Various failure causes and precautions of NTN bearing
Various failure causes and precautions of NTN bearing
2022年6月7日
Cleaning process and precautions of electric NSK bearing
Cleaning process and precautions of electric NSK bearing
2022年6月9日

Advantages of NTN bearing in application

Deep groove ball bearing is a common type of NTN bearing

 

  • The basic deep groove ball bearing is composed of an outer ring, an inner ring, a group of steel balls and a group of retaining structures.Advantages of NTN bearing in application
  • NTN bearing is a representative rolling bearing with a wide range of applications. It is suitable for high speed or even extremely high speed operation, and it is very durable without regular maintenance. Moreover, this kind of NTN bearing has the advantages of small friction coefficient, high limit speed, simple structure, low manufacturing cost and high manufacturing accuracy.
  • The size range and forms vary widely. It is used in precision instruments, low-noise motors, automobiles, motorcycles and general machinery industries. It is a kind of NTN bearing widely used in the machinery industry. It mainly bears radial load and a certain amount of axial load.
  • When choosing a larger radial clearance, the axial bearing capacity increases, and the contact angle is zero when bearing pure radial force. When there is axial force, the contact angle is greater than zero. Generally, stamping wave cage, turning solid cage and sometimes nylon cage are used.
  • After the NTN bearing is installed on the shaft, the axial displacement in both directions of the shaft or housing can be limited within the axial clearance of the NTN bearing, so it can be positioned axially in both directions. In addition, this kind of NTN bearing also has a certain centering ability. 
  • When it is inclined by 2 ′~ 10 ′ relative to the shell hole, it can still work normally, but it has a certain impact on the service life of NTN bearing. NTN bearing cages are mostly steel plate stamping wave cages, and large NTN bearings mostly adopt vehicle made metal solid cages.Advantages of NTN bearing in application
  • NTN bearings are commonly used in gearboxes, instruments and meters, motors, household appliances, internal combustion engines, traffic vehicles, agricultural machinery, construction machinery, engineering machinery, etc.
Advantages of NTN bearing in application

With the progress and development of society,NTN bearing in application

 

  •  Mechanization has been widely used in production and life. As an indispensable part of machinery, NTN bearing will be used more and more widely, because NTN bearing will be used wherever there is rotation.Advantages of NTN bearing in application
  • NTN bearing is mainly used to support and reduce friction in machinery, so the accuracy and noise of NTN bearing are directly related to the service life of machinery.Advantages of NTN bearing in application
  • NTN bearing models are generally selected by users’ technicians according to the service conditions and load of supporting products. If the NTN bearing fails to meet the use requirements, it should be recommended to re select the model as soon as possible, but unless special products, there will generally be no problem in selecting the model.Advantages of NTN bearing in application
  • NTN bearing is a high-precision product. If it is not assembled properly, it is easy to damage the NTN bearing channel, resulting in the damage of NTN bearing. NTN bearing shall be equipped with a special mold during assembly, which can not be knocked at will. Advantages of NTN bearing in application
  • When pressing the shaft, only a small ring can be stressed, and when pressing a large ring, only a large ring can be stressed. Pneumatic or hydraulic pressure is required during assembly. During press assembly, the upper and lower molds shall be outside the horizontal state. If there is inclination, the NTN bearing channel will be damaged due to stress and the NTN bearing will produce conduction sound.Advantages of NTN bearing in application
  • The service life of NTN bearing is closely related to manufacturing, assembly and use. It must be done well in each link in order to make NTN bearing in the running state, so as to prolong the service life of NTN bearing.Advantages of NTN bearing in application

The first is to identify and NTN bearing in check the rolling sound

 

  • We can use sound detector to check the rolling sound and sound quality of Timken bearing in operation. Because Timken bearing will emit abnormal sound and irregular sound even if there is slight peeling and other damage, it can be distinguished by sound detector to prevent it in advance.Advantages of NTN bearing in application
  • Secondly, the vibration of Timken bearing in operation is identified and checked
  • Timken bearing vibration is very sensitive to the damage of Timken bearing. For example, peeling, indentation, corrosion, crack, wear, etc. will be reflected in the vibration measurement of Timken bearing. Therefore, the vibration can be measured by using a special Japanese Timken bearing vibration meter (frequency analyzer, etc.), and the specific situation of abnormality can not be inferred through frequency division. Advantages of NTN bearing in application
  • The measured values are different due to the service conditions of Timken bearing or the installation position of sensor, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.Advantages of NTN bearing in application

After that, check according to the temperature of Timken bearing

  • The temperature of Timken bearing can generally be inferred from the temperature outside the Timken bearing chamber in Japan. It is more appropriate if the outer ring temperature of Timken bearing can be directly measured by oil hole. Usually, the temperature of Timken bearing rises slowly with the start of operation and reaches a stable state after 1-2 hours. The normal temperature of Timken bearing varies with the heat capacity, heat dissipation, speed and load of the machine.Advantages of NTN bearing in application
  •  If the lubrication and installation parts are appropriate, the Timken 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. Advantages of NTN bearing in application
  • According to a large number of test data, since the temperature is affected by lubrication, speed, load and environment, the value in the table only represents the approximate temperature range. Using the thermal sensor, the working temperature of Timken 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
  • In order to improve the actual fitting accuracy of NTN bearing during installation, it is necessary to accurately measure the fitting surface dimensions of the inner hole and outer circle of NTN bearing by using the measurement methods and tools that do not deform the NTN bearing. NTN bearing in
  • All the measurement items related to the inner diameter and outer diameter can be measured, and the measured data can be comprehensively analyzed. Based on this, the dimensions of the installation parts of Japanese NTN bearing that accurately match the shaft and seat hole can be measured. Advantages of NTN bearing in application
  • When actually measuring the corresponding size and geometry of the matched shaft and seat hole, it shall be carried out under the same temperature conditions as when measuring NTN bearing in
  • In order to ensure a high actual matching effect, the roughness of the surface of the shaft and seat hole matched with the NTN bearing NTN bearing in  shall be as small as possible.
  • During the above measurement, two groups of marks indicating the direction of large deviation shall be made on the outer circle and inner hole of NTN bearing and the corresponding surface of shaft and seat hole on both sides close to the assembly chamfer, so as to align the large deviation of matching two sides with the same direction during actual assembly, so that the deviation of both sides can be partially offset after assembly.NTN bearing
  • The purpose of making two groups of orientation marks is to comprehensively consider the compensation of deviation, not only improve the rotation accuracy of the supports at both ends, but also partially eliminate the coaxiality error of the seat hole between the two supports and the journal at both ends. NTN bearing
  • The implementation of surface strengthening measures on the mating surface, such as sand blasting, using a precision plug with a slightly larger diameter to plug the primary inner hole, etc., NTN bearing in are conducive to improving the mating accuracy.Advantages of NTN bearing in application

Coaxiality of main fag bearing bore

  • Focusing on the development of sea and land oil and natural gas, the demand for oil refining, ethylene and three major synthetic materials (synthetic resin, synthetic rubber and synthetic fiber) of NTN bearing in will increase at a growth rate of 6% to 9%. Advantages of NTN bearing in application
  • This requires a large number of oil and gas pipeline gathering and transportation equipment and large-scale and efficient petrochemical equipment, focusing on the development of large-scale desert and marine oil exploration and drilling and production equipment, and large-scale complete sets of equipment with an annual output of more than 600000 tons of ethylene, 450000 tons of synthetic ammonia, 800000 tons of urea and chemical fiber. Advantages of NTN bearing in application
  • Therefore, the annual market demand of ina bearings, mechanical seals and packing static seals for petrochemical equipment supporting and maintenance will increase greatly.Advantages of NTN bearing in application
  • INA Bearing has developed a series of high temperature resistant sealed self-aligning roller ina bearings suitable for harsh environments. This Japanese ina bearing is characterized by rubber seals on both sides to ensure that the Japanese NTN bearing in Raceway operates in a dust-free environment and prevent grease leakage.Advantages of NTN bearing in application
  •  It has the advantages of dust-proof, waterproof, high temperature and high pressure resistance, heavy load and other advantages. It also has open type and high temperature resistant ina bearings suitable for specific applications, It can operate continuously under the working condition of – 40 to + 350 degrees, which is the attractive feature of NTN bearing in and can not be replaced in many demanding applications. Fag bearing inner diameter
  • Before measurement, the fag bearing shall be installed according to the regulations and the bolts of fag bearing cover shall be tightened according to the specified torque. The inner diameter gauge shall be used to measure after the reference dimension is measured with the outer diameter micrometer. Advantages of NTN bearing in application
  • The thinning area shall be avoided during measurement. The difference between the fag bearing inner diameter and the corresponding journal outer diameter is the fit clearance.Advantages of NTN bearing in application
  • The coaxiality error of the inner hole of the main fag bearing is mainly caused by the coaxiality error of the bearing hole, and the coaxiality error of the bearing hole is caused by the deformation of the cylinder block. When the radial circular runout of the main journal is within the specified tolerance, check the bite mark of the main journal and fag bearing. Advantages of NTN bearing in application
  • If the bite mark position of each main fag bearing is obviously inconsistent, it indicates that the coaxiality error is large, which can be solved by scraping, boring fag bearing or replacing cylinder block, otherwise it is difficult to ensure the normal operation of the engine.Advantages of NTN bearing in application
  • JapanNTN bearing in thickness
  • The fixed probe of the outside micrometer is changed from a plane to a spherical surface, which can be used to measure the thickness of fag bearing. The thickness of fag bearing shall be controlled within 0.005 ~ 0.010 mm generally, otherwise the inner diameter of fag bearing will exceed the tolerance. Japan fag bearing has slight thinning near the opening, which should be paid attention to during measurement.Advantages of NTN bearing in application
  • The fit tightness is guaranteed by the free spring opening of fag bearing and the height of surplus surface.Advantages of NTN bearing in application
  • The method of measuring the height of the remaining surface
  • Assemble the fag bearing as required, tighten the fag bearing cover bolts to the specified torque, loosen one of the bolts, and measure the clearance at the fag bearing cover interface with a feeler gauge, which shall be within the range of 0.05 ~ 0.15mm.Advantages of NTN bearing in application

Fit tightness between fag bearing and bearing hole

  • Whether the outer packaging is clear: generally, the brands of the main factory have their own special designers to design the outer packaging, and arrange the factories with qualified production conditions for production. Therefore, the packaging is very clear from line to color block – unambiguous.Advantages of NTN bearing in application
  • Whether the steel seal words are clear: the SKF Bearing body will be printed with brand words, labels, etc. 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. Advantages of NTN bearing in application
  • 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.Advantages of NTN bearing in application
  • Whether there is any noise: hold the inner sleeve of SKF Bearing with your left hand, and turn the outer sleeve with your right hand to hear whether there is 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 SKF 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.Advantages of NTN bearing in application
  • Whether there is muddy oil on the surface: this should be paid special attention when purchasing SKF bearings. As the current domestic antirust technology is not particularly good, it is easy to leave thick oil stains when antirust the SKF Bearing body, which is sticky and thick when holdingNTN bearing in hand. Advantages of NTN bearing in application
  • However, there is almost no trace of antirust oil on the SKF Bearing originally imported from abroad. However, a particularly careful expert said that the imported SKF Bearing smells like a smell. It must be under antirust oil, but it can’t be seen.Advantages of NTN bearing in application
  • Whether the chamfer is uniform: the so-called chamfer of SKF Bearing, that is, the junction of horizontal and vertical surfaces. Due to the limitation of production technology, the fake SKF Bearing is not handled satisfactorily at these corners.Advantages of NTN bearing in application
  • In the grinding process of IKO bearing, its working surface is ground by high-speed rotating grinding wheel. Therefore, if the equipment is not operated and adjusted according to the operation instructions during grinding, various defects will appear on the working surface of IKO bearing, which will affect the overall quality of IKO bearing. During precision grinding of IKO bearing, due to high requirements for roughness, the grinding marks on the working surface can often be observed with the naked eye. The surface grinding marks mainly include the following types.Advantages of NTN bearing in application

Show signs of cross helix NTN bearing

  • The reason for this trace is mainly due to the poor flatness of the bus of the grinding wheel and the concave convex phenomenon. During grinding, the grinding wheel is only in partial contact with the workpiece. When the workpiece or grinding wheel moves back and forth for several times, the cross helix will reappear in the performance of the workpiece and can be observed by the naked eye. Advantages of NTN bearing in application
  • The pitch of these spiral lines is related to the speed of the worktable and the rotating speed of the worktable. At the same time, it is also related to the non parallelism of the axis line of the grinding wheel and the guide rail of the worktable.Advantages of NTN bearing in application
  • Before scraping and grinding, carefully check whether the journal is smooth and whether there are defects such as rust and bruise, and try to eliminate them first; Then, check the contact between the journal and the shaft. The inspection method is to apply a thin layer of display agent (such as red lead powder, red Qian oil, etc.) Advantages of NTN bearing in application
  • on the shaft diameter, then install the journal in the Koyo bearing, rotate it two or three times in the positive and negative directions by hand, take out the shaft, and check the distribution of coloring points on the Koyo bearing. If the distribution of coloring points is abnormal or does not move at all, start scraping and grinding.Advantages of NTN bearing in application
  • During scraping and grinding, the principle of first heavy and then light, scraping heavy and leaving light, scraping large and leaving small shall be adopted according to the situation. For the first few times, the hand can be heavier and scrape off more metal, so as to achieve better contact quickly. When the contact area reaches 50%, it should be scraped gently. Advantages of NTN bearing in application
  • After each scraping, wipe the tile surface, apply the display agent on the journal for inspection, and then scrape and grind according to the contact condition until it meets the technical requirements. Indicator can be used for scraping and grinding inspection, but for precision Koyo bearings with high requirements for contact points, indicator cannot be used in the later stage of scraping and grinding.Advantages of NTN bearing in application
  •  Because the coloring point on the Koyo bearing is too large after coating the display agent, it is difficult to judge the actual contact situation. At this time, the journal can be wiped clean, directly put in the Koyo bearing for verification, and then take out the shaft. It can be seen that the bright spot on the Koyo bearing is the contact point. Then scrape and grind the bright spot until it meets the technical requirements.Advantages of NTN bearing in application
  • During scraping and grinding, not only the contact point shall meet the technical requirements, but also the side clearance and contact angle shall meet the technical requirements. Generally, the contact point shall be studied first, and the contact angle shall be taken into account at the same time, and then the side clearance shall be scraped. However, there should be no obvious boundary between the contact part and the non-contact part. When wiping the surface of Koyo bearing with fingers, no trace should be detected.Advantages of NTN bearing in application

The first is to identify and check the rolling sound of NTN bearing

  • We can use sound detector to check the rolling sound and sound quality of Timken bearing in operation. Because Timken bearing will emit abnormal sound and irregular sound even if there is slight peeling and other damage, it can be distinguished by sound detector to prevent it in advance.
  • Secondly, the vibration of Timken bearing in operation is identified and checked
  • Timken bearing vibration is very sensitive to the damage of Timken bearing. For example, peeling, indentation, corrosion, crack, wear, etc. will be reflected in the vibration measurement of Timken bearing. Therefore, the vibration can be measured by using a special Japanese Timken bearing vibration meter (frequency analyzer, etc.), and the specific situation of abnormality can not be inferred through frequency division.
  •  The measured values are different due to the service conditions of Timken bearing or the installation position of sensor, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.
  • After that, check according to the temperature of Timken bearing
  • The temperature of Timken bearing can generally be inferred from the temperature outside the Timken bearing chamber in Japan. It is more appropriate if the outer ring temperature of Timken bearing can be directly measured by oil hole. 
  • Usually, the temperature of Timken bearing rises slowly with the start of operation and reaches a stable state after 1-2 hours. The normal temperature of Timken bearing varies with the heat capacity, heat dissipation, speed and load of the machine.
  •  If the lubrication and installation parts are appropriate, the Timken 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. 
  • According to a large number of test data, since the temperature is affected by lubrication, speed, load and environment, the value in the table only represents the approximate temperature range. Using the thermal sensor, the working temperature of Timken 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
  • In order to improve the actual fitting accuracy of NTN bearing during installation, it is necessary to accurately measure the fitting surface dimensions of the inner hole and outer circle of NTN bearing by using the measurement methods and tools that do not deform the NTN bearing. NTN bearing
  • All the measurement items related to the inner diameter and outer diameter can be measured, and the measured data can be comprehensively analyzed. Based on this, the dimensions of the installation parts of Japanese NTN bearing that accurately match the shaft and seat hole can be measured. When actually measuring the corresponding size and geometry of the matched shaft and seat hole, it shall be carried out under the same temperature conditions as when measuring NTN bearing.NTN bearing
  • In order to ensure a high actual matching effect, the roughness of the surface of the shaft and seat hole matched with the NTN bearing shall be as small as possible.NTN bearing
  • During the above measurement, two groups of marks indicating the direction of large deviation shall be made on the outer circle and inner hole of NTN bearing and the corresponding surface of shaft and seat hole on both sides close to the assembly chamfer, so as to align the large deviation of matching two sides with the same direction during actual assembly, so that the deviation of both sides can be partially offset after assembly.NTN bearing
  • The purpose of making two groups of orientation marks is to comprehensively consider the compensation of deviation, not only improve the rotation accuracy of the supports at both ends, but also partially eliminate the coaxiality error of the seat hole between the two supports and the journal at both ends. NTN bearing
  • The implementation of surface strengthening measures on the mating surface, such as sand blasting, using a precision plug with a slightly larger diameter to plug the primary inner hole, etc., are conducive to improving the mating accuracy.NTN bearing