The main advantages of grease lubricating are:
– very simple application
– less maintenance required
– additional sealing effect
– pre-greased sealed or shielded bearing
– simple sealing of bearing positions
– large number of different lubricants available
– greased “for-life” bearing arrangements possible
Tasks of Lubricants
All lubricants used in rolling bearings have to fulfil the following main tasks:
⁃ separation of metallic surfaces
⁃ reduction of friction in the loaded zones (i.e. both the rolling contact and in the areas having sliding friction)
Significant Values of Lubricants Viscosity
⁃ Viscosity indicates the individual layers flowing characteristics of a liquid when in motion.
⁃ It is one of the most important features when selecting oils. In the case of lubricating greases the viscosity of each base oil is indicated.
⁃ In principle, distinction is made between the nominal viscosity of a lubricant which is a specific reference value and the operating viscosity that results under given operating conditions at the bearings operating temperature.
⁃ Consistency The grade of consistency indicates the “stiffness” of grease to defined NLGI-scales according to DIN 51818