When selecting NTN bearings, the price of NTN bearings should be considered, or NTN bearings with higher load capacity but more expensive should be used, or ordinary NTN bearings should be used to prolong their service life.
NTN bearings with high load capacity are adopted, such as cylindrical roller bearings with convexity, spherical roller bearings with symmetrical rollers, reinforced tapered roller bearings and ball bearings, ball bearings with corrected ball groove bus, or 70000cd series NTN bearings are used to replace deep groove (single row centripetal) ball NTN bearings. These NTN bearings with high load capacity or due to the improvement of stress distribution, Or it may have higher fatigue life due to the large number of rolling elements.
In order to select the proper size of NTN bearing, the working load, speed and operating temperature of NTN bearing must be accurately calculated or verified. The load has a great impact on the service life of NTN bearing, so although it is difficult to measure the load, it should be measured as accurately as possible.
When the load measurement is difficult, the actual power consumed by the motor can be measured, and the power loss along the way can be calculated according to the transmission route and deducted until the NTN bearing load is closer to the actual one.
If the calculated or measured load is too large, the expected fatigue life of NTN bearing must be reduced by a greater margin, which must be remedied. If the installation position allows, NTN bearing with a larger size can be selected; If the radial dimension is limited, the wider NTN bearing should be selected when there is a wider NTN bearing; If wider NTN bearings cannot be used, NTN bearings with higher load carrying capacity can be used instead.
When selecting NTN bearing material, its price should also be taken into account, and when vacuum smelting or electroslag remelting steel has to be used, it should be noted that the lubrication conditions must be improved in order to double the expected fatigue life of NTN bearing. Of course, the cost of selecting NTN bearings made of this kind of high-quality steel is much more expensive than selecting NTN bearings with high load capacity.
However, for NTN bearings that are difficult to access in machines and are extremely difficult to assemble and disassemble, or NTN bearings used in mining and tunnel operation machinery, they must be considered sometimes in situations where maintenance is extremely difficult.
In order to maintain the original performance of INA Bearing in good condition for as long as possible, it is necessary to maintain and repair in order to prevent accidents, ensure the reliability of operation and improve productivity and economy. Maintain the operation standard of corresponding mechanical operation conditions and carry out it regularly. Select NTN bearing model with high load capacity
The contents include monitoring the operation status, replenishing or changing the lubricant, and regular disassembly inspection. As maintenance items in operation, there are rotating sound, vibration, temperature, lubricant state of INA Bearing, etc.
Cleaning of INA Bearing: when disassembling INA Bearing for maintenance, first record the appearance of INA Bearing, confirm the residual amount of lubricant, and clean ina bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used.
The cleaning of the removed Select NTN bearing is divided
which are placed in the container respectively. First, put the metal mesh bottom so that the INA Bearing does not directly contact the dirt of the container. Select NTN bearing model with high load capacity
During rough cleaning, if ina bearing rotates with dirt, it will damage the rolling surface of INA Bearing, which should be paid attention to. In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning. Fine cleaning is to carefully clean ina bearing while rotating in cleaning oil. In addition, the cleaning oil should always be kept clean
Maintenance and judgment of INA Bearing: in order to judge whether the disassembled ina bearing can be used, it should be checked after the ina bearing is cleaned. Check the state of raceway surface, rolling surface and mating surface, the wear of cage, the increase of INA Bearing Clearance and the damage related to the decline of dimensional accuracy. For non separable small ball bearings, support the inner ring horizontally with one hand and rotate the outer ring to confirm whether it is smooth.
Tapered roller bearings and other separable bearings can inspect the raceway surfaces of rolling elements and outer rings respectively. Since large bearings cannot be rotated by hand, pay attention to the appearance of rolling elements, raceway surfaces, cages, edge retaining surfaces, etc. the higher the importance of ina bearings, the more careful the inspection is.
The market requirements for various mechanical devices and instruments using rolling bearings are becoming more and more strict, and the conditions and performance required for ina bearings are becoming more and more diversified. In order to select the suitable ina bearing from a large number of structures and sizes, it needs to be studied from various angles.
The ina bearing structure is roughly determined by considering the difficulty of arrangement, installation and disassembly of ina bearings as shaft system, the allowable space and size of ina bearings, and the marketability of ina bearings.
Secondly, while comparing and studying the design life of various machines using ina bearings and various durability limits of ina bearings, the size of ina bearings is determined. When selecting ina bearings, it is often inclined to only consider the fatigue life of ina bearings.
The grease life, wear and noise caused by grease aging also need to be fully studied. Moreover, according to different applications, it is necessary to select ina bearings specially designed for accuracy, clearance, cage structure, grease and other requirements.
However, there is no certain sequence and rules for selecting ina bearings. Priority should be given to the conditions, performance and related matters required by ina bearings, which is particularly practical.
When selecting ina bearings, generally, Select NTN bearing
In order to maintain the original performance of INA Bearing in good condition for as long as possible, it is necessary to maintain and repair in order to prevent accidents, ensure the reliability of operation and improve productivity and economy. Select NTN bearing model with high load capacity
Maintain the operation standard of corresponding mechanical operation conditions and carry out it regularly. The contents include monitoring the operation status, replenishing or changing the lubricant, and regular disassembly inspection. As maintenance items in operation, there are rotating sound, vibration, temperature, lubricant state of INA Bearing, etc.Select NTN bearing model with high load capacity
Cleaning of Select NTN bearing
when disassembling INA Bearing for maintenance, first record the appearance of INA Bearing, confirm the residual amount of lubricant, and clean ina bearing after sampling the lubricant for inspection. As a cleaning agent, gasoline and kerosene are commonly used. Select NTN bearing model with high load capacity
The cleaning of the removed ina bearing is divided into coarse cleaning and fine cleaning, which are placed in the container respectively. First, put the metal mesh bottom so that the INA Bearing does not directly contact the dirt of the container. During rough cleaning, if ina bearing rotates with dirt, it will damage the rolling surface of INA Bearing, which should be paid attention to. Select NTN bearing model with high load capacity
In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning. Fine cleaning is to carefully clean ina bearing while rotating in cleaning oil. In addition, the cleaning oil should always be kept clean
Maintenance and judgment of INA Bearing: in order to judge whether the disassembled ina bearing can be used, it should be checked after the ina bearing is cleaned. Check the state of raceway surface, rolling surface and mating surface, the wear of cage, the increase of INA Bearing Clearance and the damage related to the decline of dimensional accuracy.
For non separable small ball bearings, support the inner ring horizontally with one hand and rotate the outer ring to confirm whether it is smooth. Tapered roller bearings and other separable bearings can inspect the raceway surfaces of rolling elements and outer rings respectively. Since large bearings cannot be rotated by hand, pay attention to the appearance of rolling elements, raceway surfaces, cages, edge retaining surfaces, etc. the higher the importance of ina bearings, the more careful the inspection is.
The market requirements for various mechanical devices and instruments using rolling bearings are becoming more and more strict, and the conditions and performance required for ina bearings are becoming more and more diversified. In order to select the suitable ina bearing from a large number of structures and sizes, it needs to be studied from various angles.
When selecting ina bearings, generally, the ina bearing structure is roughly determined by considering the difficulty of arrangement, installation and disassembly of ina bearings as shaft system, the allowable space and size of ina bearings, and the marketability of ina bearings. Select NTN bearing model with high load capacity
Secondly, while comparing and studying the design life of various machines using ina bearings and various durability limits of ina bearings, the size of ina bearings is determined. When selecting ina bearings, it is often inclined to only consider the fatigue life of ina bearings. The grease life, wear and noise caused by grease aging also need to be fully studied. Select NTN bearing model with high load capacity
Moreover, according to different applications, it is necessary to select ina bearings specially designed for accuracy, clearance, cage structure, grease and other requirements. However, there is no certain sequence and rules for selecting ina bearings. Priority should be given to the conditions, performance and related matters required by ina bearings, which is particularly practical.Select NTN bearing model with high load capacity
The main cause of Select NTN bearing burns is due to the poor
The so-called burn damage state of INA Bearing refers to that the raceway wheel, rolling element and cage of INA Bearing are heated sharply during rotation until they change color, soften, deposit and damage.
Irregular lubricant may be used, or too much or too little lubricant is incorrect.
The second may be excessive load (excessive preloading). Excessive speed. The clearance is too small. Intrusion of water or other foreign matters. If neither of the above two cases is true, the accuracy of the shaft and ina bearing housing is poor and the deflection of the shaft is large. Then the solution is: first, we should study the lubricant and lubrication method, select the INA Bearing Lubricant and its dosage, and correct the selection of INA Bearing. The clearance and preload of INA Bearing should be matched and imported, and the sealing device should be improved. Check the accuracy of the shaft and ina bearing housing.
Improper disassembly of shale shaker NTN bearing may cause damage to the inside of NTN bearing. Contaminants may enter NTN bearings or errors may occur during reinstallation. Therefore, great care must be taken to disassemble the vibrating screen NTN bearing, and the axis must be properly supported, otherwise the disassembly force may damage the NTN bearing.
Peripheral removal
Remove the outer ring of the interference fit. Set several screws for the outer ring extrusion screw on the circumference of the shell in advance, tighten the screw equally while removing. These screw holes are usually covered with blind plugs, separable NTN bearings such as vibrating screen tapered roller NTN bearings, set several cuts on the shoulder of the shell, use cushion blocks, disassemble with a press, or knock gently.
Disassembly of cylindrical hole bearing of vibrating screen
The inner ring can be easily removed by pressure machinery. At this time, pay attention to make the inner ring bear its pulling force.
The inner ring of NTN bearing of large vibrating screen is disassembled by oil pressure method. Oil pressure is applied through the oil hole arranged on the shaft to make it easy to pull out. The NTN bearing with large width is disassembled by the combination of oil pressure method and drawing fixture.
Induction heating method can be used to disassemble the inner ring of NTN bearing of Nu and NJ cylindrical roller vibrating screen. It is a method of drawing after heating part in a short time to expand the inner ring.
Disassembly of tapered bore Select NTN bearing
Disassemble the relatively small NTN bearing with fixed sleeve, support the inner ring with the stop fastened on the shaft, turn the nut back several times, and then knock it down with a cushion block and a hammer.
Vibration of SKF Bearing
The vibration of SKF Bearing is very sensitive to the damage of SKF Bearing, such as peeling, indentation, corrosion, crack, wear, etc. will be reflected in the vibration measurement of SKF Bearing. Therefore, the vibration can be measured by using a special SKF Bearing Vibration Meter (frequency analyzer, etc.), and the specific abnormal situation can not be inferred by frequency division. The measured values are different due to the service conditions of SKF 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.
The temperature of SKF Bearing can generally be inferred from the temperature outside the SKF Bearing chamber. It is more appropriate if the outer ring temperature of SKF Bearing can be measured directly by oil hole.
Generally, the temperature of SKF Bearing starts to rise slowly with the operation of SKF Bearing, and reaches a stable state after 1-2 hours. The normal temperature of SKF Bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are appropriate, the SKF 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.
Using the thermal sensor, the working temperature of SKF Bearing can be monitored at any time, and the automatic alarm or stop when the temperature exceeds the specified value can be realized to prevent the occurrence of combustion shaft accident.
High temperature often indicates that SKF Bearing has been in abnormal condition. High temperature is also harmful to the lubricant of SKF Bearing. Sometimes SKF Bearing Overheating can be attributed to the lubricant of SKF Bearing. If the temperature of SKF Bearing exceeds 125 ℃ for a long time, the service life of SKF Bearing will be reduced. The causes of high temperature SKF bearings include insufficient or excessive lubrication and lubricant. It contains impurities, excessive load, SKF Bearing Ring damage, insufficient clearance, high 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 can indicate that a fault has occurred.
The periodic measurement of SKF Bearing temperature can be aided by thermometer, such as digital thermometer, which can accurately measure the SKF Bearing Temperature and display it in ℃ or Fahrenheit.
SKF Bearing of importance 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.
Temperature of Select NTN bearing
Koyo bearing is a large-scale Koyo bearing enterprise that started early in Japan’s bearing industry, so its products tend to receive more attention. For ordinary Koyo bearing users, the noise of Koyo bearing is inevitable. Why does Koyo bearing produce noise?
We should know that Koyo is the basic feature of the rolling bearing, because it occurs on the rolling surface. The spherical Koyo bearing is different. The rolling sound potential of spherical Koyo bearing is irregular. Its dominant frequency does not change with the speed, but its total sound pressure level increases with the speed. For Koyo bearings with loud raceway sound, the sound pressure level of raceway sound decreases with the increase of viscosity;
The sound pressure level of Koyo bearing with low raceway noise changes from decrease to increase when the viscosity increases to more than 20mm2 / s. The greater the rigidity of Koyo bearing pedestal, the lower the total sound pressure level of raceway sound. If the radial clearance is too small, the total sound pressure level and dominant frequency of raceway sound will increase sharply with the decrease of radial clearance. The methods to control the sound of raceway are as follows:
select low-noise Koyo bearing, that is, Koyo bearing with small waviness, and carefully select the service conditions. Raceway noise often affects the noise of the whole machinery. Reducing raceway noise can reduce the noise of the whole machinery.
Secondly, the impact sound of the rolling element and its control method. When the larger model ball Koyo bearing or cylindrical roller Koyo bearing runs at low speed under pure radial load, the rolling element in the non load area will impact the cage or raceway and make noise due to the small centrifugal force of the rolling element. But as the speed increases, the sound will disappear. The control methods of impact sound of rolling elements include: appropriately reducing radial clearance and using Koyo bearing with cage with reasonable structure and flexible material.
Later, the rolling sound of Koyo bearing and its control method rolling sound is the harsh metal friction sound that can occur in cylindrical roller bearings on all occasions. Most of it occurs in grease lubricated larger Koyo bearings, which is more likely to occur in greases with degraded base oil performance, and almost does not occur in oil lubrication. In addition, it is easy to occur in winter. When bearing pure radial load, it is easy to occur in the case of large radial clearance, and it is easy to occur in a specific speed range with different models and sizes, both continuously and intermittently.
Special processing methods for the outer race raceway can prevent the occurrence of rolling sound. If necessary, this kind of Koyo bearing can be selected, or the radial clearance of Koyo bearing can be appropriately reduced, the lubricating grease with excellent performance can be used and the rigidity of parts matching with Koyo bearing can be improved.
These are the reasons why Koyo bearings are prone to noise.
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