Anti rust management and new anti rust technology of Koyo bearing
Anti rust management and new anti rust technology of Koyo bearing
2022年5月2日
How to reduce the influence of temperature and vibration on Koyo imported bearings
How to reduce the influence of temperature and vibration on Koyo imported bearings
2022年5月4日

Effect of cleanliness on service performance of NTN imported bearings

The cleanliness of NTN imported bearings has a great impact on the NTN imported bearings. 

  • NTN imported bearings have conducted special tests for this purpose, and the results show that the difference is several times or even more than dozens of times.
  •  The higher the cleanliness of NTN imported bearing, the longer the service life. The tests of others show that the lubricating oil with different cleanliness has a great impact on the service life of ball NTN imported bearing. Therefore, improving the cleanliness of lubricating oil can prolong the service life of NTN imported bearings. In addition, if the dirt particles in lubricating oil are controlled below 10um, the service life of bearings will increase several times.Effect of cleanliness on service performance of NTN imported bearings

Influence on vibration and noise NTN imported bearings

  • The test results of NTN imported bearing test center show that the cleanliness seriously affects the vibration level of the bearing, especially in the high frequency band. The vibration speed value of NTN imported bearing with high cleanliness is low, especially in high frequency band.Effect of cleanliness on service performance of NTN imported bearings
  • The influence of dust in NTN imported bearing grease on noise has been tested. It is proved that the more dust, the greater the noise.Effect of cleanliness on service performance of NTN imported bearings.Effect of cleanliness on service performance of NTN imported bearings.Effect of cleanliness on service performance of NTN imported bearings
  • Influence on lubrication performance the decrease of the cleanliness of NTN imported bearings will not only affect the formation of lubricating oil film, but also cause the deterioration of lubricating grease and accelerate its aging, thus affecting the decline of lubricating performance of lubricating grease.Effect of cleanliness on service performance of NTN imported bearings.Effect of cleanliness on service performance of NTN imported bearings

Deep groove ball bearing, contact ball bearing, NTN imported bearings

  • Rotation accuracy the type of bearing with the required rotation accuracy [the dimensional accuracy and rotation accuracy of the bearing have been standardized by GB according to the bearing type]? The spindle of machine tool, gas turbine and control machine require high rotation accuracy, high speed and low friction respectively. At this time, bearings with accuracy above grade 5 should be used.Effect of cleanliness on service performance of NTN imported bearings
  • The installation and disassembly frequency and methods of regular inspection of installation and disassembly. When the installation and disassembly are frequent, the cylindrical roller bearing with separable inner ring and outer ring, needle roller bearing and tapered roller bearing are more convenient.Effect of cleanliness on service performance of NTN imported bearings
  • The speed can adapt to the NTN imported bearing type of mechanical speed [the limit value benchmark of bearing speed is expressed by the limit speed, and its value is contained in the bearing size table] the limit speed of bearing is not only taken from the bearing type, but also limited to the bearing size, cage type, accuracy grade, load conditions and lubrication mode.Effect of cleanliness on service performance of NTN imported bearings
  •  Therefore, these factors must be considered in the selection. Ina bearing temperature is too high: when the mechanism is running, the part where the bearing is installed is allowed to have a certain temperature. When touching the mechanism shell by hand, it should be normal not to feel hot. Otherwise, it indicates that the bearing temperature is too high.Effect of cleanliness on service performance of NTN imported bearings
  • The reasons for the high temperature of INA Bearing are: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; The mechanism assembly is too tight (insufficient clearance); The bearing assembly is too tight; The bearing race rotates on the shaft or in the shell; Excessive load; Broken bearing cage or rolling element, etc.Effect of cleanliness on service performance of NTN imported bearings
  • INA Bearing Noise: the rolling bearing is allowed to make slight running noise during operation. If the noise is too loud or there is abnormal noise or impact sound, it indicates that the bearing is faulty. The reason for the noise of rolling bearing: it is more complex. It is the wear of the mating surfaces of the inner and outer rings of the bearing. 
  • Due to this kind of wear, the matching relationship between INA Bearing and shell, bearing and shaft is damaged, resulting in the axis deviation from the correct position and abnormal noise when the shaft moves at high speed. When the bearing is tired, the metal on its surface will peel off, which will also increase the radial clearance of the bearing and produce abnormal noise. Insufficient bearing lubrication, dry friction and bearing breakage will produce abnormal sound. Effect of cleanliness on service performance of NTN imported bearings
  • After the bearing is worn and shaken, the cage is loose and damaged, which will also produce abnormal noise and damage to the bearing. During the disassembly and inspection of rolling bearing, the fault and damage cause of bearing can be judged according to the damage of bearing.Effect of cleanliness on service performance of NTN imported bearings
  • Metal spalling on the raceway surface: the rolling element of INA Bearing and the raceway surfaces of inner and outer rings are subjected to periodic pulsating load, resulting in periodic contact stress. When the number of stress cycles reaches a certain value, it will be produced on the working surface of rolling element or inner and outer race raceway
  • Fatigue peeling. If the load of ina bearing is too large, this fatigue will be exacerbated. 
  • In addition, improper bearing installation and shaft bending will also produce raceway spalling. The fatigue spalling of bearing raceway will reduce the operation accuracy of shaft and cause vibration and noise of mechanism.Effect of cleanliness on service performance of NTN imported bearings
  • INA Bearing burn: the burned bearing has a return fire color on its raceway and rolling element. The causes of burns are generally insufficient lubrication, unqualified or deteriorated lubricating oil quality, and tight assembly of ina bearings.Effect of cleanliness on service performance of NTN imported bearings
  • Plastic deformation: uneven pits appear on the contact surface between raceway and roller of INA Bearing, indicating plastic deformation of bearing. The reason is that under the action of large static load or impact load, the local stress on the working surface of the bearing exceeds the yield limit of the material, which generally occurs on ina bearings rotating at low speed.Effect of cleanliness on service performance of NTN imported bearings
  • INA Bearing Race crack: the crack of bearing race may be caused by too tight bearing fit, loose bearing or inner ring, deformation of INA Bearing containing parts, poor surface processing of ina bearing installation, etc.Effect of cleanliness on service performance of NTN imported bearings
  • Broken cage: the reason is insufficient lubrication, broken rolling element, seat ring skew, etc.Effect of cleanliness on service performance of NTN imported bearings
  • The metal of the cage adheres to the rolling element, which may be due to the rolling element being stuck in the cage or insufficient lubrication.Effect of cleanliness on service performance of NTN imported bearings
  • After the installation of fag inlet bearing, in order to check whether the installation is correct, operation inspection shall be carried out. Small machinery can be rotated by hand to confirm whether it rotates smoothly. The inspection items include poor operation caused by foreign matters, scars and indentation, unstable torque caused by poor installation and poor processing of mounting base, excessive torque caused by too small clearance, installation error and sealing friction, etc. If there is no abnormality, the power operation can be started.Effect of cleanliness on service performance of NTN imported bearings

Large machinery cannot rotate manually, NTN imported bearings

  • so the power shall be cut off immediately after no-load start, and the machinery idles. Check whether there is vibration, noise, contact of rotating parts, etc. after confirming that there is no abnormality, enter the power operation.Effect of cleanliness on service performance of NTN imported bearings
  • Power operation, starting from no-load and low speed, slowly increase to the rated operation under the specified conditions. During the test run, the inspection items are whether there is abnormal sound, the temperature change of fag inlet bearing, lubricant leakage or discoloration, etc. If any abnormality is found, stop the operation immediately, check the machinery, and remove the bearing for inspection if necessary.Effect of cleanliness on service performance of NTN imported bearings
  • The temperature of fag inlet bearing can generally be inferred from the external temperature of bearing pedestal. However, it is more accurate to directly measure the temperature of the bearing outer ring by using the oil hole. The bearing temperature rises gradually from the beginning of operation, and the temperature is usually stable after 1 ~ 2 hours. Effect of cleanliness on service performance of NTN imported bearings
  • If the bearing is not installed properly, the temperature will rise sharply, resulting in abnormal high temperature. The reasons are too much lubricant, too small bearing clearance, poor installation, excessive friction of sealing device, etc. In the case of high-speed rotation, the wrong selection of fag imported bearing structure and lubrication mode is also the reason.Effect of cleanliness on service performance of NTN imported bearings
Effect of cleanliness on service performance of NTN imported bearings

The rotating sound of fag imported bearing is checked with stethoscope, NTN imported bearings

  • and there are strong metal noise, abnormal sound, irregular sound and other abnormalities. The reasons are poor lubrication, poor accuracy of shaft or bearing seat, bearing damage, foreign matter intrusion, etc. Effect of cleanliness on service performance of NTN imported bearings
  • The function of SKF imported bearing coordination is to make the stationary ring and rotating ring of SKF imported bearing consolidate with the stationary part (usually bearing seat) and rotating part (usually shaft) of the installation part respectively, so as to realize the basic task of transmitting load in the rotating state and limiting the position of the moving system relative to the stationary system.Effect of cleanliness on service performance of NTN imported bearings
  • On the shaft and in the bearing pedestal, SKF imported bearings are required to fix their positions in three directions: radial, axial and tangent directions. Radial and tangential positioning is realized through tight fit of SKF imported bearing ring, and tight fit is adopted for axial positioning only in a few cases; Generally, axial limit parts, such as end caps and retaining rings, are used to limit the axial position within the clearance range.Effect of cleanliness on service performance of NTN imported bearings
  •  When some people use Koyo imported bearings, they make major mistakes in the installation process, resulting in bearing damage. In view of this problem, I’d like to summarize some methods for the correct assembly and disassembly of Koyo imported bearings today, hoping to be helpful to you.Effect of cleanliness on service performance of NTN imported bearingsEffect of cleanliness on service performance of NTN imported bearings
  • The resultant force of force application shall pass through the axis of Koyo imported bearing as far as possible, which requires that the force application point shall be uniform, symmetrical and stable, and the force shall be applied through the spherical surface or parallel to the axis.Effect of cleanliness on service performance of NTN imported bearings
  • The force should be applied stably and evenly without impact, which requires the use of oil pressure or tools that can apply stable tension or pressure. When hammering has to be used, it should also be buffered by soft metal without chip falling, such as copper sleeve, and the knocking force should be as light as possible. Hammer with a copper bar or hammer.Effect of cleanliness on service performance of NTN imported bearings
  • Avoid applying force through the rolling element, which requires applying force through the inner ring when installing and removing the inner ring (shaft ring) and through the outer ring when installing and removing the outer ring).Effect of cleanliness on service performance of NTN imported bearings
  • The drag force shall be maintained to a proper extent. For example, when installing the bearing, stop the force when the bearing is just installed in the correct position, and ensure that the end face of the ferrule (washer) is against the seat hole or the shoulder end face of the shaft, which can not be squeezed too tightly or installed in place. At present, Timken imported bearings are frequently damaged, so how to judge the damage is more important for us.Effect of cleanliness on service performance of NTN imported bearings

Timken inlet bearing vibration NTN imported bearings

  • Timken imported bearing vibration is very sensitive to bearing damage, such as peeling, indentation, corrosion, crack, wear, etc., which will be reflected in the bearing vibration measurement. Therefore, the vibration can be measured by using a special Timken imported bearing vibration meter (frequency analyzer, etc.), and the specific abnormal situation can not be inferred by frequency division. Effect of cleanliness on service performance of NTN imported bearings
  • The measured values are different due to the service conditions of Timken imported bearings or the installation position of sensors. Therefore, it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.Effect of cleanliness on service performance of NTN imported bearings

Timken inlet bearing temperature NTN imported bearings

  • The temperature of the bearing can generally 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 the outer ring of Timken inlet bearing.Effect of cleanliness on service performance of NTN imported bearings
  • Generally, the temperature of the bearing starts to rise slowly with the operation of Timken imported bearing, and reaches a stable state after 1-2 hours. The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are appropriate, the temperature of Timken inlet bearing will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken.Effect of cleanliness on service performance of NTN imported bearings
  • The thermal sensor can monitor the working temperature of Timken imported bearing at any time, and automatically alarm or stop when the temperature exceeds the specified value to prevent the occurrence of combustion shaft accident.Effect of cleanliness on service performance of NTN imported bearings
  • High temperature often indicates that Timken imported bearing is in abnormal condition. High temperature is also harmful to the lubricant of the bearing. Effect of cleanliness on service performance of NTN imported bearings
  • Sometimes Timken imported bearing overheating can be attributed to the lubricant of the bearing. If the temperature of Timken imported bearing exceeds 125 ℃ for a long time, the service life of Timken imported bearing will be reduced. Effect of cleanliness on service performance of NTN imported bearings
  • 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.Effect of cleanliness on service performance of NTN imported bearings
  • Therefore, it is necessary to continuously monitor the temperature of Timken inlet bearing, 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.Effect of cleanliness on service performance of NTN imported bearings
  • The temperature of the bearing can be measured accurately according to the unit of TiMn or the temperature of the bearing, for example, the temperature of the bearing can be measured regularly by the thermometer of Ken type.Effect of cleanliness on service performance of NTN imported bearings
  • Important Timken imported bearings mean that when they are damaged, the equipment will be shut down. Therefore, such bearings should be equipped with temperature detectors.Effect of cleanliness on service performance of NTN imported bearings
  • Under normal circumstances, Timken imported bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days. The use factors of fag imported bearings mainly refer to whether the installation, adjustment, use and maintenance, maintenance and repair meet the technical requirements.Effect of cleanliness on service performance of NTN imported bearings

 According to the technical requirements for the installation, NTN imported bearings

  • use, maintenance and repair of fag imported bearings, monitor and inspect the load, speed, working temperature, vibration, noise and lubrication conditions borne by the running bearings.Effect of cleanliness on service performance of NTN imported bearings
  •  In case of abnormalities, immediately find out the causes and adjust them to restore them to normal. The installation condition is one of the primary factors in the use factors. The improper installation of fag imported bearings often leads to changes in the stress state between the parts of the whole set of bearings. Fag imported bearings operate in an abnormal state and end their service life early. Effect of cleanliness on service performance of NTN imported bearings
  • The internal factors mainly refer to the three factors that determine the quality of fag imported bearings, such as structural design, manufacturing process and material quality.Effect of cleanliness on service performance of NTN imported bearings
  • Design parameters of fag imported bearing: including the number of bearing rolling elements, wall thickness and clearance of ferrule, etc.Effect of cleanliness on service performance of NTN imported bearings
  • Manufacturing error of fag imported bearing parts: including surface roughness, cross grain and roundness difference of fag imported bearing raceway and rolling element. A large number of experimental studies show that the influence of Waviness on bearing vibration is dominant, while the influence of surface roughness and roundness is relatively small.Effect of cleanliness on service performance of NTN imported bearings
  • Working conditions of fag imported bearing: during the operation of the bearing, the load, speed and lubrication conditions have a great impact on the vibration of fag imported bearing.Effect of cleanliness on service performance of NTN imported bearings
  • Fag imported bearing installation parameters: the fit between bearing and shaft and bearing seat, deviation during installation and other factors also have an impact on the vibration of fag imported bearing. To use INA Bearing Grease correctly, you must know the movement of grease in the bearing. Ensure the stability of grease. The movement of the grease filled in the rolling bearing can be roughly divided into two stages with the rotation of INA Bearing.Effect of cleanliness on service performance of NTN imported bearings

In general, the filling amount of lubricating grease in INA Bearing always exceeds the actual demand for direct lubrication. 

  • It is on the holder and in the cavity of the bearing cover, and forms a contour on the periphery of the rolling element. During this process, the bearing temperature rises rapidly due to the resistance of excess grease. Although most of the excess grease is squeezed out at the initial stage of operation, and the grease squeezed in the accessories of the raceway may still be brought into the raceway by the rotating rolling element.Effect of cleanliness on service performance of NTN imported bearings
  •  In the initial stage of the bearing, most of the grease is quickly squeezed out of the raceway (less than one minute), and the accumulated grease is discharged in a small amount while circulating with the rotating body of the bearing. At this time, the Wendu of INA Bearing continues to rise until all the excess bearing grease is discharged, which can be called the running in stage of grease. According to the quality and filling amount of grease in the bearing structure, this period may last for more than ten minutes or even several hours.Effect of cleanliness on service performance of NTN imported bearings
  • Different INA Bearing Greases form different contours in the bearing. It is necessary to form the contour, which is quite draft, the running in time is short, and the ina bearing temperature is low and stable in long-term operation. This is an ideal grease, so it is particularly important for the channelization of the grease.Effect of cleanliness on service performance of NTN imported bearings
  • For the installation of separate INA Bearing, the inner ring and outer ring can be conveniently installed on the shaft or bearing seat respectively At this time, it should be noted that when inserting the shaft with the inner ring into the bearing housing with the outer ring, try to keep it concentric to prevent scratching the rolling element and raceway. When installing a non separating bearing with a tight fit between the inner ring of INA Bearing and the shaft and a loose fit in the bearing seat hole of the outer ring,Effect of cleanliness on service performance of NTN imported bearings
  • When installing the non separable bearing with tight fit between the inner ring and the shaft and loose fit in the bearing seat hole of the outer ring, the ina bearing can be installed on the shaft with a press, and then the shaft together with the ina bearing can be installed into the bearing seat hole. Effect of cleanliness on service performance of NTN imported bearings
  • If the INA Bearing is small, the end face of the ferrule can also be gently hit with a soft metal hammer to force the INA Bearing to, but the knocking force must be evenly distributed on the ina bearing ferrule. When the ina bearing ring is tightly matched with the shaft or ina bearing seat hole, a special installation barrel shall be used to press the INA Bearing onto the shaft or ina bearing seat at the same time
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