Shaft end (mainly bearing journal) broke completely.
Rotational bending fatigue caused by misalignment of screw shaft (the bearing journal was forced to bend because of eccentricity between the ball screw thread and the bearing journal)
Improve assembly accuracy of the ball screw
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Breakage of Shaft End
Part: Screw shaft Symptom: Shaft end broke completely Cause: Broken bearing journal due to rotating bending fatigue