Official Answer
Answer
Axial vibration can cause a spiral ring to 'float' within the groove if the preload is insufficient. The 'clinging' force is a result of the ring's free diameter being smaller (for a shaft) or larger (for a bore) than the groove diameter. The interference fit creates a radial pressure $p = \frac{2 E I Δ}{R_m^4}$, where $Δ$ is the interference. For high-vibration applications, the interference should be maximized within the limits of the material's elastic strain during installation. Additionally, a 'zero-clearance' groove width—where the ring thickness $t$ is nearly equal to the groove width—can be used to eliminate axial 'shucking.'
