Damage Condition

Severe friction resulted in serious wear on the rolling contact surface of raceways.

Possible Causes Insufficient lubrication Intrusion of contamination Poor assemble accuracy (Misalignment) Countermeasures Review the lubricant and lubrication method Improve sealing capability Take measures against misalignment

Wear 1

Part: Ball nut
Symptom: Serious wear due to severe friction
Cause: Severe wear developed because the grease was completely washed away from the ball nut when overhauling the ball screw

Wear 2

Part: Screw shaft
Symptom: Serious wear due to severe friction
Cause: Abnormal wear was caused because of fine iron contamination

Source: NSK