What causes fatigue spalling

Fatigue peeling is the flake peeling of bearing surface caused by rolling fatigue. When the bearing works, the load on the rolling body and inner ring (or outer ring) is not constant, but changes with the running cycle of the bearing. This load is alternating load; Because the contact area between the rolling body and the inner ring (or outer ring) is very small, the contact stress is very large. Under the high speed, under the repeated action of the huge alternating contact stress, the metal will fatigue.

At first, small cracks are found in the stress concentration. Due to the effect of lubricating oil and metal corrosion, the cracks gradually expand. When the cracks are expanded to a certain extent, the surface metal will peel off, forming small imprinting pits, similar to pitting points. When we dismantle and inspect plastic bearings, we often find that there are pitting points and a piece of metal peeling off on the inner or outer ring and rolling body surface, This is the phenomenon of metal fatigue peeling. If the bearing fatigue peeling occurs after long-term operation, it shall be regarded as natural damage. If it occurs in the middle or early stage of bearing use, it shall be regarded as unnatural peeling. At this time, the reason for the peeling shall be found out.

The non natural spalling is caused by human factors in the middle or early stage of bearing use. The main reason for the non natural peeling is due to the improper selection of bearing type or improper installation. Because of the improper choice of bearing type, the peeling off may occur early when deep groove ball bearing is selected under the condition of large axial load. The spalling mainly occurs in the raceway, which makes the rolling track of the rolling body move towards the ball loading port, and rolls over the ball mounting port, which causes serious peeling damage. The measure to prevent this damage is to choose the bearing reasonably according to the working conditions of plastic bearing.