# Study on Ring Deformation and Contact Characteristics of Thin-Walled Bearing for RV Reducer
## 4 Conclusions  
According to the actual assembly structure of the main bearing for the RV reducer, a simulation model of the planetary frame-main bearings-pin gear housing, which can fully consider the elastic deformation, is established in this paper. The validity of the proposed model is confirmed by comparing its results with those obtained from conventional methods. The effects of load conditions, ring thickness, and clearance on ring deformation, ball-raceway contact state, the relative ratio of the maximum load, and the ultimate carrying capacity are analyzed, respectively. The significant findings are as follows:  
Figure 23: Effect of radial clearance on contact characteristics: (**a**) number of loaded balls; (**b**) the relative ratio of the maximum load and ball–raceway contact stress.  
1. Ring deformation cannot be ignored in the analysis of thin-walled bearings. The distribution of ball-raceway contact loads determines both the extent and the trend of ring deformation. Ring deformation can improve the mechanical characteristics and extend the fatigue life of bearings. However, the ring deformation makes the ball-raceway contact ellipse closer or even exceeds the raceway rib, leading to ellipse truncation. Therefore, focusing on the raceway rib design is crucial when designing thin-walled bearings;
2. The optimization effect of ring deformation on load distribution varies under different conditions. The increase in axial force and ring thickness weakens this optimization effect, while the increase in radial force and clearance enhances it but also results in an increase in contact stress. In actual engineering, bearing engineers can design ring thickness, clearance, and the raceway rib reasonably according to the research results of this paper and improve the optimization effect of ring deformation on load distribution and fatigue life without plastic deformation of bearings to improve the service performance of bearings effectively;
3. Significant differences are observed in the variation trends and mutation positions in the number of loaded balls between the rigid and flexible ring models, resulting in substantial differences in the contact characteristics of the two models under the same load condition;
4. After considering the ring deformation, the carrying capacity of the bearing decreases, with a heightened sensitivity to radial force and radial clearance. In this research, the maximum carrying capacity was reduced by 38.2%, which occurred by coupling the maximum radial force and the maximum clearance.  
Conceptualization, Y.W. and F.L.; methodology, Y.W. and F.L.; software, Y.W. and F.L.; validation, Y.W. and F.L.; formal analysis, Y.W. and F.L.; investigation, Y.W. and F.L.; resources, Y.W. and F.L.; data curation, Y.W. and F.L.; writing--original draft preparation, Y.W. and F.L.; writing--review and editing, Y.W. and F.L.; visualization, Y.W. and F.L.; supervision, Y.W.; project administration, Y.W.; funding acquisition, Y.W. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (Grant No. 52075274); the Shandong Province focuses on supporting regions to introduce urgently needed talent projects (Grant No. 2023)YKQRC), the Liaocheng City Major Science and Technology Innovation Project (Grant No. 2021 ZD04), and the Shandong Province science and technology innovation ability improvement project for small and medium-sized enterprises (Grant No. 2023 TSGC0356, 2023 TSGC0374).  
Not applicable.  
Data Availability Statement: Data is contained within the article.  
The authors would like to express their appreciation to the anonymous reviewers for their help and meaningful comments on this paper.  
The authors declare no conflicts of interest.  
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