1. Single side limit position peeling of trench

At the limit position of one side of the channel, there is a serious peeling ring at the junction of the channel and the retaining edge. The reason is that the bearing is not installed in place or the axial overload occurs suddenly during operation.

The countermeasures are to ensure that the bearing is installed in place or to change the outer ring fit of the free side bearing into clearance fit, so as to make the bearing compensated when the bearing is overloaded.

If it can not be ensured to install in place, it can reduce the direct contact of the bearing by increasing the oil film thickness of the lubricant (increasing the viscosity of the lubricant), or reducing the load of the bearing.

2. The ditch peels off in a symmetrical position in the circumferential direction

The reason for the spalling in symmetrical position is that the inner ring is surrounded by spalling, while the outer ring is circumferentially symmetrical position spalling (i.e. the short axis direction of the ellipse). The main reason is that the ellipse of the shell hole is too large or the two halves of the separated shell hole structure, which is particularly obvious in the camshaft bearings for motorcycles.

When the bearing is pressed into the shell hole with larger ellipse or the two halves of separated shell are fixed tightly, the outer ring of the bearing will produce ellipse, and the clearance in the short axis direction will be significantly reduced or even negative clearance.

Under the action of load, the inner ring rotates to produce circumferential peeling marks, and the outer ring only produces peeling marks in the symmetrical position of the short axis direction. This is the main reason for the early failure of the bearing. The inspection of the failure parts of the bearing shows that the roundness of the outer diameter of the bearing has changed from 0.8um controlled by the original process to 27um. This value is much larger than the radial clearance value.

Therefore, it can be confirmed that the bearing works under severe deformation and negative clearance, and abnormal sharp wear and peeling are easy to form on the working face in the early stage.

The countermeasures are to improve the machining accuracy of the shell hole or to avoid the separation of the two halves of the shell hole.

3. Inclined peeling of raceway

When the inclination angle reaches or exceeds the critical state, it is easy to form abnormal sharp wear and peeling in the early stage. The main causes are poor installation, shaft deflection, low accuracy of journal and shell hole.

Countermeasures are taken to ensure the quality of bearing installation and improve the axial runout accuracy of shaft shoulder and bore shoulder, or to improve the viscosity of lubricating oil to obtain a thicker lubricating oil film.