Inspection of vibration fault of punching outer ring needle roller bearing during operation
Inspection of vibration fault of punching outer ring needle roller bearing during operation
2022年5月14日
Analysis of ina bearing sealing device
Analysis of ina bearing sealing device
2022年5月14日

Method of identifying INA Bearing

Method of identifying INA Bearing

  • For centripetal ball bearings in normal technical condition, the inner and outer race raceways shall be free of spalling and serious wear marks, and shall be in a bright arc groove; All balls shall be kept round without spots, cracks and spalling on the surface; 
  • The cage shall not be loose, broken or worn through. When using one hand to hold the inner ring and the other hand to quickly push the outer ring to rotate, it is required to rotate stably. Only the slight sound of the ball rolling on the raceway can be heard without vibration;
  •  The speed shall be reduced gradually when stopping, and there shall be no reverse after stopping. For normal radial ball bearings, the clearance between the inner and outer rings and the rolling element is 0.005-0.010mm. When shaking the inner and outer rings along the radial direction, there shall be no clearance. The used ina bearing can shake the inner ring several times along the axial direction by hand. When there is an obvious sound between the outer ring and the ball, it indicates that the matching clearance exceeds 0.03mm and should not be used again.
  • After the ina bearing is used, check whether the rolling element and the inner race raceway are peeling off, whether the cage is too loose, whether the front and rear edges of the inner race are complete, and whether the outer race raceway is cracked. After the inner ring and roller assembly are installed into the outer ring, the roller shall fall into the middle of the raceway and move forward no more than 1.5mm. One of them is unqualified, that is, it cannot be used.
  • Identification of self-aligning roller bearings and short cylindrical roller bearings
  • The outer ring of this kind of ina bearing is separable. Under normal conditions, the inner and outer race raceways and rollers shall be free of breakage, pitting and deep wear marks; The cage shall be free of deformation and can fold the roller on the inner ring; The fit clearance between inner and outer race raceways and rollers shall not exceed 0.06mm.Method of identifying INA Bearing
  • Thrust ball bearing qualification
  • Under normal conditions, the two raceways shall be free of peeling damage and serious wear, and the ball shall be free of breakage and pitting; The cage shall be free from deformation and collision with the two raceway washers, and the balls shall be firmly folded together.Method of identifying INA Bearing
Method of identifying INA Bearing

Identification of tapered INA bearings

  • Rolling ina bearings are generally composed of the following four basic elements:
  • Inner ring, outer ring, cage and rolling element – counter centripetal or centripetal thrust bearing (inner ring or outer ring can be collectively referred to as ferrule),Method of identifying INA Bearing
  • Shaft ring, seat ring, cage and rolling element – thrust or thrust centripetal bearing (shaft ring or seat ring can be collectively referred to as washer).Method of identifying INA Bearing
  • Rolling element is the basic structural feature of rolling ina bearing. In order to save space and position, or to install more rolling elements, a few varieties of rolling ina bearings can be without outer ring or inner ring, inner and outer ring, or cage, but all rolling ina bearings must have rolling elements.Method of identifying INA Bearing
  • Usually, the inner ring or shaft ring is installed on the shaft, the outer ring or seat ring is installed in the ina bearing seat hole, and the rolling element is assembled between the inner ring, outer ring or shaft and seat ring. The external load is transmitted from the inner ring or shaft ring to the outer ring or seat ring through the rolling element, or from the outer ring or seat ring to the inner ring or shaft ring. Method of identifying INA Bearing
  • Both sides realize relative rotation through the rolling element. The cage is used to separate the rolling elements to avoid mutual contact between the rolling elements, because the relative speed at the direct contact of the rolling elements is roughly twice that of a single rolling element, which will lead to the scratch of the rolling elements.Method of identifying INA Bearing
  • The advantages and disadvantages of rolling ina bearings are mostly related to the existence of rolling elements. For example, the rolling friction formed by rolling elements has low static and dynamic friction coefficient, high transmission efficiency and small axial size. On the other hand, it also forms high pair contact (point contact or line contact), which makes the stiffness, vibration, noise and other quality of rolling ina bearings inferior to some types of sliding ina bearings, and the radial size is also large. Method of identifying INA Bearing
  • Fag bearing vibration is very sensitive to the damage of fag bearing, such as peeling, indentation, corrosion, crack, wear, etc., which will be reflected in the vibration measurement of fag bearing. Therefore, the vibration can be measured by using a special fag bearing vibration meter (frequency analyzer, etc.), and the specific abnormal situation can not be inferred by frequency division. Method of identifying INA Bearing
  • The measured values are different due to the service conditions of fag bearing or the installation position of sensor, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.
  • Generally, the temperature of fag bearing can be inferred from the temperature outside the fag bearing chamber. It is more appropriate if the temperature of fag bearing outer ring can be directly measured by oil hole.
  • Generally, the temperature of fag bearing starts to rise slowly with the operation of fag bearing, and reaches a stable state after 1-2 hours. The normal temperature of fag bearing varies with the heat capacity, heat dissipation, speed and load of the machine. Method of identifying INA Bearing
  • If the lubrication and installation parts are appropriate, the fag 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.Method of identifying INA Bearing
  • The thermal sensor can monitor the working temperature of fag bearing at any time, and automatically alarm or stop when the temperature exceeds the specified value to prevent the occurrence of combustion shaft accident.Method of identifying INA Bearing
  • High temperature often indicates that fag bearing has been in abnormal condition. High temperatures are also harmful to fag bearing lubricants. Sometimes fag bearing overheating can be attributed to the lubricant of fag bearing.Method of identifying INA Bearing
  •  If the temperature of fag bearing exceeds 125 ℃ for a long time, the service life of fag bearing will be reduced. The causes of high temperature fag bearings include insufficient or excessive lubrication and lubricant. It contains impurities, excessive load, FAG bearing ring damage, insufficient clearance, high friction caused by oil seal, etc.Method of identifying INA Bearing
  • Therefore, it is necessary to continuously monitor the temperature of fag bearing, whether it is measuring fag bearing itself or other important parts. If the operating conditions remain unchanged, any temperature change can indicate that a fault has occurred.Method of identifying INA Bearing
  • The regular measurement of fag bearing temperature can be aided by thermometer, such as digital thermometer, which can accurately measure the temperature of fag bearing and display it according to the unit of ℃ or Fahrenheit.Method of identifying INA Bearing
  • When fag is installed on the bearing, it means that the fag equipment will be damaged.Method of identifying INA Bearing
  • Normally, FAG bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days. The feature of this Timken bearing grinding method is that all grinding allowance (0.20 ~ 0.60ram) is ground in a longitudinal cutter with a small longitudinal feed (f_; longitudinal = 0.08b ~ 0.15bmm / R). Method of identifying INA Bearing
  • Using this grinding method, the grinding wheel needs to be trimmed into a front cone part (Fig. 7-5a) or a stepped shape (Fig. 7-5b) to gradually reduce the cutting allowance. Otherwise, the cutting work is mainly concentrated on the outer corner of the grinding wheel, which makes the outer corner of the grinding wheel blunt rapidly and affects the grinding efficiency and surface quality.Method of identifying INA Bearing
  • Attention should be paid to when trimming stepped grinding wheel: the large cylindrical surface plays the role of fine grinding and polishing, so it should be trimmed more finely, and the other stepped surfaces play the role of rough grinding and should be trimmed more coarsely; 
  • In addition, the step height close to the outer layer of the workpiece shall be larger, while the step height close to the finished surface shall be smaller. In this way, we can obtain high productivity and ensure small surface roughness value.Method of identifying INA Bearing
  • However, dressing the grinding wheel is relatively complex, and the structure of the workpiece must allow the grinding wheel to exceed a large distance from both ends of the machined surface, so it is only applicable to some parts whose grinding structure meets the above requirements in mass production. 
  • Tests in some factories have proved that the productivity of this grinding method can be about twice as high as that of longitudinal grinding method, and sufficient accuracy and small surface roughness can be obtained at the same time. First of all, when the fag bearing is disassembled, a suitable puller shall be used to pull the fag bearing out. Under the condition that the size, shape and accuracy of the fag bearing assembly hole of the bearing seat are not good, the fag bearing will be affected and cannot carry out its function. 
  • For example, if the dimensional accuracy and shape accuracy of the inner hole of the common part fag bearing seat are not good, the outer ring of the fag bearing will be deformed, resulting in the deterioration of the roundness of the inner hole of the fag bearing;Method of identifying INA Bearing
  •  If the accuracy of the retaining shoulder is not good, the outer ring and roller of fag bearing will tilt, which will aggravate the concentrated load, reduce the fatigue life of fag bearing, and even lead to the damage and sintering of the holder; If the accuracy of fag bearing gear of spindle rod in fag bearing inner ring is not good, such as the accuracy of size, roundness, cylindricity, waviness, coarseness and position, it will also clearly lead to the addition of vibration value of the whole set of spindle.Method of identifying INA Bearing
  • Secondly, the complete set of fag bearings is strictly selected and matched before assembly, so the scattered fag bearing parts cannot be exchanged and used without new measurement and matching before use.Method of identifying INA Bearing
  • Third, the cleaning of fag bearing and spindle foot. Because the ingot foot structure is compact, there are many other parts in the ingot foot cavity. The device method of Qingdao Ruijing fag bearing electromechanical fag bearing will also affect the cleanliness of the fag bearing task cavity. Method of identifying INA Bearing
  • Therefore, the process of pre cleaning the spindle foot parts before the assembly and fine cleaning the assembly spindle foot including fag bearing in the future is a relatively reasonable process.
  • Fourth, FAG bearing should not be bumped and impacted during assembly. Bumping and impact are easy to form collision between fag bearing parts, resulting in fag bearing failure.Method of identifying INA Bearing
  • Fifth, when crimping the bearing seat, pay attention to controlling the crimping angle, strength and other factors to prevent unreasonable crimping from forming the deformation and failure of fag bearing parts.Method of identifying INA Bearing
  • Sixth, for fag bearings that have exceeded the anti rust period or have been stored for a long time, the fatigue life of rolling bearings has considerable development potential, which can show rust or roller sticking due to the drying of anti rust oil.Method of identifying INA Bearing

Temperature of fag bearing

  • Generally speaking, the rolling SKF Bearing itself does not produce noise. The commonly felt “SKF Bearing Noise” is actually the sound effect of SKF Bearing directly or indirectly vibrating with the surrounding structure. This is why many times noise problems can be considered as vibration problems involving the whole SKF Bearing application.
  • Excitation caused by the change of the number of loaded rolling elements
  • When a radial load is loaded on a SKF Bearing, the number of rolling elements bearing the load will change slightly during operation, that is: 2-3-2-3 This causes an offset in the direction of the load. The resulting vibration is inevitable, but can be reduced by axial preloading, which is applied to all rolling elements (not applicable to cylindrical roller bearings).
  • Waviness of components
  • In the case of close fit between SKF Bearing Ring and SKF bearing seat or transmission shaft, SKF Bearing ring may be deformed by matching with the shape of adjacent components. If deformation occurs, vibration may occur during operation. Therefore, it is important to machine the SKF Bearing Pedestal and drive shaft to the required tolerances.
  • Local damage 
  • Due to incorrect operation or installation, a small number of SKF bearing raceways and rolling elements may be damaged. During operation, rolling over damaged SKF Bearing components will produce specific vibration frequencies. Vibration frequency analysis can identify damaged SKF Bearing components.
  • Vibration behavior in applications
  • In many applications, SKF bearings have the same stiffness as the surrounding structure. Because of this feature, as long as the SKF Bearing (including preload and clearance) and its configuration in application are correctly selected, it is possible to reduce the vibration in application.
  • There are three ways to reduce vibration:
  • – remove critical excitation vibration from the application;
  • – suppress the critical excitation vibration between the excitation part and the resonance part;
  • – change the stiffness of the structure to change the critical frequency. It is becoming more and more serious to check the condition of running machines and prepare a thorough inspection plan SKF Bearing is the focus of attention, because it is an important rotating part in all machines Preventive maintenance is an important part of condition monitoring Early detection of SKF Bearing Damage to avoid equipment shutdown during unscheduled maintenance caused by SKF Bearing damage
  • However, not all of them are equipped with this advanced instrument In this case, the operator or maintenance engineer of the machine must be highly alert to the “fault signal” of SKF Bearing, such as noise, temperature and vibration “Listening”, “touching” and “observing” are three important factors The views provided below can be used as your reference
  • touch
  • High temperature often indicates that SKF Bearing is in abnormal condition High temperatures are also harmful to lubricants in SKF bearings Sometimes SKF Bearing Overheating can be attributed to the lubricant of SKF Bearing If SKF Bearing operates for a long time at a temperature of more than 125 ℃, the service life of SKF Bearing will be reduced The causes of high temperature SKF Bearing include insufficient or excessive lubrication, magazine contained in lubricant, excessive load, SKF Bearing Damage, insufficient clearance, high temperature friction caused by oil seal, etc
  • Therefore, it is necessary to continuously monitor the temperature of SKF Bearing, whether it is measuring SKF Bearing itself or other important parts If the operating conditions remain unchanged, any temperature change may indicate that a fault has occurred
  • The SKF Bearing temperature can be measured regularly with the help of thermometer, which can accurately measure the SKF Bearing Temperature and display it in degrees Celsius
  • Important SKF Bearing means that when it is damaged, it will cause equipment shutdown. Therefore, this kind of SKF Bearing should be equipped with temperature detector
  • Under normal circumstances, SKF bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days
  • observation
  • If SKF Bearing is well lubricated and properly blocks sundries and moisture, it means that the oil seal should not be worn However, when opening the SKF Bearing housing, visually inspect the SKF Bearing and regularly inspect the oil seal Check the condition of the oil seals near the SKF Bearing to ensure that they are sufficient to prevent hot or corrosive liquid or gas from penetrating into the SKF Bearing along the axis The protective ring and labyrinth oil seal should be coated with grease to ensure their great protection If the oil seal is worn, replace it as soon as possible