Fretting

Condition

Fretting surfaces wear producing red rust coloured particles that form hollows. On the raceway surface, dents called false brinelling are formed at spacing equal to distances corresponding to the rolling elements

Cause

If a vibrating load works on contacting elements resulting in small amplitude oscillation, lubricant is driven out form contact, and parts are worn remarkably. Oscillation angle of the bearing is small. Poor lubrication (no lubrication) Fluctuating load Vibration during transportation Vibration, shaft deflection, installation error, loose fit

Solution

  • Inner ring and outer ring should be packaged separately for transportation. If not separable, bearings should be preloaded.
  • Use oil or high consistency grease when bearings are used for oscillation motion.
  • Change lubricant
  • Fix shaft and housing
  • Improve fit