Common sense of Koyo bearing temperature inspection
Common sense of Koyo bearing temperature inspection
2022年4月24日
Precautions for SKF Bearing in use
Precautions for SKF Bearing in use
2022年4月24日

Analysis of causes affecting NTN bearing failure

  • Generally, the temperature of Koyo bearing starts to rise slowly with the operation of the bearing and reaches a stable state after 1-2 hours. The normal temperature of Koyo bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are appropriate, the bearing temperature will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken.

Analysis of causes affecting NTN bearing failure

  • The working temperature of Koyo bearing can be monitored at any time by using the thermal sensor, and the automatic alarm or stop when the temperature exceeds the specified value can be realized to prevent the occurrence of combustion shaft accident.Analysis of causes affecting NTN bearing failure
  • High temperature often indicates that Koyo bearing has been in abnormal condition. High temperature is also harmful to the lubricant of Koyo bearing. Sometimes bearing overheating can be attributed to the lubricant of the bearing. If the temperature of the bearing exceeds 125 ℃ for a long time, the service life of the bearing will be reduced. The causes of high temperature bearings include insufficient or excessive lubrication and lubricant. It contains impurities, excessive load, bearing ring damage, insufficient clearance, high friction caused by oil seal, etc.
  • Therefore, it is necessary to continuously monitor the bearing temperature, whether it is measuring the bearing itself or other important parts. If the operating conditions remain unchanged, any temperature change can indicate that a fault has occurred.Analysis of causes affecting NTN bearing failure
  • The periodic measurement of Koyo bearing temperature can be aided by thermometer, such as Koyo bearing digital thermometer, which can accurately measure the bearing temperature and display it in ℃ or Fahrenheit.
  • The important Koyo bearing means that when it is damaged, it will cause the shutdown of the equipment. Therefore, this kind of bearing should be equipped with temperature detector.
  • Under normal circumstances, Koyo bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days.
  • Through these three steps, you can well maintain your bearing, greatly increase its service life and save your operation cost.Analysis of causes affecting NTN bearing failure
  • Not only the surface quality of IKO imported bearing workpiece is poor, but also the crystal corrosion resistance of the workpiece is reduced. When the imported IKO bearing workpiece is seriously overheated, it will produce coarse grains and increase the volume of 8 iron cable in the steel, which is easy to deteriorate the hot working performance of the workpiece. When lCrl8Ni9Ti stainless steel companion or flange parts are overheated, orange peel surface defects are easy to occur.
  • To this end, the following preventive measures are proposed:Analysis of causes affecting NTN bearing failure
  • Strictly control lcrl8ni9]ri the forging heating temperature and heating and holding time of stainless steel box and flange parts to prevent the workpiece from overheating and coarse grain defects.
  • In the production of workpiece forging, if the forging ratio is too small and the final forging temperature is too high, it is also easy to have coarse-grained structure defects. The forging ratio of workpiece should be appropriate and sufficient and the final forging temperature should be moderate.Analysis of causes affecting NTN bearing failure
  • The solution treatment temperature of IKO imported bearing workpiece should not be too high, the holding time should not be too long, the heating temperature should not be higher than 1150 “C, and the holding time should be calculated as 1-l_5min / mm.Analysis of causes affecting NTN bearing failure
  • For the coarse workpiece with overheated structure, the method of forging and refining grain can be used to eliminate the defects, prevent the orange peel surface defects of the workpiece during cold deformation, and improve the surface quality of the workpiece. The IKO bearing of genuine goods should rotate flexibly without blocking feeling after being pressed into the bearing. Analysis of causes affecting NTN bearing failure
  • If it is obviously inflexible, it means that the size of the shaft is too large. If the IKO bearing will feel slight vibration when it is rotated by hand after being pressed into the shaft, it may be that the tolerance of the shaft is too large or the roundness of the shaft is not good. Therefore, when controlling the tolerance of shaft and bearing chamber, we should also control the roundness. Now most manufacturers only control the tolerance and do not control the roundness.
  • Prevent assembly foreign matters
  • When the IKO bearing is installed on the rotor for dynamic balance, it is easy to enter the iron filings generated during dynamic balance into the IKO bearing, so the dynamic balance is performed before installing the IKO bearing. In order to facilitate assembly, some manufacturers apply some oil or grease in the bearing chamber for lubrication effect during assembly, but it is often difficult for operators to control the amount.Analysis of causes affecting NTN bearing failure
  •  If oil or grease accumulates in IKO bearing chamber, it is easy to enter the inner part of IKO bearing along the shaft when IKO bearing rotates. The bearing chamber of IKO in Japan shall not be coated with oil or grease. If it must be coated, it shall be controlled and there shall be no accumulation in the bearing chamber.Analysis of causes affecting NTN bearing failure
  • Assembly method of IKO bearing
  • Because IKO bearing is a high-precision product, if improperly assembled, it is easy to damage IKO bearing channel, resulting in IKO bearing damage. IKO bearing shall be equipped with a special mold during assembly, which can not be knocked at will. When pressing into the shaft, only a small ring can be stressed, and when pressing a large ring, only a large ring can be stressed. It is required to use air pressure or hydraulic pressure during assembly. During press assembly, the upper and lower molds shall be outside the horizontal state. If there is inclination, the IKO bearing channel will be damaged due to stress and the IKO bearing will produce conduction sound.
  • About preventing paint rust
  • Paint rust often occurs when the sealed motor is assembled. The sound is very normal. After a long time, the abnormal noise of the motor becomes very large. There is serious rust when the IKO bearing is removed. In the past, many manufacturers thought it was the problem of IKO bearing. After our continuous publicity, now the motor factory has realized that it is mainly the problem of insulating paint. Analysis of causes affecting NTN bearing failure
  • This problem is mainly because the acidic substances volatilized from the insulating paint form corrosive substances at a certain temperature and humidity, which corrodes the IKO bearing channel and leads to the damage of IKO bearing. At present, the problem can only be to select good insulating paint and assemble it after drying.
  • The service life of IKO bearing is closely related to manufacturing, bearing quality, assembly and use. Each link cannot be pulled down and must be done well, so as to ensure that the bearing operates in a state, improve work efficiency and prolong the service life of IKO 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.
  • 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.
  • 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.Analysis of causes affecting NTN bearing failure
  • Sharp squeaking noises may be caused by improper lubrication. Improper fag inlet bearing clearance can also cause metal 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.
  • 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.
  • 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. The temperature of ina bearing can be inferred from the temperature outside the bearing chamber. It is more appropriate if the oil hole can be used to directly measure the temperature of ina bearing outer ring.
  • Generally, the temperature of INA Bearing starts to rise slowly with the operation of the bearing, and reaches a stable state after 1-2 hours. The normal temperature of INA Bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are appropriate, the bearing temperature will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken.Analysis of causes affecting NTN bearing failure
  • Using the thermal sensor, the working temperature of ina bearing can be monitored at any time, and the automatic alarm or stop when the temperature exceeds the specified value can be realized to prevent the occurrence of combustion shaft accident.Analysis of causes affecting NTN bearing failure
  • High temperature often indicates that it is in an abnormal situation. High temperature is also harmful to the lubricant of INA Bearing. Sometimes INA Bearing Overheating can be attributed to the lubricant of the bearing. If ina bearing is kept at a temperature higher than 125 ℃ for a long time, the service life of INA Bearing will be reduced. The causes of high temperature ina bearings include insufficient or excessive lubrication and lubricant. It contains impurities, excessive load, INA Bearing Ring damage, insufficient clearance, high friction caused by oil seal, etc.Analysis of causes affecting NTN bearing failure
  • Therefore, it is necessary to continuously monitor the temperature of INA Bearing, whether it is measuring ina bearing itself or other important parts. If the operating conditions remain unchanged, any temperature change can indicate that a fault has occurred.
  • The periodic measurement of ina bearing temperature can be aided by a thermometer, such as a digital thermometer, which can accurately measure the INA Bearing Temperature and display it in degrees Celsius or Fahrenheit.
  • The important ina bearing means that when it is damaged, it will cause the shutdown of the equipment. Therefore, this kind of INA Bearing should be equipped with temperature detector.Analysis of causes affecting NTN bearing failure
  • Under normal circumstances, ina bearings will have a natural temperature rise after just lubrication or re lubrication and last for one to two days. The causes of NTN bearing failure are often multifactorial. All influencing factors in the design and manufacturing process will be related to the bearing failure, which is difficult to judge by analysis. In general, it can be considered and analyzed from two aspects: use factors and internal factors. Use factors mainly refer to whether the installation, adjustment, use and maintenance, maintenance and repair meet the technical requirements. Analysis of causes affecting NTN bearing failure
  • The installation condition is one of the primary factors in the use factors. The improper installation of the bearing often leads to the change of the stress state between the parts of the whole bearing, and the bearing operates in an abnormal state and fails early. According to the technical requirements of bearing installation, use, maintenance and repair, monitor and inspect the load, speed, working temperature, vibration, noise and lubrication conditions borne by the running bearing, find out the cause immediately and adjust it to make it return to normal. In addition, it is also important to analyze and test the quality of grease and the surrounding medium and atmosphere.Analysis of causes affecting NTN bearing failure
  • Internal factors mainly refer to the three factors that determine the quality of bearings, such as structural design, manufacturing process and material quality.Analysis of causes affecting NTN bearing failure
  • First of all, the reasonable design and advanced nature of the structure will lead to longer bearing life. The manufacturing of bearings generally goes through multiple processing processes such as forging, heat treatment, turning, grinding and assembly. The rationality, advanced nature and stability of all the processing technologies will also affect the life of bearings. Analysis of causes affecting NTN bearing failure
  • Among them, the heat treatment and grinding processes that affect the quality of finished bearings are often more directly related to the failure of bearings. In recent years, the research on the metamorphic layer on the working surface of bearing shows that the grinding process is closely related to the surface quality of bearing.Analysis of causes affecting NTN bearing failure
  • The metallurgical quality of NTN bearing material was once the main factor affecting the early failure of rolling bearing. With the progress of Metallurgical Technology (such as vacuum degassing of bearing steel), the quality of raw materials has been improved. The proportion of raw material quality factor in bearing failure analysis has decreased significantly, but it is still one of the main influencing factors of bearing failure. Proper material selection is still a factor that must be considered in bearing failure analysis.
  • The main task of NTN bearing failure analysis is to find out the main factors causing bearing failure according to a large number of background materials, analysis data and failure forms, so as to put forward targeted improvement measures, prolong the service life of the bearing and avoid sudden early failure of the bearing.
Analysis of causes affecting NTN bearing failure
  • Maintaaining IKO imported bearings is a necessary condition for bearing operation. The common maintenance is for bearing lubrication. Aafter reading how to select the bearing lubrication mode and understanding the bearing lubrication mode, it is also necessary to understand the bearing system maintenance. Let’s see how to carry out IKO imported bearing lubrication and maintenance.
  • Keep the bearings lubricated clean
  • Before inspecting the bearing imported from IKO, Sweden, the surface of the bearing should be cleaned first, and then the oil seal of the bearing and its surrounding parts should be carefully inspected. If there are bad symptoms, it must be replaced. The bad oil seal will cause damage, make the cloud of the bearing abnormal and cause the shutdown of the equipment.Analysis of causes affecting NTN bearing failure
  • Take care to cover exposed bearings
  • When inspecting the bearing, do not expose the bearing to pollutants or moisture. If the work is interrupted, the machine shall be covered with oil paper, plastic sheet or similar materials. If it is possible to clean the naked bearing without disassembly, clean it with a brush coated with petroleum solvent, and then wipe it dry with a piece of lint free cloth or blow it dry with compressed air (be careful not to start the rotation of the bearing assembly). Analysis of causes affecting NTN bearing failure
  • Use a small mirror and a probe similar to that used by dentists to check the track surface, retainer and beads of the bearing. Do not clean the sealed cover or dust-proof bearing; Just wipe the outer surface. If the bearing is damaged, it needs to be replaced. It is much more economical to replace the bearing during the regular shutdown and maintenance period than the loss of sudden shutdown due to the damage of the array bearing.Analysis of causes affecting NTN bearing failure
  • Check the lubricant of the bearing
  • Lubricants are important not only for bearings, but also for all IKO imported bearings. However, please note that Japanese bearings should not add too much grease. Then it’s time to change the lubricant of the bearing. After draining the old engine oil, if possible, the bearings lubricated with engine oil should be filled with fresh engine oil and let the machine rotate at low speed for a few minutes. Make the oil collect residual pollutants as much as possible, and then drain the oil. Analysis of causes affecting NTN bearing failure
  • When replacing the grease of the bearing lubricated with grease, the Joe remover used shall avoid the contact of cotton with any part of the bearing. Because these residual fibers may wedge between rolling parts and cause damage, especially in bearing applications.Analysis of causes affecting NTN bearing failure
  • Through these three steps, you can well maintain your bearing, greatly increase its service life and save your operation cost.Analysis of causes affecting NTN bearing failure
  • Not only the surface quality of IKO imported bearing workpiece is poor, but also the crystal corrosion resistance of the workpiece is reduced. When the imported IKO bearing workpiece is seriously overheated, it will produce coarse grains and increase the volume of 8 iron cable in the steel, which is easy to deteriorate the hot working performance of the workpiece. When lCrl8Ni9Ti stainless steel companion or flange parts are overheated, orange peel surface defects are easy to occur.Analysis of causes affecting NTN bearing failure
  • To this end, the following preventive measures are proposed:Analysis of causes affecting NTN bearing failure
  • Strictly control lcrl8ni9]ri the forging heating temperature and heating and holding time of stainless steel box and flange parts to prevent the workpiece from overheating and coarse grain defects.
  • In the production of workpiece forging, if the forging ratio is too small and the final forging temperature is too high, it is also easy to have coarse-grained structure defects. The forging ratio of workpiece should be appropriate and sufficient and the final forging temperature should be moderate.Analysis of causes affecting NTN bearing failure
  • The solution treatment temperature of IKO imported bearing workpiece should not be too high, the holding time should not be too long, the heating temperature should not be higher than 1150 “C, and the holding time should be calculated as 1-l_5min / mm.Analysis of causes affecting NTN bearing failure
  • For the coarse workpiece with overheated structure, the method of forging and refining grain can be used to eliminate the defects, prevent the orange peel surface defects of the workpiece during cold deformation, and improve the surface quality of the workpiece.Analysis of causes affecting NTN bearing failure
Precautions for prolonging the service life of IKO one-way bearing