Causes and treatment of motor sliding bearing oil leakage

Spherical plain bearings work under sliding friction. Sliding bearings work smoothly, reliably and without noise. Under the condition of liquid lubrication, the sliding surface is separated by the lubricating oil without direct contact, which can also greatly reduce friction loss and surface wear, and the oil film also has a certain ability to absorb vibration. But the starting friction resistance is large. The part supported by the bearing is called the journal, and the part matching the journal is called the bearing bush. In order to improve the friction properties of the bearing bush surface, a layer of friction reducing material cast on its inner surface is called a bearing lining. The materials of bearing bushes and bearing linings are collectively referred to as plain bearing materials. Spherical plain bearing applications are generally under high-speed and light-load conditions.

 

 

Motor bearing is a kind of special bearing specially used in motor. The bearing used in the motor is a part supporting the shaft, which can guide the rotation of the shaft, and also can withstand idle parts on the shaft. There are four types of bearings commonly used in motor, namely rolling bearing, sliding contact bearing, joint bearing and oil bearing.

 

 

During the use of high-power motors, oil leakage frequently occurs, which is obviously manifested as the oil leakage of the spherical plain nearings structure. During the maintenance process, it is necessary to analyze the possible reasons for the motor oil leakage.

 

 

1. The internal and external pressure difference of sliding bearing is large.

For the plain bearing bush with forced lubrication, the lubricating oil itself has a certain pressure. When the shaft is running, the oil will generate bubbles and generate a certain pressure. When the motor is running, it will produce a certain negative pressure due to the effect of the fan, which will increase the pressure difference inside and outside the oil chamber, resulting in oil leakage. In order to balance the pressure difference between the oil chamber and the outside, a vent pipe is provided between the oil chamber and the outside to balance the pressure difference. However, in the process of use, there will be blockage, which will increase the pressure in the oil chamber and cause oil leakage.

 

Solution

Regularly check whether the balance pipe is loose and clean the fuel tank vent pipe in time.

 

 

2. The oil pressure is not adjusted in place, resulting in poor oil return.

Too high or too low oil pressure will cause poor return oil. If the oil pressure is too low, the oil will stay in the oil chamber for too long, and the temperature will rise during the operation of the shaft, and oil mist will cause the pressure to be too high. If the oil pressure is too high, the oil return capacity is insufficient, the 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 surface of the oil chamber is in the position of 1/2 to 1/3 of the sight glass and keep the oil returning unobstructed.

 

 

3. The change of oil quality causes more and more foam in the oil.

In the entire lubrication system, foam occupies more operating space, which leads to an increase in the oil pressure in the oil chamber. A large pressure difference causes the lubricating oil to escape from the shaft to the shaft clearances.

 

Solution

Regularly inspect and analyze the lubricant. If there is a problem with the oil quality, replace it in time.

 

 

The reason analysis and solution of the oil leakage of the motor sliding bearing have achieved certain effect in practical application, ensuring the safe and stable operation of the unit.