Dirt progression marks
DESCRIPTION OF THE DAMAGE
- Individual indents, one after the other, are arranged in tracks. At the end of these, there may still be particles embedded
- They generally run diagonally to the edge of the bearing
- Starting from the oil groove or lubricating holes
- Often in conjunction with scoring in the journal and scoring / particle embedding in the bearing
A dirt progression mark, starting from the parting face, has occurred. Several large particle indents one after the other – running diagonally – are visible. Particles which are still embedded may be present in part.
DAMAGE ASSESSMENT
Very large and hard particles which find their way into the lubricant gap cannot become embedded in the bearing material. They are forced through the lubricating gap, but then always become stuck again. Frequently, the pattern appears from oil grooves or oil bores as the particles were introduced here. Pronounced material accumulation along the progression track causes initial rubbing marks and seizure.
Remedy
If there are pronounced areas of material accumulation along theprogression track, or signs of an initial rubbing mark, the bearing must be replaced. The bearings can still be used, however, if the material accumulations have been flattened and there is no longer the risk of the influence of particles.