Damage state: the dark surface of imported bearing with slight wear, on which there are several micro cracks with a depth of 5-10mm from the surface to the inside, and micro peeling occurs in a large range (micro peeling)
Cause: improper bearing lubricant. Foreign matter has entered the lubricant. Poor lubricant causes rough surface. The surface finish of paired rolling parts is not good.
Damage state: the imported bearing raceway wheel, steel ball and cage are heated sharply during rotation until they change color, soften, deposit and damage.Causes and treatment measures of peeling and burn of NSK imported bearing
Reason: 1 Poor lubrication. 2. The bearing bears excessive load (excessive preload). 3. The bearing speed is too high. 4. The clearance is too small. 5. Intrusion of water and foreign matters into the bearing. 6. The accuracy of shaft and bearing box is poor and the deflection of shaft is large.Causes and treatment measures of peeling and burn of NSK imported bearing
Measures: 1 Study lubricants and lubrication methods. 2. Correct the selection of bearings. 3. Study fit, bearing clearance and preloading. 4. Improve the sealing device. 5. Check the accuracy of shaft and bearing housing. 6. Improve the installation method.Causes and treatment measures of peeling and burn of NSK imported bearing
NSK bearing is a mass-produced mechanical part with strict manufacturing accuracy and high degree of technical specialization. Therefore, for the vast majority of NSK bearing varieties that are easy to buy, it should be more cost-effective to buy than repair. The repair of NSK bearing can only be considered under the following circumstances, namely:Causes and treatment measures of peeling and burn of NSK imported bearing
The failure forms of a large number of NSK Bearings of the same model used in large factories are mainly surface wear, fatigue or fretting abrasion. In particular, most of the damaged parts are cages or bodies, and the rings or washers still have repair value;Causes and treatment measures of peeling and burn of NSK imported bearing
Large and extra large NSK Bearings are on the verge of failure or have failed without major damage to parts, or valuable NSK Bearings must try to prolong their effective service life;Causes and treatment measures of peeling and burn of NSK imported bearing
Some NSK bearing varieties that are really difficult to buy have to be repaired without spare parts after failure, especially NSK Bearings;Causes and treatment measures of peeling and burn of NSK imported bearing
NSK Bearings are slightly damaged, such as slight water rust during storage and slight fretting abrasion during transportation. Such cases are easy to repair and regrettable to discard.Causes and treatment measures of peeling and burn of NSK imported bearing.
In addition to the economy, the repair of NSK bearing also has its technicality, which requires the repairer to fully understand the corresponding technical requirements of NSK bearing and the characteristics of NSK bearing and its parts in structure, technology and materials. Otherwise, it is difficult to ensure that NSK bearing repair has the required effect.Causes and treatment measures of peeling and burn of NSK imported bearing
The specific judgment method of whether fag bearing should be reported for repair, that is, the specific judgment method of fag bearing has been fully utilized and near damage is as follows:Causes and treatment measures of peeling and burn of NSK imported bearing
Using fag bearing working state monitoring instrument.It is a convenient and reliable method to judge the working state of fag bearing and decide when fag bearing should be repaired by using such instruments as Ferrograph or SPM or i-id-1 fag bearing working state monitoring instrument.Causes and treatment measures of peeling and burn of NSK imported bearing
For example, when HD-1 instrument is used, when the pointer approaches the dangerous area from the warning area, and the pointer does not return after taking measures to improve lubrication, it can be determined that it is the problem of fag bearing itself. At this time, the fag bearing can be reported for repair before entering the dangerous area. How far away from the dangerous area to start the repair can be adjusted by experience.Causes and treatment measures of peeling and burn of NSK imported bearing
Using such an instrument, we can make full use of the working potential of fag bearings, report fag bearings for repair in time, and avoid faults. It is and economical.Causes and treatment measures of peeling and burn of NSK imported bearing
Monitor with simple tools：In the absence of the above instruments, the operator can hold a round bar or wrench and other tools to collide with the part of the machine shell close to the imported fag bearing, shame his ears on the tool and listen for the sound of fag shaft transmitted by the tool. Of course, it is also possible to refit the medical stethoscope.Causes and treatment measures of peeling and burn of NSK imported bearing
The normal fag shaft rotation sound should be uniform, stable and not harsh, while the abnormal fag shaft rotation sound has a variety of intermittent, impact or harsh sounds. First, get used to the normal fag shaft carrying sound, and then you can grasp and judge the abnormal fag shaft carrying sound. Causes and treatment measures of peeling and burn of NSK imported bearing
Then, through the accumulation of practical experience, you can further analyze what kind of abnormal sound corresponds to what kind of abnormal phenomenon of fag bearing. There are many types of abnormal sounds of fag bearings, which are difficult to speak and mainly rely on experience accumulation.Causes and treatment measures of peeling and burn of NSK imported bearing
The sound detector is used to check the rolling sound and sound quality of the running fag bearing. Even if there is slight peeling and other damage, the fag bearing will emit abnormal sound and irregular sound, which can be distinguished by the sound detector.Causes and treatment measures of peeling and burn of NSK imported bearing
listen for
It is a common method to use hearing to identify irregular operation. For example, it is often used by experienced operators to detect the abnormal noise of a part with the help of an electronic stethoscope.Causes and treatment measures of peeling and burn of NSK imported bearing
If fag bearing is in good continuous rotation state, it will make a low whine sound. If sharp hiss, squeak and other irregular sounds are made, it often indicates that fag bearing is in poor continuous rotation condition.Causes and treatment measures of peeling and burn of NSK imported bearing
Sharp squeaking noises may be caused by improper lubrication. Improper fag bearing clearance can also cause metallic sound. Dents on the concave track of fag bearing outer ring track will cause vibration and cause smooth and crisp sound. If the knocking scar caused during installation will also produce noise, the noise will vary with the speed of fag bearing.Causes and treatment measures of peeling and burn of NSK imported bearing
If there is intermittent noise, it indicates that the rolling parts may be damaged. This sound occurs when the damaged surface is rolled out. If there are pollutants in fag bearing, it will often cause hissing sound. Serious damage to the bearing will produce irregular and loud noise.Causes and treatment measures of peeling and burn of NSK imported bearing
Fag bearing damage can be detected by hearing, but usually it is time for fag bearing to be replaced immediately. Therefore, it is better to use, for example, electronic condition monitoring instruments. The fag bearing condition can be estimated more accurately by using a wooden stick than the old method In the oil supply system of hydrostatic fag bearing, except for coarse filtration and fine filtration, other components have a protective effect on hydrostatic fag bearing. Causes and treatment measures of peeling and burn of NSK imported bearing
The oil supply system is improved on the basis of the original system. The oil outlet behind the throttle plate is connected with a pressure relay and a pressure gauge (originally in front of the accumulator), so that the operator can see the chamber pressure and pressure. Causes and treatment measures of peeling and burn of NSK imported bearing
Add digital detection device:Causes and treatment measures of peeling and burn of NSK imported bearing
When the differential pressure is greater than a certain value, the machine can be shut down immediately to prevent the bearing bush from locking. For example, if the pressure is 2 MPa and the outlet cavity pressure is 1.2 ~ 1.6 MPa, the machine will be shut down if it is lower than 1.2 MPa.Causes and treatment measures of peeling and burn of NSK imported bearing
There is a gap of 0.04 ~ 0.05mm between the main shaft and bearing bush of wear-resistant electrode static pressure fag bearing, and the oil in between has a certain resistance value. By detecting the change of this resistance value, we can know the size of the phase gap. Causes and treatment measures of peeling and burn of NSK imported bearing
Take the main shaft as one pole and the bearing bush as the other pole, and measure the resistance change. After processing, the signal is sent to the photoelectric alarm and control system amplifier to control the start and stop of the spindle motor, so as to avoid the friction between the shaft and the bearing
The stiffness of thin film feedback throttling fag bearing is very large, but the phenomena such as pad holding, roughening and pressure drop often occur in the operation of machine tools. The key of film feedback is film. In practice, it is considered that the main reasons for bearing bush locking and galling are: ① plastic deformation of film; ② Feedback is slow. Causes and treatment measures of peeling and burn of NSK imported bearing
When the external load changes suddenly and the film has not reacted, the shaft and pad have been rubbed; ③ Film fatigue. The film has long service time and fatigue deformation, which is equivalent to changing the feedback parameters.Causes and treatment measures of peeling and burn of NSK imported bearing
Good results can be obtained by increasing the thickness of the film and using some fatigue resistant materials. Generally, rigid membrane, preloading and reserved gap are adopted. The specific method of fag bearing is to change the 1.4mm thick film into 4mm thick rigid film, pad 0.05mm thick tin foil paper in the lower cavity, and adjust the spindle to a position 0.05mm higher than the ideal position. The purpose is to return to the ideal center just after the spindle is stressed (grinding wheel weight, cutting force).Causes and treatment measures of peeling and burn of NSK imported bearing
Constant pressure pre tightening is the key point of pre tightening NSK imported bearing with coil spring.
Belleville spring, etc. The rigidity of the preload spring is generally much smaller than that of the INA Bearing, so the relative position of the INA Bearing preloaded under constant pressure will change in use, but the preload is largely stable.
The specific force of positioning preload and constant pressure preload is as follows:
When the preload is proportional, the positioning preload has a greater effect on the rigidity growth of INA Bearing, and the rigidity change of INA Bearing has a much smaller effect on the load of INA Bearing.
In the use of positioning preload, the axial length difference caused by the temperature difference between the shaft and ina bearing seat, the radial expansion caused by the temperature difference between the inner and outer rings and the displacement caused by load will change the preload; While the constant pressure preload is in use, the change of preload can be ignored carelessly.
The radial jacking method is mostly used in tapered bore bearings subjected to radial load. A typical example is the double row precision short cylindrical roller bearing. The nut is used to mediate the axial position of the INA Bearing relative to the sub tapered journal, so that the inner ring has a suitable expansion amount to obtain radial negative clearance. This method is mostly used in machine tool spindle and jet engine.
Axial preloading method can be roughly divided into positioning preloading and constant pressure preloading. In positioning preload, ina bearing can decide the size of adjusting bushing or gasket to obtain the appropriate preload;
It can also be decided to measure or control the starting friction torque to adjust the appropriate preload; The purpose of preloading can also be realized by directly using the paired duplex ina bearings with preload adjusted in advance. At this time, there is no need for users to mediate. In short, the relative position of ina bearings with axial preload will not change when used.
Whether there is muddy oil on the surface: this should be paid special attention when purchasing NTN bearings. Since the current domestic antirust technology is not particularly good, it is easy to leave thick oil traces when antirust the NTN bearing body, which is sticky and thick when holding it in your hand. However, there is almost no trace of antirust oil on the bearings originally imported from abroad. However, a particularly careful expert said that the imported bearings smell like a smell. It must be under antirust oil, but you can’t see it.
Whether the chamfer is uniform: the so-called chamfer of NTN bearing, that is, the junction of horizontal and vertical surfaces. Due to the limitation of production technology, the fake NTN bearing of NTN bearing is not handled satisfactorily in these corners. Whether the steel seal words are clear: brand words, labels, etc. will be printed on the NTN bearing body.
The font is very small, but most of the products produced by the original factory use steel printing technology, and they are pressed before overheating treatment. Therefore, although the font is small, it is concave – deep and very clear. The font of counterfeit products is not only fuzzy, but also floating on the surface due to the rough printing technology. Some of them can even be easily erased by hand.
Whether there is any noise: hold the inner sleeve of NTN bearing with your left hand, move the outer sleeve with your right hand to rotate it, and listen to NTN bearing for any noise. Due to the backward production conditions of most counterfeit products and the complete manual workshop operation, it is inevitable that impurities such as sand will be mixed in the production process and hidden in the NTN bearing, so it will make a noise when rotating.
This is a big difference from the factory brand that strictly implements production standards and operates with machines Constant pressure pre tightening is the key point of pre tightening INA Bearing with coil spring, Belleville spring, etc. The rigidity of the preload spring is generally much smaller than that of the INA Bearing, so the relative position of the INA Bearing preloaded under constant pressure will change in use, but the preload is largely stable.
The specific force of positioning preload and constant pressure preload is as follows:
When the preload is proportional, the positioning preload has a greater effect on the rigidity growth of INA Bearing, and the rigidity change of INA Bearing has a much smaller effect on the load of INA Bearing.
In the use of positioning preload, the axial length difference caused by the temperature difference between the shaft and ina bearing seat, the radial expansion caused by the temperature difference between the inner and outer rings and the displacement caused by load will change the preload; While the constant pressure preload is in use, the change of preload can be ignored carelessly.Causes and treatment measures of peeling and burn of NSK imported bearing
The radial jacking method is mostly used in tapered bore bearings subjected to radial load. A typical example is the double row precision short cylindrical roller bearing. The nut is used to mediate the axial position of the INA Bearing relative to the sub tapered journal, so that the inner ring has a suitable expansion amount to obtain radial negative clearance. This method is mostly used in machine tool spindle and jet engine.Causes and treatment measures of peeling and burn of NSK imported bearing
Axial preloading method can be roughly divided into positioning preloading and constant pressure preloading. In positioning preload, ina bearing can decide the size of adjusting bushing or gasket to obtain the appropriate preload;Causes and treatment measures of peeling and burn of NSK imported bearing
It can also be decided to measure or control the starting friction torque to adjust the appropriate preload; The purpose of preloading can also be realized by directly using the paired duplex ina bearings with preload adjusted in advance. At this time, there is no need for users to mediate. In short, the relative position of ina bearings with axial preload will not change when used.Causes and treatment measures of peeling and burn of NSK imported bearing
Constant pressure pre tightening is the key point of pre tightening Causes and treatment measures of peeling and burn of NSK imported bearing
with coil spring, Belleville spring, etc. The rigidity of the preload spring is generally much smaller than that of the INA Bearing, so the relative position of the INA Bearing preloaded under constant pressure will change in use, but the preload is largely stable.Causes and treatment measures of peeling and burn of NSK imported bearing
The specific force of positioning preload and constant pressure preload is as follows:Causes and treatment measures of peeling and burn of NSK imported bearing
When the preload is proportional, the positioning preload has a greater effect on the rigidity growth of INA Bearing, and the rigidity change of INA Bearing has a much smaller effect on the load of INA Bearing.Causes and treatment measures of peeling and burn of NSK imported bearing
In the use of positioning preload, the axial length difference caused by the temperature difference between the shaft and ina bearing seat, the radial expansion caused by the temperature difference between the inner and outer rings and the displacement caused by load will change the preload; While the constant pressure preload is in use, the change of preload can be ignored carelessly.Causes and treatment measures of peeling and burn of NSK imported bearing
The radial jacking method is mostly used in tapered bore bearings subjected to radial load. A typical example is the double row precision short cylindrical roller bearing. The nut is used to mediate the axial position of the INA Bearing relative to the sub tapered journal, so that the inner ring has a suitable expansion amount to obtain radial negative clearance. This method is mostly used in machine tool spindle and jet engine.Causes and treatment measures of peeling and burn of NSK imported bearing
Axial preloading method can be roughly divided into positioning preloading and constant pressure preloading. In positioning preload, ina bearing can decide the size of adjusting bushing or gasket to obtain the appropriate preload; It can also be decided to measure or control the starting friction torque to adjust the appropriate preload; The purpose of preloading can also be realized by directly using the paired duplex ina bearings with preload adjusted in advance. Causes and treatment measures of peeling and burn of NSK imported bearing
At this time, there is no need for users to mediate. In short, the relative position of ina bearings with axial preload will not change when used. Whether there is muddy oil on the surface: this should be paid special attention when purchasing NTN bearings. Causes and treatment measures of peeling and burn of NSK imported bearing
Since the current domestic antirust technology is not particularly good, it is easy to leave thick oil traces when antirust the NTN bearing body, which is sticky and thick when holding it in your hand. However, there is almost no trace of antirust oil on the bearings originally imported from abroad. However, a particularly careful expert said that the imported bearings smell like a smell. It must be under antirust oil, but you can’t see it.Causes and treatment measures of peeling and burn of NSK imported bearing
Whether the chamfer is uniform: the so-called chamfer of NTN bearing, that is, the junction of horizontal and vertical surfaces. Due to the limitation of production technology, the fake NTN bearing of NTN bearing is not handled satisfactorily in these corners. Whether the steel seal words are clear: brand words, labels, etc. will be printed on the NTN bearing body.Causes and treatment measures of peeling and burn of NSK imported bearing
The font is very small, but most of the products produced by the original factory use steel printing technology, and they are pressed before overheating treatment. Therefore, although the font is small, it is concave – deep and very clear. The font of counterfeit products is not only fuzzy, but also floating on the surface due to the rough printing technology. Some of them can even be easily erased by hand.Causes and treatment measures of peeling and burn of NSK imported bearing
Whether there is any noise: hold the inner sleeve of NTN bearing with your left hand, move the outer sleeve with your right hand to rotate it, and listen to NTN bearing for any noise. Due to the backward production conditions of most counterfeit products and the complete manual workshop operation, it is inevitable that impurities such as sand will be mixed in the production process and hidden in the NTN bearing, so it will make a noise when rotating. Causes and treatment measures of peeling and burn of NSK imported bearing
This is a big difference from the factory brand that strictly implements production standards and operates with machines Constant pressure pre tightening is the key point of pre tightening INA Bearing with coil spring, Belleville spring, etc. The rigidity of the preload spring is generally much smaller than that of the INA Bearing, so the relative position of the INA Bearing preloaded under constant pressure will change in use, but the preload is largely stable.
The specific force of positioning preload and constant pressure preload is as follows:Causes and treatment measures of peeling and burn of NSK imported bearing
When the preload is proportional, the positioning preload has a greater effect on the rigidity growth of INA Bearing, and the rigidity change of INA Bearing has a much smaller effect on the load of INA Bearing.Causes and treatment measures of peeling and burn of NSK imported bearing
In the use of positioning preload, the axial length difference caused by the temperature difference between the shaft and ina bearing seat, the radial expansion caused by the temperature difference between the inner and outer rings and the displacement caused by load will change the preload; While the constant pressure preload is in use, the change of preload can be ignored carelessly.Causes and treatment measures of peeling and burn of NSK imported bearing
The radial jacking method is mostly used in tapered bore bearings subjected to radial load. A typical example is the double row precision short cylindrical roller bearing. The nut is used to mediate the axial position of the INA Bearing relative to the sub tapered journal, so that the inner ring has a suitable expansion amount to obtain radial negative clearance. This method is mostly used in machine tool spindle and jet engine.Causes and treatment measures of peeling and burn of NSK imported bearing
Axial preloading method can be roughly divided into positioning preloading and constant pressure preloading. In positioning preload, ina bearing can decide the size of adjusting bushing or gasket to obtain the appropriate preload; It can also be decided to measure or control the starting friction torque to adjust the appropriate preload; The purpose of preloading can also be realized by directly using the paired duplex ina bearings with preload adjusted in advance. At this time, there is no need for users to mediate. In short, the relative position of ina bearings with axial preload will not change when used.Causes and treatment measures of peeling and burn of NSK imported bearing
Chat with us
Chat with us
Questions, doubts, issues? We're here to help you!
