Needle roller bearing is a sophisticated infrastructure products, safekeeping and reasonable use of the installation will give you bring satisfactory results. The bearings due to contamination, corrosion, deformation and other factors will affect and damage the quality of the original bearing, you can not achieve the desired results.
First, save: Bearings not exposed to the air, indoor save storage warehouse should be kept clean, dry, stock air relative humidity less than 55%, the temperature should be appropriate, to win the title off temporarily unused sealed bearings should be oiled. Also avoid with acid, alkali and other corrosive substances and chemicals together.
Second, Transportation: needle bearing in delivery due to avoid bump, drop deformation, damage.
Third, the cleaning: In addition to two-sided lid sealed bearings, bearing the rest are added at the factory anti-rust oil, should be cleaned before use, usually immersed in the bearing 8-10% mineral oil mixed with gasoline, Hold one hand and the other hand the inner rotating bezel bearing surface rust wash, wash clean after bearing can no longer rotate, so that after the volatile gasoline, oil or grease injection. Do not glue dust, water, hand sweat, so as not to affect the rotation accuracy and rust.
Fourth, the loading and unloading: the installation of shaft or hole should be smooth, no glitches, if carefully measured the diameter of the shaft or hole standard, identify bearing plane, for mounted shaft bearing can only force acting on the inner ring, mounted bearing in the hole, the force on the outer ring, the force should be evenly distributed over the circumference of the ring face, avoid hard-sided hit, bite avoid skew phenomenon, handling large amount of interference bearings, bearings shall be pre thermal method, the heating temperature is between 90-100 ℃, for double row spherical roller bearings and single cone bearing more attention, because in the garden wall is very thin, and accidentally hole to be broken.
Fifth, check: After bearing installation, you should rotate flexible, non-stop phenomenon stay. Another front bearing factory have checked dimensional accuracy and rotation accuracy, ensure quality, black circle marks on the bearing inner ring and bearing ring chamfer on both quality assurance and inspection methods due process method. Purely normal, does not affect product quality.
First, the lubrication is critical. Select the appropriate lubrication system and high-quality lubricants. The lubricant film due to the oil film bearing surface contact with each other but separated from, and provide the necessary protection against corrosion and wear, and therefore all rotating or reciprocating moving parts, especially in terms of bearings and gears, For normal operation, the lubricant film can not be or missing. Such as splash lubrication or lubrication system, the film also transfer heat. Factories often due to improper lubrication unnecessary downtime and equipment status deteriorated. Oil shortage will lead to increased wear and temperature rise, causing excessive wear and / or early bearing failure and damage. Excessive lubrication, particularly high speed device, due to excessive heat and stir the oil, chemical degradation of the lubricant, can lead to bearing damage.
Proper lubrication, regular maintenance, to avoid damage due to needle bearing lubrication problems caused. Ensure reasonable lubrication should be done:
• Follow the equipment manufacturer for each device using the guidelines set;
• grease when it should be filled with rolling element bearings and housing (or retainer) between, in order to ensure a sufficient amount of grease into the key raceway surface sufficiently lubricated;
• Be careful when greasing the bearings should be;
• monitoring equipment indicating instrument for early detection of signs of problems, such as temperature fluctuations and / or abnormally high temperatures;
• Pay attention to abnormal noise or vibration equipment;
• Observe the lubricant leakage;
• regularly lubricant sampling, and see if contamination.
Second, To improve the performance of needle roller bearings, a reasonable adjustment is very important. Assembly or installation, such as the internal bearing clearance is too large or too small, or in some cases, pre-load is too high, may cause early damage and reduced bearing life. In addition to downtime and costly repairs, the bearing assembly and improper installation may have more negative effects, such as the impact of other parts of the operation, shorten its service life.
According to the device manufacturer's instruction manual, assembly, installation and regular maintenance is the best way to prevent problems arising. If time is tight, you can adjust the device before pushing or remove shims to correct the excessive pine cone Rolling group. On the other hand, bearing adjustment too tight, it may lead to overheating damage, had to replace the bearings. Install the bearing assembly process must be accurate, repeatable, and can be verified after the installation is complete. You must also consider other parts of parameters to optimize system performance.
In addition, in accordance with the requirements of the OEM used equipment, set the appropriate predictive maintenance items, such as monitoring of oil or grease, which should include root cause analysis. Thus, even if the device in question, its uptime can be greatly extended.
Proper lubrication and maintenance is critical, the proper installation and use is indispensable, and then leveraging existing condition monitoring equipment escort. Failure to follow installation and maintenance requirements will result in equipment failure, constitute a major safety hazard.
Bearing installation inspection
Bearing installation is correct or not, has a direct impact on their life and hosts accuracy. If installed properly, bearing not only the vibration, noise, low accuracy, temperature increments big, but there is the risk of stuck burned; on the contrary, the installation goes, not only to ensure accuracy, life will be greatly extended. Therefore, after mounting the bearing, must be tested.
Focus on test items are as follows: After testing the installation location bearing installation, the first test run is touching parts and fixed parts, lubricating oil can flow to flow into the bearing, seal and axial fastening device is properly installed.
In addition to radial clearance test installation with preloaded bearings, the radial clearance should be tested. Deep groove ball bearings can be turned by hand inspection to smooth and flexible, no vibration, no swing around as well. Cylindrical roller and spherical roller bearings are available feeler test, insert the feeler gauge between the rollers and bearing rings, feeler insertion depth should be more than half the length of the roller. When the bearing radial clearance can not be measured with a feeler gauge, measure the amount of movement of the bearing in the axial direction, instead of reducing the amount of radial clearance. Typically, as the bearing inner ring is a conical hole, the amount of movement in the axial direction of the conical surface of the radial clearance is reduced about 15 times the amount.
Bearing radial clearance, after some failed installation can be adjusted, such as angular contact ball bearings, tapered roller bearings; some are modulated in accordance with the manufacture of a good standard, can no longer be adjusted after installation failed, as drawn cup needle roller bearings, deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, spherical roller bearings. After the test, if these bearings installed by unqualified assembly radial clearance is too small, then the selection of the bearing with improper parts or assembly process is not correct. In this case, the bearing must be removed, to identify the reasons, to be re-installed after the elimination. Of course, the bearing clearance is too large too.
Under the extent abutting test bearing and shaft shoulder general, tight fit interference must try to be installed bearing shaft shoulder. Inspection methods:
(1) lighting method. Upcoming lamp bearing and shaft alignment shoulder, watching the situation leaked judgment. If you do not leaked, the installation is correct; even if the surrounding light leakage along the shoulder, did not explain the bearing and the shaft shoulder abutting cope bearing pressure to make it try to be; if there are some leaked, tilt bearing installation instructions, can be hand hammer, copper or tap the bearing inner sleeve, slowly being safe.
(2) feeler test. The thickness of 0.03mm thickness gauge should begin. When the inspection, the bearing inner ring over the entire circumference of the end face and shoulder several test plug, if there is a gap, and very uniform, the bearing is not installed in place described, pressurizing it to deal with the bearing inner ring abutting shaft shoulder; if increased pressure by not tight, indicating too journal fillet fillet portions, the bearing stuck journal fillet should be trimmed to make it smaller; if you find the bearing inner ring face and shoulder bearing the individual parts can feeler by explained not be removed at this time, to be trimmed, re-install.
If the bearing is installed with an interference fit in the housing bore hole when the bearing outer shell retaining shoulder is fixed, its outer face and the shoulder end of the housing aperture stop is try to be, installed correctly, can also be used feeler test.
Thrust bearing inspection after installation
When you install the thrust bearing, should examine the vertical axis of the ring and the shaft centerline. Dial indicator method is fixed to the end face of the enclosure, so that touch the head of the table in the upper bearing shaft rotating bearing raceway, while observing dial gauge pointer, if the pointer deflection, indicating ring and shaft centerline axis is not perpendicular. When the tank shell hole deeper, may use an extension of the dial gauge testing head.
When thrust bearing is installed correctly, the seat can automatically adapt to the rolling of the rolling elements, ensuring located up and down the rolling element raceway. If installed backwards, not only bearing is not working properly, and each of the mating surfaces are heavily worn. Since the shaft ring and seat and the difference is not very clear, the assembly should be careful not to mistake. Furthermore, it should be left between the seat and the bearing bore thrust bearing clearance 0.2-0.5mm, and to compensate for parts processing, installation errors caused by inaccurate, when in operation center offset bearing ring this gap can ensure its automatic adjustment, avoid touching the friction to normal operation. Otherwise, it will cause severe damage to the bearing.
Commissioning, the noise test bearing temperature, vibration meets the requirements. General bearing operating temperature should be below 90 ℃, when the temperature is too high will cause bearing annealing heat or burning, reduce the service life.
