Rolling bearing fatigue remedy caused by poor lubrication

Phenomenon (1): Different loads will have different rolling bearing failure modes under poor lubrication conditions. When the load is low and there is slippage, fine surface peeling occurs. Because they are numerous and look like pockmarks on the raceway, we use pitting to describe them. When the load is large and the lubricating oil film becomes thin, such as water intrusion, when the raceway is subjected to pressure polishing, a shell-like pit appears. When the load is high and the lubrication is poor, a very obvious heated area appears on the raceway, and after the operation continues, an initial crack occurs.

Causes: – Poor lubrication due to: • insufficient lubricant supply • too high operating temperature • excessive water intrusion on the raceway surface causing excessive friction and material stress – sometimes slipping

Remedy: – Increase the amount of lubricant – Use a highly viscous lubricant and use as much of the tested EP additive as possible – Cooling lubricant/bearing – Use softer grease as much as possible – Prevent water ingress • Fatigue due to wear .

Phenomenon (2): For example, there are spalling and banding tracks on the rolling elements of tapered roller bearings.

Cause: Due to contamination of the lubricant, such as seal damage, foreign particles enter, causing the bearing parts to wear in the rolling contact area, resulting in a change in the geometry of the part. The result of local overload is partly related to improper adjustment of tapered roller bearings.

Remedy: – Replace the lubricant in time – Filter the lubricant – Improve the seal – Replace the damaged seal in time – Special heat treatment of the ferrule and roller • Fatigue of the hardened layer.

Phenomenon (3): Surface hardened bearing parts, large flakes of the raceway.

Causes: – Cracking or separation of the hardened layer – too much load or insufficient depth of the hardened layer under a given load, eg due to incorrect design load

Remedy: – Adjust the depth of the hardened layer to suit the load condition – Avoid overloading. Evaluate the running characteristics and damage of the removed bearing. Rolling contact mode: Wear in different areas can change the geometry of the part contact area, so that local overload leads to fatigue Failure a: cross-sectional profile of the roller; b: inner ring raceway and roller with fatigue damage. Fatigue mechanism, wear at the edge of the raceway, cross-sectional profile of the roller.