Official Answer
Answer
The effective thrust capacity is highly sensitive to the groove depth $d$. A shallow groove reduces the contact area, increasing the bearing stress. Furthermore, the groove corner radius $r$ must be kept minimal (typically $< 0.1 \cdot T$) to prevent the ring from 'ramping' out of the groove. If the radius is too large, the load $P$ creates a radial component $P \cdot \tan(\phi)$ that forces the ring to expand (for internal) or contract (for external), leading to premature failure. The safety factor $S_f$ should be adjusted based on the ratio of $r/d$; as $r$ increases relative to $d$, the rated thrust capacity must be derated by as much as 50%.
