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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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 it is difficult to measure the load, 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.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN 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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
When using fag bearings, we should first check the appearance of fag bearings to judge whether they meet the standards we require. Let’s share with you what parts we should check.Three principles of how to prolong the service life of NTN bearings
The inspection of fag bearing should be carried out under the astigmatism lamp, and the appearance, cracks and other parts of fag bearing should be carefully observed.Three principles of how to prolong the service life of NTN bearings
Various mechanical scars, such as abrasion, scratch, crush and bruise, will cause poor installation of fag bearing, cause eccentric load and stress concentration, and reduce rotation accuracy and service life.Three principles of how to prolong the service life of NTN bearings
Rust, black skin and pitting. The latter two are defects that are easy to store moisture and dirt, which are easy to develop into rust. Corrosion is the pollution source leading to poor installation, early wear and fatigue. Serious corrosion will scrap fag bearings.Three principles of how to prolong the service life of NTN bearings
Various cracks, such as raw material cracks, forging cracks, heat treatment cracks and grinding cracks, will become the source of stress concentration and expand rapidly in the future operation of fag bearing, resulting in the fracture of fag bearing, which has a great impact on the service life and workability of fag bearing. In fact, for fag bearings with important applications, FAG bearing factory has conducted 100% magnetic or radiographic inspection on its components.Three principles of how to prolong the service life of NTN bearings
Peeling and folding, the local combination of these two defects with the base metal is not firm, and decarburization or carbon deficiency often exist around them to varying degrees. The material is easy to collapse, dent or wear, which is very unfavorable to the service life and accuracy of fag bearing.Three principles of how to prolong the service life of NTN bearings
For the riveting or welding quality of the cage, mainly observe whether the rivet head is offset, skewed, loose, lack of meat or “double eyelid”, whether the welding position is correct, whether the welding spot is too large or too small, and whether the rolling element is stuck due to loose welding or excessive welding.Three principles of how to prolong the service life of NTN bearings
The above items are the key inspection parts in the inspection of fag bearings. In addition to the above inspection parts, in addition, if the typing quality is poor, such as illegible and damaged, they shall be considered defective, and the serious ones can also be rejected. 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.Three principles of how to prolong the service life of NTN bearings
The main cause of INA Bearing burns is due to the poor lubrication of INA Bearing. Irregular lubricant may be used, or too much or too little lubricant is incorrect.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
SKF Bearing of importance means that when it is damaged, it will cause equipment shutdown,Three principles of how to prolong the service life of NTN bearings
Therefore, this kind of SKF Bearing should be equipped with temperature detector.Three principles of how to prolong the service life of NTN bearings
Under normal circumstances, SKF bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days.Three principles of how to prolong the service life of NTN bearings
Select appropriate NTN bearing material
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?NTN bearings
First of all, we should know that the sound of Koyo bearing occurs because its rolling element rolls on the raceway surface, which is the basic feature of all Koyo bearings. The spherical Koyo bearing is different. The rolling sound potential of spherical Koyo bearing is irregular.NTN bearings
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; NTN bearings
For NTN bearings with low raceway sound.
the sound pressure level 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.NTN bearings
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. NTN bearings
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.NTN bearings.Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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. Three principles of how to prolong the service life of NTN bearings
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.Three principles of how to prolong the service life of NTN bearings
These are the reasons why NTN bearings are prone to noise.
Application of body lubricated INA Bearing in modern industry and agriculture
Gas lubricated ina bearing is a sliding INA Bearing with gas as lubricant. It uses the transmissibility (diffusivity, viscosity and thermal conductivity), adsorption and compressibility of gas to form a complete gas film between friction pairs under the action of fluid dynamic pressure effect, static pressure effect and extrusion effect, which has the function of supporting load and reducing friction.Three principles of how to prolong the service life of NTN bearings
Gas lubricated ina bearings are generally divided into three types: gas dynamic pressure ina bearings, gas static pressure ina bearings and gas extrusion ina bearings. In practice, the lubrication state of INA Bearing often exists in the form of dynamic and static pressure, dynamic and extrusion, static and extrusion and dynamic, static and extrusion mixed lubrication state.Three principles of how to prolong the service life of NTN bearings
Application example of gas lubricated NTN bearings in machine tool
Gas lubricated ina bearings are mainly used for spindle support in machine tools, including workpiece shaft, tool shaft, grinding wheel shaft, etc. The INA Bearing of machine tool spindle generally adopts two types: aerostatic INA Bearing and dynamic hydrostatic hybrid ina bearing.Three principles of how to prolong the service life of NTN bearings
Small high-speed spindles can also use wave foil ina bearings. Aerostatic ina bearings are widely used in machine tools, including small hole throttling and annular throttling ina bearings. Porous aerostatic ina bearings are increasingly used in active hydrostatic hybrid lubrication ina bearings for machine tools in recent years. Three principles of how to prolong the service life of NTN bearings
In recent years, ina is a new type of high-speed gas bearing, which is used in the development of high-speed static bearing. At present, the grinding speed of ultra-high speed air ina bearing internal grinding head can realize the precision grinding of small holes and micro holes. Using air INA Bearing, the machining accuracy of the machine tool is improved by 2-3 orders of magnitude, and precision mirror machining can be realized.Three principles of how to prolong the service life of NTN bearings
Give a brief introduction NTN bearings.
As one of the widely used NSK Bearings in daily life, electric NSK bearing will inevitably encounter various problems in its use. Today, we will discuss the cleaning process of electric NSK bearing
According to the service time, the motor should be cleaned and refueled after 2000 hours. There are two cleaning methods for NSK Bearings:Three principles of how to prolong the service life of NTN bearings
Hot oil cleaning method for NSK Bearings hardened with soft dry oil or anti rust paste due to long use, they should be immersed in 100-200 ℃ hot engine oil, clamp NSK Bearings with pliers, and clean the oil on NSK Bearings with a brush. The soft dry oil or antirust paste will melt when heated to 100-200 ℃, which is easy to wash out from the gap of NSK bearing. Sometimes, just shake the NSK bearing in the oil for many times. Oil will also flow away from the gapThree principles of how to prolong the service life of NTN bearings.
When cleaning the centripetal spherical NSK bearing of old motor or imported motor, the ball, bead frame and inner ring should be turned laterally from the outer ring and then immersed in hot oil. When cleaning the short cylindrical roller NSK bearing, the roller, bead frame, inner ring and outer ring should also be separated.
During hot oil cleaning, the oil temperature shall not exceed 20 ℃. When heating directly with open fire, attention should be paid to prevent the oil from burning. NSK bearing should be hung in the oil pan and sink to the bottom, which will cause overheating and reduce the hardness.Three principles of how to prolong the service life of NTN bearings
General cleaning method: soak NSK bearing in kerosene for 5-10 minutes, hold the inner ring with one hand and rotate the outer ring with the other hand, and the dry oil or anti rust paste on NSK bearing will fall off. Then put the NSK bearing into clean kerosene, brush it with a soft brush, clean the oil stain in the ball and gap, then put it into gasoline for cleaning once, take it out and put it on clean paper.
When cleaning centripetal spherical ball NSK bearing and short cylindrical roller NSK bearing, the ball, bead holder, inner ring and outer ring shall be separated for cleaning.Three principles of how to prolong the service life of NTN bearings
The cleaning of NSK bearing installed on the shaft mainly depends on the method of spraying oil or spraying with oil gun. The oil stain that is easy to be cleaned is first kerosene and then gasoline; For oil stains that are difficult to be cleaned, first wash them with 100-200 ℃ hot engine oil or spray them with an oil gun, and then clean them with gasoline. Be careful not to scrape NSK bearing with sharp tools: hard oil dirt or rust, so as not to damage the smoothness of NSK bearing rolling body and groove ring. Clean NSK bearing and dry it with clean cloth.
The judgment of whether SKF Bearing is available is mainly determined by considering the damage degree.
mechanical performance, importance, operating conditions and the period until the next maintenance of SKF Bearing. If there are the following defects, it can no longer be used, and the SKF Bearing must be replaced with a new one. There are cracks or notches on any one of the inner ring, outer ring, rolling element and cage.
Any one of the ferrule and rolling element is broken. There are significant card injuries on the rolling track surface, retaining edge and rolling body. Significant wear of cage or significant relaxation of rivets. There is rust and damage on the raceway surface and rolling element. There are serious indentations and scratches on the raceway surface and rolling element.
There is obvious creep on the inner diameter surface of the inner ring or the outer diameter surface of the outer ring. Discoloration caused by heat is obvious. SKF Bearing sealed with grease, sealing ring or dust cover are obviously damaged The rolling IKO bearing is widely used by users. When using the rolling IKO bearing, we must pay attention to maintenance.
If the rolling IKO bearing is damaged, how can we deal with it? First of all, let’s understand what is rolling IKO bearing? How to use IKO bearing correctly? Now let me explain the relevant knowledge to you, hoping to help you.
Rolling bearing is a kind of precision mechanical element that changes the sliding friction between the running shaft and the shaft seat into rolling friction, so as to reduce the friction loss
The damage of rolling IKO bearing includes the following situations:
On the one hand, if the rolling IKO bearing can be used correctly without selection error, it can be used for a long time before the service life of IKO bearing.
On the other hand, there are unexpected early damage, and the early damage that can not withstand use. As the reasons for this early damage, there are insufficient consideration on use and lubrication, and then there are foreign matter intrusion, IKO bearing assembly error and shaft burning, insufficient research on shaft and IKO bearing housing, etc. In other words, there are many cases where these reasons coincide with each other.
How to avoid the reoccurrence of rolling IKO bearing damage is as follows:
On the basis of fully understanding the machines used by IKO bearings, service conditions and the peripheral structure of IKO bearings, we must find out what factors are the main conditions, and then investigate in combination with the damage of IKO bearings and various reasons, so as to prevent the recurrence of similar accidents.
The outer spherical ina bearing is also a common ina bearing type. What is the outer spherical INA Bearing? How does the outer spherical INA Bearing work? What are its characteristics?
Question 1: what is the concept of outer spherical INA Bearing?
Answer 1: the outer spherical ball ina bearing is actually a variant of the deep groove ball INA Bearing, which is characterized in that the outer diameter surface of its outer ring is spherical and can be matched into the corresponding concave spherical surface of ina bearing seat to play the role of centering.
Question 2: what are the characteristics of outer spherical ina bearings?
Answer 2: the outer spherical ina bearings are mostly used in rough machinery. When the installation and positioning are not accurate enough, the axis to neutral difference between the shaft and the seat hole, or the shaft is long and the deflection is large, and the accuracy of ina bearings is not high enough, and some structures are rough. Therefore, the actual performance of common performance is quite discounted compared with deep groove ball ina bearings of the same specification.
Question 3: how does the outer spherical INA Bearing work?
Answer 3: it is mainly used to bear the combined radial and axial load dominated by radial load. Generally, it is not suitable to bear the axial load alone. This ina bearing can be installed with inner ring (with full set of rollers and retainer) and outer ring respectively.
The outer spherical ina bearing does not allow the shaft to tilt relative to the housing, which will produce additional axial force under radial load. The axial clearance of outer spherical ina bearing has a great relationship with whether ina bearing can work normally. When the axial clearance is too small, the temperature rise is high; Ina bearing is easy to be damaged when the axial clearance is large.
Therefore, during installation and operation, special attention should be paid to adjusting the axial clearance of INA Bearing. If necessary, pre interference installation can be carried out to increase the rigidity of INA Bearing. How to ensure the normal operation of SKF Bearing in the process of application, how to make SKF Bearing undamaged and make SKF Bearing life longer.
In general, the precautions to ensure the reliable operation of SKF Bearing are as follows:
NTN bearings Clearance should be appropriate.
If it is too large, there will be impact. If it is too small, there will be poor lubrication and Bush burning.
Second: improve the lubrication quality, control the pressure, temperature and flow of engine oil, and strengthen the filtration of engine oil.
Third: the surface quality and geometry of SKF Bearing and journal shall be strictly guaranteed.
Fourth: use fuel oil and lubricating oil that meet the regulations.
Fifth: controlling the temperature state of the diesel engine is disadvantageous in the case of undercooling and overheating. In cold weather, the diesel engine should be preheated before starting, and rotate the crankshaft by hand to make the oil enter the friction surface.
The temperature of IKO bearing can be inferred from the temperature outside the NTN bearings chamber.
It is more appropriate if the oil hole can be used to directly measure the outer ring temperature of IKO bearing.
Generally, the temperature of IKO bearing starts to rise slowly with the operation of IKO bearing, and reaches a stable state after 1-2 hours. The normal temperature of IKO bearing varies with the heat capacity, heat dissipation, speed and load of the machine.NTN bearings
If the lubrication and installation parts are appropriate, the temperature of IKO bearing will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken.NTN bearings
High temperature is also harmful to the lubricant of IKO bearing. Sometimes the overheating of IKO bearing can be attributed to the lubricant of IKO bearing. The causes of high temperature IKO bearings include insufficient or excessive lubrication and lubricant. NTN bearings
It contains impurities, excessive load, IKO bearing ring damage, insufficient clearance, high friction caused by oil seal, etc. Therefore, it is necessary to continuously monitor the temperature of IKO bearing, whether it is measuring IKO bearing itself or other important parts. If the operating conditions remain unchanged, any temperature change can indicate that a fault has occurred.NTN bearings
Regular measurement of IKO bearing temperature can be made by means of thermometer. The important IKO bearing means that when it is damaged, it will cause the shutdown of the equipment. Therefore, this kind of IKO bearing should be equipped with temperature detector. Under normal circumstances, IKO bearings will have a natural temperature rise after just lubrication or re lubrication and last for one or two days.NTN bearings
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