CC type double row self-aligning roller bearings, as a high load-bearing capacity self-aligning bearing, are widely used in heavy-duty scenarios such as steel mills, lifting equipment, and port machinery. To ensure its stable operation and extend its service life, the following precautions should be paid special attention to:
1. Precautions during installation
Strictly check the fit tolerance. Before installation, confirm the dimensional accuracy and positional tolerance of the shaft and bearing seat holes to ensure that the fit with the bearing inner and outer rings meets the design requirements. Excessive interference or clearance can lead to early failure of bearings.
Example: Steel mill bearings must meet shaft diameter tolerance ≤ h6 and seat hole tolerance ≤ H7 to ensure alignment performance.
.When standardizing the heating installation process for interference fit, it is recommended to use induction heaters to heat the inner ring of the bearing to 80-100 ℃, in order to avoid material annealing caused by open flame heating.
. The heating temperature should not exceed 120 ℃ to prevent deformation of the holder. After installation, it is necessary to check the fit between the bearing and the shaft shoulder to ensure no axial movement.Retaining frame protection Stamped steel plate retaining frame is sensitive to foreign objects, and clean tools should be used during installation to prevent metal shavings, sand particles, etc. from entering the interior of the bearing.
.II. Maintenance points during operation
Lubrication management should prioritize the use of lithium based pressure grease (such as SKF LGHB2), with a recommended filling amount of 30% -50% of the free space of the bearing.
. Under heavy load conditions, it is necessary to replenish the lubricating grease every 3 months to prevent aging.It is prohibited to mix different brands of lubricating grease to avoid chemical reactions that may cause performance degradation.
.Vibration monitoring: Regularly detect the operating status of bearings through vibration analyzers, focusing on the vibration values of 1st harmonic (shaft misalignment) and 2nd harmonic (bearing defects).
. When the vibration speed exceeds 7.1mm/s, the machine needs to be stopped for inspection.Temperature monitoring: The operating temperature of the bearing should be ≤ 80 ℃. Abnormal temperature rise may be caused by insufficient lubrication, overload, or improper installation.
. Real time monitoring with thermal resistance or infrared thermometer is required.III. Sealing and Protection Measures
When selecting the sealing structure for outdoor or dusty environments, bearings with contact seals (such as 2RS type) should be used to prevent foreign objects from entering.
. Stainless steel sealing rings should be used in water vapor environments, and the wear of the sealing lip should be checked regularly. Rust prevention treatment: When the machine is shut down for a long time, anti rust oil (such as MOLYKOTE G-Rapid Plus) should be applied and moisture-proof packaging should be used. Thoroughly clean and re lubricate before reusing.Fourth, Regular Inspection and Maintenance
Appearance Inspection: Check the surface of the outer ring of the bearing monthly for cracks, wear of the cage, or indentation on the raceway.
. Immediate shutdown is required upon discovery of abnormalities to avoid catastrophic failure.Track and roller inspection: Use an endoscope to inspect the surface of the track every six months, with a focus on fatigue peeling areas.
. When the peeling area exceeds 5% of the raceway area, the bearing needs to be replaced.Alignment performance verification: Measure the bearing alignment angle annually to ensure that it is still within the allowable range of 1 ° -2.5 °.
. Excessive deviation of the alignment angle may lead to intensified shaft vibration.V. Typical Failure Cases and Prevention
Reason for Cage Fracture: Insufficient lubrication leads to abnormal friction between the cage and the rollers.
.Prevention: Ensure that the filling amount of lubricating grease meets the standard, and regularly check the degree of grease contamination (ISO 4406 standard).
. Reason for track peeling: Overloading or improper installation can cause excessive contact stress.Prevention: Check the rated load of the bearing and use hydraulic tools during installation to ensure a centering accuracy of ≤ 0.05mm.
Causes of seal failure: aging of the seal ring or intrusion of foreign objects.
.Prevention: Replace the sealing ring every 2 years, and shorten it to 1 year in harsh environments.
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