When the vibration energy is large, such as broken tooth, serious tooth profile error and serious shaft bending, it will not only produce the meshing frequency modulation of tractor gear, but also arouse the natural frequency of the gear itself, resulting in the natural frequency vibration modulation of tractor gear. That is, the resonance modulation phenomenon of tractor gear with the natural frequency of the gear itself as the carrier frequency and the conversion frequency as the modulation frequency.
At this time, the dynamic expression of vibration measured in the tractor gearbox is:
Where: XGA (T) represents the vibration of the natural frequency of the gear itself.
For this kind of abnormal gear vibration, sometimes the natural frequency vibration component is dominant, but sometimes the meshing frequency modulation component can not be ignored. The practical research shows that the resonance modulation phenomenon of tractor gear is a very important factor causing gearbox failure, and it often occurs, which should be paid enough attention.