Part of the material of the moving surface of the bearing is detached like a fish scale. This phenomenon is called fatigue flaking. During the operation of the dynamic spring bearing, it bears a certain load, even if it is a static load, but the stress is reincarnation for the steel ball and the raceway. Reciprocating, the material will be fatigued and the bearing will reach the end of its life. In addition, there are several different definitions of the bearing "life", one of which is the so-called "working life", which means that the actual life that a needle roller bearing can reach before it is damaged is usually caused by wear and damage, not caused by fatigue. It is caused by wear, erosion, seal damage and other reasons.
However, whether in the laboratory test or in actual use, it can be clearly seen that the same bearing has the same appearance under the same working conditions, and the actual life is very different.
The number of revolutions of the bearing life (or the number of hours of operation at a certain speed), defined: needle bearings within this life should be initially fatigued (flaking or missing) on any of the bearing rings or moving bodies. Most of the bearings are damaged for many reasons – beyond the original estimated load, non-effective seals, too tight bearing clearance caused by too small bearing clearances.
Any of these factors have their particular type of damage and leave a special mark of damage. Therefore, inspection of damaged bearings can be found in most cases. In general, one-third of the needle bearing damage is caused by fatigue damage, and the other third is due to poor lubrication. The other third is due to contaminants entering the bearing or improperly installed.
However, these types of damage are also related to the industry. For example, the pulp and paper industry is mostly due to poor lubrication or contamination resulting in bearing damage rather than material fatigue.
Large metal noise
Reason 1: Abnormal load, countermeasure: Correct the fit, study bearing clearance, adjust and load, and correct the position of the housing shoulder.
Cause 2: Poor installation, countermeasures: Machining accuracy of shaft and outer casing, improvement of mounting accuracy, and installation method.
Cause 3: The lubricant is insufficient or unsuitable. Countermeasure: Replenish the lubricant and select the appropriate lubricant.
Cause 4: The rotating parts are in contact. Countermeasure: Modify the contact part of the curved path seal.
Regular noise
Cause 1: Indentation, rust, or scratch on the rolling surface due to foreign matter. Countermeasures: Replace the bearing, clean the parts, improve the sealing device, and use a clean lubricant.
Cause 2: (after steel carburization) surface deformation, countermeasures: replace the bearing, pay attention to its use.
Cause 3: The raceway surface is peeled off. Countermeasure: Replace the needle roller bearing.
Irregular noise
Reason 1: The clearance is too large. Countermeasure: Study the fit and bearing clearance, and modify the preload.
Reason 2: Intrusion of foreign matter, countermeasures: Study replacement of bearings, cleaning related parts, improving sealing devices, and using clean lubricants.
Cause 3: Spherical injury, peeling, countermeasure: Replace the bearing.
Abnormal temperature rise
Reason 1: Excessive lubricant, countermeasures: Reduce the lubricant, use it in moderation, and choose a harder grease.
Cause 2: The lubricant is insufficient or unsuitable. Countermeasure: Replenish the lubricant and select the appropriate lubricant.
Reason 3: Abnormal load, countermeasure: Modify the fit, study the clearance of the bearing, adjust the preload, and modify the position of the shoulder of the outer casing.
Cause 4: Poor installation, countermeasures: Improve machining accuracy, mounting accuracy, and mounting method for the shaft and housing.
Reason 5: Creep of the mating surface and excessive friction of the sealing device. Countermeasures: Replace the needle bearing, study the fit, modify the shaft and the outer casing, and change the sealing form.
Large vibration (bounce of the shaft)
Reason 1: (after steel carburizing) surface deformation, countermeasures: pay attention to bearing replacement operation.
Reason 2: Peeling, countermeasure: Replace the bearing.
Cause 3: Poor installation, countermeasures: modify the shaft, the right angle of the housing shoulder, and the straight angle of the side of the pad.
Cause 4: Foreign matter intrusion, countermeasures: Replace the bearing, clean the parts, and improve the sealing device.
Lubricant leaks too much, discoloration
Cause: Excessive lubricant, foreign matter intrusion, abrasion of powder, foreign matter, etc. Countermeasures: Use a proper amount of lubricant, study and change the choice of lubricant, study the replacement of needle roller bearings, and clean the outer casing.
However, whether in the laboratory test or in actual use, it can be clearly seen that the same bearing has the same appearance under the same working conditions, and the actual life is very different.
The number of revolutions of the bearing life (or the number of hours of operation at a certain speed), defined: needle bearings within this life should be initially fatigued (flaking or missing) on any of the bearing rings or moving bodies. Most of the bearings are damaged for many reasons – beyond the original estimated load, non-effective seals, too tight bearing clearance caused by too small bearing clearances.
Any of these factors have their particular type of damage and leave a special mark of damage. Therefore, inspection of damaged bearings can be found in most cases. In general, one-third of the needle bearing damage is caused by fatigue damage, and the other third is due to poor lubrication. The other third is due to contaminants entering the bearing or improperly installed.
However, these types of damage are also related to the industry. For example, the pulp and paper industry is mostly due to poor lubrication or contamination resulting in bearing damage rather than material fatigue.
Large metal noise
Reason 1: Abnormal load, countermeasure: Correct the fit, study bearing clearance, adjust and load, and correct the position of the housing shoulder.
Cause 2: Poor installation, countermeasures: Machining accuracy of shaft and outer casing, improvement of mounting accuracy, and installation method.
Cause 3: The lubricant is insufficient or unsuitable. Countermeasure: Replenish the lubricant and select the appropriate lubricant.
Cause 4: The rotating parts are in contact. Countermeasure: Modify the contact part of the curved path seal.
Regular noise
Cause 1: Indentation, rust, or scratch on the rolling surface due to foreign matter. Countermeasures: Replace the bearing, clean the parts, improve the sealing device, and use a clean lubricant.
Cause 2: (after steel carburization) surface deformation, countermeasures: replace the bearing, pay attention to its use.
Cause 3: The raceway surface is peeled off. Countermeasure: Replace the needle roller bearing.
Irregular noise
Reason 1: The clearance is too large. Countermeasure: Study the fit and bearing clearance, and modify the preload.
Reason 2: Intrusion of foreign matter, countermeasures: Study replacement of bearings, cleaning related parts, improving sealing devices, and using clean lubricants.
Cause 3: Spherical injury, peeling, countermeasure: Replace the bearing.
Abnormal temperature rise
Reason 1: Excessive lubricant, countermeasures: Reduce the lubricant, use it in moderation, and choose a harder grease.
Cause 2: The lubricant is insufficient or unsuitable. Countermeasure: Replenish the lubricant and select the appropriate lubricant.
Reason 3: Abnormal load, countermeasure: Modify the fit, study the clearance of the bearing, adjust the preload, and modify the position of the shoulder of the outer casing.
Cause 4: Poor installation, countermeasures: Improve machining accuracy, mounting accuracy, and mounting method for the shaft and housing.
Reason 5: Creep of the mating surface and excessive friction of the sealing device. Countermeasures: Replace the needle bearing, study the fit, modify the shaft and the outer casing, and change the sealing form.
Large vibration (bounce of the shaft)
Reason 1: (after steel carburizing) surface deformation, countermeasures: pay attention to bearing replacement operation.
Reason 2: Peeling, countermeasure: Replace the bearing.
Cause 3: Poor installation, countermeasures: modify the shaft, the right angle of the housing shoulder, and the straight angle of the side of the pad.
Cause 4: Foreign matter intrusion, countermeasures: Replace the bearing, clean the parts, and improve the sealing device.
Lubricant leaks too much, discoloration
Cause: Excessive lubricant, foreign matter intrusion, abrasion of powder, foreign matter, etc. Countermeasures: Use a proper amount of lubricant, study and change the choice of lubricant, study the replacement of needle roller bearings, and clean the outer casing.
