Bearing Maintenance

Rust, corrosion
Injury Status: rust and corrosion of spherical ball bearings have raceways round of pit-like rolling surface rust, rust and corrosion round.
The reason: water, corrosive substances (paint, gas, etc.) intrusion. Lubricants inappropriate. Due to condensation of water vapor with water droplets. Temperature and humidity when stopped. During transport heavy rustproof bad. Inappropriate custody status. Inappropriate use.
Measures: to improve the sealing device. Research lubrication. Turn when stopping corrosion protection. Improve storage methods. To be used with caution.
Installation scars
Damage state: When you use during installation and removal, etc. to the roll axis linear scars road surface and rolling surface caused.
Cause: The installation, disassembly of the inner and outer rings tilt installation, impact load of destruction.
Measures: the impact load to prevent the use of appropriate tools to use punch. Centering each other during installation.
Discolor
Damage state: As temperatures rise and lubricants reactions, raceways and rolling elements and the wheel cage discoloration.
The reason: poor lubrication. Causing hot oiled and reflect lubricant. Large temperature rise.
Measures: improving lubrication.
From the foregoing, regardless of the gap can be adjusted or non-adjustable gap bearings, they have to adjust the axial clearance in the assembly (the gap is not adjustable but some do not have to stay thrust roller bearing xial clearance), when the temperature rises to compensate for shaft the thermal elongation, thus ensuring the normal operation of thrust ball bearing body. If the axial clearance is too small, it will cause the bearing to rotate difficulties, fever, and even bearing body stuck or damaged; if the axial clearance is too large, it will result in different sound operation, vibration or even cause serious damage to the retainer .

Thrust ball bearings common faults and necessary remedial measures

Bearings and shaft diameter or bearing bore interference small, multi-use push method assembly. The easiest way is to use copper and hand hammer, according to a certain order to beat self aligning bearing with symmetrical interference fit of the seat, the thrust ball bearings successfully pushed. Alternatively, use a soft metal hammer into the casing by hand or push press. If improper operation, will make the seat deformation cracking, or hammering at the hands of non-interference fit on the seat, then make the body produce bearing raceways and indentation or indirect bearing is damaged.
Bearing in the assembly, if interference with the shaft diameter is large, the general assembly of thermal loading method. Upcoming needle roller bearings into drums filled with oil, the oil drums external heating with hot water or flame, the process requires heating the oil temperature control at 80 ℃ ~ 90 ℃, generally not more than 100 ℃, up to no more than 120 ℃. Quickly removed after the suit in the journal bearing heating. If the temperature control to improper heating temperature is too high, then make the bearings caused tempering hardness decreased, thrust ball bearings running on easy to wear, peeling, or even cracking.
Stripped
Injury Status: under load bearing and then rotate the inner ring, outer ring raceway or rolling a decent showing scaly due to rolling fatigue peeling phenomenon.
Cause: The load is too large. Install bad (non-linearity) torque loads foreign invasion, water. Poor lubrication, improper lubricant thrust ball bearing clearance inappropriate. Bearing box accuracy is not good, the deflection of the bearing box uneven shaft rigidity large rust, caused by the development of erosion points, scratches and indentations (surface deformation phenomena).
Measures: The size and re-use of the Institute to improve the load agricultural bearings checking installation methods to improve the sealing device shutdown rust. Using the appropriate viscosity lubricant to improve lubrication method. Check the shaft and precision bearing housing. Check the clearance.
Peeling.

Self-aligning ball bearings judgment in the use of the method of fault maintenance

bearings exhibit during its use in the strong regularity and repeatability is very good. Normal quality Full complement cylindrical roller bearing (Bearings) at the start of use, vibration and noise are relatively small, but some scattered spectrum amplitude are small, may be due to some defect in the manufacturing process, such as the surface of burrs caused.
Some time after exercise, maintain a certain level of vibration and noise, the spectrum is a single, there is only one or two multiplier. Rarely occurs more than three times the power frequency spectrum, self-aligning ball bearing condition is very stable to stable period.
After continuing to run into the post-use, bearing vibration and noise begins to increase, sometimes different sound, but changes in vibration increases more slowly this time, suddenly began bearing kurtosis value reaches a certain value. We believe that at this time that the performance of the initial bearing failure.
At this time, it requires close monitoring of the  bearings, pay close attention to the changes. Since then, single direction thrust ball bearing kurtosis began a rapid decline, and close to normal, and the vibration and noise began to significantly increase its growth began to accelerate dramatically, when the vibration exceeds the vibration standards (such as ISO2372 standard), which began bearing kurtosis Rapid increases, when both exceed vibration standards, and kurtosis values ​​than normal (available kurtosis relative standard), we believe that self-aligning ball bearing has entered the late failure of production, the need for timely maintenance equipment, replacement of bearings.
bearings exhibit features advanced fault to a serious failure (usually as axle bearing damage, burns, sand shelf spallation, raceway, wear beads, etc.) is not more than a week the big time, the greater the equipment capacity, the faster the speed, The shorter time intervals. Therefore, the actual self-aligning ball bearing fault diagnosis, once found fault with advanced features, faulty judgment should be decisive rolling mill bearing arrangements for maintenance as soon as possible.
Use the adjustment factor mainly refers to the installation, use and maintenance, repair and other maintenance meets the technical requirements. According to bearing installation, use, maintenance, maintenance of the technical requirements for the operation of bearings to withstand load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, abnormal immediately find reasons to adjust, to return to normal.
First, the spindle of the spindle bearings in operation, to fully ensure lubrication, and regularly add oil according to the actual situation, not long off the oil. So, for the user enterprise, should be used better and more appropriate spindle oil. New special spindle oil can significantly improve the lubrication performance, extended drain intervals, extend the spindle and self-aligning ball bearing life, but also has good rust and corrosion performance.
Secondly, the use of reinforced nylon material bearing cage, temperature should be below 120 ℃, non-oil cooking cleaning.
In addition, the spindle maintenance cleaning method should pay attention to prevent damage, scratches the roller surface. bearing parts to try to clear the residue should be rinsed clean bolster internal suction method is better than oil. Should be taken to avoid the use of cleaning garbage dump type leaving residues accumulate in the bearing area, leading to self-aligning ball bearing noise, wear failure and other problems.

Aligning ball bearing failure in the use of reason analysis

According to incomplete statistics, cement fan failure rate of abnormal vibration and up to 58.6% maximum, due to vibration will cause the fan to run unbalanced. Which,  thin section angular contact bearings with adapter sleeve to adjust properly, can cause abnormal bearing temperature and vibration. If a cement plant during equipment maintenance and replacement of the turbine vanes. Vanes on both sides with an adapter sleeve bearings and bearing a fixed match. Re-test the free end of the bearing temperature occurs, the value of high vibration failures. Open housing cap, manual slow rotating fans, found in a particular location shaft bearing roller, roll the situation there in a non-load area, which can determine changes in the high bearing running clearance and the installation space may be insufficient. After measuring that, self-aligning ball single-row crossed roller slewing bearing internal clearance of only 0.04mm, the eccentric shaft up to 0.18mm.
Preferred to correctly grasp the bearing parts in mechanical devices used to select suitable bearing premise. Whom, the following aspects need to obtain data and information:
1, the function and structure of mechanical devices
2, bearing the use of the site
3, bearing load (size, direction)
4, the rotational speed
5, vibration, shock
6, the bearing temperature (ambient temperature, temperature)
7. Select the ambient atmosphere (corrosive, cleaning, lubrication) usually bearing configuration.
bearing shaft is a two-aligning ball bearings in radial and axial be supported at this time, the side of the bearing is called a fixed-side bearing its two kinds of radial and axial loads from the fixed axis and effect relative axial displacement between the bearing housing. The other side is called the free side, only radial loads, axial relative movement, in order to solve the problem and retractable portion angular contact ball bearing installation interval error due to temperature changes resulting from the axis. For fixed-side bearing, the rolling bearing need to select an available surface in the axial direction to the mounting surface to move or moves. In a relatively short shaft, and the free-side fixed-side little other cases, the use of only one-way axial movement of the fixed bearing. Select the type of the selected bearing bearing type, self-aligning ball bearings to fully grasp the conditions of use are essential.

Thrust ball bearings imported process need to pay attention

Imported thrust ball bearings in addition to excellent quality, they are all very precise parts, both high-performance import thrust ball ferris wheel bearing  if used improperly during use, not only fail to achieve performance results, and very easy to import thrust ball bearing damage, in lubrication we certainly have attention.
First, when used carefully to be allowed to install a powerful punch, does not allow a direct hit with a hammer bearing, are not allowed to pass through the rolling pressure.
Second, the use of appropriate, accurate installation tools to make use of special tools, try to avoid using fabric and staple fiber stuff like that.
Third, try to keep clean thrust ball bearings imported and its surroundings smile even invisible dust into the mobile crane bearing  will increase wear, vibration and noise of the bearing.
Fourth, to prevent the import of thrust ball bearings rust bare hands when handling the import thrust ball bearings, to fully wash hands sweat, and coated with high quality mineral oil and then operate in the rainy season and summer with particular attention to prevention rust.
In some special operating conditions, import thrust ball bearings can get a longer life than traditional computing, especially in the light-load conditions. These particular operating conditions that, when the rolling surface (track and rolling elements) are effectively separated and limit pollutants may cause surface damage of a lubricant film. In fact, under ideal conditions, the so-called permanent import thrust ball bearing life is possible.

Spherical roller bearing temperature rise causes and treatment methods

When the bearing temperature rises, first determine whether the malfunction, as indeed increased, should be treated as follows:
1, bearing installation position is not correct, it will cause a large ball end and bearing inner race and outer race gear units of the axial force, resulting in bearing overheating.
2, the best selection of bearings specified levels of precision linear motion bearings.
3, using the bearing shaft bending or fever caused by different heart box hole solution is to repair the spindle
4, bearing belt too tight cause fever solution is to adjust the belt so elastic appropriate.
5, the heat caused by poor lubrication solution is chosen lubricating materials specified grades and properly cleaned.
6, the heat caused by the low quality of assembly solution is to improve the quality of assembly.
7, bearing in the housing causing fever lap solution is to replace worn parts bearings and related balance correct impeller diameter and check static equilibrium value
8, the axial force caused by too much heat solution is clean, align the seal ring clearance requirements
9, bearing damage caused by the heat of solution is to replace the bearings. When we use spherical roller bearings, and if we find that under high temperature conditions, then quickly stop the operation of equipment, and then to find out why, and processed in accordance with the above solutions provided, but may be due to bearing fever for different reasons, so the solution in different ways, they still want to treat specific conditions, completed with the help of the technical staff.

The reason cylindrical roller bearing failure analysis failure

Before cylindrical roller bearings completely destroyed, it provides users find enough time, do not ignore the existence of such friction, it will make riding the rate of decline, so long-distance physical consumption bigger slower. If the surface roughness for fine, if appropriate lubricant film thickness, the probability of surface stress generated quite low, which is why the proper selection of a suitable lubricating oil to reason, however, if the load exceeds the pressure the film's pu value (fatigue load limits, such as high speed, high pressure shock), the fatigue of materials will come sooner or later.
Cylindrical roller bearings metallurgical data quality was once the primary factor affecting early bearing out effective. Followed by metallurgical skills (such as bearing steel vacuum degassing, etc.) to improve the original data quality improvement. Raw material quality factors bearing out the efficiency analysis in the proportion had clearly declined, but it is still one of the main factors bearing out the effect of the impact. Proper selection can still be bearing out the efficiency analysis is necessary to think of the elements.
Cylindrical roller bearings off the primary obligation of efficiency analysis is based on a lot of sets of information, analyze data, and out-efficient way, the primary elements of the bearing to find out the effect of the formation, so that puts forward improved ways to extend bearing service constitutes execution , to prevent the onset of unexpected early bearing off effect.
(1), the impact of cylindrical roller bearing fatigue life factor very much, can not be estimated or through standardized test to eliminate all the premise, which forms bearing fatigue life of the great practice of discrete, thus bearing dejected expression parameter for life extra life L10, R281 in the ISO specification referral understand the meaning of the L10 following rules:
"The number enough thrust roller bearing the same group, with its extra revolutions L10 life (or unchanged by the number of hours to disclose the performance in speed, bearing 90% of the batch before the occurrence of fatigue exploitation can reach or exceed this the number of revolutions (or hours). "So far, the world's nations are subject to the above rules.
In the United States and other countries, and also with the use of the concept of the value of life. Median life means a group of the same LM cylindrical roller bearings of the median life, meaning 50% of a bearing before fatigue spalling can reach or exceed the total number of revolutions or rotational speed of the tasks in a number of inevitable from time to time, the value LM bearing life is not the life of a group of arithmetic uniform value. The median life expectancy of ordinary LM is about five times the extra life.
(2), the concept of extra life together only for a sufficient number of the number of bearings, and the sub for a single bearing.
40 sets of 6204 patients if their use shall be regarded as bearing its lifetime 1000h without additional episodes dejected destroyed, the other four sets is possible that less than 1000h showing off dejected efficient excavator bearing, meaning extra fatigue life on behalf of these cylindrical Roller bearings in the information to develop their potential to the normal life of hope. Thus greatly in both conditions, the user selects the cylindrical roller bearing fatigue life is still first for accounting, and then based on the practice of checking out the effect of categories, such as checking the wear life, take the smaller value accounting consequences bearing life calculation .
The reason cylindrical roller bearings in advance damaged (improper lubrication)
Although you can install the "maintenance" of the rubber seal bearing, but the early failure of the bearings are still 36 percentage is due to the incorrect application of grease caused.
Any improper lubrication of cylindrical roller bearings, early failure are inevitable, due to the plastic hub ball and roller combined bearing is not easy to dismantle the site, and congenital incorrect use grease, while later use without replacing the grease, or not promptly replaced after deterioration pollution carbonized grease, your hub is difficult to have a sufficiently long life and good lubrication.

Four cylindrical roller bearing temperature and vibration troubleshooting methods

A bearing vibration:
Bearing vibration of the bearing damage is very sensitive, such as peeling, indentation, corrosion, cracks, wear, etc. will be in four cylindrical roller bearing vibration measurement reflected, therefore, through the use of special bearing vibration measurements (frequency analyzer, etc. ) measure the size of vibration frequency can not be inferred by abnormal circumstances. The measured values ​​due to the conditions of use or the sensor mounting position of the bearing, etc., and therefore requires prior to measurements after the analysis of each machine were compared to determine the criteria.
Two, bearing temperature:
The bearing temperature, generally room temperature outside the bearing can be inferred, if the use of the hole can be measured directly bearing outer ring temperature, is more appropriate position.
Typically, four cylindrical roller bearings with four point contact ball slewing bearing operating temperature slowly began to rise 1-2 hours to reach steady state. The normal temperature of the bearing due to heat capacity, heat capacity, speed and load of the machine and different. If lubrication, install the appropriate department, the bearing temperature will be rapid rise, there will be abnormal high temperature, when to stop running and take the necessary precautions.
You can always use the thermal sensor to monitor bearing operating temperature, and automatic alarm or stop to prevent burning shaft accident temperature exceeds a predetermined value.
Four row cylindrical roller bearing fault characteristic showed severe failure does not exceed a week when a large, larger equipment, capacity, speed, the shorter time interval. Therefore, the actual bearing fault diagnosis, once found fault with advanced features, should decisively determine the spherical roller bearing failure, repair as soon as possible.
1, the shaft and the bearing chamber tolerances choice and control: bearings pressed into the bearing should be flexible rotation without blocking sensation. If significant rotation is not flexible, it means that the shaft size is too big, the tolerance to be reduced.
2, the bearing assembly methods: Because spherical roller bearing are precision products, such as improper assembly easy on the four-row cylindrical roller bearing channel damage, leading to bearing damage.
3, the assembly to prevent foreign bodies: four-row cylindrical roller bearings in the rotor balancing equipment to do when it is easy to scrap generated when balancing into the interior of the bearing, so it is best to do before loading bearing balancing.
4, paint rust prevention: after the paint rust is characterized by multiple sealed-type motor, the motor assembly, sound good, but put in the warehouse for some time, the motor becomes very abnormal sound, remove the bearing severe rusting.
Four row cylindrical roller bearings in the process of checking, if too many problems, but also that this may be counterfeit bearings imported bearings. That is to remind everyone in the choice must be careful.