Rolling bearings are an integral part of machines. For the large part, the whole industries' performance and production value depend on these small entities, which, if not appropriately lubricated, can fail the whole system.
Grease is a crucial component to ensure high reliability and optimum performance of roller bearings and therefore is essential to maintain the entire business.
While it is essential to look for the chemical composition of the grease when selecting, it is not the only factor that can determine the right quality of grease for your bearings.
Unlike oil, grease is more viscous and stays in place without leaking out. This provides the machine's bearings with long-lasting lubrication that requires low maintenance and monitoring. Even under extreme conditions, grease does not fail to smooth out the operation and provides maximum reliability. It prevents corrosion, contamination, friction, and acts as a shock absorber.
However, it’s not like one size fits all. Selecting the right kind of grease depends on the load and type of application performed by the bearing and its life expectancy.
For example, in spindle applications that require precise bearings, grease that has mineral base oil with lithium thickener is suitable. This type of grease sticks well to the surface and operates in temperature from –30 °C to 110 °C.
For applications that have a long service life or have high speed and high temperature, then grease with synthetic base oil is the best choice.
For angular contact ball bearing, grease with mineral or ester base oil with calcium complex thickener works best in most operations.
Other factors that contribute to the proper lubrication of bearings through grease are viscosity, temperature, over-greasings, and under greasing.
Viscosity is the most crucial factor in lubrication. The viscosity level of any lubricant should depend on the speed and load of bearings. When speed increases, the viscosity should be lowered accordingly.
High speed lowers the viscosity of the grease. This results in quicker consumption of the lubricant and requires frequent application. If the grease entirely runs out, it can cause bearing failure, which can be disastrous.
All types of grease have specific operational temperatures in which they work best. If the grease encounters a temperature lower than its threshold, it can face starvation where it becomes too dry for the bearing and causes oil bleeding. Similarly, if the grease encounters a higher temperature than its threshold, it faces degradation. In degradation, it undergoes oxidation and evaporation and becomes too soft to perform well.
When to re-apply the grease holds the same importance in lubrication as selecting it. Over and under-greasing can shorten the life span of your bearing and cause failures.
Over-greasing can increase the operating temperature and increase the risk of heat build-up that damages the bearings.
Under-greasing, on the other hand, causes metal contact creating friction. This results in extreme wear of the bearing.
Selecting the right kind of grease is crucial to maintain the life of your bearings and prevent them from early failure and damage. Micro-lube is an all-type industrial grade lubricant supplier based in Edmonton, Alberta. Here we strive to help you select the best lubricant for your machine and rolling bearings. Visit our webpage for further information or contact us for a free quote.