## 3 Statement of Basic Materials
The processing of the results of experimental studies, according to a special program, made it possible to create regression models for determining the maximum values of the torque \(M_{t}\) on the rotor axis, the traction force \(T\), and the turning moment in the plan \(M_{xoy}\) relative to the intermediate frame mounting swived on the base chassis. Regression models for determining the maximum values of the parameters listed above have the following form:  
\[ \begin{array}{c}M_{t}=28.38+3.59x_{1}+6.25x_{2}-2.18x_{5}+12.51x_{6}-0.92x_{1 }x_{3}+1.11x_{1}x_{4}-0.99x_{1}x_{5}+\\ +2.29x_{1}x_{6}-1.21x_{2}x_{5}+3.48x_{2}x_{6}+1.26x_{3}x_{4}-1.68x_{3}x_{6}-2.1 3x_{5}x_{6},\text{ kN}\cdot\text{m},\\ T=5.11+1.79x_{3}+2.43x_{6}-2.13x_{1}x_{4}-3.17x_{2}x_{3}-1.59x_{2}x_{4}-1.39x_{ 2}x_{5}+\\ +1.33x_{2}x_{6}-1.3x_{3}x_{6}-1.35x_{5}x_{6},\text{ kN}\cdot\text{m},\\ M_{xoy}=39.9-14x_{4}+14x_{6}+16.8x_{1}x_{4},\text{ kN}\cdot\text{m},\end{array} \]  
The variables in the obtained equations are: \(x_{1}\)--the soil strength according to the DorNDI impactor, \(x_{2}\)--the trench width, \(x_{3}\)--the time of the intermediate frame additional rotation at the end of each half cycle, \(x_{4}\)--the speed of the actuator lateral supply to the face, \(x_{5}\)--soil cutting speed, and \(x_{6}\)--the speed of the actuator supply to the face. To perform the calculations, it is necessary to use the values of the variables according to the mode studied into each equation. The absolute values of each of the variable factors are within \(-1\) and \(+1\), according to the coding in Table 1.  
After substituting the coded values of the variables into the formulas, the maximum values of the load parameters in the considered modes are obtained. The maximum values of the variables given in the table determine the limiting conditions for applying the obtained regression models, the confidence interval of which is 0.95 with a measurement error of 10%. The torque on the rotor relative to the axis of its rotation (hereinafter--on the rotor) \(M_{\rm t}\) is one of the main parameters of the UEM operating equipment load. Special attention should be paid to the determination of the nature of changes in its value during the operating cycle (half-cycle) in different modes of operation, in different soil conditions, with additional rotation of the intermediate frame at the end of each half-cycle and without it. According to the results of experimental studies, it was established that the nature of the \(M_{\rm t}\) change during the cycle (half-cycle) remains the same in different modes of operation, if there is no additional rotation of the intermediate frame and the absolute torque values change. Figure 4 shows graphical dependences of the \(M_{\rm t}\) change during the cycle in different operating modes. The most loaded is the mode of the highest efficiency when developing the soil by a rotor with a cutting speed \(V_{c}\) = 6 m/s, \(V_{Lm}\) = 0.7 m/s. The \(M_{\rm t}\) maximum value is 74 kN\(\cdot\)m, the minimum is 14 kN\(\cdot\)m, i.e., the torque change coefficient for the half-cycle \(k_{\rm Mt}\) is 5.28. At the time of changing the direction of the rotor lateral movement, the torque is reduced from maximum to minimum within 1.1 and 1.5 s.  
Increasing the soil cutting speed to 9 m/s reduces the torque on the rotor, especially its peak values. Thus, the \(M_{\rm t}\) maximum value decreases to 52-56 kN\(\cdot\)m, i.e., by 24-30%, the minimum value decreases to 12 kN\(\cdot\)m, i.e., by 14%. Reducing the speed of the longitudinal supply of the actuator to the face from 104 m/h to 27 m/h, other things being equal, reduces both the torque maximum values to 22-23 kN\(\cdot\)m (average by 70%) and the torque change factor up to 2.8, i.e., by 47%. When the rotor approaches the side wall of the face, the buckets separate the shavings of maximum thickness from the ground by both the side and front borders of their cutting edges. The forces of digging the soil with buckets are maximum.