How to judge the quality of bearings by appearance


Bearing is not only widely used in various mechanical equipment, but also has great effect on vehicle wheels. The key is to make it run normally. So how to distinguish the quality of bearing from its appearance? The following aspects are several aspects that must be paid attention to in appearance inspection:


(1) All kinds of cracks, such as raw material cracks, calcination cracks, heat treatment process cracks and cutting cracks, will become a stress source and expand rapidly in the whole process of bearing operation, resulting in bearing cracking, which will do great harm to the service life and safety factor of the bearing. How to distinguish the quality of bearings according to their appearance


(2) All kinds of scars of mechanical equipment, such as abrasion, scratch, crush and knock, will lead to poor bearing installation, wheel weight and stress, and reduce the rotation accuracy and service life.


(3) Rust, black skin and black spots. The latter two are very easy to store water and waste, and are most likely to develop into rust. Corrosion is the pollutant that causes poor installation, initial damage and fatigue. More serious corrosion will damage the bearing.


(4) Peeling and stretching, the two disadvantages are that the part is not firmly integrated with the base metal material, and there is usually carburization or carbon deficiency around it at different levels. The raw materials are very easy to collapse, dent or wear, which is very bad for the service life and accuracy of the bearing.


(5) The key to the riveting or electric welding quality of ball bearing is to check whether the bolt head is deviated, inclined, loose, lack of meat or "double eyelid", whether the electric welding position is appropriate, whether the spot welding is too large or too small, whether the electric welding is not firm or welded


To distinguish the quality of the bearing, we can start from whether there are cracks, black spots, peeling and expansion on the appearance. If the turnover body can not rotate the ball bearing easily, it will reduce the bearing noise and rotation accuracy, and even lead to equipment failure if it is more serious.