After decades of unremitting efforts of Chinese scholars, China has thoroughly studied the basic technology and theory of Gleason spiral bevel gears, and designed and manufactured domestic mechanical spiral bevel gear processing machine tools. China’s spiral bevel gear machine tools were originally imitated, and most of the imitation work was carried out by Tianjin No. 1 Machine Tool General Factory. The original imitated models were domestic y2250 and y2280 gear milling machines (as shown in Figure 1). At that time, when the demand for spiral bevel gears in various domestic industries was very large, these machine tools became the main undertaker of production tasks. After the relaxation of Sino US relations in 1972, China imported a large number of Gleason gear milling machines. During this period, Tianjin No.1 Machine Tool General plant produced y2250a with tool tilting mechanism by imitating Gleason No.116 machine tool (see Figure 2).
After the mechanical spiral bevel gear processing machine tools have been used in China for decades, since the 1990s, China has also started the research and development of CNC spiral bevel gear processing machine tools, which has also developed with the development of China’s CNC technology. At the beginning, it only carried out local CNC transformation on the basis of traditional mechanical machine tools, such as yh2240 and yk2280 CNC gear milling machines. In the real sense, the CNC spiral bevel gear processing machine tool is the yk2212 six axis five linkage CNC gear milling machine developed by the gear Research Institute of Central South University in 1999, followed by the successful development of yk2245 six axis five linkage CNC gear milling machine in 2001. Later, other enterprises also developed a small number of CNC spiral bevel gear processing machines; Through school enterprise cooperation, China soon also has the first digital closed-loop production line for spiral bevel gears. So far, high-precision spiral bevel gears of general specifications made in China have replaced imported gears.
However, in the current factories in China, the processing of spiral bevel gears still mainly depends on the traditional spiral bevel gear milling machines. Although the products processed by these machines can be ground on the spiral bevel gear grinding machine after heat treatment, or other advanced processing technologies can be used to improve the gear processing accuracy, this will increase the manufacturing cost a lot. Foreign CNC spiral bevel gear processing machine tools are very expensive, which many enterprises cannot afford. Although China has also introduced them, the number is too small. In addition, foreign countries have strictly blocked this core technology, so they are rarely used in China; Although China also has similar equipment, due to the limited development time, many technologies are not very mature. As a result, most enterprises in China still use traditional machine tools or machine tools that have been numerically modified on traditional machine tools to produce spiral bevel gears.
