Comparison and summary of fatigue pitting test results of spur gears

In order to better reflect the effect of the test gear on the dynamic response characteristics of the system due to the change of tooth surface characteristics during the test. In order to facilitate the description of the data characteristics, the statistical values of the 12 stages will be numbered in the order of No. 1-12, that is, No. 1-3 belongs to 4 million statistical results, No. 4-6 belongs to 6 million statistical results, and so on.

(a) Maximum G1 (b) Average G3

As shown in the figure, the curves of the statistical indexes G1 and G3 changing with the cycle stage are drawn. The maximum value G1 can show the maximum vibration amplitude characteristics that may occur during the operation of the system, while the average value G3 can briefly show the concentrated location domain and overall trend of the amplitude signals in each stage of the system.

The change of statistical index G1 in figure (a) shows that there is a weak change in the geometric features of the tooth surface, such as tooth wear or local gray spots, which causes the peak value to increase slowly; when the initial pitting trace or even fatigue pitting occurs on the tooth surface, the peak value will rise sharply, which indicates that the fatigue pitting feature of the tooth surface can cause the dynamic instability of the system The balance response expands or increases.

Similarly, the change of statistical index G3 in figure (b) shows that the overall value is increasing. According to the effect of amplitude growth rate, the growth rate of statistical index g caused by fatigue pitting can reach 215%, and the statistical index ﹣ can reach 192%. It can be seen that the amplitude effect of dynamic response caused by tooth surface fatigue pitting can reach more than 2 times of that without pitting, which effectively promotes the alarm value set by the system during real-time monitoring of the test as a reference, realizes the earlier identification of tooth surface pitting characteristics, and paves the way for the later fault diagnosis and identification of gearbox.