Grease is indispensable for imported bearings in their work. The maintenance of any imported bearing cannot be separated from grease. Someone asked whether the more grease, the better? Of Nsk Bearings Use course, the answer is No. here are the precautions for NSK Bearings when using grease.
During the maintenance of NSK Bearings, too much grease Nsk Bearings Use actually has many hazards. Because the grease has good adhesion, wear resistance, temperature resistance, rust resistance and lubricity, it can improve high-temperature oxidation resistance,
delay aging, dissolve carbon deposition, prevent the agglomeration of metal wear debris and oil, and improve the wear resistance, pressure resistance and corrosion resistance of machinery.
The more grease is filled, the greater the friction torque will be. With the same filling amount, the friction torque of sealed bearing is greater than that of open bearing. After the grease filling amount is equivalent to 60% of the internal space volume of the bearing, the friction torque will no longer increase significantly.
This is because most of the grease in the open bearing has been extruded and the grease in the sealed bearing has leaked. With the increase of grease filling amount, the temperature rise of NSK bearing increases linearly. At the same filling amount, the temperature rise of sealed bearing is higher than that of open bearing.
It is generally believed that the grease filling amount of sealed rolling bearings shall not exceed Nsk Bearings Use about 50% of the internal space. The tests of shawki and Mokhtar show that 20% to 30% is suitable for ball bearings.
The accuracy and speed of a bearing are important. What they specifically refer to is explained by NSK bearing.
NSK bearing accuracy:
For bearing configuration requiring high rotation accuracy (such as Nsk Bearings Use machine tool spindle) and working conditions applied to high speed, bearings with higher accuracy than ordinary grade shall be selected.
It can provide a variety of high-precision bearings, including single row angular contact ball bearings, single row and double row cylindrical roller bearings, as well as one-way and two-way angular contact thrust ball bearings
NSK bearing speed:
The running speed of rolling Nsk Bearings Use bearings is limited by the allowable working temperature. Low friction bearings have relatively low internal heat, so they are suitable for high speed conditions.
Compared with other bearings, deep groove ball bearings and self-aligning ball bearings can withstand higher speed under pure radial load or combined load of angular contact ball bearings.
The precision angular contact ball bearing or deep groove ballNsk Bearings Use bearing with ceramic rolling element can even reach higher speed. Due to design reasons, the running speed of thrust bearing cannot be as high as that of radial bearing.
1： Bearing grease rheology:
1. When the grease is not affected by external force, it can maintain a certain shape like a solid, that is, it Nsk Bearings Use will not lose automatically at rest.
2. Under the condition of extremely high shear stress (large shear speed), the flow of lubricating grease is like Newtonian fluid, and the viscosity can maintain a constant without changing with the change of shear speed.
3. Elastic deformation occurs when subjected to weak external force; After removing the external force, it can return to its original position and shape, showing the elastic properties of the solid.
4. When the applied external force is large enough, the grease Nsk Bearings Use deforms and flows, so it can no longer automatically return to its original position and shape. Therefore, the starting torque of the grease on the mechanical running parts is greater than that of the liquid lubricant.
The ambient temperature is high and the grease lubrication is not suitable. At present, the molybdenum disulfide grease used for forging the INA Bearing of mobile bomb is considered to be high-temperature resistant grease. We know that its base oil is petroleum products.
Add a small amount of high-temperature resistant molybdenum disulfide additive, and its temperature resistance limit is 120 ℃. Moreover, there are more than 30 oil filling points of the whole machine. This cumbersome oil filling operation cannot be realized for long-term operation and maintenance.
Therefore, it is necessary to pour the thin oil pot on the outside of Nsk Bearings Use the running bearing sleeve. It is difficult for the lubricating oil to enter the friction pair of the bearing, and most of the bearings are in the friction state.
It is measured that the working temperature of INA Bearing of forging machine can reach 200 ℃, which has far exceeded the temperature resistance limit of lubricating grease. Under the premise of such high temperature,
the base oil in the lubricating grease will become thin and evaporate gradually, and the remaining carbon slag, molybdenum disulfide and dust will be mixed into solid blocks and solidified on the cage of the movable bearing,
which will not only lose its lubricating effect, but also hinder the normal operation of the movable bearing and wear quickly. It will have to shut down for more than 2 weeks, remove the bearing, clean and replace the grease.
The self-lubricating ina bearing has wide service temperature, sufficient solid lubricating material content and average release. It has good self-lubricating function and bite, which can effectively protect the journal and achieve the purpose of lasting use.