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Needle roller bearing is a precision -based products , safekeeping and rational use of the installation will give you bring satisfactory results. The bearings due to contamination, corrosion , distortion and other factors, will affect the quality of the original bearings and damage can not achieve your desired results.
First, save : Bearing not exposed to the air, to save storage warehouse room should be kept clean , dry, stock air relative humidity less than 55% , the temperature should be appropriate, not off to win the title temporarily sealed bearings should be greased . Also avoid with acid, alkali and other corrosive chemicals substances together.
Second, Transportation: needle bearing in delivery to avoid the bump , drop deformation , damage.
Third, cleaning : In addition to two-sided lid sealed bearings , bearing rest are added at the factory rust oil to be cleaned before use , usually bearing immersed in the 8-10 % mineral oil mixed with gasoline , Hold the inner hand wash the other hand rotating bezel bearing surface rust , wash and clean the bearing can no longer be rotated , so that after the volatile gasoline , oil or grease injection . Do not pick up dust , moisture , hand sweat , so as not to affect the rotation accuracy and rust.
Fourth, handling : mounting shaft or bore to be smooth , burr , is carefully measured and the diameter of the shaft or bore standard , identify bearing plane, a bearing for the shaft mounted only allowed a force acting on the inner ring, fitted bearing in the hole , the force on the outer ring, the force should be evenly distributed on the circumference of the ferrule end face , avoid hitting hard -sided , to avoid the phenomenon of skewed bite , handling a large amount of interference bearings , bearings shall be used for pre- thermal method , the heating temperature is between 90-100 ℃, the double row spherical roller bearings and single cone bearing more attention , because the garden wall is thin , the hole should accidentally broken .
Fifth, check : After installing the bearing should rotate flexible, non phenomenon stay ended . Another front bearing factory have checked dimensional accuracy and precision rotation, to ensure quality, black circle marks on the bearing inner and outer rings and bearing ring chamfer on the quality assurance processes are methods and inspection methods due. Entirely normal and 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 and separated, and provides the necessary protection for corrosion and wear , and therefore the rotation or reciprocating movement of all parts, especially the bearings and gears , the additional normal operation , oil film not or missing . As for the splash lubrication or lubrication system , the film also transfer heat . Factories often due to improper lubrication unnecessary downtime and equipment status deteriorated. Supply shortage will lead to increased wear and temperature rise , resulting in excessive wear and / or early bearing failure and damage. Excessive lubrication , especially high-speed operation of the device, because of the oil agitation excessive heat, chemical degradation of the lubricant , can lead to bearing damage.
Proper lubrication, regular maintenance , needle roller bearings to avoid damage caused by lubrication problems . Ensure reasonable lubrication should be done:
• Follow the equipment manufacturer for each device set user guide ;
• grease when it should be filled with rolling elements and bearing housing ( or retainer ) between , in order to ensure a sufficient amount of grease into the key raceway surface sufficiently lubricated ;
• It should be noted when the bearing grease should be added ;
• monitoring equipment indicating instrument for early detection of signs of problems , such as temperature fluctuations and / or abnormally high temperatures ;
• Note that the device noise or abnormal vibration ;
• observe the oil leak ;
• Regular oil sampling , and see if contamination.
Second , for needle roller bearings to improve performance , reasonable adjustments is very important. Assembly or installation, as the bearing internal clearance is too large or too small , or in some cases , pre-load is too high , it may cause early damage and shorten the life of the bearing . In addition to causing downtime and costly repairs , the bearing assembly and improper installation may have more negative effects, such as the impact on other parts of the operation , shorten its service life .
The apparatus according to the manufacturer's manual for assembly, installation and regular maintenance is the best way to prevent problems arise. If time is tight , you can adjust the device before pushing or remove shims to correct the over- tapered rolling bearings set loose . On the other hand , bearing adjustment too tight , it may lead to overheating and damage , had to replace the bearings. Bearing assembly installation process must be accurate , repeatable, and can be verified after installation is complete. In addition you must also consider other parts parameters to optimize system performance.
In addition, in accordance with the requirements of the use of OEM equipment , set the appropriate predictive maintenance projects, such as the monitoring of oil or grease , which should include root cause analysis . Thus , even if the device in question , its normal running time can be greatly extended.
Proper lubrication and maintenance is critical, the proper installation and use is indispensable , and then leverage existing condition monitoring equipment escort . Failure to follow the installation and maintenance requirements will result in equipment failure , constitute a major security risk.
Bearing installation inspection
Bearing installation is correct or not , has a direct impact on their life and hosts accuracy. If improperly installed , bearing not only the vibration, noise , low accuracy , temperature increment large, and there is the risk of stuck burned ; Instead, install well, not only to ensure accuracy, life will be greatly extended. Therefore , after mounting the bearing must be tested.
Focus test items as follows : After testing the installation position of the bearing installation, first test run parts and fixed parts are touching , lubricating oil can flow to flow bearings, seals and axial fastening device is installed correctly.
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 child and the roller bearing rings , feeler insertion depth should be more than 1 / 2 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 , if the bearing inner ring with tapered bore , in the axial movement of the conical surface of the radial clearance is reduced about 15 times the amount .
Bearing radial clearance , after some unqualified installation can be adjusted , such as angular contact ball bearings, tapered roller bearings ; others are modulated in the manufacture of a good standard requirements , failure can no longer be adjusted after installation , as drawn cup needle roller bearings, deep groove ball bearings , aligning ball bearings , cylindrical roller bearings, spherical roller bearings. After the installation has been tested if these bearings failed, radial assembly clearance is too small, then the choice of bearings with improper processing or assembly parts are incorrect. In this case, you must remove the bearings , to identify the reasons , to be reinstalled after the elimination . Of course, the bearing clearance is too large too.
Under the extent of testing bearings and shaft shoulder abutting the general situation , a tight interference fit bearings must be mounted close together shoulder . Inspection methods:
( 1 ) lighting method. Upcoming lamp aligning bearings and shaft shoulder , watching leaked case judgments. If you do not leaked , the instructions to install correctly ; If evenly along the axis light leakage around the shoulders , indicating that the bearing is not in close contact with the shaft shoulder , applying pressure to respond to the abutting bearing ; If some leaked , tilt bearing installation instructions , can be hand hammer , copper or tap the bearing inner sleeve , slowly Anzheng .
( 2 ) feeler test method. Feeler thickness shall be 0. 03mm starts. When tested on the entire circumference of the end face of the bearing inner ring and the shaft shoulder several test plug , and if there is a uniform gap , the bearing is not described in place, the response to the pressure bearing inner ring abutting shaft shoulder ; increased if pressure by not tight , indicating the journal fillet fillet parts too , stuck to the bearing , the journal fillet should be trimmed so that it becomes smaller ; If you find that the end face of the bearing inner ring and the bearing shoulder feeler individual parts can by this time must be removed without explanation , to be trimmed , re-install.
If the bearing is installed with an interference fit in the bearing bore , the bearing outer ring is fixed to the housing bore shoulder block , its outer end and the end face of the housing bore shoulder block is in close contact , installed correctly , can also be used feeler test.
After testing the thrust bearing installation
When installing the thrust bearing , should examine the vertical axis of the ring and shaft centerline. Method is to dial gauge fixed on the end face of the enclosure , so that touch the head of the table in the upper bearing shaft rotating bearing ring 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 , but also test dial gauge head with lengthened .
When the 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 mating surface would be subjected to severe wear . As the shaft ring and seat ring 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 bearing ring center offset this gap can ensure its automatic adjustment to 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 , the heat will cause the bearing annealing or burning, reduce service life.
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