Bearing Failure RCA: Creep

 

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 

Creep is the phenomenon in bearings where relative slippage occurs between fitting surfaces and thereby creates a clearance between them surface. Creep causes a shiny appearance, occasionally with Scoring or Wear.

Possible Causes

  • Insufficient interference or loose fit
  • Insufficient sleeve tightening

Countermeasures

  • Check the interference, and prevent rotation
  • Correct the sleeve tightening
  • Study the shaft and housing precision
  • Preload in the axial direction
  • Tighten the raceway ring side face
  • Apply adhesive to the fitting surface
  • Apply a film of lubricant to the fittingsurface

 

Creep 1

Part: Inner ring of a spherical roller bearing
Symptom: Creep accompanied by Scoring of bore surface
Cause: Insufficient interference

 

Creep 2

Part: Outer ring of a spherical roller bearing
Symptom: Creep over entire circumference of outside surface
Cause: Loose fit between outer ring and housing

 

Source: NSK