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Influence of vibration and temperature on failure of NTN linear bearing

  • During the use of NTN bearing, it can be said that vibration and temperature have a great impact on linear bearing. Let’s take a look at the impact of bearing vibration on bearing.

Influence of vibration and temperature on failure of NTN linear bearing

  • Vibration is very sensitive to bearing damage. Peeling, indentation, corrosion, crack and wear will be reflected in NTN bearing vibration measurement. Therefore, the vibration can be measured by using a special linear bearing vibration meter (frequency analyzer, etc.), and the specific situation of abnormality can not be inferred through frequency division. Influence of vibration and temperature on failure of NTN linear bearing
  • The measured values are different due to the service conditions of the bearing or the installation position of the sensor. Therefore, it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.Influence of vibration and temperature on failure of NTN linear bearing
  • In the grinding process of fag bearing, a small amount of energy is consumed in the contact area between the grinding wheel and the workpiece, a small amount of grinding heat occurs, and the part of the grinding area is suddenly low temperature.Influence of vibration and temperature on failure of NTN linear bearing 
  • 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.Influence of vibration and temperature on failure of NTN linear 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.Influence of vibration and temperature on failure of NTN linear bearing
  •  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.Influence of vibration and temperature on failure of NTN linear bearing
  •  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.Influence of vibration and temperature on failure of NTN linear bearing
  • 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). Influence of vibration and temperature on failure of NTN linear 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.Influence of vibration and temperature on failure of NTN linear bearing
  • High temperature often indicates that NTN bearing has been in abnormal condition. High temperature is also harmful to the lubricant of linear 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 temperature of NTN bearing, whether it is measuring the linear bearing itself or other important parts. If the operating conditions remain unchanged, any temperature change can indicate that a fault has occurred.Influence of vibration and temperature on failure of NTN linear bearing
  • The periodic measurement of NTN bearing temperature can be aided by thermometer, such as digital thermometer, which can accurately measure the bearing temperature and display it in ℃ or Fahrenheit.Influence of vibration and temperature on failure of NTN linear bearing
  • The important linear 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.Influence of vibration and temperature on failure of NTN linear bearing
  • When investigating the damage of INA Bearing, it is difficult to know the real cause of the damage. However, if we know the use machinery, service conditions, the structure around the bearing, understand the situation before and after the accident, and investigate the damage state of the bearing and several causes, we can prevent the recurrence of similar accidents.Influence of vibration and temperature on failure of NTN linear bearing
Influence of vibration and temperature on failure of NTN linear bearing
  • As for the damage state of the bearing, such as the clamping damage of the ring and retaining edge of the roller bearing, these reasons can also be considered as insufficient lubricant, unsuitable, defects of the oil supply and drainage structure, invasion of foreign matters, installation error of the railway bearing and excessive deflection of the shaft.Influence of vibration and temperature on failure of NTN linear bearing
  • The judgment of whether the bearing is available is mainly determined by considering the damage degree, mechanical performance, importance, operating conditions and the period until the next maintenance of INA Bearing. 
  • If there are the following defects, it can no longer be used, and the 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.Influence of vibration and temperature on failure of NTN linear bearing
  • 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, temperature change of railway bearing, leakage or discoloration of lubricant, etc. If any abnormality is found, stop the operation immediately, check the machinery, and remove the bearing for inspection if necessary.
  • The bearing temperature can generally be inferred from the external temperature of the bearing seat. However, it is more accurate to directly measure the temperature of ina bearing outer ring with oil hole. Bearing temperature: conduct operation inspection on railway bearings from the following aspects. The operation starts to rise gradually, and the temperature is usually stable after 1 ~ 2 hours.Influence of vibration and temperature on failure of NTN linear bearing
  •  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 bearing structure and lubrication mode is also the reason.Influence of vibration and temperature on failure of NTN linear bearing
  • The rotation of the bearing is checked with a stethoscope, and there are strong metal noise, abnormal sound, irregular sound and other abnormalities. The reasons include poor lubrication, poor accuracy of shaft or bearing seat, INA Bearing Damage, foreign matter intrusion, etc.Influence of vibration and temperature on failure of NTN linear bearing
Common faults and necessary remedial measures of Timken thrust ball bearing
  • Size limitations. Generally, the space where ina bearings can be installed is limited. In most cases, the shaft diameter (or bearing inner diameter) is limited by mechanical design or other design. Influence of vibration and temperature on failure of NTN linear bearing
  • Therefore, the selection of bearing type and size is determined according to the inner diameter of universal joint bearing. Therefore, the main dimension tables of standard bearings are compiled according to the inner diameter dimensions of international standards.Influence of vibration and temperature on failure of NTN linear bearing
  • There are many sizes and forms of scale bearings. Scale bearings are used in the design of mechanical devices. The nature, size and direction of the load of bearings and the load imposed on bearings are changeable. In general, the rated base load is shown on the dimension table.Influence of vibration and temperature on failure of NTN linear bearing
  •  However, axial load and radial load are also important factors in selecting suitable bearings. When the size of the ball and needle roller bearing is commensurate, the needle roller bearing usually has high load capacity and bears large vibration and impact load.Influence of vibration and temperature on failure of NTN linear bearing
  • The speed and allowable speed are determined according to the type, size, accuracy, cage type, load, lubrication mode, cooling mode and other factors of INA Bearing. Influence of vibration and temperature on failure of NTN linear bearing
  • The table of universal joint bearing lists the allowable speed of scale precision bearing under oil lubrication and grease lubrication. In general, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are all suitable for high-speed operation.Influence of vibration and temperature on failure of NTN linear bearing