In recent years, the research on face gear transmission has been carried out abroad, and the team led by F. L. Litvin is committed to the research on spur gear and helical gear. His main research achievements include: tooth surface generation and machining method of face gear; The theories of the coincidence degree, structural stress and finite element modeling analysis of face gear are further studied; According to the principle of meshing geometry, the conditions of undercutting and tooth tip sharpening are obtained; The point contact theory of face gear transmission is developed; Using the point contact theory and tooth surface modification method, Dr. Litvin has realized the reduction of noise and vibration, which plays a very important role in promoting the development of face gear transmission. For the latest research on face gear, Art jointly implemented by the U.S. military and NASA The advanced rotor craft transmission plan shows the latest trend of face gear research. The starting point of the plan is to replace the traditional spiral bevel gear transmission with face gear transmission in the high-speed and heavy-duty aviation gear transmission system. Its purpose is to reduce the weight, vibration and noise of the whole transmission system by adopting its torque split transmission mode Sound. The plan focuses on the face gear transmission system under high speed and heavy load, and designs the shunt transmission structure of face gear transmission applied to the new helicopter main reducer, as shown in Figure 1. If two traditional spiral bevel gears are regarded as transmission shunting links, not only the structure is more complex, but also the weight is increased. The structure comparison of the main reducer with ordinary spiral bevel gear and face gear is shown in Figure 2. The main advantage of the helicopter main reducer with the split face gear structure is that its weight has dropped by 40% compared with the traditional structure, simultaneous interpreting power flow effect is good, vibration is small, noise is low, and the application prospect is also very broad. After completing the art project, DARPA (Defense Advanced Research Projects Agency) of the United States carried out further research on face gear transmission technology in the Trp project (technology reinvestment program). Its research background is mainly the use of face gear transmission technology in the new generation Apache armed helicopter.
In China, the research on face gear began in the 1990s. Great achievements have been made in the theoretical research of face gear transmission technology in China. For example, the research group led by Professor Zhu Rupeng of China Southern Airlines has carried out a series of theoretical research on face gear transmission. In recent years, Beijing University of Aeronautics and Astronautics and Yanshan University have also conducted some research on face gear, which plays an important role in the development of face gear.
The research group of NSFC led by Professor Fang Zongde of Northwest University of technology has also carried out research on helical gear. The main contents of their research include: the research on the tooth width of helical gear, and the problems that helical gear does not produce undercutting in the tooth root and does not produce cusp in the tooth top.