Simple daily maintenance of forklift bearing abnormal conditions.
Contact fatigue failure refers to the failure of the working surface of the bearing due to alternating stress. Contact fatigue spalling occurs on the working surface of forklift bearings, often accompanied by fatigue cracks, which are first generated from the maximum alternating shear stress below the contact surface, and then extend to the surface to form different spalling shapes, such as pitting or pitting spalling, spalling into small flakes called shallow spalling. Due to the gradual expansion of the exfoliation surface, it tends to expand to the deep layer, forming a deep exacher. Deep spalling is a source of fatigue for contact fatigue failure.
Editorial wear failure refers to the failure caused by the continuous wear of the metal on the working surface due to the relative sliding friction between surfaces. Continued wear and tear will lead to gradual deterioration of bearing parts and eventually loss of dimensional accuracy of forklift bearings and other related problems. Wear may affect the shape change, with the increase of clearance and the change of the topography of the working surface, may affect the lubricant or make it polluted to a certain extent and cause the complete loss of lubrication function, thus making the bearing lose the rotation accuracy and even can not run normally.
1. When the bearing runs to a certain period of time (or the maintenance period), remove all the bearings;
2. Soak the bearings with diesel or kerosene for cleaning, and open the sealing cover for cleaning if there are technical conditions
3. After cleaning, the cleaning oil should be dried dry, and the appearance should be checked for damage
4. Use a wooden rod (preferably a hollow tube) with an inner diameter of about 150mm and an equal diameter of the bearing, and fix a bearing at one end
5. While quickly rotating the bearing by hand, put the other end of the wooden stick (wooden tube) on the ear or the audio amplifier microphone to listen to the bearing rotation noise
6. After fixing the bearing, turn the wooden rod laterally to check whether the bearing is worn and loose
7. Forklift bearings with serious looseness, excessive rotation noise and serious defects should be eliminated and replaced with the same model
8. Take a bucket and melt an appropriate amount of grease (high-quality yellow dry oil) with a simmer (not overheated), and soak the tested bearing in the bucket until there is no bubble overflow.
Remove the bearing before the grease cools, and the amount of residual grease is small. After the grease cools, the bearing is removed, and the amount of residual grease is large. Determine the amount of grease residue as needed.
Edit: Use a soft cloth or toilet paper to wipe the grease on the outside of the bearing, and assemble the forklift bearing to the pulley in its original state, and the maintenance work is over.
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Railway bearing maintenance needs to solve the problem of damage cause phenomenon analysis.
When the mechanism is running, the part where the railway bearing is installed is allowed to have a certain temperature, and when the shell of the mechanism is touched by hand, it should be normal not to feel hot, otherwise it indicates that the bearing temperature is too high.
The reasons for the high temperature of the bearing are: the quality of the lubricating oil does not meet the requirements or deteriorates, and the viscosity of the lubricating oil is too highThe mechanism is assembled too tightly (insufficient clearance);The bearing assembly is too tight;The bearing race rotates on the shaft or in the shell;Overloaded;Fragmentation of INA bearings, cages or rolling elements, etc.
Rolling bearings are allowed to have a slight running sound during operation, if the noise is too loud or there is abnormal noise or impact sound, it indicates that the bearing is faulty.
The causes of noise in rolling bearings are complex, one of which is the wear of the mating surfaces of the inner and outer rings of the bearing. Due to this wear, the fit relationship between the bearing and the shell and the railway bearing and the shaft is destroyed, resulting in the axis deviating from the correct position, and the shaft produces abnormal noise when it moves at high speed. When the bearing is fatigued, the metal on the surface will peel off, which will also increase the radial clearance of the INA bearing and produce abnormal noise. In addition, insufficient lubrication of the bearing, the formation of dry friction, and the breakage of the bearing can produce abnormal sounds. After the bearing is worn loosely, the cage is loose and damaged, and abnormal noise will also occur.
1.Bearing maintenance and overhaul essentials.
Maintenance & Overhaul.
In order to maintain the bearings in good condition for as long as possible, maintenance and overhaul are required to prevent accidents, ensure reliable operation, and improve productivity and economy.
Maintenance is best carried out on a regular basis according to the operating conditions of the machine. This includes monitoring of operating conditions, replenishment or replacement of lubricants, and periodic disassembly inspections.
1) Maintenance in the running state INA bearing rotation sound, vibration, temperature maintenance and lubricant characteristics and condition maintenance, judge lubricant replenishment or replacement period.
2) Bearing overhaul in the machinery for regular maintenance and replacement, the take out of the railway bearing fully observed, the track surface condition and whether there is damage, whether it can be reused to confirm.
2.Overhaul in operating condition.
The maintenance items in operation include the rotation sound of the bearing, vibration, temperature, lubricant condition, etc.
1) The rotation sound of the bearing.
Listen to the sound of noise and other ways to investigate the amount and quality of noise.
Even if a small number of railway bearings have abnormal and irregular sounds in the state of fatigue peeling, it is possible to hear them if you are proficient.
Typical anomalous sounds are shown on the next page.
2) Vibration of the bearing.
The amplitude and frequency of the vibration are quantitatively measured and analyzed using a bearing vibrator, and the damage condition of the bearing is inferred from this method.
However, since the operating conditions and measurement position of INA bearings are different, it is necessary to make use of the measured values of the machine to determine the judgment standard.
3) The temperature of the bearing.
The bearing temperature usually rises slowly after the start of operation and reaches saturation after a period of time. The constant temperature of railway bearings varies depending on the mechanical heat capacity, heat release, speed and load.
If the bearing temperature rises abnormally before saturation, stop the operation and take necessary measures for the reasons shown on the following page.
4) Lubrication. Investigation of the grease and lubricating oil in use is effective in understanding the operation of railway bearings. Of course, the leakage, discoloration, and deterioration of grease or oil can be judged by the moisture, debris, and iron powder contained in it.
If lubricant leakage or contamination of foreign substances such as iron powder and metal powder is suspected, the leakage, INA bearing temperature, and vibration are quantitatively observed, and if there is an abnormality, early maintenance is performed.
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