Rolling bearing fault analysis
Thread Content
There is one fan on the 2.jpg device, and its operating noise is abnormal. Upon inspection, it was found that there is a pit the size of a soybean in the inner ring of the bearing at the motor pulley end, while there is a pit about 3 centimeters long in the outer ring. Please analyze the reasons for such conditions in the bearings; difficult issues related to mechanical equipment are welcome
Common problems related to bearing damage can be mainly classified into the following categories: flaking, scorching, crack defects, cage damage, abrasion and jamming, rust and corrosion, wear, electroerosion, indentation and impact damage, and creep. 1. Delamination phenomenon: Delamination on the operating surface; after delamination, the surface becomes noticeably uneven. Causes: Excessive load, improper use, poor installation, poor precision of the shaft or bearing housing, too small a clearance, intrusion of foreign objects, rusting, reduction in hardness due to abnormally high temperatures. Measures: Re-examine the operating conditions, select different bearings, reconsider the clearance value, check the machining precision of the shaft and bearing housing, examine the design around the bearings, check the installation method, and inspect the lubricant and lubrication method.
2. Burning phenomenon: The bearings heat up and change color, eventually becoming so damaged that they can no longer rotate. Causes: Too small a clearance (including too small a clearance in deformed areas), insufficient lubrication or inappropriate lubricant, excessive load (excessive preload), misalignment of the rollers. Measures: Set an appropriate clearance (increase the clearance), check the type of lubricant and ensure proper application, examine the operating conditions, prevent positioning errors, check the design around the bearings (including heat generation by the bearings), improve the method of assembling the bearings.
3. Crack defects: Presence of gaps and cracks in the bearings. Causes: Excessive impact loads, excessive interference fit, significant delamination, friction-induced cracks, poor precision on the installation side (too large radius at corners), improper use (use of hammers, insertion of large foreign objects). Measures: Check the operating conditions, set an appropriate interference fit and examine the material quality, improve the installation and usage methods, prevent friction-induced cracks (check the lubricant), and examine the design around the bearings.
4. Damage to the cage: Loosening or breaking of bolts, as well as cracking of the cage. Causes: Excessive torque loads, high-speed rotation or frequent changes in speed, poor lubrication, intrusion of foreign objects, severe vibrations, poor installation (installation in an inclined position), abnormal temperature rise (in the case of resin cages). Measures: Check the operating conditions, check the lubrication conditions, re-examine the choice of cage, pay attention to proper use of the bearings, and examine the stiffness of the shaft and bearing housing.
5. Scratching and jamming: Rough surface with minor welding effects. Scratching between the rim of the ring and the end face of the roller is referred to as jamming. Causes: Poor lubrication, intrusion of foreign objects, misalignment of rollers due to an inclined shaft, interruption of oil supply to the rim surface due to excessive axial load, rough surface, excessive sliding of the rolling elements. Measures: Re-examine the lubricant and lubrication method, check the operating conditions, set an appropriate preload, improve sealing performance, and use the bearings properly.
6. Rusting and corrosion: Local or complete rusting on the surface, with rust patterns similar to those on the teeth of rolling elements. Causes: Poor storage conditions, improper packaging, insufficient rust inhibitors, intrusion of water, acidic solutions, etc., handling of bearings with bare hands. Measures: Prevent rusting during storage, improve sealing performance, regularly check the lubricant, and pay attention to proper use of the bearings.
7. Abrasion: Reddish-brown wear particles appear on the mating surfaces. Causes: Insufficient interference fit, small deflection angle of the bearings, insufficient lubrication (or no lubrication at all), unstable loads, vibrations during transportation. Measures: Check the interference fit and the condition of lubricant application, package the inner and outer rings separately during transportation; if separation isn’t possible, apply preload, select a different lubricant, or choose different bearings.
8. Wear: Surface wear leading to dimensional changes, often accompanied by scratches and marks. Causes: Foreign objects mixed in the lubricant, poor lubrication, misalignment of rollers. Measures: Check the lubricant and lubrication method, improve sealing performance, and prevent positioning errors.
9. Electroerosion: Pits resembling spray nozzles appear on the rolling surfaces; these can develop into wavy patterns over time. Cause: Electric current flowing through the rolling surfaces. Measures: Install current bypass valves and take insulation measures to prevent electricity from passing through the bearings.
10. Indentations and damage: Pits on the surface caused by solid foreign objects or impacts, as well as scratches during installation. Causes: Intrusion of solid foreign objects, insertion of delaminated pieces, impacts or detachment due to poor installation, installation in an inclined position. Measures: Improve installation and usage methods, prevent foreign objects from entering, and if metal fragments are the cause, check other parts as well. Pump turn Pump Manager
2. Burning phenomenon: The bearings heat up and change color, eventually becoming so damaged that they can no longer rotate. Causes: Too small a clearance (including too small a clearance in deformed areas), insufficient lubrication or inappropriate lubricant, excessive load (excessive preload), misalignment of the rollers. Measures: Set an appropriate clearance (increase the clearance), check the type of lubricant and ensure proper application, examine the operating conditions, prevent positioning errors, check the design around the bearings (including heat generation by the bearings), improve the method of assembling the bearings.
3. Crack defects: Presence of gaps and cracks in the bearings. Causes: Excessive impact loads, excessive interference fit, significant delamination, friction-induced cracks, poor precision on the installation side (too large radius at corners), improper use (use of hammers, insertion of large foreign objects). Measures: Check the operating conditions, set an appropriate interference fit and examine the material quality, improve the installation and usage methods, prevent friction-induced cracks (check the lubricant), and examine the design around the bearings.
4. Damage to the cage: Loosening or breaking of bolts, as well as cracking of the cage. Causes: Excessive torque loads, high-speed rotation or frequent changes in speed, poor lubrication, intrusion of foreign objects, severe vibrations, poor installation (installation in an inclined position), abnormal temperature rise (in the case of resin cages). Measures: Check the operating conditions, check the lubrication conditions, re-examine the choice of cage, pay attention to proper use of the bearings, and examine the stiffness of the shaft and bearing housing.
5. Scratching and jamming: Rough surface with minor welding effects. Scratching between the rim of the ring and the end face of the roller is referred to as jamming. Causes: Poor lubrication, intrusion of foreign objects, misalignment of rollers due to an inclined shaft, interruption of oil supply to the rim surface due to excessive axial load, rough surface, excessive sliding of the rolling elements. Measures: Re-examine the lubricant and lubrication method, check the operating conditions, set an appropriate preload, improve sealing performance, and use the bearings properly.
6. Rusting and corrosion: Local or complete rusting on the surface, with rust patterns similar to those on the teeth of rolling elements. Causes: Poor storage conditions, improper packaging, insufficient rust inhibitors, intrusion of water, acidic solutions, etc., handling of bearings with bare hands. Measures: Prevent rusting during storage, improve sealing performance, regularly check the lubricant, and pay attention to proper use of the bearings.
7. Abrasion: Reddish-brown wear particles appear on the mating surfaces. Causes: Insufficient interference fit, small deflection angle of the bearings, insufficient lubrication (or no lubrication at all), unstable loads, vibrations during transportation. Measures: Check the interference fit and the condition of lubricant application, package the inner and outer rings separately during transportation; if separation isn’t possible, apply preload, select a different lubricant, or choose different bearings.
8. Wear: Surface wear leading to dimensional changes, often accompanied by scratches and marks. Causes: Foreign objects mixed in the lubricant, poor lubrication, misalignment of rollers. Measures: Check the lubricant and lubrication method, improve sealing performance, and prevent positioning errors.
9. Electroerosion: Pits resembling spray nozzles appear on the rolling surfaces; these can develop into wavy patterns over time. Cause: Electric current flowing through the rolling surfaces. Measures: Install current bypass valves and take insulation measures to prevent electricity from passing through the bearings.
10. Indentations and damage: Pits on the surface caused by solid foreign objects or impacts, as well as scratches during installation. Causes: Intrusion of solid foreign objects, insertion of delaminated pieces, impacts or detachment due to poor installation, installation in an inclined position. Measures: Improve installation and usage methods, prevent foreign objects from entering, and if metal fragments are the cause, check other parts as well. Pump turn Pump Manager
It’s so dirty – it must be due to wear and tear
It is driven by a belt; it is recommended to run it with the belt tightened.
The belt is too loose, causing the bearing to come under excessive stress at a fixed point; of course, it’s also possible that there is a manufacturing defect in the bearing itself.
The belt has been checked and is relatively tight
Judging from this bearing of yours, it seems to have suffered from poor lubrication over a long period of time. The bearing may be exposed to water, or moisture may enter over time, causing the outer ring of the bearing to slide and become corroded, as a result of impact loads. Recommendation: Improve lubrication by adhering to the five principles of lubrication: fixed location, fixed quality, fixed timing, fixed quantity, and fixed person in charge. If it is outdoors, ensure proper sealing of the bearing caps to prevent water from entering. Good morning; align the fan and motor pulleys to avoid pulling them at an angle. Adjust the belt tension properly.
It’s worth taking as a reference, but the original poster didn’t explain the specific issues that occurred. It’s a shame such talent goes to waste