Several knowledge elements need to be paid attention to in the correct installation of SKF non-standard bearings
Several knowledge elements need to be paid attention to in the correct installation of SKF non-standard bearings
2022年4月11日
Three common maintenance techniques for bearing fatigue failure of SKF rolling mill
Three common maintenance techniques for bearing fatigue failure of SKF rolling mill
2022年4月11日

Fault causes of SKF universal joint bearing caused by vibration

  • The failure of universal joint bearing accounts for a large proportion of motor failure. The loss caused by bearing damage is quite serious. The motor in operation will emit various sounds and vibrations.Fault causes of SKF universal joint bearing caused by vibration
  • If it is found that there are rattling sound, sliding sound and metal sound, and the temperature rises significantly, it is necessary to find out the reason when it is different from that in normal operation. 
  • Is it caused by SKF Bearing? Or other faults. Bearing maintenance of motor bearings mainly depends on timely and regular replacement of lubricating grease. Motor bearings are rolling bearings. Rolling bearings are lubricated with grease. Fault causes of SKF universal joint bearing caused by vibration
  • The purpose of lubrication is to prevent the direct contact between metal and metal on the bearing surface during rolling and sliding and to prevent the corrosion of the bearing surface. 
  • The lubricating grease used for the motor bearing needs to be replaced with fresh lubricating grease regularly, and the operating temperature of the motor rolling bearing should be kept below 90 ℃, so as to make the lubricating grease reach the expected normal life.Fault causes of SKF universal joint bearing caused by vibration
  • Small parts of SKF bearing raceways and rolling elements may be damaged. Partial damage due to installation error or operation. Rolling over damaged bearing parts will produce a specific vibration frequency. Vibration frequency analysis can identify damaged bearing components. 
  • Vibration behavior in application places in many applications, the stiffness of the bearing is the same as that of the surrounding structure. Because of this feature, as long as the bearing (including preload and clearance) and its configuration in the application are correctly selected, it is possible to reduce the vibration in the application.Fault causes of SKF universal joint bearing caused by vibration

Fault causes of SKF universal joint bearing caused by vibration

  • The rolling bearing in the universal joint bearing itself does not produce noise. Generally, the “bearing noise” is actually the sound effect of vibration between the bearing and the surrounding structure directly or indirectly. Generally speaking.Fault causes of SKF universal joint bearing caused by vibration
  • The noise intensity is not high. If there is a faint uniform rolling sound in the inner and outer rings of the rolling body (the tester feels relaxed), it indicates that the universal joint bearing operates normally.Fault causes of SKF universal joint bearing caused by vibration
  •  If an abnormal sound is heard, SKF Bearing will make a uniform and continuous “hissing” sound, which is generated by the rotation of the rolling element in the inner and outer rings, including irregular metal vibration sound irrelevant to the speed. The general performance is that the amount of lubricating grease added in the bearing is insufficient, so the cause should be identified and handled.Fault causes of SKF universal joint bearing caused by vibration
  • Hearing the sound of similar whistle, mixed with the rolling sound of “Gulu Gulu” of the rolling body, indicates that there is a lack of grease or the grease is improperly selected, and the appropriate grease should be cleaned, supplemented or replaced. When the bearing is running, it emits a uniform periodic “clatter” sound in the continuous “clatter”. Fault causes of SKF universal joint bearing caused by vibration
  • This sound is caused by scars, grooves and corrosion spots on the rolling element and inner and outer ring raceways. The period of sound has a corresponding relationship with the speed of universal joint bearing. SKF Bearing should be replaced.Fault causes of SKF universal joint bearing caused by vibration.
  • SKF Bearing ring may be deformed by matching with the shape of adjacent parts. If deformation occurs, the waviness of the component is in the case of close fit between the bearing ring and the bearing seat or transmission shaft. Vibration may occur during operation. Therefore, it is important to machine the bearing pedestal and drive shaft to the required tolerances.Fault causes of SKF universal joint bearing caused by vibration
Fault causes of SKF universal joint bearing caused by vibration
  • SKF Bearing ring may be deformed by matching with the shape of adjacent parts. If deformation occurs, the waviness of the component is in the case of close fit between the bearing ring and the bearing seat or transmission shaft. Vibration may occur during operation. Therefore, it is important to machine the bearing pedestal and drive shaft to the required tolerances.

Bearings to keep their working environment clean.

  • Even if the eyes can not see the fine dust, will bring adverse effects on the linear bearing. Therefore, keep the surroundings clean so that dust will not invade the SKF Bearing.
  • Use with care.
  • Bearing in use gives a strong impact, there will be a scar and indentation, the cause of the accident. In serious cases, cracks and fractures must be paid attention to.
  • Use appropriate operating tools.
  • To avoid existing tools, you must use the right tools.
  • Pay attention to bearing corrosion.
  • When the bearing runs, the hands will rust because of sweat. Pay attention to clean hands and wear gloves as much as possible.
  • There are many causes of SKF Bearing Failure. All the design and manufacturing process factors and the influence of linear bearing failure are not easy to determine. Under normal circumstances, in general, you can consider and analyze factors and internal factors.
  • When the bearing temperature rises, first judge whether there is misoperation. If it does rise, the following treatment shall be carried out:
  • Check whether the cooling water pressure, water flow and pipeline system are normal. If the water pressure is low, the filter may be blocked and cannot be handled in time, it can be shut down for treatment. When it is confirmed that it can work, it can be put into use.
  • Check the oil pressure of the governor. If the oil pressure is low, the cooling water hydraulic valve may be closed.
  • Check whether SKF Bearing has abnormal sound and whether bearing swing is abnormal.
  • Take an oil sample to observe whether the oil color has changed, and test to see whether it has deteriorated. If the deterioration is confirmed, stop the machine and replace it with new oil.
  • Check whether the oil level of the oil gauge is normal. If not, check whether the oil drain valve of the oil tank is tightly closed. If it has been closed tightly, oil shall be added. If it is oil leakage from the sealant pad, it shall be shut down for treatment.
  • When we use linear bearings, if we find that the temperature is very high, we should stop the operation of the equipment quickly, find out the cause, and deal with it according to the solutions provided above. However, the solutions may be different due to the different causes of SKF Bearing heating, so we should treat it on a case by case basis and complete it with the help of technicians.
  • For heavy load occasions, it is usually tighter than that in light load and normal load occasions. The heavier the load, the greater the fit interference.Fault causes of SKF universal joint bearing caused by vibration
  • The device and disassembly method of the bearing shall be determined according to the structure and size of SKF Bearing and the matching nature with oil-free bearing parts. Therefore, there is sufficient discussion in the design and device assembly department. The device shall comply with the specifications. The tasks of this project are as follows: General specifications
  • The inner ring of the bearing is tightly matched with the shaft, and the outer ring is loosely matched with the shell. Press the bearing on the bearing with a press, and then install the shaft together with the bearing into the shell. When pressing, pad a soft metal assembly sleeve (copper or soft steel pipe) on the end face of SKF Bearing. Fault causes of SKF universal joint bearing caused by vibration
  • The inner diameter of the assembly sleeve shall be slightly larger than the diameter of the journal, and the outer diameter shall be less than the diameter of the retaining edge of the inner diameter of the bearing to avoid being pressed on the holder. When a large number of devices have no oil bearings, a handle can be added to the casing.Fault causes of SKF universal joint bearing caused by vibration
  • The inner ring of the bearing is tightly matched with the shaft, and the outer ring is tightly matched with the shell hole. The end face of the assembly sleeve should be made into a ring that can compress the end faces of the inner and outer rings of the bearing at the same time, or use the disc and assembly sleeve to transfer the pressure to the inner and outer rings at the same time, and press the SKF Bearing into the shaft and shell. This device method is especially suitable for the device of centripetal spherical bearing with automatic centering.
  • The outer ring of the bearing is tightly matched with the shell hole, and the inner ring is loosely matched with the shaft. The bearing can be pressed into the shell first. At this time, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the shell hole.Fault causes of SKF universal joint bearing caused by vibration
  • Heating device: before hot assembly, put SKF Bearing or separable bearing ring into oil tank or special heater and heat it to 80 ~ 100 ℃ (no more than 100 ℃).Fault causes of SKF universal joint bearing caused by vibration
  • The quality of imported bearing cage is very good, but in the daily operation of oil-free bearing, incorrect operation will reduce the service life of bearing cage and even lead to its fracture. Improper installation, inclination, excessive interference, etc. are easy to reduce the clearance, aggravate friction and heat generation, soften the surface, and premature abnormal peeling. Fault causes of SKF universal joint bearing caused by vibration
  • With the expansion of peeling, the peeling foreign matter enters the pocket hole of the cage, resulting in the operation block of the cage and additional load, which intensifies the wear of the cage. Such a deteriorating cyclic effect may cause the cage to fracture.
  • The oil-free bearing is running in a lean oil state, which is easy to form adhesive wear and deteriorate the working surface. The tear caused by adhesive wear is easy to enter the cage, resulting in abnormal load on the cage, which may lead to cage fracture. 
  • Creep mostly refers to the sliding phenomenon of the ferrule. When the interference of the mating surface is insufficient, the load point moves to the surrounding direction due to sliding, resulting in the deviation of the ferrule from the axis or shell to the circumferential direction
  • In addition, according to different uses, it is necessary to select specially designed bearings with requirements on accuracy, clearance, cage structure, grease and so on. However, there is no certain order and rules for the selection of Timken bearings. Priority should be given to the conditions, performance and related matters required by the bearings, especially practical.
  •  As long as the bearings in order to maintain the original performance as intact as possible, they should be maintained and maintained in the first place, so as to prevent accidents, ensure the reliability of operation, improve productivity and economy. Corresponding mechanical operation and maintenance operation standards, regular operation and maintenance conditions. This includes monitoring the operation status, replenishing or changing lubricants, and regular inspection and removal. As a problem of maintenance operation, bearing rotation sound, vibration, temperature, lubrication conditions, etc.
  • Bearing cleaning: remove the bearing for repair, record the appearance of the bearing for the first time, confirm the remaining amount of lubricant, and clean the bearing with the lubricant used after sampling inspection. As a cleaning agent, gasoline and kerosene are generally used. Remove the bearing for cleaning, cleaning and fine washing, and place it in the container. 
  • Put the metal mesh bottom of the container so that it does not directly contact the dirt of the bearing. Rough washing, if the bearing rotates dirt and damages the bearing rolling surface, attention should be paid to it. In crude oil cleaning, brush with a brush to remove grease, viscous materials, general cleaning and washing into a fine. Fine washing is to wash the oil carefully while rotating the bearing on one side. In addition, the cleaning oil must be kept clean
  • Maintenance and judgment of Timken bearing: determine whether it can be used to check the bearing after cleaning and remove the bearing. Check the raceway, raceway, surface condition, cage wear, bearing clearance and improvement of dimensional accuracy, irrelevant damage and abnormality. Non separable small ball bearing, inner ring, support level with one hand, rotate the outer ring to confirm smooth. 
  • Tapered roller bearings, such as separable bearings, can roll the body, and the outer race raceway surface has been inspected. For large bearings, because they cannot rotate by hand, pay attention to check the raceway, cage and wall of the rolling element, such as appearance. For the importance of higher bearings, they should be checked more carefully.Fault causes of SKF universal joint bearing caused by vibration
  • When inspecting the rivet head, the main observation is whether there is a relationship between skew and loose welding position is incorrect. Welding quality. Whether the welding point is too small, whether there is welding or welding, the problem caused by solid ball card. Bearing testing requires special attention in the process. There are also some problems that need attention.Fault causes of SKF universal joint bearing caused by vibration
  • Let’s share with you the experience of many years in the local bearing inspection. Timken bearing’s secondary inspection of the environment should be in the light environment, which is astigmatism, so as to better observe the appearance of the bearing on the surface and be free of cracks and other abnormalities. Fault causes of SKF universal joint bearing caused by vibration
  • In the process of cloud like mechanical wear, scratches and touch pressure, the bearing equipment will lead to displacement, poor equipment position, flat bearing shape, load and stress concentration, and reduce accuracy and service life.Fault causes of SKF universal joint bearing caused by vibration
  • In addition to paying special attention to the pollutants in the working environment or water, which may lead to bearing rust, rust is to lead to bad Timken bearing installation, early wear will lead to more serious waste. Therefore, special attention should be paid to the moisture in water, of course.Fault causes of SKF universal joint bearing caused by vibration
  • The assembly quality index of ina imported bearings, that is, the assembly accuracy requirements are mainly radial clearance and width. There is a certain functional relationship between axial clearance and radial clearance. Therefore, the axial clearance can be indirectly controlled by controlling the radial clearance.Fault causes of SKF universal joint bearing caused by vibration
  • For deep groove ball bearings, cylindrical roller bearings, self-aligning ball bearings and self-aligning roller bearings, the radial clearance is mainly controlled.Fault causes of SKF universal joint bearing caused by vibration
  • For thrust ball bearing, thrust roller bearing and tapered roller bearing, the height and width are mainly controlled.
  • For angular contact ball bearings, the contact angle is mainly controlled.Fault causes of SKF universal joint bearing caused by vibration
  • The basic requirements of rolling bearing assembly are: on the premise of ensuring the assembly quality index, the sleeve rate should be high, which should generally be more than 95%.Fault causes of SKF universal joint bearing caused by vibration
  • Obvious loose defects are not allowed on the finished ina bearing ring. It will reduce the density of ferrule and enrich more micropores, low melting point impurities, gases and non-metallic inclusions Like the ribbon carbide, it plays the role of dividing the continuity of the matrix, causing component segregation and matrix embrittlement, which greatly reduces the comprehensive mechanical properties of the ferrule.Fault causes of SKF universal joint bearing caused by vibration
  • The black-and-white concentration difference of martensite matrix in quenching and tempering state, high macro hardness value and loose defects are also potential factors that can not be ignored to induce grinding cracks. The appearance of black-and-white concentration difference indicates that there are serious banded carbides in the original structure, resulting in the segregation of carbon lattice concentration on and between bands. Therefore, after quenching, the overheating tendency between bands and the difference of MS point are increased.Fault causes of SKF universal joint bearing caused by vibration
  • The influence of grinding quality on the premature failure of ina bearing can be judged from the above test results. The grinding crack and grinding burn on one side of the raceway are a direct cause of the collapse of the ferrule and the premature failure of the bearing.Fault causes of SKF universal joint bearing caused by vibration
  •  The macro morphology of the crack and the distribution characteristics of grinding burn revealed in this example show that the original position of the raceway is too deviated or the R of the raceway is not round, which increases the grinding allowance on one side of the raceway. When the feed rate is large in the coarse grinding stage When the grinding speed is fast, the whole raceway produces uneven grinding. Fault causes of SKF universal joint bearing caused by vibration
  • If the grinding wheel is not trimmed in time, it will promote the embedding or adhesion of grinding debris, resulting in the blockage and passivation of the grinding wheel pores, which will increase the imbalance of the grinding wheel, aggravate the spindle vibration, and even the grinding chatter caused by the vibration of the machine tool. Obviously, the grinding force changes periodically, forming intermittent burn strips.Fault causes of SKF universal joint bearing caused by vibration
  • In order to further understand the hardness distribution of ferrule and the microstructure characteristics of quenching and tempering microstructure and surface layer, the partially cracked inner ring and its fragments are selected, the macro hardness is set on the end face, and the longitudinal metallographic samples are intercepted near the crack by wire cutting method.Fault causes of SKF universal joint bearing caused by vibration
  • In the working process of INA Bearing, due to the influence of external or internal factors, the original matching clearance is changed, the accuracy is reduced, and even “bite” is called clearance change failure. External factors such as excessive interference, improper installation, expansion caused by temperature rise, instantaneous overload, etc., and internal factors such as residual austenite and residual stress in an unstable state are the main reasons for the change and failure of clearance.Fault causes of SKF universal joint bearing caused by vibration