The modal module is used to simulate and test the transmission shaft structure. As shown in the figure, when using the sixth order modal analysis, the transmission shaft has local torsion and vibration, and when the modal order increases, it will produce more significant vibration mode. Through the analysis, it is found that the first two modes only deform in a specific direction, while the third to sixth modes also twist.

The first six order frequencies of the transmission shaft are in the range of 625 ~ 1339hz, and the lowest natural frequency is higher than the highest meshing frequency, which can effectively prevent the resonance of the gearbox and the transmission shaft. Using Med to decompose the acceleration vibration signal to obtain the first two order IMF components, the bispectrum slice test shows that it can reduce the degree of modal aliasing and simplify the signal data. The results show that the experimental analysis method to design the transmission shaft structure is in line with the requirements.

When the modal order is larger, the higher frequency value is formed. Among them, the first six natural frequencies of the transmission shaft range from 610 Hz to 1325hz. At the same time, it can be seen that the rotation frequency of the gear system ranges from 1.3 Hz to 581.32hz. Through comparison, it can be seen that the transmission shaft reaches the lowest natural frequency higher than the highest meshing frequency, so as to prevent the resonance between the gearbox and the transmission shaft.

The first six natural frequencies of the transmission shaft range from 610 Hz to 1325hz, and the gear system rotation frequency ranges from 1.3 Hz to 581.32hz. The transmission shaft reaches the lowest natural frequency higher than the highest meshing frequency, so as to prevent the resonance between the gearbox and the transmission shaft.