## 5 Flow Field Analysis in the Fully Lubricated State
### Oil Distributions on the Large/Small Roller Walls  
The lubricating oil distributions on the rollers of the two types of bearings with different rib structures are shown in Figure 11, and the volume fractions of the lubricating oil on the walls of the large and small rollers are listed in Table 6. It can be observed that: (1) the lubrication conditions of the large and small rollers of the bearing with the outer ring rib structure are better than those with the inner ring rib structure. (2) For the bearing with the inner ring rib structure, the lubrication condition of the large roller wall is better than that of the small roller wall. (3) For the bearing with the outer ring rib structure, the lubrication condition of the small roller wall is better than that of the large roller wall. (4) The oil volume fraction of the roller wall of the outer ring rib structure bearing is twice that of the inner ring rib structure.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**No.** & \begin{tabular}{c} **Inlet Oil Volume** \\ **(kg/s)** \\ \end{tabular} & **No.** & \
\begin{tabular}{c} **Inlet Oil Volume** \\ **(kg/s)** \\ \end{tabular} & **No.** &
\begin{tabular}{c} **Inlet Oil Volume** \\ **(kg/s)** \\ \end{tabular} \\ \hline
1 & 0.0200 & 6 & 0.0063 & 11 & 0.0020 \\
2 & 0.0160 & 7 & 0.0050 & 12 & 0.0016 \\
3 & 0.0126 & 8 & 0.0040 & 13 & 0.00126 \\
4 & 0.0100 & 9 & 0.0032 & 14 & 0.0010 \\
5 & 0.0080 & 10 & 0.0025 & 15 & 0.0008 \\ \hline \endFigure 11: Oil distributions on the large/small roller walls. (**a**) Outer ring rib structure; (**b**) Inner ring rib structure.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Large Roller** & **Small Roller** & **Average** \\ \hline Inner ring rib & 0.8254 & 0.4248 & 0.00647 \\ Outer ring rib & 1.1613 & 1.5719 & 0.01344 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Volume fraction of lubricating oil on the roller wall (%).  
Figure 10: Oil distributions on the inner/outer ring wall of the bearings. (**a**) Outer ring rib structure; (**b**) Inner ring rib structure.  
The roller directly below the bearing oil inlet is numbered as 1, and the rest of the rollers are numbered along the bearing's rotation direction (as shown in Figure 12). The volume fraction of the oil on the wall of all the rollers is calculated. The variation of the lubricating oil volume fraction on the walls of the large and small rollers with the change of the roller position is shown in Figure 13. It can be deduced that: (1) the distribution trend of the lubricating oil on the roller walls of bearings with the two types of rib structures is the same. The closer it is to the bearing oil inlet, the higher the lubricating oil volume fraction on the roller wall. Further, the lubricating oil volume fraction on the roller gradually decreases along the bearing rotation direction. (2) For the bearing with the outer ring rib structure, the lubrication condition of the small roller wall is better than that of the large roller wall; however, for the bearing with the inner ring rib structure, the lubrication condition of the large roller wall is better than that of the small roller wall.