Causes of universal joint bearing failure
2022年4月12日
Solution and principle of IKO high temperature bearing noise
2022年4月12日

Precautions for prolonging the service life of IKO one-way bearing

  • If the flow IKO bearing is used in harsh environment, the sealing ring and sealing cover of one-way bearing are essential, because they can prevent dirt from invading and prolong the service life of the bearing. The roll is usually supported by four rows of sealed bearings in the rolling mill. When in use, it is required to bear strong impact load and intrusion of water and debris.Precautions for prolonging the service life of IKO one-way bearing
  • Under severe lubrication conditions, the load of IKO bearing is increased by 34%, and it has high reliability, long service life and easy maintenance. This performance improvement is the result of optimizing mechanical design, adopting new materials and patented sealing technology. Precautions for prolonging the service life of IKO one-way bearing
  • Compared with the traditional roller neck bearing, this sealed roller neck one-way bearing not only increases the basic rated dynamic load by 34%, but also prolongs the service life by 2.7 times.Precautions for prolonging the service life of IKO one-way bearing
  • The second factor to improve the performance of IKO bearing with super capacity sealing and cleaning roll neck. This material solves the problem of one-way bearing life under the condition of pollution or insufficient lubrication. Experience has shown that under contaminated operating conditions, bearings are vulnerable to debris intrusion and contamination. Precautions for prolonging the service life of IKO one-way bearing
  • The research shows that the bearing life under the condition of pollution or edge lubrication can be improved by improving the microstructure of bearing steel. The new sealing structure is the main seal and hole seal.Precautions for prolonging the service life of IKO one-way bearing
  • Regularly check the oil level and quality of lubricating oil. Generally, the normal oil level should be within 1 / 3-2 / 3 of the equipment oil level window or mark. The oil replenishment mode is the oil cup, and the displayed oil level only represents the oil replenishment capacity, while the oil level of IKO bearing box meets the operation requirements. If the oil level in the oil cup is lower than 1 / 4 of its total volume, oil replenishment can be considered.Precautions for prolonging the service life of IKO one-way bearing
  • Check and replenish oil methods. Take a small amount of lubricating oil as a sample and compare it with fresh lubricating oil. Competent units can consider oil quality test to ensure that the oil quality is qualified. If the sample looks like a cloud, it may be the result of mixing with water, which is often called oil emulsification. At this time, the lubricating oil should be replaced. Precautions for prolonging the service life of IKO one-way bearing
  • If the sample becomes darker or thicker, it may indicate that the lubricating oil has begun to carbonize, and the old lubricating oil should be completely replaced. If possible, flush the oil circuit with fresh lubricating oil. When replacing the lubricating oil, ensure that the new and old models of the replaced lubricating oil are the same, and supplement it to meet the required oil level.Precautions for prolonging the service life of IKO one-way bearing
  • According to the inspection results, if IKO bearing is found to be damaged or abnormal, please find out the causes and formulate countermeasures according to the damage phenomenon of one-way bearing. In addition, according to the inspection results, if there are the following defects, the bearing can no longer be used and needs to be replaced with a new bearing.Precautions for prolonging the service life of IKO one-way bearing
  • How to ensure the normal operation of the bearing in the application process, how to make the bearing free of damage and make the bearing life longer. Let’s explain the precautions to ensure the reliable operation of the bearing.
  • In general, the precautions for ensuring the reliable operation of IKO bearing are as follows:Precautions for prolonging the service life of IKO one-way bearing
  • Any one of the inner and outer rings, rolling elements and cage has cracks and fragments.Precautions for prolonging the service life of IKO one-way bearing
Precautions for prolonging the service life of IKO one-way bearing
  • Any one of the inner and outer rings and rolling elements has peeling.
  • The raceway surface, retaining edge and rolling element are significantly jammed.
  • The cage is seriously worn or the rivets are loose.
  • The raceway surface and rolling element are rusty and scarred.
  • The rolling surface and rolling body have significant indentation and indentation.
  • There is creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.Precautions for prolonging the service life of IKO one-way bearing
  • Overheated and discolored.Precautions for prolonging the service life of IKO one-way bearing
  • The sealing ring and dust cover of grease sealed one-way bearing are damaged to cause serious damage
  • In the grinding process of IKO bearing, a small amount of energy is consumed in the contact area between the grinding wheel and the workpiece, and a small amount of grinding heat occurs, resulting in an instant low temperature in the part of the grinding area. It can be found that the instantaneous temperature in the grinding area can be as high as 1000 ~ 1500 ℃ in 0.1 ~ 0.001 MS by deducing and calculating the practical heat transfer formula of linear static heat source or measuring the instantaneous temperature under the test conditions by using the red inner line method and thermocouple method. Precautions for prolonging the service life of IKO one-way bearing
  • Such an instant low temperature is enough to cause low-temperature oxidation, amorphous structure, low-temperature tempering, secondary quenching, and even burn cracking of the outer layer with a certain depth on the surface of the task.Precautions for prolonging the service life of IKO one-way bearing
  • The major factor is the surface oxide layer
  • In an instant, the steel surface under the action of low temperature acts with oxygen in the air to form an extremely thin (20 ~ 30nm) thin layer of iron oxide. It is worth noting that there is a corresponding relationship between the thickness of oxide layer and the total thickness of surface grinding transformation layer. This explains that the oxide layer thickness is indirectly related to the grinding process, which is an important mark of grinding quality.Precautions for prolonging the service life of IKO one-way bearing
  • The second major factor is the amorphous structure layer
  • When the instantaneous low temperature in the grinding area makes the surface of the workpiece reach the melting state, the molten metal molecular flow is evenly coated on the surface of the task and cooled by the base metal at a very fast speed to form an extremely thin amorphous structure layer. It has high hardness and toughness, but it is only about 10nm and can be easily removed in fine grinding.Precautions for prolonging the service life of IKO one-way bearing
  • The third major factor is the low temperature tempering layer
  • The instantaneous low temperature in the grinding area can make the surface heated to a temperature higher than the tempering heating of the workpiece within a certain depth (10 ~ 100nm). Precautions for prolonging the service life of IKO one-way bearing
  • Under the condition of not reaching the austenitizing temperature, with the progress of the heated temperature, the microstructure change of re tempering or low-temperature tempering absolutely corresponding to the heating temperature will occur layer by layer, and the hardness will also decrease. The higher the heating temperature, the fiercer the hardness drop.
  • Judgment of bearing:
  • treatment.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • How to protect it and prolong its service life, the following matters should be paid attention to when using the bearing:
  •  Precautions for prolonging the service life of IKO one-way bearing
  • The installation and adjustment of low-noise NTN bearing can also follow the grouping method of long-life bearing, so that the matching interference is more consistent, and the clearance of NTN bearing is also more consistent. It is hoped that the matching interference will take a smaller value within the possible range, so as to ensure that the deformation of NTN bearing raceway is small, and the noise caused by the passage of rolling element will be reduced.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • The clearance has a great influence on the noise. The ideal state is that when the NTN bearing is in the high temperature state of operation, the clearance value is just zero. The methods to judge the excessive clearance are: the axial displacement of the bearing in the static state, the reciprocating amplitude is large, and a large and turbid noise is emitted during operation.
  • If there is an annoying shriek during operation, it indicates that the preload of NTN bearing is too large and the bearing has too large pre interference. The preload should be slightly relaxed. If the clearance is too large, the two bearing rings can be slightly offset along the axial direction: it not only reduces the clearance, but also increases the axial rigidity and reduces the bearing noise.
  • When the rolling element enters the no-load area, it will slip or move left and right, which will not only increase the noise, but also cause wear. Small clearance and large axial stiffness can eliminate this phenomenon. However, the clearance should not be too small, so as not to cause excessive temperature and shorten service life.
  • Sometimes, due to the large working temperature range of the main engine or the large dispersion of the size between the shaft and the bearing seat hole, it is impossible to obtain a more appropriate clearance at one time. In this case, the elastic constant pressure preloading method can be adopted for the outer ring of NTN bearing.
  • Koyo imported bearing, in most cases, working state: use appropriate clearance. According to different uses, and in the assembly bearing, the bearing is advanced to make the internal stress and make the negative bearing clearance used. This method is called using preload. More suitable, such as angular contact ball bearings, tapered roller bearings, two family bearings, bearing clearance, can be adjusted.
  • Main purpose of preloading: the main purpose of preloading can be proved by some representative examples:
  • In the correct direction and radial position, the axial direction determines the shaft and suppresses the runout of the shaft.
  • Increase the rigidity of the bearing. Machine tool spindle bearing, bicycle and small agent bearing, gear differential.
  • To prevent the axial direction of vibration and resonance of different sounds. Small motor bearings.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • Suppresses scrolling, rotating slides, sliding and rotating revolution slides. High speed rotating center thrust bearing, thrust ball bearing.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • Ring and keep rolling in the correct position. Thrust ball bearing, thrust spherical roller bearing, and horizontal shaft.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • Preloading method: the pre positioning of load is the preloading method that the relative position of Koyo imported bearing shaft will not change in use. Here is an example:
  • In oder to implement the difference before the adjustment of the width between preloads or the fastening method after the axial clearance of bearings.
  • Adjust the size of the pad, gasket and bearing preload to make way.
  • The method adopted after tightening the screw and nut clearance with adjustable shaft direction. In this case, adjust the friction torque on the hand side with an appropriate preload to determine the start.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • The so-called constant pressure preload is the use of coil springs and Belleville springs to give the load-bearing of appropriate preparation methods. When in use, even if the relative position of the Koyo inlet bearing changes, the preloading method. When in use, it will even change its relative position, and the preload can be maintained at a certain level.
  • 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. Note: the engine oil is filtered before use.
  • 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 the application of small bearings.
  •  Precautions for prolonging the service life of IKO one-way bearing
  • When inspecting Koyo imported bearings, never expose the bearings to pollutants or moisture. If the work is interrupted, cover the machine with oil paper, plastic sheet or similar materials.
  • Tile surface corrosion: abnormal concentration of non-ferrous metal elements is found by spectral analysis; Submicron wear particles with many non-ferrous metal components appear in ferrography; The water content and acid value of lubricating oil exceed the standard.
  • Journal surface strain: there are ferrous cutting abrasive particles or black oxide particles in the ferrogram, and there is tempering color on the metal surface.
  • Journal surface corrosion: the spectral analysis found that the concentration of iron was abnormal. There were many submicron particles of iron in the ferrogram, and the water content or acid value of lubricating oil exceeded the standard.
  • Surface strain: cutting abrasive particles are found in the Ferrograph, and the abrasive particles are composed of non-ferrous metals.
  • Fretting wear of tile back: abnormal iron concentration is found by spectral analysis. There are many iron components, submicron wear particles, abnormal moisture and acid value of lubricating oil in the ferrogram.
  • The judgment of whether the bearing is available is mainly determined by considering the degree of bearing damage, mechanical performance, importance, operating conditions and the period until the next maintenance. Precautions for prolonging the service life of IKO one-way bearing
  • If there are the following defects, it can no longer be used, and the rolling mill bearing must be replaced with a new one. There are cracks or notches on any one of the inner ring, outer ring, rolling element and cage.Precautions for prolonging the service life of IKO one-way bearing

Precautions for prolonging the service life of IKO one-way bearing

  • Any one of the ferrule and rolling element is broken.
  • There are significant card injuries on the rolling track surface, retaining edge and rolling body.Precautions for prolonging the service life of IKO one-way bearing
  • Significant wear of cage or significant relaxation of rivets.
  • There is rust and damage on the raceway surface and rolling element.
  • There are serious indentations and scratches on the raceway surface and rolling element.
  • There is obvious creep on the inner diameter surface of the inner ring or the outer diameter surface of the outer ring.
  • Discoloration caused by heat is obvious.
  • The bearing, sealing ring or dust cover of the rolling mill sealed with grease are obviously damaged.
  • The inspection of bearing in operation is very important and can not be ignored. It mainly checks the rolling sound, vibration, temperature, lubrication state and so on. Let’s first briefly introduce the rolling sound of IKO bearing. The size and sound quality of rolling sound should be checked with a sound detector. Precautions for prolonging the service life of IKO one-way bearing
  • The problem will be accurately judged with advanced tools. Even if the bearing has slight peeling and other damage, it will emit abnormal sound and irregular sound, which can be distinguished with a sound detector.Precautions for prolonging the service life of IKO one-way bearing
  • Then check the vibration of the bearing to see if the damage of the bearing is very sensitive. Whether peeling, indentation, corrosion, crack, wear, etc. will be reflected in the bearing vibration measurement. Therefore, the vibration can be measured by using a special automobile bearing vibration measuring instrument (frequency analyzer, etc.), and the specific situation of abnormality can not be inferred by frequency division. Precautions for prolonging the service life of IKO one-way bearing
  • However, the values measured by each machine are different due to the service conditions of IKO 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.Precautions for prolonging the service life of IKO one-way bearing
  • When using the bearing, keep the surrounding environment clean and do not stick sweat and dirt. It should be used by staff who know the bearing. It is especially necessary to be careful of acid, indentation, insufficient damage, etc. 
  • In order to ensure the use function of the bearing, the bearing shall be protected, maintained and inspected on schedule according to the homework standard of the equipment, including monitoring the operation condition, making up the smoothing agent and checking the assembly on schedule.Precautions for prolonging the service life of IKO one-way bearing
  • Bearings shall not be stored directly on the ground (more than 30cm above the ground) to prevent direct light and cold walls. In order to prevent rust, keep it in an environment with a temperature of about 20 ℃ and a humidity of 65%. The automobile bearing is arranged in an acidic atmosphere, which is easy to rust and change color. Precautions for prolonging the service life of IKO one-way bearing
  • Wipe the bearing, shaft and shell with gloves and kapok return wire. The reason for the abnormality is that the waste enters the outside of IKO bearing and common departments, so it is necessary to be careful.
  • The measurement deviation of bearing shall be 10% of public service as follows. The general measurement deviation is 10% ~ 33% of the military merit difference. With the progress of public service grade, the larger the proportion of deviation is, that is, the smaller the public service is, the higher the proportion of deviation is. 
  • However, it is difficult to reach 10% when the public service of automobile bearing is more than it5. Measurement deviation not only means that the inspection of public service can be relaxed by 10%, but also to give a certain safety margin to ensure that users pass the acceptance according to the scale.Precautions for prolonging the service life of IKO one-way bearing
  • Before inspection, the bearing must be arranged on a metal plate in the inspection occasion in cooperation with the measuring block, scale piece and measuring instrument used for inspection, so as to quickly homogenize the temperature and room temperature of these objects. The IKO bearings that have been dried or dried should be dripped with smooth oil according to the regulations and entrusted for inspection immediately. 
  • At this time, there is no oil film shelter outside the bearing. In the whole inspection process, it is not allowed to fight directly and the skin of hands. The operator should wear clean gloves or apply antirust agent on his hands, but it is necessary to prevent the antirust agent on his hands from mixing into the rotation profile of automobile bearings, otherwise the measurement results will be faulty.
  • Generally, the temperature of the bearing can be inferred from the temperature outside the bearing chamber, because this is relatively simple. It is more appropriate if the oil hole can be used to directly measure the temperature of the outer ring of the bearing. 
  • Usually, the temperature of the bearing rises slowly with the start of operation and reaches a stable state after 1-2 hours. The normal temperature of IKO 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.Precautions for prolonging the service life of IKO one-way bearing
  •  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 thermal sensor should be used to monitor the working temperature of automobile bearings at any time, and automatically alarm the user or stop when the temperature exceeds the specified value to prevent the occurrence of shaft combustion accidents.