The matching of machining quality and machining efficiency is an issue to be seriously considered in finishing machining. After the selection of machine tool, cutting tool, workpiece and fixture, the selection of cutting parameters directly affects the morphological characteristics of finishing surface. There are many factors affecting the tooth surface quality of spiral bevel gears, such as the accuracy error of the machine tool itself, the adjustment error of the milling cutter head, the vibration deformation of the machine tool, tool wear and so on. In addition, the error caused by NC system interpolation can not be ignored. The causes of tooth surface quality problems are complex, and it is difficult to form a unified mathematical model.
For different machining processes, scholars at home and abroad have established a variety of roughness mathematical models, and established the quantitative relationship between machining surface roughness and cutting parameters. Han Jiaying and others solved the problem of how to calculate the average residual height from the cutting parameters in machining spiral bevel gears by the tool inclination method of mechanical gear milling machine, but did not deeply analyze the influence of cutting parameters on the average residual height of tooth surface. Due to the complexity of the tooth surface topology of spiral bevel gear, there is no instrument for quantitative measurement of the surface roughness of spiral bevel gear in the spiral bevel gear processing industry. The common practice is to use the roughness measurement block for visual and qualitative measurement. If the average residual height of the machined tooth surface can be predicted by theoretical calculation before machining, the tooth surface roughness can be effectively controlled and the adjustment times of cutting parameters can be reduced. When the NC gear milling machine uses the hobbing method to process the spiral bevel gear, the contact trace between the tool and the workpiece is determined by the gear cutting principle, and there is no problem of optimal selection of the tool path. The cutting parameters that can affect the residual height of the tooth surface include: cutting speed, x-axis and y-axis linkage speed, and single-step interpolation degree. The purpose of the research is to quantitatively analyze the influence of cutting parameters on the average residual height of tooth surface from the perspective of theory and experiment.
According to the machining principle of precision milling spiral bevel gear by NC Hobbing method, the formation mechanism of residual height of tooth surface when precision milling spiral bevel gear pinion by NC Hobbing method is analyzed, the analytical relationship between cutting parameters and average residual height of tooth surface is deduced, and the mathematical model for theoretical calculation of average residual height of tooth surface is established. The theoretical calculation of the average residual height of the tooth surface shows that selecting a higher cutting speed (VC) can reduce the average residual height of the tooth surface; Selecting a smaller moving speed (vxy) of the linkage shaft can reduce the average residual height of the tooth surface; Reduce single step interpolation degree（ Δ Q) it has the most obvious effect on reducing the average residual height of the tooth surface.