Bevel gear is a new type of space power transmission. Compared with the standard spiral bevel gear transmission, bevel gear has the advantages of light weight, high interchangeability, simple structure and insensitive to axial error. At present, it has been applied to the heavy-duty transmission system of helicopter and has a broad application prospect in the future. In order to improve the machining efficiency of bevel gear, the research on efficient forming method of bevel gear and its related tools is the key factor to realize its engineering application.
Summarize the bevel gear processing methods. The existing processing technologies include gear shaping, gear milling, gear hobbing processing methods and some non mainstream processes, such as additive manufacturing, forging, gear milling and so on. Among them, the most common is the bevel gear shaper machining method, which is also the earliest bevel gear machining method. The tooth surface is machined by simulating the meshing motion of the shaper cutter and the bevel gear. The disadvantage is that the feed rate of the shaper cutter has a great impact on the accuracy of the bevel gear tooth surface and the machining efficiency is low. Gear hobbing is an efficient machining method, which continuously develops the complete bevel gear tooth surface through the proportional rotation of the tool and the bevel gear. The disadvantage is that the shape of the hob is complex and the manufacturing cost is high. Therefore, it is necessary to propose a new efficient machining method of bevel gear, which can improve the machining efficiency and control the manufacturing cost of cutting tools at the same time.
Strong turning gear technology was put forward in 1910. Due to its special cutting method, the machining efficiency of strong turning gear is very high and the machining method is more simple, especially in the machining of involute cylindrical internal gear.
In order to realize the efficient machining of bevel gears, the research of gear turning tools is also a key part. In recent years, the design and manufacturing technology of gear turning tools have made great progress, and various new high-performance gear turning tools are emerging, including involute gear turning tools and non involute gear turning tools. Chen put forward the design method of error free straight tooth turning tool for internal helical gear, and gave the grinding method of the main tooth surface of the tool. Jia et al. Proposed a general calculation method of non involute cylindrical gear to reverse calculate the profile of gear turning tool according to the shape of workpiece.
Gear turning machining is a continuous generation method for machining cylindrical internal gears. Its design is based on the meshing principle of spatial staggered shaft gears. In the process of machining, the cutter and the workpiece rotate in a fixed proportion, and the cutter moves radially along the workpiece to cut off the material on the surface of the workpiece, so as to achieve the purpose of machining the tooth shape. At present, the gear turning method has been applied to various types of gear machining, especially the involute cylindrical internal gear, which is less applied to bevel gear machining. Wang Yanzhong team of Beihang carried out the research on bevel gear turning gear processing. The research shows that turning gear processing bevel gear can not only realize the continuous generation of tooth surface, but also improve the surface integrity of tooth surface.
In order to shorten the manufacturing cycle of bevel gear, the continuous generation gear turning method of bevel gear is studied. Firstly, the gear system and machining coordinate are established. The cutting speed of the cutting point at the cutting edge of the gear turning tool is deduced. Secondly, the rack surface and flank of the gear turning tool are designed, the mathematical model of the cutting angle is established, and the variation law of the cutting angle of the tool in the machining process is analyzed. Finally, the gear turning process is verified by simulation analysis software, and the influence law of machining parameters on cutting force is analyzed.