When installing self-aligning roller bearings for fans, it is necessary to control the details in three stages: preparation before installation, operation during installation, and inspection after installation, to ensure the coaxiality, lubrication effect, and operational stability of the bearings and the fan spindle. The following are specific precautions:
1. Preparation stage before installation
Inspection of bearings and accessories
Appearance integrity: Check for cracks, rust, or wear on the inner and outer rings, rollers, retainers, and other components of the bearing, especially paying attention to whether the sealing ring is intact (if it is a sealed bearing).
Dimensional compatibility: Check whether the parameters such as bearing inner diameter, outer diameter, width, etc. are consistent with the dimensions of the fan spindle and bearing seat, to avoid installation difficulties or operational delays caused by dimensional deviations.
.Accessory integrity: Confirm that the random accessories (such as locking nuts, washers, seals) are complete and free from damage or deformation.
.Installation environment cleaning
Work area cleaning: Remove dust, metal shavings, and other impurities from the installation site to prevent them from entering the bearing interior, affecting lubrication effectiveness or causing wear.
.Tool cleaning: Clean tools such as wrenches and micrometers before use to avoid contamination of bearings or spindles with oil or impurities on the tools.
.Lubrication preparation
Lubricant selection: Select the appropriate lubricating grease (such as lithium based grease, polyurea based grease) according to the fan operating conditions (such as speed, temperature, load), ensuring that its viscosity and extreme pressure resistance meet the requirements.
.Lubrication control: The filling amount of lubricating grease should be moderate, usually 1/3~1/2 of the internal space of the bearing. Too much will cause excessive temperature rise, while too little will result in insufficient lubrication.
.II. Installation Process Operation Stage
Treatment of Spindle and Bearing Seat
Spindle Cleaning and Inspection: Use non-woven fabric dipped in alcohol or special cleaning agent to wipe the installation area of the spindle, ensuring that there is no oil, rust or burrs;
; Check the spindle runout, with a deviation of ≤ 0.01mm.Bearing seat installation surface inspection: Confirm that the bearing seat installation surface is flat, without deformation or protrusions;
; If it is a split type bearing seat, the gap between the upper and lower half joints should be checked, and the gap should be ≤ 0.05mm.Bearing heating and installation
Heating method selection: Induction heater or oil bath heating (temperature 80-100 ℃) should be preferred to avoid bearing annealing or deformation caused by open flame heating; After heating, it needs to be installed immediately to prevent shrinkage caused by temperature drop.
Installation direction confirmation: Determine the installation direction based on the bearing structure (such as the inner ring with a blocking edge and the outer ring with an oil groove), ensuring that the matching between the blocking edge or oil groove and the fan spindle and bearing seat meets the design requirements.
.Installation tool usage: Use a specialized press in tool or copper rod to gently tap the inner ring of the bearing, avoiding direct tapping of the outer ring or rollers to prevent bearing damage;
; The installation force should be uniform to avoid bearing jamming caused by unbalanced load. Locking and sealing treatmentTorque control of locking nut: According to the bearing manual, use a torque wrench to tighten the locking nut in stages (such as initial torque of 50% of rated torque and final torque of 100%), to prevent over tightening from causing excessive bearing preload or loosening during operation.
.Sealing installation: If the bearing is equipped with a sealing ring, it is necessary to ensure that the sealing ring is not twisted or damaged;
; Apply a small amount of lubricating grease during installation to reduce friction and improve sealing effectiveness.III. Post installation inspection stage
Pre operation inspection
Manual turning test: manually rotate the fan spindle to check whether the bearing rotates flexibly, whether there is any jamming or abnormal noise;
; If it is a belt driven fan, it is necessary to check whether the belt tension is appropriate.Gap measurement: Use a feeler gauge or micrometer to measure the bearing clearance (radial clearance is usually 0.05~0.15mm), ensuring that the clearance is within the design range and avoiding vibration or heating caused by excessive clearance or insufficient clearance.
.Initial operation monitoring
Temperature rise monitoring: After starting the fan, use an infrared thermometer to monitor the bearing temperature. The temperature rise should be ≤ 15 ℃ within 1-2 hours of operation, and the final stable temperature should be ≤ 70 ℃ (when the ambient temperature is 40 ℃).
.Vibration detection: Use a vibration analyzer to detect the vibration value of the bearing. The effective value of the axial vibration velocity should be ≤ 4.5mm/s, and the effective value of the radial vibration velocity should be ≤ 7.1mm/s.
.Noise assessment: Auscultation should be conducted at a distance of 1 meter from the fan, and the running noise of the bearings should be uniform and free of noise. If there is periodic abnormal noise (such as "buzzing" sound), it may be due to bearing damage or improper installation.
.Long term maintenance recommendation
Regular lubrication: Add or replace lubricating grease according to the running time of the fan (such as every 2000 hours) to avoid bearing wear caused by grease aging.
.Regular inspection: Check the bearing clearance, seal condition, and locking nut tightening every 3 months, and promptly address any issues found.
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