I would like to find some technical info covering the ISO VG oil specs for greases. I need to know what viscosity oil in the grease is suggested for waht applications. If anyone knows where I can get this info please let me know.
Thanks

Min viscosity at operating temperature - you can get from bearing manufacturers. Linked below is one from SKF. Remember viscosity at operating temp is typically lower than viscosity grade which is referenced to 40C.

Max viscosity - selected to avoid overheating. Generally grease manufacturer's will express this limitation as a maximum d*N (diameter times speed). As long as you are within their D*N you generally don't have to worry about having viscosity too high (unless you have unusual situation such as heating from outside the bearing).

Actual viscosity grade - you can get from the grease manufacturer - We generally use Mobilith SHC100 which is VG100. It seems to work for us in a range of motors roughly up to 3600 rpm 100hp. Above this I think it begins to get marginal - particularly for TEFC motor because the inboard bearing heated by heat from the windings and not well cooled by the external fan.

MinViscosity.ppt (94 Kb, 19 downloads)