Through the appearance of the evaluation of bearing pros and cons

The key points to note in the appearance inspection are as follows:

(1) Various cracks, such as raw material cracks, forging cracks, heat treatment cracks and grinding cracks, etc. will become the stress concentration source and rapidly expand in the future operation of the bearing, resulting in bearing fracture, which has a great impact on bearing life and work safety.

(2) all kinds of mechanical scars, such as abrasion, scratch, compression and bump, will cause poor bearing installation, cause partial load and stress concentration, resulting in the decline of rotation accuracy and service life.

(3) rust, black skin and pitting, the latter two are easy to store water and dirt defects, the most easy to develop into rust. And corrosion is the source of bad installation, early wear and fatigue, serious corrosion will make the bearing scrap.

(4) peeling and folding, the local combination of these two defects with the matrix metal is not strong, and the surrounding often exists in varying degrees of decarburization or carbon poverty phenomenon, material easy to collapse, pressure concave or wear, is very bad for bearing life and accuracy.

(5) For the riveting or welding quality of the cage, the main observation is whether the rivet head is deviated, skewed, slack, lack of flesh or "double eyelid", whether the welding position is correct, whether the solder joint is too large or too small, whether the phenomenon of stuck rolling body is caused by poor welding or excessive welding.

Whether the quality of some cages' pressure slope, edging, seam and gouge is guaranteed, and whether the rolling body can not fall out of the cages and turn freely. If these points are not satisfactory, the bearing noise and rotation accuracy will be reduced at the least, and the cages may fall apart at the large, resulting in mechanical failure or accident.