The most traditional method of producing driving spiral bevel gear blank in China is pre forging cross forging method, which has many disadvantages, such as large flash volume, very low material utilization rate, low product quality, many defects, high defective rate, serious energy waste, poor production environment and high labor intensity in the production process. With the research of cross wedge rolling technology abroad, the production of shaft parts by cross wedge rolling method is becoming more and more mature. After the introduction of cross wedge rolling method into China, academician Hu Zhenghuan of our country has done a lot of research on cross wedge rolling, which makes the production of shaft parts by cross wedge rolling gradually popularized in factories all over our country.
As one of the shaft parts, the driving spiral bevel gear blank is produced by cross wedge rolling process, which has very high efficiency, so it is widely used at present. In order to further improve the quality of the formed driving spiral bevel gear blank, the process of producing driving spiral bevel gear blank by cross wedge rolling is studied, and the improvement scheme is studied according to the shortcomings in the forming process.
The finite element simulation analysis of cross wedge rolling forming process of driving spiral bevel gear blank is carried out. It is found that folding burrs are easy to appear in forming, and the damage value at the joint of shaft and cone head is large, which is a very unsafe part. In order to improve the quality of the connecting part between the blank shaft and the cone head of the driving spiral bevel gear, reduce defects, and improve the connection strength and fatigue resistance. In the second half of this chapter, the scheme is improved, the vertical inclined plane on the side of the rolling wedge is changed to an inclined inclined plane, and the edge of the rolling wedge is changed to a fillet. After repeated modification and simulation, the final improvement scheme successfully reduces the defects of the connection position between the cone head and the shaft, eliminates the folding burr, and the damage value of this part is only half of that before the improvement. The improved metal flow is also greatly improved, the tensile stress is significantly reduced, and the stress on the workpiece is more stable in the forming process. The final analysis results show that the improvement scheme is feasible and reasonable. However, due to the influence of cross wedge rolling head, the material utilization rate of driving spiral bevel gear blank is limited. At the same time, affected by the forming characteristics of cross wedge rolling, the radial dimension of the product has a large error. During cooling, the cooling speed of each part is not synchronous, the temperature difference is easy to appear, and the product is easy to bend, which makes the coaxiality of the product poor, so the straightening process needs to be added later.