The causes and treatment of oil leakage in motor sliding bearings: High power motors frequently experience oil leakage during use, particularly in the sliding bearing structure. During maintenance and repair, the possible causes of oil leakage in the motor were analyzed and the following solutions were proposed.
1. The pressure difference between the inside and outside of the sliding bearing is large. Forced lubrication of the bearing pads, the lubricating oil itself has a certain pressure, and during the operation of the shaft, the oil will generate bubbles, resulting in a certain pressure. When the motor is running, a certain negative pressure will be generated due to the action of the fan, which will increase the pressure difference between the oil chamber and the outside, leading to oil leakage. In order to balance the pressure difference between the inside and outside of the oil chamber, the oil chamber and the outside are equipped with a Submarine snorkel for pressure difference balance. However, in the process of use, blockage will occur, which will increase the pressure in the oil chamber and cause oil leakage.
Solution: Regularly check whether the balance pipe is loose and timely clean the oil tank Submarine snorkel.
2. Improper adjustment of oil pressure leads to poor oil return. High or low oil pressure can cause poor oil return. The oil pressure is too low, causing the oil to stay in the oil chamber for too long, causing the temperature to rise during the operation of the shaft, resulting in oil mist and high pressure; If the oil pressure is too high, it will result in insufficient oil return capacity, resulting in an excessive amount of oil stored in the oil chamber, resulting in a higher oil level and increased internal pressure.
Solution: Adjust the forced lubrication pressure to 0.1~0.8MPa, so that the oil level in the oil chamber is at the position of 1/2~1/3 of the sight glass, and it is advisable to keep the return oil unobstructed.
3. Unreasonable design of the oil return pipeline can also lead to poor oil return, leading to increased pressure in the oil chamber. Impurities in the return oil pipeline or unclean cleaning in the pipeline can lead to clogging of the filter, resulting in poor return oil.
Solution: The oil chamber outlet of the return pipeline should be on the same level as the oil inlet, and the entire return pipeline should be tilted at a 15 ° angle to the return tank, so that the return pipeline can naturally return oil. At the same time, the filter and the entire lubricating oil pipeline should be cleaned regularly.
4. The contact surface between the floating palace and the shaft is severely worn due to prolonged friction, resulting in excessive clearance between the palace and the shaft; The elastic coefficient of the fixed spring of the floating palace seal changes, causing the floating palace seal to loosen and leading to a larger gap.
Solution: Regular inspection and timely replacement.
5. The wear of the contact surface between the sealing oil baffle and the shaft causes excessive clearance; The return oil hole in the sealed oil baffle is too small or blocked by impurities, which cannot meet the actual return oil volume.
Solution: Replace the sealing oil baffle and modify it. Change the material of the contact surface between the sealing oil baffle and the shaft to wear-resistant material; Enlarge the oil return hole to meet the actual oil return needs (not too large).
6. During the installation process of sliding bearings, the sealing between the upper and lower bearing covers of the bearing box was improperly handled between the sealing oil baffle and the oil chamber; Long term operation leads to loosening of fastening bolts, aging and deterioration of sealant, resulting in poor sealing.
Solution: During the reinstallation process, use high-performance and reliable sealant on the contact surface, and apply evenly and appropriately. During the second reinstallation, it is necessary to clean the original sealant before applying new sealant.
7. The change of oil quality causes more and more foam in the oil. In the whole lubrication system, foam occupies more operating space, which leads to the increase of oil pressure in the oil chamber, and the large pressure difference leads to the contact between the lubricating oil and the shaft clearance between the shaft and the floating palace seal, seal oil baffle, etc
