Judgment skills of damage degree of IKO combined bearing
Judgment skills of damage degree of IKO combined bearing
2022年4月4日
Basic principles for selection and application performance of fag oil-free bearing
Basic principles for selection and application performance of fag oil-free bearing
2022年4月4日

Wear failure and fracture failure of IKO flange bearing

Wear failure and fracture failure of IKO flange bearing

  • Wear failure refers to the failure caused by the continuous wear of the metal on the working surface caused by the relative sliding friction between the surfaces. The continuous wear will cause the IKO bearing parts to be damaged gradually, and eventually lead to the loss of bearing dimensional accuracy and other related problems. Wear may affect the change of shape
  • The increase of fit clearance and the change of working surface morphology, may affect the lubricant or make it polluted to a certain extent, resulting in the complete loss of lubrication function, so that the bearing loses the rotation accuracy and even cannot operate normally. 
  • Adhesive wear is one of the common failure modes of bearing.Wear failure and fracture failure of IKO flange bearing
  • Abrasive wear refers to the wear caused by the relative movement of the contact surface due to the extrusion of foreign hard particles or hard foreign matters or wear debris on the metal surface between the working surfaces of flange bearings.
  •  It often causes furrow like scratches on the working surface of IKO bearings. Wear failure and fracture failure of IKO flange bearing
Wear failure and fracture failure of IKO flange bearing

 

  • Hard particles or foreign matters may come from the inside of the host machine or from other adjacent parts of the host system, and are sent into the bearing by the lubricating medium. Adhesive wear refers to the uneven stress on the friction surface due to the micro bulge or foreign matter on the friction surface. 
  • When the lubrication conditions are seriously deteriorated, the local deformation and friction micro welding of the friction surface are easy to be caused due to the heat generated by local friction.Wear failure and fracture failure of IKO flange bearing
  •  In serious cases, the surface metal may be locally melted, and the force on the contact surface will tear the local friction welding point from the substrate and increase the plastic deformation.
  •  This cycle of adhesion tear adhesion constitutes adhesive wear. Generally speaking, slight adhesive wear is called scratch and severe adhesive wear is called bite.Wear failure and fracture failure of IKO flange bearing
  • The main causes of flange bearing fracture failure 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 main cause of overload is the sudden failure or improper installation of the host. Wear failure and fracture failure of IKO flange bearing
  • The defects of IKO bearing parts, such as microcracks, shrinkage cavities, bubbles, large foreign objects, overheated tissue and local burns, will also cause fracture at the defect during impact overload or violent vibration, which is called defect fracture. Wear failure and fracture failure of IKO flange bearing
  • It should be pointed out that in the manufacturing process of bearings, the presence of the above defects can be correctly analyzed by instruments in the factory re inspection of raw materials, quality control of forging and heat treatment, and processing process control, and the control must be strengthened in the future.
Wear failure and fracture failure of IKO flange bearing

 However, generally speaking, the fracture failure of IKO bearing is mostly overload failure.

  •  Oil bath lubrication
  • Oil bath lubrication is a common lubrication method in IKO bearings, which is suitable for the lubrication of low and medium speed bearings. Part of the imported bearing is immersed in the groove, and the lubricating oil is brought up by the rotating outer spherical ball bearing with seat, and then flows back to the oil groove. The oil level should be slightly lower than the center of the low rolling element.
  •  Drip lubrication
  • Oil dripping lubrication is suitable for IKO imported bearing parts requiring quantitative supply of lubricating oil. The amount of oil dripping is generally one drop every 3-8 seconds. Excessive amount of oil will increase the bearing temperature.Wear failure and fracture failure of IKO flange bearing
  • Circulating oil lubrication
  • The filtered oil is transmitted to IKO bearing parts by oil pump, and the lubricating oil after passing through the bearing is filtered and cooled before use. Since the circulating oil can take away a certain amount of heat and cool the bearing, this method is applicable to the components of outer spherical ball bearing with seat with high speed.Wear failure and fracture failure of IKO flange bearing
  • Spray lubrication
  • The dry compressed air is mixed with the lubricating oil through the sprayer to form an oil mist. In the jet IKO bearing, the airflow can effectively cool the bearing and prevent impurities from invading. This method is suitable for the lubrication of high-speed and high-temperature bearing parts.Wear failure and fracture failure of IKO flange bearing
  •  Jet lubrication
  • Use the oil pump to inject the high-pressure oil into the bearing through the nozzle, and the oil injected into the bearing flows into the oil groove through the other end of IKO bearing. When the bearing rotates at a high speed, the rolling element and cage also form airflow in the surrounding air at a fairly high rotation speed. 
  • It is difficult to send the lubricating oil to the bearing by general lubrication methods. At this time, the lubricating oil must be sprayed into the outer spherical ball bearing with seat by high-pressure injection. The position of the nozzle should be placed between the inner ring and the center of the cage!
  •  Special instrument measurement method shall be adopted as far as possible;
  •  Using the hand push method requires the surveyor to have high measurement skills. The measurement error of this method is large, especially when the clearance is in the edge state, it is easy to cause error. At this time, the instrument measurement should prevail;
  •  When measuring with a feeler gauge, it shall be operated according to the provisions of the standard, and the method of rolling the roller from the feeler gauge is not allowed;
  •  During the measurement, ensure that the ball falls into the ditch bottom; The closed bearing shall be measured before sealing; When using a loaded instrument, the measured value shall also subtract the increase of clearance caused by load.
  •  For multi row bearings, the clearance of each row is required to be qualified, and the arithmetic mean of the clearance of each row is taken as the radial clearance of the outer spherical ball bearing with seat.Wear failure and fracture failure of IKO flange bearing
Wear failure and fracture failure of IKO flange bearing
  • When the bearing is installed on the rotor for dynamic balance, it is easy to put the iron filings generated during dynamic balance into the joint bearing, so it is necessary to perform dynamic balance before installing the bearing. In order to facilitate assembly, some manufacturers apply some oil or grease in the bearing chamber for lubrication effect during assembly, but it is often difficult for operators to control the amount.Wear failure and fracture failure of IKO flange bearing
  •  If more oil or grease is accumulated in the bearing chamber, it is easy to enter the bearing along the shaft when the bearing rotates. The bearing shall not be coated with oil or grease. If it must be coated, it shall be controlled and there shall be no accumulation in the bearing chamber.
  • The metallurgical quality of joint bearing materials was once the main factor affecting the early failure of rolling bearings. With the progress of Metallurgical Technology (such as vacuum degassing of bearing steel), the quality of raw materials has been improved. Wear failure and fracture failure of IKO flange bearing
  • The proportion of raw material quality factor in IKO bearing failure analysis has decreased significantly, but it is still one of the main influencing factors of bearing failure. Proper material selection is still a factor that must be considered in bearing failure analysis.Wear failure and fracture failure of IKO flange bearing
  • The main task of joint bearing failure analysis is to find out the main factors causing bearing failure according to a large number of background materials, analysis data and failure forms, so as to put forward targeted improvement measures, prolong the service life of the bearing and avoid sudden early failure of IKO bearing.Wear failure and fracture failure of IKO flange bearing
  • Selection and control of shaft and bearing housing tolerances
  • IKO bearing shall rotate flexibly without blocking feeling after being pressed into the bearing. If there is obvious inflexible rotation, it indicates that the size of the shaft is too large and the tolerance should be reduced. Wear failure and fracture failure of IKO flange bearing
  • If the thrust cylindrical roller bearing rotates by hand after being pressed into the shaft, there is an obvious “rusty” feeling, it may be that the tolerance of the shaft is too large or the roundness of the shaft is not good. Therefore, when controlling the tolerance of shaft and bearing chamber, it is also necessary to control the roundness. At present, many domestic manufacturers only control the tolerance, not the roundness.Wear failure and fracture failure of IKO flange bearing
  •  Assembly method of bearing
  • Because IKO bearing is a high-precision product, if it is not assembled properly, it is easy to damage the bearing channel and lead to bearing damage. The thrust cylindrical roller bearing shall be equipped with a special mold during assembly, and can not be knocked at will.Wear failure and fracture failure of IKO flange bearing
  •  When pressing the shaft, it can only be stressed by a small ring, and when pressing a large ring, it can only be stressed by a large ring. 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 bearing channel will be damaged due to stress and the bearing will make a guide sound.
  • Prevention of foreign matters during assembly
  • When the bearing is installed on the rotor for dynamic balance, it is easy to put the iron filings generated during dynamic balance into the IKO bearing, so it is necessary to perform dynamic balance before installing the bearing. In order to facilitate assembly, some manufacturers apply some oil or grease in the bearing chamber for lubrication effect during assembly, but it is often difficult for operators to control the amount.Wear failure and fracture failure of IKO flange bearing
  •  If more oil or grease is accumulated in the bearing chamber, it is easy to enter the bearing along the shaft when the thrust cylindrical roller bearing rotates. The bearing chamber shall not be coated with oil or grease. If it must be coated, it shall be controlled and there shall be no accumulation in the bearing chamber.Wear failure and fracture failure of IKO flange bearing
  • Prevention of paint rust
  • The feature of paint rust is that it often occurs in sealed motors. The sound of the motor is very good during assembly, but after it is put in the warehouse for some time, the abnormal noise of the motor becomes very large, and there is serious rust when the IKO bearing is removed.
  •  In the past, many manufacturers thought it was the problem of thrust cylindrical roller bearing.Wear failure and fracture failure of IKO flange bearing
  • After our continuous publicity, now the motor factory has realized that it is mainly the problem of insulating paint. This problem is mainly because the acidic substances volatilized from the insulating paint form corrosive substances at a certain temperature and humidity, which corrodes the bearing channel and leads to bearing damage. At present, the problem can only be to select good insulating paint and assemble after drying and ventilation for a period of time.Wear failure and fracture failure of IKO flange bearing