It is necessary to create a three-dimensional geometric model of the gear before carrying out the loaded contact analysis. For a specific spiral bevel gear entity, its tooth surface shape is complex, which makes it difficult to obtain the analytical expression of its tooth profile equation. Although the discrete data points of tooth surface can be obtained through numerical calculation, it can not express the real machining environment. The essence of virtual machining is to simulate the actual production process through the virtual production system in the computer. This method is carried out in the computer simulation environment. It has the advantage of not consuming physical resources. At the same time, it can describe the real manufacturing process of the product. The process of machining spiral bevel gears is actually the process of cutting blanks with cutting tools. In the process of feeding, the tool cuts off the overlapping area between the tool and the blank. After continuous cutting for many times, the surface of spiral bevel gear is obtained.
According to the adjustment parameters and motion mechanism of spiral bevel gear processed by actual machine tool, the relative position and motion relationship between tool and blank are constructed in CATIA software. Using Boolean operation to remove the overlapping area between the tooth blank geometry and the tool geometry, the model of spiral bevel gear blank cutting once by the tool is obtained. Using the macro command secondary development technology in the software, the automatic continuous cutting process can be realized, and finally the model corresponding to the actual cutting of a single tooth slot can be obtained. Based on the geometric model after cutting, the cogging surface is reconstructed to obtain a smooth cogging surface, and then a complete geometric model of spiral bevel gear can be obtained.