Bibliography Related Suppliers NMB Tech. Grease is convenient since it is viscous enough to not drip out of the bearing, but it does not flow well enough for it to be used as a continuous-flow coolant.
Oil is used when a cooling fluid is needed for high speed bearings.
Circulated oil also serves to clear away particulate debris. The following table summarizes the relative advantages between oil and grease. Viscous so seals are simplified, plus it acts as its own sealant. Permits prelubrication of sealed or shielded bearings. Lubrication is easily controlled.