According to the actual meshing sequence of the helical gear, the overall error curve of the unit helical gear pair is unified in the meshing plane to obtain the overall error curve of the helical gear pair in the complete meshing cycle.
It can be seen from Figure 1 that within the range of ABCO in the meshing area, there are 4 contact lines in go section and CH section, and 3 contact lines in Hg section. The overall error curve of 4 unit helical gear pairs represents that 4 pairs of teeth are engaged at the same time, and the overall error curve of 3 unit helical gear pairs represents that 3 pairs of teeth are engaged at the same time. Figure 2 shows the overall error curve of helical gear pair from which the tangential comprehensive error can be read Δ Fi’, one tooth tangential comprehensive error Δ Fi’, cumulative pitch error Δ FP, pitch error Δ FP, tooth profile error Δ FF and base node error Δ fpb 。
The envelope of the overall error of the helical gear pair is the transmission error curve of the helical gear when it is unloaded, as shown in Figure 3. Compared with the transmission error, the overall error of the helical gear pair has more information, which can not only evaluate the transmission quality of the helical gear pair, but also reveal the influence of the helical gear geometric error on the transmission quality in the actual meshing process of the helical gear.