The test diagram of vibration amplitude spectrum caused by tooth profile error of automobile gear is shown in Figure 1. Substitute N1 = 624 R / min and N2 = 128 R / min into the formula, F1 = 65.4 Hz and F2 = 12.8 Hz; Substitute into the formula to get FC = 83 Hz.
The prominent peak of the meshing frequency 83 Hz appears on this spectrum diagram, and then the frequency band near 83 Hz is refined. The refined spectrum diagram is shown in Figure 2. At this time, it is found that there is a 12.8 Hz sideband near 83 Hz, and 12.8 Hz is just the rotation frequency of the driven wheel, forming the sideband structure.
According to the obtained information, it can be seen that there is tooth profile error in automobile gear, which mainly occurs on the driven wheel. After parking and disassembling the main reducer for inspection, it was found that the teeth of the automobile gear driven wheel were deformed, resulting in the tooth profile error of the automobile gear.
The frequency components of automobile gear vibration caused by this situation are: the sideband generated by the automobile gear meshing frequency modulation phenomenon with the automobile gear meshing frequency and its high-order harmonics as the carrier frequency and the automobile gear conversion frequency and its high-order harmonics as the modulation frequency.