Now many bearings are defective. What does that mean?Is said to be unqualified bearing, no mold guide sleeve fit using the specification, the primary reason is that the factory inspection is not caused by severe, in this case, the bearing would become defective, such bearings assuming that we use, then the bad damaged bearings commonly used a few days, or simply can't use, also can cause the damage of the machinery in use, so that rolling bearing don't fit standard bearings must not use, you know what?Never use a bearing like this.We want to use bearings, it is best to use imported bearing products, because of the import of bearing enterprises more stringent detection, generally will not present quality problems, of course, there are exceptions to the oil bearing, to completely avoid us to buy do not fit the specification of the bearing, then we should learn to distinguish the quality of the bearing.Let's introduce some common sense in this aspect.
In the selection of bearing, we first to investigate the appearance of the bearing, can be judged by the appearance of the bearing does not fit the specification.Bearing appearance inspection should be carried out under the astigmatism lamp, the bearing appearance, cracks and other parts of a careful investigation.Now let's explain the specific method. This method is not only applicable to imported bearings, but also can determine whether other brands of imported bearings conform to the specifications.
1, all kinds of cracks, such as the original data crack, forging crack, heat treatment crack and grinding crack, etc., these cracks in the future in the process of bearing operation, will become the source of stress convergence and rapid expansion, forming a bearing crack, bearing life and work safety has a great impact.
2, rust, black and pitting, the latter two are simple storage of water and dirt shortcomings, the most simple development into rust.Corrosion is the source of poor installation, early wear and fatigue, severe corrosion will make the bearing useless.
3, peeling and folding, the two shortcomings of the part and the matrix metal is not strong, and the surrounding often exist in varying degrees of decarbonization or poor carbon phenomenon, data simple collapse, pressure concave or wear, on the life and precision of the bearing is very unfavorable.
4, all kinds of mechanical scars, such as abrasion, scratch, pressure, collision, etc., will form poor bearing installation, causing off-load and stress convergence, the formation of rotary accuracy and the decline in service life.
5, the retainer riveting or welding quality, the first investigation rivet head is out of place, tilt, lax, lack of meat or 'double eyelid', the welding position is correct, welding spot is too big is too small, whether the welding is not strong or excessive welding cause stuck rolling body phenomenon.
6, other such as typing quality, such as handwriting fuzzy, damaged, should be considered inferior, severe also can not be tested.