Elimination of oilless bearing using process problems
oilless bearings in the work to allow a slight operation of the sound, if the sound is too large or there is no abnormal noise or impact, then the oilless bearing failure.
Rolling bearing noise causes more complex, one is the bearing, the outer ring with the surface wear. As a result of this wear and tear, damage the bearing and shell, bearing and shaft with the relationship, resulting in the axis deviation from the correct position in the shaft at high speed movement abnormal sound. When the bearing fatigue, the surface of the metal peeling off, but also the bearing radial clearance increased abnormal sound. In addition, INA bearing lubrication is insufficient, the formation of dry friction, and bearing broken and so will produce abnormal sound. oilless bearing wear loose, the cage loose damage, will produce abnormal sound.
In the operation of the body, the installation of the bearing parts allow a certain temperature, when the hand touch the body shell, should not feel hot as normal, otherwise it shows that the bearing temperature is too high.
Lubricant quality does not meet the requirements or deterioration, the viscosity of the lubricating oil is too high; the assembly is too tight (gap is insufficient); INA bearing assembly is too tight; oil bearing race ring on the shaft or shell rotation; load is too large; bearing cage Or rolling elements such as fragmentation.
From the peeling, indentation, corrosion, cracks, wear, etc. will be reflected in the INA bearing vibration measurement, bearing vibration on the oilless bearing damage is very sensitive, so by using a special oilless bearing vibration measuring device (frequency analysis Etc.) can measure the size of the vibration, through the frequency can not be inferred from the specific circumstances of the exception. Since the measured values are different depending on the conditions of use of the bearings or the position of the sensor installation, it is necessary to determine the judgment criteria after analyzing and comparing the measured values of each machine in advance.
Because the INA oilless bearing even if there is a slight divestiture damage, but also issued an abnormal sound and irregular sound, so the sensor can be used to distinguish, the use of sound, the operation of the oilless bearings rolling sound size and sound quality to carry out Check, play the role of early prevention.
If the use of oil hole can directly measure the bearing outer ring temperature, the more appropriate. Under normal circumstances, INA bearing the temperature, generally based on the bearing outside the room temperature can be speculated. If the lubrication, the installation of appropriate, the bearing temperature will rise sharply, there will be abnormal high temperature, then must stop running, take the necessary precautions. Normally, the temperature of the bearing rises slowly as the operation begins, reaching a steady state after 1-2 hours. The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If necessary, the use of thermal sensors can be monitored at any time the operating temperature of oilless bearings, and to achieve the temperature exceeds the specified value when the police automatically stop or stop the prevention of combustion shaft accidents.
Domestic for oilless bearing wear is generally used in welding, bracing sets, playing pitting and other methods, but when the shaft material for the 45 steel (quenched and tempered), if only the use of surfacing treatment, will produce welding Internal stress, in the case of heavy load or high-speed operation, there may be cracks in the shoulder and even fracture phenomenon, if the use of stress relief annealing, it is difficult to operate, and the processing cycle is long, maintenance costs; when the shaft material HT200 When the use of cast iron welding is not ideal. Some of the higher maintenance companies will use brush plating, laser welding, micro-arc oilless bearing welding and even cold welding, etc., these maintenance techniques often require higher requirements and high costs.