The manufacturing technology of face gear is based on their manufacturing principles, which can be divided into three categories: Based on the “accurate simulation” of the engagement between the small wheel and face gear, gear shaping, worm tool rolling, gear grinding, disc tool milling and gear grinding belong to this category; based on the “close simulation” of the engagement between the small wheel and face gear, that is to say, in the process of movement, the tool is made to approach the involute of the profile wheel to develop the machined face gear, Plane cutter milling, grinding, planing and slotting machining face gear belong to this category; based on 3D printing, stamping, powder metallurgy and other additive manufacturing methods, face gear is directly formed by blank machining. With the deepening of research, the manufacturing principles and methods of face gear have been gradually mastered by people, and the next stage of development will take a new step. Considering from the characteristics and application fields of face gear transmission, improving processing efficiency, reducing production costs, intelligent manufacturing and other aspects, the main research trends in the future are as follows:
(1) Precision machining and intelligent manufacturing. Because the future application of face gear will face the field of high-speed, reassembly and precision transmission, the accurate simulation based on the meshing of small wheel and face gear, especially the grinding technology, has the inherent advantage that manufacturing accuracy can be guaranteed, and is the key field of faceresearch in the future. With the introduction and implementation of the 13th five year plan and the intelligent manufacturing plan, the manufacturing method based on accurate simulation will be more integrated and intelligent. For example: self parameter design – gear coordinate data – workpiece preparation – clamping and cutting – Online on-line detection – data feedback – tool trimming – all intelligent operation of any link of the machining chain up to the adjustment of the machine tool spindle. Because the relative position and movement of cutter, trimming wheel, machine tool spindle and workpiece and the test results have a crucial influence on the final accuracy and surface quality of workpiece, it is necessary to describe the parameters in these links and expose the coupling law of these parameters on the manufacturing accuracy.
(2) Manufacturing technology for surface integrity and fatigue resistance. It can be seen from the above-mentioned processing methods that, when the front gear processing is mainly focused on the exploration of the principle and feasibility of various processing methods, it has not been deeply into the study of the influence mechanism of processing quality on the transmission performance of the gear. However, the surface defects of gears are very easy to appear in the heat treatment, especially in the machining of the final process, while the surface integrity of gears determines its service performance to a great extent. Surface integrity refers to the surface state without damage or reinforcement , mainly involving fatigue, friction and wear and other performance indicators. Due to the limitation of undercutting and cusp changing conditions, the width of bearing gear is limited, so it is very important to improve the surface integrity of face gear for high-speed and heavy-duty applications in order to strengthen its anti fatigue ability. In the future, we should strengthen the development of material selection, heat treatment and surface treatment technology, such as shot peening, rolling, grinding, polishing, laser shock strengthening and other surface treatment technologies.
(3) Industry synergy development. From the distribution of research literature on face gear transmission, the joint research and development of face gear transmission technology in foreign countries should not be ignored. For example, in rds-21 and other programs, the U.S. military, NASA, Boeing, Northstar Canada, University of Illinois at Chicago and other agencies are all involved in the design, manufacturing, testing and other aspects of face gear drive. As a new type of transmission, face gear transmission involves a wide range of problems, which is related to the system engineering of material, manufacturing, equipment, testing, control, performance, dynamics and other multi-technical integration. Therefore, in the research and development of face gear drive and its manufacturing technology, a number of joint research and development teams will be formed in the future to overcome the technical problems of high-quality face gear manufacturing.
(4) Sustainability and green manufacturing. There are a lot of literature about the green and sustainable development of gear manufacturing technology at home and abroad. Domestic environmental pollution is becoming more and more serious. In order to develop environment-friendly gear manufacturing technology, we have to introduce foreign advanced technology, digest, absorb and develop again. Therefore, the sustainability and green manufacturing of face gear is also a clear trend of future development. For the face gear, if considering from the perspective of sustainability and green manufacturing, we should focus on the development of manufacturing methods based on “approximate simulation”, in order to improve the applicability and versatility of tools, and to achieve the standardization and serialization of tools. In order to reduce the application of materials, we should focus on the development of rapid prototyping billet methods, such as 3D printing, stamping, forging, powder metallurgy, precisionand other preparation methods.
(5) The development of new manufacturing technology. With the development of intelligent technology and independent drive and control technology of multi axis machine tools, the “approximate simulation” manufacturing method of face gear will gradually replace the “accurate simulation” manufacturing method. There are three reasons: first, it is more practical to obtain ideal meshing performance than to simply pursue manufacturing accuracy. For example, in order to reduce vibration and reduce noise and improve fatigue life, it is often necessary to carry out shape processing on standard and theoretical tooth surface. “Approximate simulation” can not obtain accurate tooth surface, but it can obtain good meshing performance through adjustment of manufacturing parameters. Secondly, if the machining efficiency is not high, the precise tooth surface can be obtained by using the point contact method in the “approximate simulation” machining, and the manufacturing accuracy depends on the control accuracy of each axis of the machine tool. Thirdly, because the cutter has already abandoned the rigid limitation of solid surface, it will form the profile wheel surface completely based on the movement, and the development of manufacturing technology based on “approximate simulation” will be more flexible. For example, the research on the continuous grinding method of face gear based on the straight edge tool. Therefore, for face gear, there will be the development of new manufacturing technology based on “approximate simulation”. In addition, the manufacturing method applied to other types of gear transmission will also be applied to the processing of face gear, that is, the development of new manufacturing technology of face gear based on technology transfer, such as the development of new manufacturing and surface treatment technologies such as shaving, rolling, multi process composite processing, ion implantation, vibration finishing, etc.
To sum up, the face gear transmission has certain advantages and wide application prospects in the future. The manufacturing technology of face gear abroad is becoming more and more mature, and the manufacturing technology of face gear transmission in our country has also made great progress. In the next stage, the development of the manufacturing technology of face gear in our country will definitely improve in quantity and quality. Its research trends mainly focus on precision machining, intelligent manufacturing, improvement of surface integrity and anti fatigue ability, collaborative development in the industry, sustainability and green manufacturing, development of new manufacturing technology, etc.