There are two kinds of machining methods for hypoid gears, one is to use single index end face milling Face milling (FM) processing has the advantages of low processing efficiency, more equipment and high production cost; the other is to use face hobbing (FH) machining, also known as two cutter method, which can reduce the processing time of each group of gears by about 30%, and increase the service life of cutter head and cutter by 3 Therefore, FH hypoid gear is widely used at home and abroad. For example, Benz S450 4matic coupe, Beijing bj2022a, Changan Yidong DT, Ford new Taurus (Figure 1-2 (a), (b), (c), (d)) and other models have been applied.
FH hypoid gear is one of the most complex gear transmission forms. As a key component of automobile power transmission system, the meshing performance of hypoid gear has a significant impact on the reliability, stability and service life of the transmission system and even the whole vehicle.
The meshing performance of gears is generally evaluated by tooth contact marks and transmission errors. With the appearance of high-performance gear processing and testing equipment, the meshing performance of paired tooth surfaces can be actively controlled through the design of complex tooth surface topological shapes. Therefore, the design of paired tooth surfaces for hypoid gears has become a research hotspot.
FH hypoid gear pair tooth surface design includes tooth contact analysis (TCA), tooth surface error sensitivity analysis (tsesa), loaded tooth contact analysis (LTCA), tooth surface pre correction, and active tooth surface design The results of TCA can be used to estimate the life of hypoid gears. However, in the process of TCA calculation, complex curvature calculation is needed, which can not reflect the real situation of tooth contact.