## 5 Results Analysis
### Bearing Contact under Combined External Loads
#### 5.1.2 Deformation of Bearing Inner Raceway  
Figure 7 shows the three-dimensional diagram of the optimized non-circular raceway and the circular raceway. Figures 7a and 7b represent the inner lower and upper raceways, respectively, where the red curve represents the traditional circular raceway, and the blue curve represents the actual shape of the optimized raceway. The three-dimensional diagram is projected to the bottom surface and the two sides respectively, and the radial and axial deformation of the non-circular raceway relative to the circular raceway can be clearly seen.  
Figure 8 shows the comparison diagram of the non-circular raceway relative to the circular raceway after bearing load, where Figures 8a and 8b are the projections of the three-dimensional graphics in Figure 7a,b towards the bottom surface, respectively, indicating the radial deformation of the non-circular raceway relative to that of the circular raceway. Similarly, Figures 8c and 8d are three-dimensional diagrams. From the radial diagrams in Figure 8a,b, it can be seen that the inner lower raceway of the bearing deforms in the \"left lower\" direction relative to the circular raceway, and the inner upper raceway deforms in the \"right upper\" direction relative to the circular raceway. Comparing to Figure 6, it can be seen that the position where the non-circular and circular raceways deform is the very place where the contact force is different before and after optimization. When the contact force before optimization is greater than the contact force after optimization, the non-circular raceway displays \"outward\" deformation (\(\Delta_{i,r}>0\)) relative to the circular raceway in the radial diagram; when the contact force before optimization is less than the optimized contact force, it displays as an \"inward\" deformation of the non-circular raceway relative to the circular raceway (\(\Delta_{i,r}<0\)). The position where the maximum deformation of the non-circular raceway relative to the circular raceway occurs is the azimuth corresponding to the maximum contact force, which is \(213.86^{\circ}\) and \(32.08^{\circ}\), respectively.  
Figure 6: Contact force distribution before and after optimization: (**a**) contact force \(Q_{1}\); and (**b**) contact force \(Q_{2}\).  
Figure 7: Three-dimensional diagram of bearing inner raceway: (**a**) inner lower raceway; and (**b**) inner upper raceway.  
It can be seen from the axial graph on Figure 8c,d that when the contact force before optimization is greater than the contact force after optimization, the deformation of the non-circular raceway relative to the circular raceway is different, namely: the inner and lower raceways undergo \"downward\" deformation (\(\Delta_{i,a}<0\)), while an \"upward\" deformation (\(\Delta_{i,a}>0\)) occurs in the inner upper raceway.  
By contrast, when the contact force before optimization is less than the contact force after optimization, the inner and lower raceways have an \"upward\" deformation relative to the circular raceway (\(\Delta_{i,a}<0\)); and a \"downward\" deformation (\(\Delta_{i,a}>0\)) occurs in the inner and lower raceways. In the same way as in the radial diagram, the position where the maximum deformation occurs is also the position corresponding to the maximum contact force.  
The above discussion reveals the optimal shape of the inner raceway of the bearing under the combined load in Table 2. Because the radial force of the wind turbine bearing is small in the working process, this paper mainly studies the influence of the axial force and overturning moment on the deformation of the bearing's inner raceway.