Damage Condition
Shaft end (mainly bearing journal) broke completely.
Possible Causes
- 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)
Countermeasures
- Improve assembly accuracy of the ball screw
Breakage of Shaft End
Part: Screw shaft
Symptom: Shaft end broke completely
Cause: Broken bearing journal due to rotating bending fatigue
Source: NSK
