In recent years, the research on rotary forging in China has made substantial development. For the research on swing rolling, China began in 1973. Wuhan Automobile gear factory successfully trial produced a swing rolling equipment, and then Chinese units successively successfully manufactured swing rolling machines of different specifications. In 1985, the 59th Institute of ordnance industry successfully studied the cold swing rolling process for the first time in China to realize the cold forming of end gear. In 1988, it cooperated with Xi’an Jiaotong University to study the cold swing rolling forming of planetary bevel gear, mainly studying the influence of blank shape, swing rolling time and feed rate, swing head shape and motion trajectory on the filling degree of planetary bevel gear tooth shape, The forming force of rotary forging is calculated and the metal blank flow in the forming process is simulated. In 1986, Wuhan Institute of technology also studied the powder metallurgy process of forming differential planetary bevel gear by warm rotary forging. In 1991, China began cold rotary forging to produce spiral bevel gears. In 1992, China successfully realized the cold rotary forging of motorcycle starting ratchet with “ears”. The cold rotary forging process of the part solves the difficult forming of the traditional forging process and the labor and time consumption of the cutting process. In 1995, China produced differential planetary bevel gear with modulus less than 4 by using rotary rolling machine. In 1997, the 59th Institute of ordnance industry successfully rolled another part with end face tooth profile and spiral surface. According to statistics, 56 rotary forging machines have been put into production in China. So far, China has been able to produce a variety of parts, such as automobile shafts, thin-walled discs, flanges, various gear blanks and cake forgings. China’s cold rotary forging is still in the trial production stage, including automotive planetary bevel gear, rear axle driven gear, half shaft bevel gear, steel synchronizer ring and other forgings.
Sheu J, et al. Studied the rotary forging straight tooth cylindrical gear, and found a method to prolong the service life of the swing head from the stress value of the swing head. Hu Rui and others used DEFORM-3D rigid plastic finite element to simulate the swing rolling deformation process of spur bevel gear, and obtained the time curves of metal flow, equivalent stress and swing rolling force in the deformation process, as well as the influence of process parameters on the failure of swing rolling die. Combining theoretical calculation with production and processing, LV Shijie made an experimental study on the swing rolling process design in bevel gear production, including material preparation, bevel gear forging design, swing rolling force calculation, determination of swing rolling machine tonnage, determination of swing rolling process parameters, etc. He compared the product quality of different processing processes, and summarized the advantages and disadvantages of each process on this basis. Yang Mingxuan and Ren Zhiyong analyzed the key technologies of cold rotary forging process. The results show that the cold rotary forging semi shaft bevel gear has high quality, long die life, high material utilization and low production cost.