Based on the accumulated Basic test data of surface grinding, the actual grinding test of spiral bevel gear on NC gear grinding machine is planned to be carried out. For the grinding surface performance of spiral bevel gear, the key is its surface residual stress and grinding surface roughness, which have a great impact on the service life, fatigue strength and wear resistance of the gear.
According to the experience accumulated in practical use, the parameter index generally requires that the surface roughness Ra of spiral bevel gear after grinding is ≤ 0.8, and the residual stress is compressive stress. As for the microhardness of the tooth surface, although the research in Chapter 3 shows that the microhardness of the grinding surface can be further improved through reasonable process parameters under the condition of dry grinding, the microhardness of the carburized layer HRC 58-62 after carburizing and quenching has basically met the requirements of the anti fatigue performance of the gear. On the contrary, if the hardness of the tooth surface is too high, the surface brittleness will rise sharply and the risk of tooth fracture will be increased.
Under the condition of wet grinding, the residual compressive stress on the tooth surface is obviously better than that under the condition of dry grinding, which also reduces the possibility of grinding burns and grinding cracks. Therefore, in the actual processing and production of spiral bevel gears, wet grinding is adopted, and the grinding fluid is generally oil-based extreme pressure grinding fluid.
Firstly, the grinding test of spiral bevel gear is designed according to the test data of plane grinding Basic test, and the influence of different grinding parameters on the surface morphology and residual stress of spiral bevel gear after grinding is analyzed. Then, the grinding process parameters of spiral bevel gear are optimized, and the regression experimental model is established to obtain the optimal combination of process parameters.