Two ways of machining high-precision spiral bevel gears

High-precision spiral bevel gears are key transmission components in the automotive, petroleum, energy and aerospace industries. The geometric features of the tooth surface of the high-precision spiral bevel gear are complex, and the manufacturability is very strong. In terms of mathematical theory, even if the module, pressure angle, helix angle and tooth surface contact area of ​​the bevel gear are known, the tooth profile of the bevel gear cannot be completely determined. With the popularization of controllable gear machine tools and grinding technology, the processing methods of gear systems in my country have developed rapidly. All use cycloid contour teeth, the calculation is simple, and the contact area is better than shrinkage. The research results show that, in the processing of small batch products, especially in the processing of high-precision spiral bevel gears, the use of circular arc contour teeth is an ideal choice. The tooth surface of bevel gear has countless meshing conditions in a certain space, so the processing parameters are complicated. It can be seen that the geometric calculation parameters of the spiral bevel gear and the structure of the additional bed are very complex and cumbersome. And tooth surface generation technology, detection technology, correction technology, etc. These are produced accordingly, far behind normal gears.

There are two methods of machining gear teeth. One is the double-sided method to process the large gear, and the single-sided method to process the pinion. The other is that the large and small gears are processed by the single-sided method. When the former method is adopted, the radius of the cutter head on both sides of the gear teeth of the large gear is different, and the helix angle of the center point is also different, so the bottom groove of the large gear will cause the dislocation distance of the cutter head of the bottom groove of the pinion to be too small, which will affect the strength and life. The latter method will not produce the above situation when machining gears, but the machining efficiency is relatively low. Only through various tooth cutting correction calculations can the correct meshing be ensured. Only when the axis of the cutter head is perpendicular to the root cone of the processed gear, the The root surface can be properly expanded. Therefore, the profile angle of the cutter teeth is modified to be symmetrical with the pitch line, but this also leads to an increase in the size and number of cutter heads.