Breakage of Shaft End

Damage Condition	Possible Causes	Countermeasures
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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Part: Screw shaft
Symptom: Shaft end broke completely
Cause: Broken bearing journal due to rotating bending fatigue