Surface roughness is not only the most important index to measure the surface morphology, but also an important standard to measure the integrity of grinding surface. It affects the accuracy, service performance, reliability and durability of gear tooth surface to a great extent. Therefore, the surface roughness of spiral bevel gear under different grinding parameter combinations is further studied and analyzed. The white light interferometer is used to measure the surface roughness of the tooth sample after grinding. The white light interferometer measures the optical path difference between the coherent lights and the related physical quantities based on the interference principle. In order to reduce the random error, in the test, 10 points are randomly selected at different positions on the surface of each tooth sample for measurement, and finally the average value is taken as the final measured value of surface roughness under this group of parameters. The measured results are as follows.
(1) Effect of grinding speed on surface roughness of spiral bevel gear
Generating speed of fixed spiral bevel gear w = 10 ° / s, grinding depth AP = 30 μ m. The test is carried out under vs different grinding speeds. The influence of grinding speed on the surface roughness of spiral bevel gear is shown in Figure 1.
It can be seen from Figure 1 that the value range of tooth surface roughness after grinding is roughly between 0.4 and 0.6, and other parameters remain unchanged. With the continuous improvement of grinding speed, the surface roughness generally shows a downward trend. This is because increasing the grinding speed increases the number of effective abrasive particles per unit time, and the cutting times of each abrasive particle on the workpiece surface increase. Under the cumulative cutting action of multiple abrasive particles, the residual height of the machined surface decreases, resulting in the decrease of the machined surface roughness. Therefore, in the actual grinding of 30crmnti material, the grinding speed can be appropriately improved, the machining surface quality can be improved, and the machining efficiency can be improved at the same time.
(2) Effect of grinding depth on surface roughness of spiral bevel gear
The fixed grinding speed vs = 20.3 M / s and the spiral bevel gear generating speed w = 10 ° / s are tested under different grinding depths AP. The influence of grinding depth on the surface roughness of spiral bevel gear is shown in Figure 2.
It can be seen from Figure 2 that the value range of tooth surface roughness after grinding is roughly between 0.4 ~ 0.65, and other parameters remain unchanged. The grinding surface roughness increases gradually with the increase of grinding depth. This is because the increase of grinding depth will increase the undeformed thickness of a single abrasive particle in the grinding area, increase the groove depth and bulge on both sides of the abrasive particle on the workpiece, and finally increase the value of surface roughness.
(3) Influence of spiral bevel gear generating speed on gear surface roughness
Fixed grinding speed vs = 20.3 M / s, grinding depth AP = 30 μ m. The test is carried out under different spiral bevel gear generating speeds W. the influence of spiral bevel gear generating speed on gear surface roughness is shown in Figure 3.
It can be seen from Figure 3 that other parameters remain unchanged, and the grinding surface roughness decreases gradually with the increase of spiral bevel gear forming speed. This is because with the increase of the development speed of the spiral bevel gear, the height value of the theoretical residual area increases slightly, and the possibility of the abrasive particles falling off and embedded on the substrate surface is reduced. Therefore, in the case of little change, the grinding efficiency can be improved by increasing the generation speed.