(1) Look at the symbol, etc. Mark the outer ring of the bearing. Marks such as the code name, place of manufacture, and delivery time must be observed. 2 Look at the outer and inner ring of the rolling bearing and the rolling elements. After wiping off the rust-proof oil, the surface should be clean as a mirror. The hand touch should be smooth and delicate like glass, and the end face can allow invisible processing marks. With a dust-proof shell, the surface roughness of the dust-proof shell can be larger, but no corrosion can occur on any part. 3 Test clearance Now take a
Deep Groove Ball Bearing as an example to illustrate the test method of oil gap. (1) The inner ring is supported by one hand and the outer ring is rotated by the other hand. The outer ring should be able to rotate quickly and freely and then gradually stop. (2) Hold the inner and outer rings in both hands so that they move relative to each other in the radial direction and in the axial direction. Generally, there should be no gaps. Larger bearings can feel gaps, but there should be no metal impact noise. 4 Test Hardness After completing the above checks, confirm that there are no problems and decide to purchase. It is advisable to negotiate with the supplier before the test, when the supplier indicates that the hardness meets the standard requirements, and if it does not meet the requirements, it can be returned. During the test, the outer ring and the inner ring of the bearing shall be plunged or sawn with a force of about 10 N with a guillotine knife or with a force of about 5 N with a hacksaw. If a "grilling" noise is produced and no swarf is left, at most no obvious marks are left. Hardness is sufficient when settling or sawing. Where it can be set off or sawed off, indicating that the hardness does not meet the requirements.
