Needle roller bearings with machined rings, with flanges
SKF needle roller bearings with flanges on the outer ring are available open (without seals) or sealed (→ Sealing solutions) on one or both sides and with or without an inner ring. Bearings with an outside diameter D ≤ 17 mm (Fw ≤ 10 mm), are available with non-separable closure rings that act as flanges (fig. 1). The flanges on larger bearings are an integral part of the outer ring, and the bearings have an annular groove and one or more lubrication holes in the outer ring (fig. 2). With the exception of RNA 69 (fig. 3) and NA 69 series double row bearings with an outside diameter D ≥ 52 mm (Fw ≥ 40 mm), needle roller bearings with flanges are generally designed as single row bearings.
The roller and cage assembly and outer ring of a needle roller bearing with flanges form a non-separable unit.
Needle roller bearings with machined rings, without flanges
SKF needle roller bearings without flanges on the outer ring are separable, i.e. the outer ring, needle roller and cage assembly and inner ring, can all be mounted separately. Therefore, the needle roller and cage assembly can either be mounted together with the outer ring or with the shaft or inner ring, depending on the arrangement design. It can also be inserted between the outer ring and shaft or inner ring as the final step. However, needle roller and cage assemblies and bearing outer rings must always be kept together as supplied.
Arrangements with other bearings
To accommodate combined radial and axial loads, needle roller bearings with machined rings can be combined with a needle roller thrust bearing with a centring flange, AXW series (fig. 6, fig. 7), if the outside diameter D of the radial bearing is equal to the flange diameter D1 of the thrust bearing. For additional information, refer to Needle roller thrust bearings.