## 3 Results  
In the presented measurement example, the efficiencies for all working points according to sample Figure 1 are collected in Table 1.  
In modes 5, 9, and 13, the power flow reversed in the direction from the generator to the motor, which was reflected in a change in the polarity of the signal from the measured components. To calculate the efficiency in these cases, the output of the gearbox was therefore considered an input, and conversely, the input was considered an output. Table 1 can be clearly interpreted graphically like finalized efficiency map (Figure 12). From the measured data and the determined efficiencies (Table 1), it is evident that the investigated gearbox achieves the highest efficiency above 97%. The gearbox achieves this maximum efficiency at speeds from 1800 rpm to 2700 rpm and at a nominal input torque of 600-1000 Nm. This area, which is clear on the efficiency map (Figure 12), is the optimal functional area of the gearbox. Figure 12 also shows that when the nominal input torque is reached, at speeds below 1800 rpm, the efficiency of the gearbox approximately drops to 96%. The same applies to speeds above 2700 rpm. In this area, however, the gearbox approaches the power limitation and the input torques should not exceed 700 Nm. Furthermore, it is also evident that, for the total speed range, at torques lower than 500 Nm,the efficiency of the gearbox decreases significantly. The least favorable in terms of efficiency are input torques below 100 Nm. In this area, efficiency is below 85%. Figure 12: The efficiency map–graphical interpretation of measured data. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Input Shaft**} & \multicolumn{2}{c}{**Output Shaft**} & \\ \hline
**Mode** & **Speed [1/min]** & **Torque [Nm]** & **Torque [Nm]** & **Efficiency** & **Deviation** \\ \hline
1 & 12.2 & 20.46 & 131.07 & 89.89\% & 0.31\% \\ \hline
2 & 12.2 & 409.95 & 2808.87 & 96.14\% & 0.25\% \\ \hline
3 & 12.2 & 756.13 & 5169.80 & 95.93\% & 0.21\% \\ \hline
4 & 12.2 & 1106.13 & 7607.35 & 96.50\% & 0.12\% \\ \hline
5 & 1840 & \(-\)39.94 & \(-\)347.03 & 82.02\% & 0.33\% \\ \hline
6 & 1840 & 271.82 & 1853.23 & 95.66\% & 0.28\% \\ \hline
7 & 1840 & 595.86 & 4128.51 & 97.22\% & 0.088\% \\ \hline
8 & 1840 & 1007.57 & 7018.25 & 97.73\% & 0.068\% \\ \hline
9 & 2670 & \(-\)35.93 & \(-\)322.31 & 79.45\% & 0.36\% \\ \hline
10 & 2670 & 304.77 & 2071.48 & 95.37\% & 0.23\% \\ \hline
11 & 2670 & 651.44 & 4509.53 & 97.13\% & 0.074\% \\ \hline
12 & 2670 & 1016.67 & 7080.37 & 97.72\% & 0.063\% \\ \hline
13 & 4200 & \(-\)54.89 & \(-\)507.55 & 77.08\% & 0.34\% \\ \hline
14 & 4200 & 181.76 & 1147.52 & 88.58\% & 0.28\% \\ \hline
15 & 4200 & 428.56 & 2888.15 & 94.56\% & 0.083\% \\ \hline
16 & 4200 & 700.97 & 4803.84 & 96.16\% & 0.075\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The efficiency—measured data. Table 1 shows the deviations of the determined efficiencies for the individual measured modes. The deviations are based on the definition of statistical evaluation described in Section 2.6, which was applied to the measured data. The resulting percentage deviations show that the efficiency values for the nominal functional area of the gearbox are determined most accurately (approximately for input torques from 600 to 1000 Nm, at 1800-2700 rpm). For measured data in this area, the deviations range corresponds to higher units of hundredths of percent--specifically, 0.063-0.088%. If the gearbox is outside its optimum operating range, i.e., the input torques are less than 500 Nm, the deviation values are equal to low tenths of a percent (0.12-0.36%). It can therefore be stated that the determination of the deviation and the most accurate efficiency depends on the quality and nature of the measured data, which is related to the functional area of the gearbox (i.e., values of torque and operating speed).