## 3 Centralized Lubrication and Waste Grease Recovery Test Platform Test
### Vacuum Degree Test
#### 3.1.2 Power Oil Pressure Test of the Grease Suction and Drainer Device
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Variable** & **Sample** & **Sample** & **Minimum** & **Mean** & **Standard** \\
**Name** & **Size** & **Size** & **Value** & **Value** & **Deviation** \\ \hline Port A/MPa & 39 & 5 & 4 & 4.751 & 0.304 \\ Port B/MPa & 39 & 5.3 & 4.5 & 5.028 & 0.132 \\ \hline
**Variable** & **Median** & **Variance** & **Kurtosis** & **Skewness** & **Coefficient of Variation (CV)** \\ \hline Port A/MPa & 4.8 & 0.093 & 0.097 & \(-1.021\) & 0.0640 \\ Port B/MPa & 5 & 0.017 & 7.143 & \(-0.7\) & 0.0262 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of descriptive statistics of power oil pressure after 12,000 fatigue tests. 3.1.3. Vacuum Degree Test of the Grease Suction and Drainer Device  
The vacuum degree of the grease suction and drainer device will affect the effect of the waste oil discharged from the bearing cavity, and the vacuum degree is destroyed, indicating that the grease suction and drainer device has poor sealing and liposuction, and the waste grease is difficult to be stably sucked out from the bearing cavity. In order to check whether the sealing performance of the suction and drainer device is reliable, the vacuum degree of the grease suction and drainer devices is tested, and the vacuum degree change of the grease suction and drainer devices after 12,000 times fatigue tests is tested. The test results of the vacuum degree are presented in Figure 10.  
In order to verify the reliability of the measured vacuum degrees of the grease suction and drainer grease devices, descriptive statistical analysis was performed based on the test data of the comparison of the vacuum degrees of the grease suction and drainer grease devices before and after 12,000 cycles in Figure 10. The results of the calculations are presented in Table 3.  
Table 3 shows the descriptive statistical results of the vacuum degree of the grease suction and drainer devices before and after 12,000 fatigue tests, including statistics such as sample size, maximum value and minimum value, which are used to study the overall situation of the vacuum degree change before and after the test. The absolute kurtosis of the vacuum before and after the test is less than 10, and the absolute skewness of  
Figure 10. Vacuum degree of the grease suction and drainer devices before and after 12,000 fatigue tests. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Variable** & **Sample** & **Sample** & **Minimum** & **Mean** & **Standard** \\
**Name** & **Size** & **Size** & **Value** & **Value** & **Deviation** \\ \hline Vacuum degree & & & & & \\ before the & 39 & 0.097 & 0.083 & 0.094 & 0.002 \\ test/MPa & & & & & \\ Vacuum degree & & & & & \\ after the & 39 & 0.097 & 0.082 & 0.093 & 0.003 \\ test/MPa & & & & & \\ \hline
**Variable** & **Median** & **Variance** & **Kurtosis** & **Skewness** & **Coefficient** \\
**Name** & & & & & **(CV)** \\ \hline Vacuum degree & & & & & \\ before the & 0.094 & 0 & 11.676 & \(-\)2.895 & 0.0253 \\ test/MPa & & & & & \\ Vacuum degree & & & & & \\ after the & 0.094 & 0 & 8.798 & \(-\)2.332 & 0.0274 \\ test/MPa & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Results of descriptive statistics of vacuum degree before and after 12,000 fatigue tests. the vacuum before and after the test is less than 3, so the vacuum essentially follows a normal distribution. The coefficient of variation (CV) of the vacuum degree before the test was 0.025, and there was a small probability of an abnormal value (CV < 0.15) in the vacuum degree data before the current test. The average value was used to represent the vacuum degree before the test in 39 groups of tests, which was 0.094 MPa. The coefficient of variation (CV) of the vacuum degree after the test was 0.027, and the abnormal value (CV < 0.15) was small in the current data. The average value was used to represent the vacuum degree after the test in 39 groups of tests, which was 0.093 MPa.