(1) The oil level is too high.

When the oil level is too high, the lubricating oil will be sucked into the motor along the rotating motor shaft.

(2) Oil return is not smooth.

Poor oil return will cause the oil level in the bearing bush box to rise and the internal pressure to increase, so that the oil mist is more easily inhaled into the motor cavity.

Solution: the return pipe of the motor is tilted downward (15°), the proper setting of the breathing valve on the return pipe is conducive to rapid oil return, and the filter and the whole lubricating oil line are cleaned regularly.

(3) Large internal and external pressure difference of sliding bearing.

When the motor is running, it will produce certain negative pressure due to the action of the fan, which will increase the pressure difference between the inside and outside of the bearing bush box, leading to oil leakage.

In order to balance the pressure difference between inside and outside the bearing bush box, the bearing bush box and the outside world are provided with a ventilation pipe (balance pressure pipe) to balance the pressure difference, but in the use of the process will produce blockage, aging and other phenomena, resulting in oil leakage.

Solution: regularly check whether the balance pipe is loose and timely clean the bearing box vent pipe.

(4) The floating seal ring and the shaft contact surface because of long time friction, wear is serious, and the gap between the shaft becomes larger; Or the elastic change of the fixed spring on the floating sealing ring makes the floating sealing ring loose, resulting in an increase in the gap.

Solution: Check periodically and replace in time.

(5) After long-term operation of the motor, the sealant on the joint surface of the upper and lower tile seat ages, and the seal is not strict, resulting in oil leakage of the bearing bush.

Treatment plan: regular maintenance, the upper and lower tile seat joint surface of the original sealant clean, re-coated sealant (uniform, appropriate amount). (Loctite plane or 704 anaerobic glue).

(6) Forced lubrication motor, high air pressure in lubricating oil pipeline.

There is more oil and gas (lampblack) in the pipeline and more oil and gas (lampblack) in the oil tank of the oil station, resulting in the increase of oil pressure in the bearing bush box.

Treatment scheme: increase the exhaust capacity of oil station; Install breather valve on return line.