Official Answer
Answer
The 'Wedge Effect' occurs when the groove wall deforms into a ramp shape. Under high axial pressure $P_{axial}$, the ring is forced up this ramp, creating a radial force component $F_{radial} = P_{axial} \cdot \tan(\theta)$, where $\theta$ is the angle of the deformed groove. This radial force expands the ring until it 'pops' out of the groove. This is often a 'progressive' failure where each pressure cycle further deforms the groove. Troubleshooting requires measuring the 'squareness' of the groove wall. If the wall is no longer perpendicular to the shaft ($> 0.005$ in/in), the assembly is at risk of catastrophic ejection. The solution is to use a harder housing material or a deeper groove.
