High-power motors in the use of frequent oil leakage phenomenon, significantly manifested in the sliding bearing structure of the oil leakage phenomenon, in the maintenance process, for the motor oil leakage may be the cause of the analysis, came up with the following solutions.
1. Large pressure difference between inside and outside of the sliding bearing. Forced lubrication of the shaft tile, the lubricant itself has a certain pressure, the oil will produce bubbles in the shaft running to produce a certain pressure. Motor in operation due to the fan will produce a certain negative pressure, thus increasing the pressure difference between inside and outside the oil chamber, resulting in oil leakage. In order to balance the pressure difference between inside and outside the oil chamber, the oil chamber and the outside world are equipped with a ventilation pipe to balance the pressure difference, but in the process of use will produce a blockage, so that the pressure inside the oil chamber increases resulting in oil leakage.
Solution: Regularly check whether the balance pipe is loose and clean the oil tank vent pipe in time.
2. Oil pressure adjustment is not in place, resulting in poor oil return. Oil pressure is too high or too low will lead to poor oil return. Oil pressure is too low, resulting in oil in the oil chamber to stay too long, in the operation of the shaft in the process leading to higher temperatures, resulting in oil mist leading to high pressure; oil pressure is too high, will make the return capacity is not enough, so that the oil chamber in the storage of oil is too large, the oil level is too high, thus increasing the internal pressure.
Solution: Adjust the forced lubrication pressure at 0.1 ~ 0.8MPa, so that the oil level of the oil chamber in the sight glass 1/2 ~ 1/3 of the position, and keep the oil back to the appropriate.
3. The unreasonable design of the oil return pipeline can also lead to poor oil return, resulting in increased pressure inside the oil chamber. Return pipeline impurities or pipeline cleaning is not clean, etc. will lead to clogging of the filter, resulting in poor oil return.
Solution: The oil chamber outlet of the oil return line should be on the same level as the oil inlet, and the whole oil return line is inclined at 15° down to the oil return tank, so that the oil return pipe can return oil naturally. At the same time should be regularly cleaned filter and the entire lubricating oil pipeline.
4. floating Palace and shaft contact surface due to long time friction, wear and tear, resulting in excessive clearance between the shaft; floating Palace seal (Figure 1) fixed spring elasticity coefficient changes, so that the floating Palace seal loose, resulting in increased clearance.
Solution: Regular inspection and timely replacement.
5. Seal oil block and shaft contact surface wear gap is too large; seal oil block in the oil return hole is too small or impurities blocked, can not meet the actual oil return volume.
Solution: Replace the sealing oil block and make modification to the sealing oil block. Change the material of the contact surface between sealing oil block and shaft, replace it with wear-resistant material; increase the oil return hole (Fig. 2) to meet the actual oil return needs (not too large).
6. During the installation of plain bearings, the sealing between the upper and lower tile covers of the bearing box and the oil chamber is not properly handled; prolonged operation leads to loosening of the fastening bolts and aging and deterioration of the sealant, which leads to poor sealing.
Solution: In the process of reinstallation, use reliable sealant on the contact surface and apply it evenly and in the right amount. The second time back to install the original sealant must be clean before applying new sealant.
7. Oil quality changes in the oil foam and increasing. In the whole lubrication system, the foam occupies more running space, which leads to the oil pressure inside the oil room increases, the pressure difference is larger resulting in lubricant from the shaft and floating seal and seal oil block and other contact between the shaft gap.
Solution: Regular inspection and analysis of the lubricant, such as oil quality problems should be replaced in a timely manner.
Post time: Jan-11-2024
