Rolling mill bearing lubrication method

1, the importance of lubrication

The lubrication of the bearing is to use the oil film to separate the relatively moving rolling surfaces from each other, so as not to cause excessive wear due to rough contact. Users who attach great importance to bearing lubrication technology can maintain stable performance and rotational accuracy for a given working life.

2, the type and performance of grease

The lubrication of rolling mill bearings is divided into grease lubrication and oil lubrication. The advantages of grease lubrication are that the lubrication facilities are simple, the grease is not easy to leak, and there is a certain ability of waterproof, gas and other impurities to enter the bearing. Therefore, grease lubrication is widely used under normal circumstances. Lubricated with oil under heavy load, high speed, high temperature and other working conditions.

Grease consists of a base oil, a thickener and a filler. The viscosity of the base oil plays an important role in the lubricating properties of the grease. The composition of the thickener has an important influence on the properties of the grease, especially the temperature characteristics, water resistance and oil repellency. The filler is mainly used to enhance the resistance of the grease. Gasification, rust prevention, extreme pressure and other properties.

Greases are classified according to the type of thickener, and are classified into lithium base and nano base. Rolling mill bearings are commonly used lithium-based greases. Lithium-based greases are characterized by good water resistance and high dropping point. They can be used in

Moist and mechanical parts in contact with water. Grease is divided into several stages according to its fluidity, ie penetration. The greater the penetration value, the softer the grease.

The domestically produced roll bearing grease is a multi-component lithium base grease compounded by a high-grade fat acid-proofing and synergist, and is also suitable for lubrication of rolling mill bearings.

3. Filling amount of grease

The filling amount of the grease is preferably one-third and one-half of the space for filling the bearing and the bearing housing. If too much fat is added, the deterioration of the grease may be deteriorated or denatured due to stirring and heating. Only fill up to one-third or less at high speeds. When the rotational speed is very low, the housing space can be filled to prevent external physics from entering the bearing.

4, the replacement of grease

The service life of grease is limited, its lubricating performance is gradually reduced during use, and wear is gradually increasing, so it must be replaced every time for a certain interval.

The replenishment cycle of the grease is related to the structure, speed, temperature and environment of the bearing, and should be determined for the specific working conditions of the enterprise. When replacing the grease, it should be noted that the greases with different grades cannot be mixed. The grease phase containing different kinds of thickeners will destroy the structure and consistency of the lubrication. If it is necessary to replace the grease with different grades, the original bearing should be used. After the grease is completely removed, add new grease. Rolling mill bearing lubrication method

[Chinese bearing net] 6/2/2012 Author: China Bearing Network

1, the importance of lubrication

The lubrication of the bearing is to use the oil film to separate the relatively moving rolling surfaces from each other, so as not to cause excessive wear due to rough contact. Users who attach great importance to bearing lubrication technology can maintain stable performance and rotational accuracy for a given working life.

2, the type and performance of grease

The lubrication of rolling mill bearings is divided into grease lubrication and oil lubrication. The advantages of grease lubrication are that the lubrication facilities are simple, the grease is not easy to leak, and there is a certain ability of waterproof, gas and other impurities to enter the bearing. Therefore, grease lubrication is widely used under normal circumstances. Lubricated with oil under heavy load, high speed, high temperature and other working conditions.

Grease consists of a base oil, a thickener and a filler. The viscosity of the base oil plays an important role in the lubricating properties of the grease. The composition of the thickener has an important influence on the properties of the grease, especially the temperature characteristics, water resistance and oil repellency. The filler is mainly used to enhance the resistance of the grease. Gasification, rust prevention, extreme pressure and other properties.

Greases are classified according to the type of thickener, and are classified into lithium base and nano base. Rolling mill bearings are commonly used lithium-based greases. Lithium-based greases are characterized by good water resistance and high dropping point. They can be used in

Moist and mechanical parts in contact with water. Grease is divided into several stages according to its fluidity, ie penetration. The greater the penetration value, the softer the grease.

The domestically produced roll bearing grease is a multi-component lithium base grease compounded by a high-grade fat acid-proofing and synergist, and is also suitable for lubrication of rolling mill bearings.

3. Filling amount of grease

The filling amount of the grease is preferably one-third and one-half of the space for filling the bearing and the bearing housing. If too much fat is added, the deterioration of the grease may be deteriorated or denatured due to stirring and heating. Only fill up to one-third or less at high speeds. When the rotational speed is very low, the housing space can be filled to prevent external physics from entering the bearing.

4, the replacement of grease

The service life of grease is limited, its lubricating performance is gradually reduced during use, and wear is gradually increasing, so it must be replaced every time for a certain interval.

The replenishment cycle of the grease is related to the structure, speed, temperature and environment of the bearing, and should be determined for the specific working conditions of the enterprise. When replacing the grease, it should be noted that the greases with different grades cannot be mixed. The grease phase containing different kinds of thickeners will destroy the structure and consistency of the lubrication. If it is necessary to replace the grease with different grades, the original bearing should be used. After the grease is completely removed, add new grease.

For more information and purchase please visit: https://www.supplyforever.com

Judging the fault damage adjustment pre-tightening method of ntn angular contact ball bearing

From the peeling, indentation, rust, crack, wear and so on, it will be reflected in the vibration measurement of the bearing. The ntn bearing vibration is very sensitive to the damage of the bearing. Therefore, the angular contact ball bearing adopts a special bearing vibration measuring device ( The frequency analyzer can measure the magnitude of the vibration, and the specific situation of the abnormality cannot be inferred by the frequency division. Since the measured values ​​differ depending on the conditions of use of the bearing or the mounting position of the sensor, it is necessary to analyze and compare the measured values ​​of each machine in advance to determine the judgment standard.
Because the ntn bearing emits abnormal sounds and irregular sounds even if it is slightly peeled off, it can be distinguished by the sounder. The sounder is used to measure the size and sound quality of the angular contact ball bearings in operation. Check it to prevent it in advance.
If the oil hole can directly measure the bearing outer ring temperature, it is more suitable. In general, the temperature of the ntn bearing is generally estimated based on the temperature outside the bearing. If the lubrication and installation parts are suitable, the bearing temperature will rise sharply and abnormal temperature will occur. At this time, it is necessary to stop the operation and take necessary precautions. Usually, the temperature of the bearing rises slowly as the operation starts, and reaches a steady state after 1-2 hours. The normal temperature of an angular contact ball bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If necessary, use the thermal sensor to monitor the working temperature of the bearing at any time, and automatically alarm the household when the temperature exceeds the specified value or stop the burning shaft accident.
The assembly of the ntn bearing is the basic operation in the assembly and repair work of the fitter, and the adjustment and preloading of the clearance is an important part of the assembly work of the rolling bearing. Accurately grasping the process concept of clearance adjustment and pre-tightening, and correctly applying this process in assembly work is the guarantee of the quality of bearing assembly work.
The clearance of the ntn bearing refers to the maximum amount of movement of the other ferrule in the radial or axial direction when one ferrule is fixed, so the clearance is divided into radial clearance and axial clearance. When angular contact ball bearings are assembled, the clearance should not be too large or too small. If the clearance is too large, the number of rolling bodies that can bear the load at the same time is reduced, and the load of the single rolling element is increased, thereby reducing the rotation precision of the bearing and reducing the service life; if the clearance is too small, the frictional force is increased, and the generated heat is generated. Increased, increased wear and tear, can also reduce the service life of the bearing. Therefore, the bearings must be tightly controlled and adjusted during assembly.
The pre-tightening is that the bearing is assembled with an axial force to the inner ring or the outer ring to eliminate the bearing play and cause initial deformation of the rolling element in contact with the inner and outer rings. Preloading can improve the rigidity and rotation accuracy of the bearing under working conditions, and the bearing with large load and high rotation precision requires most of the work without clearance or even a small amount of interference. In this case, The bearings need to be pre-tensioned during assembly. Adjustment and preloading of the clearance are usually accomplished by appropriate axial relative displacement of the inner ring to the outer ring. It is not difficult to see from the above technical concept that the bearing capacity and rotation accuracy of the bearing can be improved by adjusting the clearance of the angular contact ball bearing to improve the service life of the bearing. At the same time, the friction of the ntn bearing is intensified, and the heat generation is increased, so good lubrication and heat dissipation must be ensured when adjusting the clearance or pre-tightening. If improperly adjusted or poorly lubricated, it will in turn increase bearing wear and reduce life. Correctly adjust and pre-tighten the bearing clearance, and pay attention to the following problems.

For more information and purchase please visit: https://www.supplyforever.com