What are the causes of IKO thrust tapered roller bearing heating failure
What are the causes of IKO thrust tapered roller bearing heating failure
2022年6月11日
Cement machinery SKF import bearing
Cement machinery SKF import bearing failure analysis
2022年6月20日

Analysis of noise detection technology of INA needle roller bearing raceway

In case of any abnormality, INA needle roller bearing

  • The use factor mainly refers to whether the installation adjustment, use and maintenance, maintenance and repair meet the technical requirements. According to the technical requirements for installation, use, maintenance and repair of INA Bearing, the load, speed, operating temperature, vibration, noise and lubrication conditions borne by the running tapered roller bearing are monitored and checked. 
  • In case of any abnormality, the cause shall be immediately found and adjusted to make it return to normal. 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. The bearing operates in an abnormal state and ends its service life early
  • Internal factors mainly refer to the three major factors that determine the quality of bearings, such as structural design, manufacturing process and material quality.
  • The metallurgical quality of bearing materials was once the main factor affecting the early failure of bearings. With the development of Metallurgical Technology (such as vacuum degassing of bearing steel, etc.), 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 ina bearing failure. Proper material selection is still a factor that must be considered in bearing failure analysis.
  • The manufacturing of bearings usually goes through many processing procedures, such as forging, heat treatment, turning, grinding and assembly. The rationality, progressiveness and stability of each processing technology will also affect the service life of the bearing. The heat treatment and grinding processes that affect the quality of finished tapered roller bearings are often more directly related to the failure of ina bearings. In recent years, the research on the deteriorated layer of bearing working surface shows that the grinding process is closely related to the bearing surface quality.
  • Bearing raceway sound and its control method raceway sound is a kind of smooth continuous sound generated by the rolling body rolling on the raceway surface when the shaft is running. It is a unique basic sound that occurs in all rolling bearings. The general INA Bearing sound is the raceway sound plus other sounds. The raceway sound of ball bearing is irregular, and its frequency is above 1000Hz. Its main frequency does not change with the speed, but its sound pressure level increases with the speed.
  • For imported bearings with high raceway noise, the sound pressure level of raceway noise decreases with the increase of viscosity; For bearings with low raceway noise, the sound pressure level changes from decrease to increase when the viscosity increases to more than 20mm2/s. The greater the rigidity of the bearing pedestal, the lower the sound pressure level of the raceway sound. 
  • If the radial clearance is too small, the sound pressure level and dominant frequency of the raceway sound will increase sharply with the reduction of the radial clearance. If you don’t want it to have sound, the way is to turn off the electricity. Ha ha, in fact, we can take some measures to greatly reduce the noise of ina bearings. Generally speaking, to control the noise impact of tapered roller bearings, we must take countermeasures against the root causes of these noises in order to get the permanent effect.
  • It is easy to occur in winter. When ina bearing bears pure radial load, it is easy to occur in the case of large radial clearance, and it is easy to occur within a specific speed range with different models and sizes, both continuously and intermittently.
  •  Special processing method for outer ring raceway can prevent the occurrence of rolling sound. If necessary, this kind of tapered roller bearing can be selected, or the radial clearance of the bearing can be appropriately reduced, and the lubricating grease with excellent performance can be used to improve the rigidity of parts matching with the bearing.
Analysis of noise detection technology of INA needle roller bearing raceway

INA Bearing parts and components are damaged.

  • Therefore, whether ina bearing can work normally has a direct impact on the quality and cost of mechanical products, especially in the environment of changing mechanical speed and rolling force, the service life of bearing has become particularly important. The failure of combined bearing in use mainly shows in the following aspects.
  • Surface fatigue damage is a kind of damage that a small amount of material peels off from the surface of the raceway or rolling element. Spalling is a kind of cracking phenomenon related to stable stress caused by subcritical cyclic load. It is mainly due to the existence of foreign particles in the Hertz contact area. Through countless rolling between the ferrule and the rolling body, the stress on the surface will be concentrated in the pressure ellipse area, usually located at the large orthogonal shear stress.
  •  This stress concentration will gradually expand under the action of alternating stress as time goes on, and cracks will be formed, Eventually, part of the material will peel off from the surface. Surface fatigue spalling is mainly due to the existence of impurities in the lubricant, the existence of scratches, pitting and other defects on the contact surface, resulting in local stress concentration and the development of surface fatigue, resulting in surface source spalling.
  • Internal spalling this form of spalling is typically characterized.

INA needle roller bearing is a fixed part of machinery and the main

  • Large cracks are formed under the surface. Before spalling, these cracks expand parallel to the surface where the load stress reaches a large value. If the crack under the surface extends to the surface, or if the distance from the crack at the surface to the changed tissue area adjacent to the surface is generally one, it will peel off. The spalling under the raceway surface is caused by the bonding strength between the non-metallic inclusions and the steel matrix and the plastic deformation of the material.
  • INA Bearing parts and components are damaged. Bearing parts and components are damaged mainly under bad working conditions, such as large rolling force, high rolling speed, poor lubrication conditions, combined bearing fever, etc. In the current optimization design, the service life of the bearing is reflected in the overall life of the bearing. 
  • The damage of any part of the bearing will lead to the termination of the overall service life of the bearing. For example, the optimization design of cage strength, the optimization design of strut strength of strut cage, the welding performance between strut and cage, and the contact form between rolling element and retaining edge.
  • Bearing is a fixed part of machinery and the main body of machinery. Its function is basically to maintain the central position of the shaft and control the movement of the part. Combined bearing plays an important role in any machine. Without bearing, the machine can not run.
  • Many users have reported that the bearing heating fault is common when using INA Bearing, and this fault will also affect the service life and performance of the combined bearing. So, how did this kind of fault come into being? Here are a few points of knowledge summarized for you.
  • Prevention of assembly foreign matters: when ina bearing is installed on the rotor for dynamic balancing, it is easy to put the iron filings generated during dynamic balancing into the bearing, so it is necessary to perform dynamic balancing before installing the bearing.INA needle roller bearing raceway
  •  In order to facilitate assembly, some manufacturers apply some oil or grease in the bearing chamber for lubrication, but it is often difficult for operators to control the amount. If there is a large amount of oil or grease in the bearing chamber, it is easy to enter the high-temperature bearing along the shaft when the bearing rotates. The bearing chamber shall not be coated with oil or grease. If it must be coated, it shall be controlled that there shall be no accumulation in the bearing chamber.INA needle roller bearing raceway
  • Prevention of paint rust: paint rust is often found in sealed motors. The motor makes a good sound during assembly. However, after being stored in the warehouse for some time, the abnormal noise of the motor becomes very large. There is serious rust when the ina bearing is removed. In the past, many manufacturers thought it was the bearing problem. INA needle roller bearing raceway
  • After our continuous publicity, the motor factory has realized that the main problem is the insulation paint. The main reason for this problem is that the acid substances volatilized from the insulating paint form corrosive substances at a certain temperature and humidity, which corrodes the high-temperature bearing channel and leads to bearing damage. At present, only good insulating paint can be selected and assembled after drying and ventilation for a period of time.INA needle roller bearing raceway
  • Assembly method of bearing: because the bearing is a high-precision product, it is easy to damage the bearing channel if it is improperly assembled, resulting in bearing damage. INA Bearing shall be equipped with a special mold during assembly, and can not be knocked at will. INA needle roller bearing
  • When pressing the shaft, only a small circle can be stressed, and when pressing a large circle, only a large circle can be stressed. Pneumatic or hydraulic pressure is required during assembly. The upper and lower moulds shall be outside the horizontal state during press assembly. If there is inclination, the bearing channel will be damaged due to stress, and the high-temperature bearing will produce conduction sound. INA needle roller bearing
  • The correct and timely maintenance of NTN bearings is an important aspect to ensure the normal operation of highway machinery. If the bearing is well maintained, it can work for thousands of years or even longer; On the contrary, the service life of the bearing will be greatly reduced, and even serious accidents such as Bush burning and shaft holding will occur. INA needle roller bearing
  • Generally, the operating temperature of lubricating oil of one-way bearing shall not be higher than 50 ℃ In order to ensure sufficient and reliable lubrication, the oil level shall be checked timely or regularly to keep the oil level within the specified range. Keep some clean and timely replace according to the quality requirements of oil products. The fault of bearing shall be analyzed and eliminated in time. Common faults of bearings and their treatment methods are as follows.INA needle roller bearing
  • The bearing is hot. If the lubricating oil of NTN bearing is insufficient, add oil and check whether the oil circuit is smooth; If there are impurities in the lubricating oil, clean the bearing, replace it with new oil and clean the filter; If the assembly is poor, the journal and bearing are skewed, and there is eccentric load, shims can be added at the bottom of the bearing seat; If the bearing clearance is too small, readjust the clearance.INA needle roller bearing raceway
  • Shaft heating. If the oil baffle or rubber sealing ring on the shaft is too tight, adjust the position of the packing back cover; If there is radial friction between the shaft and the bearing cover, check and adjust the radial clearance between the shaft and the bearing cover, which is generally 0.25~0.3mm.INA needle roller bearing raceway
  • Less oil on the main friction surface. If the oil pipe is blocked and the oil trench is shallow, clean the pipeline and deepen the oil trench; If the oil temperature is low and the fluidity is poor, replace the lubricating oil according to the ambient temperature; If the oil ring rotates slowly and the oil splashes poorly, check whether the oil ring falls off and wipes the edge. If the oil level is too high, drain the oil to the standard height; If the adjusting shim blocks the lubricating oil, check the position of the adjusting shim.INA needle roller bearing raceway
  • Oil leakage. If the oil quantity is large, the oil supply quantity shall be adjusted to maintain the standard height of the oil level; If the sealing device fails, press the gland, thicken the felt ring or replace the sealing material; If the NTN bearing seat has holes or oil leakage, replace the bearing seat or fill the air holes with lead.INA needle roller bearing raceway
  • Axial runout. If the bearing clearance is too large, remove the gasket and adjust it; If the dynamic balance of the rotating body (gear, belt pulley, etc.) is not good, check and adjust the dynamic balance; If the bearing is unstable, tighten the bearing seat bolts; If the installation offset of the coupling is large, shims shall be added to the bearing seat ground to adjust the installation accuracy of the coupling.INA needle roller bearing raceway
  • The main causes of fracture failure of NTN bearing are defect and overload. When the external load exceeds the material strength limit and causes the part to break, it is called overload fracture. The overload is mainly caused by sudden failure or improper installation of the host. The micro crack, shrinkage cavity, bubble, large foreign matters, overheated structure, local burn and other defects of one-way bearing parts will also cause fracture at the defect during impact overload or severe vibration, which is called defect fracture. INA needle roller bearing raceway
  • It should be pointed out that during the manufacturing process of bearings, the factory re inspection of raw materials, the quality control of forging and heat treatment, and the processing process control can correctly analyze whether the above defects exist through instruments, and the control must be strengthened in the future. But generally speaking, most of the bearing fracture failures are overload failures.INA needle roller bearing raceway
  • During the operation of NTN bearing, due to the influence of external or internal factors, the original fit clearance is changed, the accuracy is reduced, and even “seizing” is called clearance change failure. External factors such as excessive interference, improper installation, expansion caused by temperature rise, instantaneous overload, and internal factors such as residual austenite and residual stress in an unstable state are the main reasons for the change of clearance.INA needle roller bearing raceway
  • If ina bearing is well lubricated and properly blocks sundries and moisture, it means that the oil seal should not be worn However, when opening the bearing housing, check the bearing and regularly check the oil seal Check the condition of oil seals near the ball screw bearing to ensure that they are sufficient to prevent hot liquid or corrosive liquid or gas from penetrating into the bearing along the axis. If the oil seal is worn, replace it as soon as possible
  • High temperature often indicates that the bearing is in abnormal condition High temperatures are also detrimental to lubricants in bearings Sometimes bearing overheating can be attributed to bearing lubricant If INA Bearing operates for a long time at a temperature exceeding 125 ℃, the bearing life will be reduced
  • Bearing vibration is very sensitive to bearing damage, such as spalling, indentation, corrosion, crack, wear, etc., which will be reflected in bearing vibration measurement. Therefore, the vibration can be measured by using a special bearing vibration meter (frequency analyzer, etc.), and the specific abnormal conditions can not be inferred from the frequency division. 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.INA needle roller bearing raceway
  • The bearing temperature can generally be inferred from the temperature outside the bearing chamber. It is more appropriate if the bearing outer ring temperature can be directly measured by using the oil hole.
  • Generally, the temperature of ball screw bearing begins to rise slowly with the operation of INA Bearing, and reaches a stable state after 1-2 hours. The normal temperature of the bearing varies with the thermal 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.INA needle roller bearing raceway
  • The thermal sensor can monitor the working temperature of the bearing at any time, and automatically alarm or stop when the temperature exceeds the specified value to prevent the occurrence of combustion shaft accidents.INA needle roller bearing raceway
  • High temperature often indicates that ina bearing is in abnormal condition. High temperature is also harmful to the lubricant of ball screw bearings. 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
  • The causes of INA Bearing include insufficient or excessive lubrication, magazine in lubricant, excessive load, bearing damage, insufficient clearance, high temperature friction caused by oil seal, etc
  • Both the bearing rolling element and the inner and outer race raceways are subject to periodic fluctuating loads, resulting in periodic contact stress. When the number of stress cycles reaches a certain value, fatigue spalling will occur on the rolling element or the inner and outer race raceways. If the load of the bearing is too large, this fatigue will be aggravated. In addition, the bearing is improperly installed and the shaft is bent, It will also produce the phenomenon of roll path spalling. The fatigue spalling of the bearing roll path will reduce the operating accuracy of the shaft and cause vibration and noise to the mechanism
  • The causes of the burning of the burned bearings are generally insufficient lubrication, the quality of the lubricating oil does not meet the requirements or deteriorates, and the bearing assembly is too tight.INA needle roller bearing raceway
  • Uneven pits appear on the contact surface between the raceway and the roller of INA Bearing, indicating that the ball screw bearing produces plastic deformation. The reason is that the local stress on the working surface of the bearing exceeds the yield limit of the material under the action of large static load or impact load. This usually occurs on the bearing rotating at low speed