Bearing Failure RCA: Fretting

 

When a rolling bearing is damaged during machine operation, the entire machine or equipment can seize or malfunction. Since bearings that fail prematurely or unexpectedly cause trouble, it is important to be able to identify and predict failure beforehand, so that preventive measures can be adopted.

Damage Condition 

Wear occurs due to repeated sliding between the two surfaces.

Fretting occurs at fitting surface and also at contact area between raceway ring and rolling elements.

Fretting corrosion is another term used to describe the reddish brown or black worn particles.

Possible Causes

  • Poor lubrication
  • Vibration with a small amplitude
  • Insufficient interference

Countermeasures

  • Use a proper lubricant
  • Apply a preload
  • Check the interference fit
  • Apply a film of lubricant to the fitting surface

 

Fretting 1

Part: Inner ring of a deep groove ball bearing
Symptom: Fretting on the bore surface
Cause: Vibration

Fretting 2

Part: Inner ring of an angular contact ball bearing
Symptom: Fretting over entire circumference of bore surface
Cause: Insufficient interference fit

Fretting 3

Part: Outer ring of a double-row cylindrical roller bearing
Symptom: Fretting on the raceway surface at roller pitch intervals

 

Source: NSK