretical results to prove the correctness of simulation results. The rolling defects are also simulated to study their forming mechanics. Series solutions is put forward for the rolling defects.(3) The gear rolling experiment platform is put forward to study on the actual processing. The shape of the forming part and the change of the microstructure is studied with this platform. By observing the microstructure of the shaped parts in different locations of formed part and combining with the results of finite element analysis, the characteristics of the forming parts were studied.(4) Comparative analysis is executed to study the advantages and disadvantages under different rolling temperatures. Taking the gear steel 20 CrMnTi as an example, combined with the experimental results of thermal simulation, the influence of temperature changes on the process parameters and microstructure of the gear rolling process was studied. The temperature distribution in gear rolling process is obtained by the finite element coupled thermal-mechanical analysis. Based on the theory of softening and grain refinement in the process of thermal processing, the properties of the molded parts after different temperature were predicted.Based on this research, the process of involute gear generated rolling will be comprehensive researched. The microstructure and the material flow of the forming part are detailed analyzed, which can be a strong support for the further study of gear generated rolling process.