Rolling bearings are mass-produced mechanical parts, and they have strict requirements for manufacturing accuracy, high technical specialization, and the most common failure is severe fever. If it is newly installed or cleaned and changed oil, it will heat up immediately after running, and it will have a severe fever, but there is no abnormal sound or vibration during operation. The reason is most likely that the grease is too much, and a certain amount should be appropriately filled. Of grease.

    

    At the same time of severe fever, if there is still a phenomenon of "stopping" of the bearing, the possible reason is that the bearing cover of the two shafts pushed the outer ring of the bearing too tightly, and did not leave enough clearance between the shafts in accordance with regulations. Due to the elongation of the shaft caused by temperature rise, it should be adjusted appropriately. Special attention should be paid to tapered cylindrical bearings.

 

    In some cases, the inner ring of the bearing and the shaft are too tightly matched, so that the inner ring expands; or the bearing seat and the outer ring of the bearing are too tightly matched, so that the outer ring is compressed and deformed to produce cracks. For the former, if the interference dimension left when processing the shaft is too large, you can remove the bearing, polish the journal to the proper assembly size, and assemble it separately. The latter often occurs on the split bearing housing, which makes the bearing housing "flexible". One or two layers of paper pads can be added on the opposite side of the bearing seat to eliminate the fault. In addition, if dust particles and impurities enter the raceway of the rolling bearing with the grease, the phenomenon of "stuck" may also occur. Once this occurs, the oil should be cleaned and changed.

 

    If the fever appears on the rolling bearing after it has been operating normally for a period of time, and dry friction noise or irregular impact sounds occur when you touch it with a metal rod, it may be lack of oil or dirty, or it may be the rolling of the bearing Partial damage should be disassembled and cleaned for oil change or bearing replacement.

 

    4.What defects must be replaced when the rolling part of the bearing appears?

 

    ① Corrosion. When the bearing is out of service or wet, there is water in the moor, which will cause rusting on the surface of the rolling element or the raceway.

 

    ② Indentation. When hard objects enter the raceway, pits are often pressed out on the surface of the raceway or the raceway body. Not only noise or impact sounds during operation, but excessively large pits can also cause vibration and severe fever in the bearings.

 

    ③ The bearing diagram is broken. In addition to manufacturing reasons, if the interference size of the shaft is too large and the assembly method is improper, it will also rupture and damage the inner and outer rings of the bearing, and the thrust bearing dynamic ring will be broken.

 

    ④ Fatigue peeling of the raceway surface. If used improperly, this normal wear and tear will rapidly accelerate.

 

    ⑤ The cage is broken. Basically it is a matter of material and manufacturing. Occasionally, damage to the cage during installation can cause premature breakage.

 

    ⑥ The rolling element is broken. There must be a lot of noise or even vibration during operation, most of which are improper materials or heat treatment.

 

    ⑦Current corrosion. During electric welding, if the current passes through the bearing, the fever generates sparks, which locally burns the raceway body. Therefore, when welding, the "ground wire" of the welding must be as close as possible to the welding point, and the welding current must not be allowed to pass through the bearing.

 

    ③ The wear is severely exceeded. Severe fever during operation, abnormal noise and vibration, because the gap has been enlarged at this time. When dust enters and the surface is scratched, the wear will accelerate.

 

    In addition, if the size is not matched properly during processing, it will cause "inner circle" or "outer circle", which will also cause noise, high temperature and vibration. The inner circle of the bearing is easier to find, because the inner ring of the bearing is “loose” on the shaft; when the outer circle is taken, the outer ring of the bearing or the inner ring of the bearing seat must be carefully inspected to find traces of sliding between them.

 

    Bearing repair issues are only considered if:

 

    (1) A large number of bearings of the same type used in large factories, the main failure modes of which are the wear of rolling surfaces, fatigue or fretting, especially the damaged parts are mostly cages or rolling bodies, and the ferrules or washers are still repaired. value;

 

    (2) Large and extra large bearings are on the verge of failure or have failed without significant damage to the parts, or valuable bearings must try to extend their useful life;