Spiral bevel gear is a concept relative to straight bevel gear and helical bevel gear. It is a key part in the field of mechanical transmission, mainly used to transmit intersecting or staggered axial force. In the transmission of spiral bevel gears, the meshing of gear teeth is gradually expanded from one end to the other, which has the advantages of good bearing capacity, strong transmission performance, high overlap coefficient, stable transmission, low transmission noise, etc. The diameter of the large wheel of the large spiral bevel gear is more than 800 mm, and the precision of the finished product is more than Grade 5. It is mainly used in the manufacturing of railway locomotives, ships, mining machinery, coal engines and large transportation, tunneling and loading equipment. It has a good application effect in the oil development, mining and metallurgy industries, greatly improving the service life and reliability of related products, and obtaining good economic benefits.
With the rapid development of China’s heavy industry, the domestic demand for large specifications and high-precision spiral bevel gears is increasing. However, many difficulties and challenges have been encountered in this kind of gear processing, and there is still a long way to go to realize large-scale digital manufacturing. At present, there are two main types of large size and high precision spiral bevel gears: large scale spiral bevel gears with circular arc shrinkage teeth and large size cycloid spiral bevel gears with high teeth. The difficulties in the design and processing of large size circular arc shrinkage high-precision spiral bevel gears are reflected in two aspects: on the one hand, the shrinkage teeth of bevel gears cannot be conjugate in theory, and the contact adjustment of gear surfaces is difficult. On the other hand, the machining accuracy of the cutter head tooth shape angle of the shrinking gear in processing is relatively high, which needs to be corrected in time, and the design is relatively complex, which leads to the small application range of this kind of gear in China at present. In the processing of spiral bevel gears with large cycloid and other high teeth, the technical requirements for adjustment are not high, the operation is convenient, and the machining cutter head is few. However, the machining cutter head of this gear can only use the double-body cutter head produced by German companies, and there is no independent production capacity in China; Moreover, the processing machine tools can only use the products of German companies, which are currently under embargo against China. These problems have led to the import of most large specifications and high-precision spiral bevel gears currently needed in China, which not only has high purchase price and long delivery period, but also has an important impact on national security development and sustainable economic construction.