Annular groove and lubrication holes
Bearings without an annular groove and lubrication holes are typically lubricated either with the requisite minimum quantity of grease or with accurately metered, small quantities of oil or oil-air. In this case, the lubricant is delivered through a nozzle, positioned to the side of the bearing (fig.2, → product table).
If NN 30 series bearings with a bore diameter d ≤ 130 mm (table 1) require an annular groove and lubrication holes, check SKF for availability early in the design phase.