The research on spiral bevel gear machining machine tools and related technologies in China began in the 1970s, much later than that in foreign countries. In 1970, China introduced a number of Gleason bevel gear processing machine tools. Domestic researchers began to study various structures of Gleason machine tools, deduced the calculation formula of its internal adjustment card, and made a breakthrough. In 1971, a new mathematical method, the relative differential method, was applied to the spiral bevel gear machining technology. The application of this method brought the spiral bevel gear meshing theory into a new era and established an independent research system. Gong Daoxiang, a domestic scholar, proposed a method to measure and compensate the tooth profile error of each tooth. Professor Zheng Changqi and Professor Zeng Tao use the “pitch analysis method” to calculate the parameters of a pitch surface of spiral bevel gear, take points with surfaces, push the whole with surfaces, and deduce many calculation formulas about the adjustment parameters of machine tools. In 2001, sun Dianzhu proposed using B-spline curve to analyze the error of tooth surface machining. The principle is to use the real tooth surface measurement data. In 2004, a new design concept came into being, that is, the design method of point meshing tooth surface proposed by Wu Xuncheng, and the specific formula for determining the machining parameters of machine tool through tooth surface parameters was deduced. Wang Yanzhong and others proposed that the latest method to correct the machine tool data is the difference surface method. This method is used in ordinary five coordinate NC machine tools, that is, set an imaginary value of the gear surface, compare it with the actual value, generate a regular function equation, find its eigenvalue and correct it, so as to correct the machine tool. Through motion conversion, the machining adjustment of spiral bevel gear is simplified, and a new method for spiral bevel gear machining is provided. These studies have laid a good foundation for the NC support of spiral bevel gear machining. Beijing gear factory, Tianjin Gear Machine Tool Research Institute and Xi’an Jiaotong University jointly sorted out and translated the technical materials attached to the bevel gear processing machine tool sold by Gleason company, and published the translation, which provided good materials for the designers and processors of bevel gears.
In the early 1980s, China’s machine tool factories began to trial produce some gear processing machines, and successively launched many spiral bevel gear CNC milling machines, such as yk2240 produced by Qinchuan machine tool group company; Changsha Railway Institute has developed yk2245, y221a produced by Shanghai No. 1 machine tool, etc., but these machine tools have not got rid of the shackles of traditional machine tool mechanisms, and still maintain the complex transmission process, lengthy and lengthy, time-consuming and laborious adjustment and processing, difficult efficiency, and poor gear accuracy. These machine tools can only be semi automated. Many universities in China, such as Huazhong University of science and technology, Xi’an Jiaotong University and Central South University, have conducted in-depth research on spiral bevel gear processing technology. In August 1999, the gear Research Institute of Central South University grandly launched the numerical control gear milling machine yk212, which is the first six axis five linkage machine tool produced in China. The numerical control system adopts FANUC 160m to process gears with small specifications. The diameter is less than 125mm and the end face modulus is no more than 3mm. In the same year, another CNC gear grinding machine yk2250 (see Figure) came out. It is a seven axis five linkage machine tool, which was put into mass production in 2003. In 2006, China produced YK20100, the world’s largest CNC gear processing machine tool. This machine tool can process spiral bevel gears with large specifications, with a maximum diameter of 1m. The three feed shafts are directly driven by servo motors, three-axis linkage, and the spindle operation adopts frequency conversion speed regulation. The numerical control system adopts Siemens 802D to realize the manual and automatic control, interface diagnosis and troubleshooting of the machine tool. Xi’an Jiaotong University and Qinchuan Machine Tool Group Co., Ltd. jointly researched and manufactured a six axis and five linkage machine tool – spiral bevel gear machining center yh2240, which is a major breakthrough in domestic history. The CNC system of this machine tool adopts the French high-grade system num1060i, transforms the complex mechanism into a simple mathematical model, and uses the tool magazine of three knives to change the knives, The concept of “machining center” was born. The transmission structure of this machine tool is advanced and the processing method is new, which greatly improves the production efficiency and the processing quality.
At present, a large number of spiral bevel gear processing machine tools have been produced in China, and many spiral bevel gears have been processed accordingly. However, due to the complex shape and high precision requirements of spiral bevel gears, the spiral bevel gears processed by machine tools produced in China are still of poor quality, low speed and high noise, so it is difficult to give full play to the excellent characteristics of spiral bevel gears, Relatively speaking, it is difficult to meet the technical requirements of users. In order to process spiral bevel gears with high precision and good flexibility, it is necessary to introduce high-quality and high-precision machining machines from abroad. These machine tools are very expensive, and few powerful companies spend a lot of money to buy such high-grade machine tools. Therefore, it is of great significance to speed up the development and research of spiral bevel gear NC processing equipment and technology in China.