1. Observation method

Observe the rolling bearing directly with your eyes, and its inner and outer raceways should be a smooth and shiny circular groove without peeling or any wear.

The surface of all rolling elements should be smooth, without spots, cracks, peeling or delamination on the surface. The rolling elements of the same bearing should have the same size and uniform wear.

The cage should be undamaged, undamaged, and not too loose, and the gap with the rolling element should not be too large.

During observation, no matter which point is found to be problematic, it is not advisable to continue using it reluctantly.

2. Touch method

The clearance between the inner and outer races of new bearings and the rolling element is generally between 0.005-0.01mm.

For rolling bearings that have been in use for a period of time, you can use your fingers to pinch the inner race and shake it axially. If there is no sound, it indicates that they can continue to be used; If there is a noticeable movement sound. It indicates that the gap has exceeded 0.02mm and should be repaired or replaced.

3. Rotation method

Use one hand to rotate the inner race of the bearing and the other hand to rotate the outer race. If the bearing rotates flexibly without jamming and there is no radial shaking without feeling any clearance, the bearing can continue to be used.

If the rotation is not flexible, it may be due to peeling or other damage to the inner and outer race raceways or rolling elements; If the noise is too loud during rotation, it indicates that the bearing has been severely worn and should be replaced.

To make a correct judgment on rolling bearings, the above three methods should be combined during inspection.

For tapered roller bearings, it should also be observed whether the moving body falls in the middle of the outer race. If there is a forward movement, it should not exceed 1.5mm. Otherwise, it should be replaced.

For used rolling bearings and inner and outer raceway bearings, the gap between the inner and outer raceways and the rolling element should not exceed 0.06mm. Those exceeding this limit should be replaced.