INA Bearing uses a cage made of glass fiber reinforced nylon 66, which is suitable for the steady state of operating temperature of 120 degrees. Oil is used to lubricate the bearing. If the oil contains additives, it may shorten the life in the cage. When the temperature exceeds 120 ℃, PetroChina will shorten the aging life of the cage. Observation and oil change shall be arranged.Limit speed of NSK bearing
The need for grease filling of sealed bearings and the requirements of contact seal life and allowable temperature.Limit speed of NSK bearing
Cutting set temperature and cutting chip temperature, using the experimental method, through a tool, ina bearing can be used to determine the distribution of heat transfer and theoretical calculation of temperature field.Limit speed of NSK bearing
Sealed ina bearings use specially tested high-quality lithium base grease. This grease can withstand a short period of high temperature of 120 degrees. If the stable temperature is 70 degrees or higher, the service life of standard lithium grease will be shortened.Limit speed of NSK bearing
To always work at high temperatures, you must use a special grease, but also pay attention to the need to use heat-resistant materials for sealing. The temperature of standard contact seal shall not exceed 110 degrees.
If you use a high-temperature sealing composite, then you should consider that this very effective fluorine-containing material is more than 300 degrees, which will release gases and smoke harmful to health. Especially in the use of dismantling bearing torch, we should pay more attention to this point.Limit speed of NSK bearing
The contact area between INA Bearing workpiece and cutting tool, due to the effect of heat forming hot end temperature, and the end result side of the tool and workpiece, maintains room temperature and forms the cold end of thermocouple. Limit speed of NSK bearing
The thermoelectric electromotive force that will be generated by the tool and workpiece in circulation. Meter or millivolt potential difference, force recording, according to the pre calibrated thermocouple calibration curve tool, INA Bearing cutting temperature, the average contact surface between the tool and the workpiece can be measured by measuring the workpiece.Limit speed of NSK bearing
In order to ensure that the deformation of ina bearing mounting roll is small, the amount of interference can not be too large, which is offset by high-speed centrifugal force and high-temperature thermal expansion, or the surface with normal pressure. Or surface relaxation, under the premise that the interference amount must be considered, these two factors are carefully calculated under the interference of constant speed and effective amount of high-speed INA Bearing, which may be invalid at room temperature. Limit speed of NSK bearing
When selecting NSK imported bearings, the price of bearings should be taken into account, or bearings with higher load capacity but more expensive, or ordinary bearings should be used to prolong their service life. NSK imported 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 NSK imported bearings of 70000cd series are used to replace deep groove (single row centripetal) ball bearings. These bearings with high load capacity may improve the stress distribution, Or it may have higher fatigue life due to the large number of rolling elements.Limit speed of NSK bearing
Internal factors mainly refer to the three factors that determine the quality of Timken imported bearings, such as structural design, manufacturing process and material quality.Limit speed of NSK bearing
First, the reasonable design and advanced nature of the structure will lead to longer TIMKEN bearing life. The manufacturing of bearings generally goes through multiple processing processes such as forging, heat treatment, turning, grinding and assembly. The rationality, advanced nature and stability of all the processing technologies will also affect the life of TIMKEN imported bearings. Limit speed of NSK bearing
Among them, the heat treatment and grinding processes that affect the quality of Timken imported bearings are often more directly related to the failure of bearings. In recent years, the research on the metamorphic layer of the bearing working surface shows that the grinding process is closely related to the surface quality of Timken imported bearings.Limit speed of NSK bearing
The metallurgical quality of Timken imported bearing materials was once the main factor affecting the early failure of Timken imported rolling bearings. With the development of Metallurgical Technology (such as vacuum degassing of bearing steel), the quality of raw materials has been improved. The proportion of raw material quality factor in Timken imported bearing failure analysis has decreased significantly, but it is still one of the main influencing factors of Timken imported bearing failure. Proper material selection is still a factor that must be considered in bearing failure analysis.Limit speed of NSK bearing
The main task of Timken imported bearing failure analysis is to find out the main factors causing bearing failure according to a large number of background materials, analysis data and failure forms, so as to put forward targeted improvement measures, prolong the service life of Timken imported bearings and avoid sudden early failure of Timken imported bearings.Limit speed of NSK bearing
For sealed Timken imported bearings, appropriate grease has been filled during production; For the bearing, a sealing device is also set in the main engine to prevent the leakage of lubricating grease.Limit speed of NSK bearing
There is a problem of how much grease should be injected into Timken imported bearings.Limit speed of NSK bearing
Too little grease injection is easy to cause lack of grease or dry friction and affect service life. Excessive grease injection will lead to a large amount of grease leakage, which will not only pollute the environment, but also cause waste. It can be seen that the amount of grease injected into Timken imported bearing is the less the better on the premise of ensuring the full lubrication of Timken imported bearing.Limit speed of NSK bearing
Advantages and disadvantages of grease lubrication under normal working conditions, grease lubrication can be used for most Timken imported bearing applications.Limit speed of NSK bearing
The advantage of grease is that it is easier to retain in Timken imported bearing configuration, especially in applications where the vertical axis or axis is inclined at a certain angle. The grease also has the function of sealing, which can prevent the influence of pollutants, moisture or moisture on Timken imported bearings. However, if there is too much grease, it will lead to the increase of bearing working temperature, especially in the application of high speed.Limit speed of NSK bearing
In most cases, the Timken inlet bearing can be completely filled with grease only at the initial stage, while the Timken inlet bearing seat is only filled with an appropriate amount of grease and left with a certain free space. Before fully reaching the working speed, the excess grease must be discharged from the bearing during the running in stage, so that an appropriate amount of grease can be left in the Timken inlet bearing. When the operating temperature drops significantly, it indicates that the grease has run in with the bearing and is evenly distributed in the Timken imported bearing configuration.Limit speed of NSK bearing
Limit speed of NSK bearing
In order to select the appropriate size of NSK imported bearing, the working load, speed and operating temperature of the bearing must be accurately calculated or verified. The load has a great impact on the service life of NSK imported bearings, so although the load is difficult to measure, it should be measured as accurately as possible. Limit speed of NSK bearing
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 NSK imported bearing load is closer to the actual one. If the calculated or measured load is too large, the expected fatigue life of the bearing must be reduced by a greater margin, which must be remedied. Limit speed of NSK bearing
If the installation position allows, NSK imported bearing with a larger size can be selected; If the radial dimension is limited, the wider bearing should be selected when there is a wider bearing; If wider bearings cannot be used, NSK imported bearings with higher load carrying capacity can be used. Limit speed of NSK bearing
When selecting NSK imported bearing materials, 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 the bearing. Of course, the cost of NSK imported bearings made of this kind of high-quality steel is much higher than that of bearings with high load capacity.Limit speed of NSK bearing
However, for bearings that are difficult to access in machines and are extremely difficult to assemble and disassemble, or bearings used in operation machinery in mines and tunnels, where maintenance is extremely difficult, they must still be considered sometimes. For large machinery that cannot be turned by hand, it can be started under no-load state first, and then turn off the power immediately for inertial operation. At this time, after confirming that there is no abnormal vibration or noise and the rotation is normal, enter the power operation.Limit speed of NSK bearing
When entering power operation, start at low speed and no load and gradually reach the specified operating conditions. The power operation inspection is mainly based on the sound, temperature rise and vibration. The cause shall be found out immediately, and the Koyo bearing shall be removed for inspection when necessary.Limit speed of NSK bearing
For the sound inspection of Koyo bearing, generally, a sound stick can be used.Limit speed of NSK bearing
The temperature inspection of Koyo bearing can generally be inferred from the shell temperature, but it is correct to directly measure the temperature of the outer ring of Koyo bearing by using oil hole, etc.
The temperature of Koyo bearing rises gradually from operation. If there is no abnormality, it will reach a stable state after 1-2 hours.Limit speed of NSK bearing
In case of sharp temperature rise or abnormal high temperature, it can be considered that some kind of fault has occurred. First of all, IKO bearing design structure and properties will have a longer service life of the bearing. Bearing manufacturing will go through multiple processes of forging, heat treatment, turning, grinding and assembly. Limit speed of NSK bearing
The rationality, advanced nature and stability of the treatment will also affect the service life of the bearing. The influence of heat treatment and grinding process quality of imported bearing products is often more directly related to bearing failure. In recent years, the study of metamorphic layer on the working surface of bearing has shown that the grinding process and quality of IKO bearing are close to the surface.Limit speed of NSK bearing
Second, the metallurgical quality of IKO bearing material is the main factor affecting the early failure of rolling bearing. With the progress of Metallurgical Technology (such as bearing steel, vacuum degassing, etc.), the quality of raw materials has been improved. The failure analysis of IKO bearing proportion has a significant decline in the factors of raw material quality, bearing failure, but it is still one of the main factors.Limit speed of NSK bearing
Third, IKO bearing is still an appropriate material selection, which must be considered in the failure analysis of imported bearing. The main task of bearing failure analysis is based on a large number of background materials, data and failure mode analysis, failed to find the main factors of the cause, made targeted improvements, and extended the IKO bearing during the service period, so as to avoid unexpected early bearing failure. Installation conditions are one of the important factors in use. Limit speed of NSK bearing
The main factor is often due to the change of stress state of various components between incorrect installation packages, IKO bearings in abnormal operation state and early failure. According to the technical requirements for the installation, use, maintenance and maintenance of IKO imported bearings, the contact load, speed, temperature, vibration, noise and lubrication status of the bearings shall be monitored and inspected, and the causes of abnormalities shall be found immediately and adjusted to make it return to normal. Limit speed of NSK bearing
Timken bearing is an important part of the rear axle drive wheel movement. Timken bearing is the main compound in the work, which can withstand bending and torque and absorb some impact loads at the same time. Limit speed of NSK bearing
The axle integral carbon alloy quenched steel and induction heating hardening commonly used in quenching have a hardened layer depth of 4 – 6mm and a hardness of 50 ~ 55HRC. In the production of Timken bearings, it is found that Timken bearings are often burned out, which seriously affects the induction quenching quality of Timken bearings and parts.Limit speed of NSK bearing
The test shows that the burned out area of Timken bearing is located in coil 225. Expand the regularity of fault characteristics of both sides near the construction site. The limit speed of NSK bearing depends on some specific conditions, including the stability or strength of the cage structure of Ruidian NSK bearing, the lubrication condition of the cage surface, the centrifugal force and rotary force acting on the rolling body, the manufacturing accuracy and other factors that limit the speed of NSK bearing, such as the seals and grease of sealed bearing.Limit speed of NSK bearing
The experience obtained from laboratory experiments and practical applications shows that for technical reasons, or the cost of maintaining the bearing working temperature at an acceptable level is too high, the high speed that NSK bearing can achieve is limited.Limit speed of NSK bearingLimit speed of NSK bearing
The limit speed listed in the product table is only applicable to NSK Bearings with standard cage.Limit speed of NSK bearing
If NSK bearing is required to operate at a speed higher than the limit speed of product calibration, some factors that limit the speed must be improved, such as rotation accuracy, material and structure of cage, lubrication conditions and heat dissipation mode. For more information, please consult Avery.Limit speed of NSK bearing
In the case of grease lubrication, there are more other factors to be considered, such as the lubrication conditions of the cage surface and the shear strength of the lubricant, which depend on the base oil and thickener of the grease. Limit speed of NSK bearing
The friction of some open ball bearings is very low, and the reference speed calibrated in the product parameters may be higher than the limit speed. In this case, it is necessary to compare the allowable speed and limit speed obtained by calculating the bearing, and take the lower value between them.Limit speed of NSK bearing
Please note that in order for NSK bearing to work normally at high speed, it must bear a given small load.
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