Official Answer
Answer
Centrifugal lift-off occurs when the outward radial force $F_c = m \omega^2 r$ generated by rotation exceeds the inward spring tension of the ring. The ring expands, loses contact with the groove bottom, and then is easily ejected by any axial thrust. This is a common failure in high-RPM electric motors. The failure is 'clean'—the ring is often found intact but outside the groove. The solution is either a heavier cross-section ring to increase the spring force or a 'Self-Locking' ring design which uses a tab to physically limit expansion.
