Common Bearing Failures and Causes

Bearings often fail in the process of operation. Correct treatment measures should be taken after accurately analyzing the cause of the failure.

1. Bearing temperature is too high

When the equipment is running, the part where the bearing is installed allows a certain temperature. When touching the shell of the mechanism by hand, it is normal not to feel hot, otherwise, it indicates that the bearing temperature is too high.

Reasons for excessive bearing temperature: the quality of the lubricating oil does not meet the requirements or deteriorate, and the lubricant viscosity is too high, the mechanism assembly is too tight (insufficient clearance), the bearing assembly is too tight, the bearing housing ring rotates on the shaft or in the shell, the load is too large, the bearing cage or rolling body is broken, etc.

2. Bearing noise

Rolling bearings are allowed to run slightly at work. If the sound is too loud or there is abnormal noise or impact sound, it indicates that the bearing is faulty.

◆ It is the surface wear of the inner and outer rings of the bearing. Due to this wear, the cooperation between the bearing and the shell, the bearing and the shaft is destroyed, resulting in the axis deviation from the correct position and abnormal noise when the shaft moves at high speed. When the bearing is tired, the surface metal peels off, which will also increase the radial clearance of the bearing and produce abnormal noise.

◆ Insufficient bearing lubrication, formation of dry friction, and broken bearings will produce abnormal sound.

◆ After the bearing wears loosely, the cage is loose and damaged, and abnormally sound bearings will also be damaged. During the disassembly inspection of rolling bearings, the fault of the bearing and the cause of damage can be judged according to the damage of the bearing.

3. Metal peeling off the surface of the raceway

Bearing rolling bodies and inner and outer ring paint pavements are subjected to periodic pulsation loads, thus generating periodic change of contact stress. Reasons for metal peeling off the surface of the raceway: When the number of stress cycles reaches a certain value, fatigue peeling occurs on the rolling body or the working surface of the inner and outer ring raceway. If the load of the bearing is too large, it will aggravate this fatigue. In addition, if the bearing is not properly installed and the shaft is bent, the raceway peeling will also occur. Fatigue peeling of bearing raceway will reduce the operation accuracy of the shaft and cause vibration and noise of the mechanism.

4. Bearing burns

Burned bearings have tempering colors on their raceways and rolling bodies. Causes of burns: insufficient lubrication, non-conforming or deterioration of lubricating oil quality, and overtight bearing assembly, etc.

5. Plastic deformation

There are uneven pits on the contact surface between the raceway of the bearing and the roller, indicating that the bearing produces plastic deformation. Reasons for plastic deformation: Under the action of large static or impact loads, the local stress on the working surface exceeds the yield limit of the material, which generally occurs on low-speed rotating bearings.

6. Bearing housing ring cracks

Reasons for cracks in bearing housing rings: over-tight bearing coordination, loose outer or inner rings of bearings, deformation of bearing inclusion parts, poor surface processing of installed bearings, etc.

7. The cage is broken

Causes of cage fragmentation: insufficient lubrication, broken rolling body, crooked seat ring, etc. At this time, the use conditions and lubrication conditions should be checked, and the selection of the cage should be re-examined.

8. The metal of the levation adheres to the rolling body

Reasons for why the metal of the cavage adheres to the rolling body: the rolling body is stuck in the cadling or is not lubricated enough.

9. Circle raceway is seriously worn out

Reasons for serious wear and tear of the seat ring raceway: foreign matter falls into the seat ring, insufficient lubricating oil or inappropriate lubricating oil brand.

The author of this article is Shaanxi Gainhui Heavy Industries Co., Ltd., which is a professional bearing manufacturer and distributor in China. The company supplies many types of the bearings, such as single row tapered roller bearings, single row cylindrical roller bearings with cage, etc. With high quality and competitive bearing products, we sincerely provide services to customers all over the world.

Contact us for more details:

E-mail: emily@gainhui.com

Tel: +86-029-88692376

Mob/WhatsApp: +86-18710850036