◆The role of bearing lubrication
Lubrication has an important influence on the fatigue life and friction, wear, temperature rise and vibration of rolling bearings. Without normal lubrication, the bearing cannot work. Analysis of the causes of bearing damage shows that about 40% of bearing damages are related to poor lubrication. Therefore, good lubrication of bearings is an effective measure to reduce bearing friction and wear. In addition, the lubrication of the bearing also has various functions such as heat dissipation, rust prevention, sealing, and shock mitigation.
Grease is a lubricant composed of base oil, thickener and additives. When choosing, you should choose a grease that is very suitable for the bearing conditions. Due to different brands, there will be great differences in performance, so you must pay attention when choosing.
Commonly used greases for bearings include calcium-based grease, sodium-based grease, calcium-sodium-based grease, lithium-based grease, aluminum-based grease, and molybdenum disulfide grease.
The amount of grease filled in the bearing is suitable to fill 1/2-1/3 of the inner space of the bearing. It should be reduced to 1/3 at high speed. Excessive grease will increase the temperature rise.
Under the conditions of high speed and high temperature, oil lubrication can be used when grease lubrication is not suitable. Through the circulation of lubricating oil, a large amount of heat can be taken away.
Viscosity is an important characteristic of lubricating oil. The size of viscosity directly affects the fluidity of lubricating oil and the thickness of the oil film formed between the friction surfaces. The viscosity of lubricating oil at bearing operating temperature is generally 12-15cst. The higher the rotation speed, the lower the viscosity should be selected, and the heavier the load, the higher the viscosity should be. Commonly used lubricating oils are mechanical oil, high-speed mechanical oil, turbine oil, compressor oil, transformer oil, cylinder oil, etc.