It can be seen from the previous analysis that before tooth profile modification, the transmission error of straight bevel gear fluctuates greatly with the increase of frequency from 0Hz to 5000Hz. When the frequency is 400Hz ~ 1120hz and the corresponding speed of straight bevel gear is 1080r / min ~ 3300r / min, the transmission error will suddenly change, and the maximum transmission error of straight bevel gear pair reaches 3.39 μ m. The difference between the maximum and minimum values is 0.87 μ m. The dynamic response curve excited by transmission error reflects the instability in the transmission process of straight bevel gear. When the frequency is 730hz, the linear modal flexibility of spur bevel gear meshing dynamic response reaches the maximum value of -4.96 × ten μ M / N, at this time, the vibration of straight bevel gear transmission is the most intense, which makes the greatest contribution to the vibration and noise of the whole straight bevel gear transmission. At the same time, it can be seen that the vibration fluctuation in the whole straight bevel gear transmission process is large.
The straight bevel gear is modified by arc modification of tooth profile and equidistant modification of tooth direction. The dynamic analysis of the modified straight bevel gear system is carried out by using RomaxDesigner software. It can be seen that the transmission error and vibration of the bevel gear system are significantly reduced, and the effect of equidistant modification of tooth direction is better than that of arc modification of tooth profile. The maximum transmission error of straight bevel gear is reduced from 3.39 by equidistant modification of tooth direction μ M down to 1.13 μ m. The transmission error of the straight tooth profile is improved by about 3.67% by the circular arc transmission error of the bevel gear μ M down to 1.19 μ m. The transmission error is improved by about 65%; The maximum value of the dynamic response curve (linear modal flexibility value) of the straight bevel gear system is changed from -4.96 to -4.96 × 10 down to – 4 1.1 × ten μ m. The vibration and noise of straight bevel gear system are improved by about 78%; The maximum value of the dynamic response curve (linear modal flexibility value) of the straight bevel gear system after tooth profile modification is -4.96 × 10 down to 4 1.35 × 10- μ m. The vibration and noise of spur bevel gear system are improved by about 73%.
Comparing the dynamic performance of straight bevel gear transmission before and after modification, it can be concluded that the equidistant modification of tooth direction and arc modification of tooth profile effectively reduce the transmission error and vibration characteristics of straight bevel gear in the meshing process, improve the vibration in the transmission process of the system, and improve the accuracy and stability of straight bevel gear transmission; At the same time, it can also be concluded that using different modification methods to modify the straight bevel gear will improve the dynamic performance of the straight bevel gear system differently.