# Optimization of Excavator Bucket Structure by a Coupled Simulation Method
## 3 Results and Discussion
### Excavation Resistance of the Main Components of the Bucket  
To compare the excavation resistance before and after optimizing the structure of the bucket, the main load-bearing components of the bucket (Figure 15), including the bottom plate, lateral plate, bucket teeth and blade plate, were selected for comparative analysis of excavation resistance. \begin{table}
\begin{tabular}{p{113.8 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Structural Parameters of the original bucket** & \begin{tabular}{c} **Edge** \\ **Angle** \\ **\(\theta\) (\({}^{\circ}\))** \\ \end{tabular} & \begin{tabular}{c} **Flare Angle** \\ **\(\theta\) (\({}^{\circ}\))** \\ \end{tabular} & \begin{tabular}{c} **Bucket Width** \\ **\(D\) (mm)** \\ \end{tabular} & \begin{tabular}{c} **Arc radius of** \\ **Bucket Bottom** \\ **\end{tabular} & \begin{tabular}{c} **Filling** \\ **Rate (\%)** \\ \end{tabular} & \
\begin{tabular}{c} **Energy** \\ **Consumption-** \\ **tion (\%)** \\ \end{tabular} &
\begin{tabular}{c} **Excavation** \\ **Resistance (\%)** \\ \end{tabular} \\ \hline Structural parameters of the original bucket & 62.3 & 7.6 & 2192 & 350 & & & \\ Structural parameters & Mengdong mudstone & 55 & 7.6 & 2292 & 330 & \(\uparrow\)2.41\% & \(\downarrow\)16.74\% & \(\downarrow\)20.16\% \\ of the gridstone & Shanxi griststone & 62.3 & 7.6 & 2192 & 350 & \(\uparrow\)6.46\% & \(\downarrow\)9.3\% & \(\downarrow\)16.7\% \\ bucket & Shanxi coal & 50 & 5 & 2192 & 330 & \(\uparrow\)8.77\% & \(\downarrow\)7.63\% & \(\downarrow\)4.8\% \\  & Wuhai mudstone & 55 & 5 & 2092 & 350 & \(\uparrow\)4\% & \(\downarrow\)4.5\% & \(\downarrow\)5.3\% \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Structural parameter combinations of optimized bucket models under different geological conditions (Note: \(\uparrow\) means increase, \(\downarrow\) means decrease). Figure 16 shows the comparison of the excavation resistance of the main load-bearing components before and after the optimization of the bucket structure under different geological conditions. Among them, the optimal bucket model for mining Shanxi coal is the original model of the bucket. During the excavation process, the bucket teeth first come into contact with the ore material. As the main load-bearing component, the bucket teeth are subjected to the greatest excavation resistance. As the excavation progresses, the blade plate and lateral plates of the bucket come into contact with the ore material. The bucket teeth are installed on the blade plate, and the excavation resistance suffered by the bucket teeth is transmitted to the blade plate. In addition, during the excavation process, the blade plate and lateral plates have the function of assisting in excavating ore materials, so the blade plate and lateral plates are also subjected to significant excavation resistance. Figure 14: Variation trends of energy consumption of excavating per unit mass of ore material and filling rate of buckets with different structures under different geological conditions: (**a**) Mengdong mudstone, (**b**) Shanxi griststone, (**c**) Shanxi coal, (**d**) Wuhai mudstone. Figure 15: Main load-bearing components of the bucket: (**a**) bottom plate, (**b**) lateral plate, (**c**) bucket teeth, (**d**) blade plate. However, the excavation resistance of the blade plate and lateral plates is much smaller than that of the bucket teeth. During the excavation process, there are random fluctuations in the excavation resistance of the bucket teeth, blade plate, and lateral plates, mainly due to the inconsistent particle size of the ore material and the fluidity of the ore material. With the filling of the ore materials in the bucket, the excavation resistance of the bottom plate gradually increases. In addition, because the bottom plate only bears the mass of the ore material, the excavation resistance is low and there is no significant fluctuation.