What is Grease?
Definition of Grease By JIS (Japanese Industrial Standards)
A solid or semi-solid product of dispersion of a thickening agent in lubricating oil. Other ingredients imparting special properties may be included.
Classification of Lubricants
On the basis of its physical state, grease is classified as semi-solid lubricant.
Grease vs. Oil Lubrication - Advantages and Disadvantages
|Item||Grease Lubrication||Oil Lubrication|
|Feeding device||Grease sealed bearing does not require relubrication for an extended period.||Requires a device that continuously feeds oil (drip-feed, splash feed, recirculation system).|
|Consumption||Can be kept to the minimum necessary.||Significant amount required.|
|Leakage||Unlikely because of its seal forming characteristics.||Possible if sealing system is adequate.|
|Use for high-speed application||Limited.||Yes.|
|Contaminant removal||No.||Continual removal by filtration or centrifuge.|
|Cooling efficiency||No cooling capacity.||High cooling capacity.|
|Friction loss||Generally high, but torque reduction can be achieved by channeling in roller bearings.||Generally low.|