Classification of Surface Hardening Technology of Imported Bearing Materials
Classification of Surface Hardening Technology of Imported Bearing Materials
2022年3月25日
Fault causes and solutions of bearing inner race, outer race and bearing race
Fault causes and solutions of bearing inner race, outer race and bearing race
2022年3月25日

Factors Causing Bearing Aging

  • During the use of rolling fag bearing, due to its own quality and external conditions, its bearing capacity, rotation accuracy and antifriction energy performance will change. 
  • When the performance index of the bearing is lower than the use requirements and can not work normally, it is called bearing damage or failure. Once the bearing is damaged and other accidents occur, its machine and equipment will stop running and its function will be damaged.

Factors Causing Bearing Aging

  • If the bearing is broken, first analyze the cause of the failure, and then find a solution. Therefore, it is necessary to find out the causes in a short time and take corresponding measures.Factors Causing Bearing Aging
  • The factors that cause the old and bad bearings are mostly caused by improper use of bearings? The following is an explanation of the factors that lead to frequent bearing damage. The information shared by axis search is as follows:
  • Bearing is a kind of wear and tear part, which will definitely be damaged as long as it is used. It only shows up when it is accumulated to a certain extent In addition to the improper design and use of the rolling bearing, the damage of the rolling bearing is much more complex than that of the rolling bearing. 
  • Of course, the damage must be caused by the improper design and use of the rolling bearing, Poor sealing and other external factors. The following 8 points are the main factors of bearing failure:Factors Causing Bearing Aging
  •  Metal corrosion occurs. If there is no lubrication, it is easy to be oxidized and rusted by air Prevent the bearing from rusting and do not use blisters. Bearings are made of refined steel, but they are also afraid of water. When taking the bearing by hand, fully wash the sweat from your hands and apply high-quality mineral oil before operation. Pay special attention to rust prevention in rainy season and summer.
  • The specific causes of natural corrosion and wear of bearings mainly include the following:
  • Oxidation wear. The tiny peaks and valleys on the friction surface squeeze each other, causing the brittle surface to gradually fall off and wear. The tiny peaks and valleys on the surface of the relative movement of the bearing are combined with the oxidation in the air to form brittle oxides that are not firmly bonded with the base metal. The oxides are easy to fall off in friction, and the wear is called oxidation wear.Factors Causing Bearing Aging
  •  Friction generates heat and wear. When the bearing works under high speed, heavy load and poor lubrication, the high temperature at the peak and valley of the outer surface, the hardness and wear resistance of the contact point are reduced due to friction, and even adhesion and tear occur. This kind of wear is called frictional heat generating wear.
  • Hard grain wear. If ina bearing is in relative motion. The surface structure of the bearing is uneven, there are hard particles, or impurities such as sand particles, friction chips and chips fall between the moving surfaces of the bearing. During the relative movement of the bearing, hard particles or impurities will scratch the surface of the bearing and even form grooves. This kind of wear is called hard particle wear.
  •  Pitting wear. The rolling contact surfaces of gears and bearings are periodically subjected to great contact pressure in the relative process. Under the action of long time, the metal surface is fatigue, resulting in small cracks and denudation on the bearing surface. This kind of wear is called pitting wear.
  • Cause rust or corrosion, wear caused by chemical corrosion. The bearing surface is eroded by acid, alkali, salt liquid or harmful gas. It accelerates the wear process, which is called the wear caused by chemical corrosion.
  • Corrosion damage due to temporary contact with water, acid, alkali, salt and other liquids or harmful gases: non moving bearings on the equipment. Damage caused by rust or corrosion is called corrosion damage.
  •  Bearing overload or improper use. Do not exceed the load of the bearing when using Like a car, it may be that the load is too heavy, which is easy to damage the bearing Therefore, there are more problems with trucks than cars, which is caused by the inability of many parts to withstand.Factors Causing Bearing Aging
  •  The bearing clearance is too small. The front wheel of the car is a diagonal thrust bearing, which needs to adjust the clearance. Too loose will lead to abnormal noise, deflection and wheel shaking Too tight will accelerate wear Both are bad All unfavorable For old bearings, check the ball surface for burrs, scratches and cracks. Whether the radial clearance and axial clearance of the old bearing are qualified, generally only the radial clearance is measured. For new bearings, first check whether the bearing model is correct.Factors Causing Bearing Aging
  • Use inferior bearings. The bearing is produced by some small factories. The production process can not meet the requirements. The accuracy of the shaft or bearing box is poor. The bearing steel is pressed and produced without treatment Therefore, the bearings produced are not durable.
  • Reckless driving can also lead to bad car bearings, but this reason is a little far fetched Because if you drive carelessly, other parts will break down before the bearing.Factors Causing Bearing Aging
  •  Poor installation. To install the bearing, follow the installation steps of the bearing. Do not install and disassemble it savagely. Whether the bearing is installed correctly is related to the service life of the bearing, so we must pay attention to it. When installing the bearing, avoid holding it directly by hand, because the sweat on your hand may also cause corrosion. 
  • Don’t ignore small links. During the installation of bearings, it is important not to press with force or directly knock the bearing with a hammer. It is not afraid of being damaged, but afraid of being deformed, and the deformed bearing can not be used. Also, it is not allowed to transfer pressure through the rolling element.Factors Causing Bearing Aging
  • Foreign body intrusion. Try to use special tools and try to avoid using cloth and short fiber, so as to avoid unnecessary damage caused by fine fiber entering the bearing. For another example, when installing the bearing, the staff once used the copper rod tapping method.
  • which is easy to cause uneven axial force of the bearing, resulting in deformation of the cage, damage to the rolling element and larger clearance. In addition, during the tapping process of the copper rod, the copper end flew into the bearing cage, which is easy to cause bearing failure. There is also the use process
  • The hardness caused by abnormal high temperature and the change of metallographic structure or chemical composition of metal reduce the wear resistance and hardness of NSK bearing surface and speed up the wear process. This kind of wear is called wear caused by high temperature. Wear caused by high temperature. When the bearing works temporarily at high temperature.
  • For bearings with insulation design on the outer ring, pay attention to ensure that the insulation is intact. If the bearing insulation is damaged during installation, the very thin bearing oil film will be broken down by the shaft voltage.
  •  After the oil film breaks down, not only the lubrication conditions of the rolling element are poor, but also the electric spark will form electric corrosion on the bearing rolling element, causing the surface of the rolling element to be not smooth and accelerating the wear of the bearing.Factors Causing Bearing Aging
  • Bearing wear can be repaired in this way. The solution is to re study the service conditions or re select the bearing, observe the clearance and check the machining precision between the shaft and the bearing strip, check the design around the bearing, and study and check the installation method, lubricant and lubrication method.
Factors Causing Bearing Aging

Bearing wear can be repaired in this way

  •  Do a good job in the preliminary preparation, that is, the disassembly of equipment to ensure sufficient construction space and safe working environment;Factors Causing Bearing Aging
  • The preliminary cleaning of the shaft surface, that is, wipe the oil on the surface of the bearing position and positioning surface, remove the high points, burrs, rust layers, etc., and clean the surface of the bearing position with 99.7% absolute ethanol to ensure that there is no dirt and dry;
  •  Wipe the inner and outer surfaces of the mold, wipe a thin layer of SD7000 release agent on the inner surface of the mold, discharge chute, bolt, bolt hole, positioning pin and positioning pin hole, the thinner the better, and dry it for standby;
  •  Mix the material sd7101h in strict accordance with the proportional volume ratio of 2:1, mix it fully without color difference, and quickly apply the mixed material to the surface of the bearing position;
  •  Quickly install the mold in place, tighten the bolts and install the locating pins. Pay attention to the mold during the installation of the mold to avoid the axial movement of the mold. At the same time, knock the mold with a rubber hammer in the circumferential direction during the fastening of the mold to make the material distribution more uniform and avoid the deformation of the mold;Factors Causing Bearing Aging
  • Material curing: when the ambient temperature is 24 ℃, it is recommended to remove the mold for at least 4 hours; When the ambient temperature is below 24 ℃, it is recommended to use iodine tungsten lamp for heating for no less than 3 hours;
  •  Be careful when removing the mold to avoid material damage or falling off during the disassembly process. After the mold is disassembled, use a saw blade or cutting blade to remove the excess material extruded at the discharge chute, and grind it below the overall surface;
  •  Assembly parts: when assembling parts, it is recommended to apply a thin layer of release agent on the mating surface of the parts in advance and a thin layer of material on the surface of the bearing position, and install them quickly in strict accordance with the assembly process.Factors Causing Bearing Aging
  • It is of great significance to study the formation and causes of rolling NTN bearing damage. On the one hand, it can improve the use method, use the bearing correctly and give full play to the due efficiency of the bearing. On the other hand, it is helpful to develop new products with better performance. 
  • This paper not only describes the precautions, installation methods and operation supervision in the use of rolling bearings, but also focuses on the forms and causes of bearing damage and the countermeasures that should be taken.Factors Causing Bearing Aging
  • The service life of the bearing has a certain number of years. If we use it well and pay normal attention to the above matters, the bearing will give full play to its role. Generally, the brand bearings of regular manufacturers provide three guarantee services. If it is a quality problem, you can go to the corresponding specialty store for replacement. General specialty stores have this service.Factors Causing Bearing Aging
Factors Causing Bearing Aging