## 7 Conclusions  
The rock-breaking characteristics of arcing-blade cutters under various cutting parameters using both finite element analysis and experimental methods were investigated in this paper. The study leads to the following conclusions:  
1. At a penetration of 2 mm, the rock-breaking load of the cutter remained constant across three directions, regardless of the cutter spacing. However, when the penetration increased to 4 mm and 6 mm, the vertical and rolling force of the cutter initially rose with an increase in the cutter spacing before stabilizing. In contrast, the tangential force decreased at first and then stabilized with an increase in the cutter spacing.
2. When the penetration was 2 mm, two cutters performed sequential cutting without any synergy effect at different cutter spacings, resulting in a rock ridge formation between two sequential cuts. With a penetration of 4 mm, the rock ridge could be crushed under cutter spacings of 40 mm and 50 mm. Increasing the penetration to 6 mm allowed for the successful crushing of the rock ridge under cutter spacings of 40 mm, 50 mm, and 60 mm.
3. There was no significant difference in the specific energy among different cutter spacings at a 2 mm penetration, and it remained consistently high. However, for the penetrations of 4 mm and 6 mm, the specific energy initially decreased, then increased, and ultimately stabilized. The optimal cutter spacings were 50 mm and 60 mm, respectively, at the penetrations of 4 mm and 6 mm.
4. The change trend of the crushing state and specific energy under different cutting parameters observed from the experiments was consistent with that observed from the simulations, confirming the reliability of the simulation results.
5. The rock-breaking characteristics of the arcing-blade cutter are also related to other factors, such as rock types and the blade radii of the arcing-blade cutter. In the future, the impacts of different blade radii of the arcing-blade cutter and the rock types on rock-breaking characteristics will be studied.  
**Author Contributions:** Conceptualization, Z.M.; methodology, Z.M. and J.Y.; software, Z.M.; validation, Z.M. and J.Y.; formal analysis, X.Z.; investigation, X.Z.; resources, J.Y.; data curation, X.Z.; writing--original draft preparation, Z.M.; writing--review and editing, X.Z.; visualization, W.Y.; supervision, J.Y.; project administration, W.Y.; funding acquisition, J.Y. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This work was supported by the National Natural Science Foundation of China under grant nos. 52175112.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** All data, models and codes that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy restrictions.  
**Acknowledgments:** The experimental operation process was supported by [PERSON], Thanks for his help.  
**Conflicts of Interest:** Authors [PERSON] and [PERSON] were employed by the company Shanxi Tiandi Coal Mining Machinery Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.