Causes and treatment of oil leakage of motor sliding bearing

The oil leakage phenomenon occurs frequently during the use of high-power motors, which is manifested by the oil leakage phenomenon of the sliding bearing structure. During the maintenance and repair process, the possible causes of the oil leakage of the motor are analyzed, and the following solutions are obtained.

1. The sliding bearing has a large internal and external pressure difference. Forced lubrication of the bearing bush, the lubricating oil itself has a certain pressure, the oil will generate bubbles when the shaft is running, and a certain pressure will be generated. When the motor is running, a certain negative pressure is generated due to the action of the fan, thereby increasing the pressure difference between the inside and the outside of the oil, resulting in oil leakage. In order to balance the pressure difference between the oil chamber and the outside, the oil chamber is provided with a vent pipe to balance the pressure difference, but a blockage occurs during use, causing an increase in oil pressure to cause oil leakage.

Solution: Check regularly if the balance tube is loose and clean the tank vent tube in time.

2. The oil pressure adjustment is not in place, resulting in poor oil return. If the oil pressure is too high or too low, the oil return will be poor. If the oil pressure is too low, the oil stays in the oil chamber for too long, and the temperature rises during the operation of the shaft, so that the oil mist causes the pressure to be too high; if the oil pressure is too high, the oil returning capacity is insufficient, so that the oil chamber The medium oil storage is too large, and the oil level is too high to increase the internal pressure.

Solution: Adjust the forced lubrication pressure to 0.1 to 0.8 MPa, so that the oil level of the oil chamber is at 1/2 to 1/3 of the sight glass, and it is better to keep the oil returning smoothly.

3. The unreasonable design of the return line will also result in poor oil return and increase the pressure in the oil chamber. Impurities in the return line or improper cleaning in the pipe will cause the filter to become clogged, resulting in poor oil return.

Solution: The oil chamber outlet of the return line should be at the same level as the inlet port, and the entire return line should be inclined at 15° to the return tank so that the return line can naturally return to the oil. The filter and the entire lubrication line should be cleaned regularly.

4. Due to long-term friction between the floating palace and the shaft, the wear is severe, causing the gap between the shaft and the shaft to be too large; the floating palace seal changes the spring modulus of the fixed spring, causing the floating valve seal to loosen, resulting in an increase in the gap.

Solution: Regular inspection and timely replacement.


5. The wear of the sealing oil block and the shaft contact surface makes the clearance too large; the oil return hole in the sealing oil block is too small or the impurities are blocked, which cannot meet the actual oil return amount.

Solution: Replace the sealing oil block and modify the sealing oil block. Change the material of the sealing oil block and the shaft contact surface, replace it with wear-resistant material; increase the oil return hole to meet the actual oil return requirements (not too large).


6. During the installation of the sliding bearing, the sealing between the sealing oil block and the oil chamber sealed between the tile cover and the lower tile cover on the bearing box is improper; the long-term operation causes the fastening bolt to loosen and the sealant to deteriorate and lead to deterioration. The seal is not strict.

Solution: During the reloading process, the sealing surface is made of reliable sealing glue and applied evenly and appropriately. When the second reloading is completed, the original sealant must be cleaned before applying a new sealant.

7. Oil quality changes cause more and more foam in the oil. In the entire lubrication system, the foam occupies more operating space, which leads to an increase in oil pressure in the oil chamber. The large pressure difference causes the lubricating oil to escape from the shaft gap between the shaft and the floating valve seal and the seal oil block.

Solution: Regularly check and analyze the lubricating oil. If there is any problem with the oil quality, it should be replaced in time.

The cause analysis and solution of the above-mentioned motor sliding bearing oil leakage have achieved certain effects in practical application, ensuring the safe and stable operation of the unit.

Reprinted from the network