Cylindrical Roller Bearings are separable radial bearings, except for the full complement cylindrical roller bearings where several variations are not separable due to their internal design features.
Due to the possibility of fitting the Outer, Inner or other loose parts individually the bearing mounting becomes easier and simpler even for volume assembly mounting.
Furthermore, this enables the use of tight fits where appropriate for both Outer and Inner rings. This is of advantage in applications where vibrations or shock loads occur.
For Single Row Cylindrical Roller bearings the radial loads and speed ratings are relatively higher when compared to other roller bearings. Depending on their particular design the single row cylindrical roller bearings are ideal non - locating radially loaded bearings, although several design variations will also accept limited amounts of axial loading in one or both directions.
In the case of bearing arrangements with limited available space (i.e. gear boxes) the single row cylindrical roller bearings N-type and NU-type may be used without their respective outer or inner rings, namely, RN-type and RNU-type bearings, respectively. These bearing design types allow the rolling elements to run directly onto the adjacent contacting surface of either the housing or shaft. In these bearing arrangements the adjacent contacting surface parts must be designed as for bearing raceways (i.e. hardened and ground etc).
Single Row Cylindrical Roller Bearings are available in several basic designs, that differ from each other in the number and arrangement of their flanges, as standard. The most important design variants are shown below (see below).
Cylindrical roller bearings of NJ - design have two integral flanges on their outer ring and one integral flange on the inner ring. This allows them to accommodate axial loads in one direction only. Typical locating bearings are NUP - design cylindrical roller bearings. These have two integral flanges on their outer ring, one integral flange on the inner ring and a loose rib. NUP - type bearings are able to accept axial loads in
either direction.
Separate Thrust collars, type HJ, are designed to guide shafts when used in conjunction with cylindrical roller bearings.
NJ - type cylindrical roller bearings build, when used in conjunction with thrust collars, locating bearings that provide shaft guidance in both directions (NJ + HJ = NH).
When standard cylindrical roller bearings of the NU-Type, are used in conjunction with a HJ-separate thrust collar, care must be taken to avoid the possibility of clamping the rollers in error.
These bearing types are able to accommodate axial forces acting in one direction only.
NKE Single Row Cylindrical Roller Bearings are normally produced with the latest design (suffix E), as standard.
This incorporates an optimised internal design providing increased load carrying capabilities.

The exception to this "standard" are some of the larger cylindrical roller bearings and bearing types of the 1000 and 400 series for which the NON-E-design remains the standard.
However, in certain applications, particularly in the "Aftermarket' the historic NON-E-design remains, therefore, for all sizes these are produced on customer order request.
NKE Single Row Cylindrical Roller Bearings Feature rolling elements with modified contact geometry to minimise edge loading stresses between the rollers and contacting raceways. For applications operating under normal conditions the misalignment must not exceed 2 angular minutes from their centre position. It must be accepted that when bearings run misaligned they are subjected to additional forces which result in a reduced service life and additionally generate higher running temperatures and noise.

For applications where higher misalignments occur, (e.g. vibrating screens or compactors for road rollers), NKE also produce cylindrical roller bearings with special crowned inner ring raceways, (suffix "B"), to enable higher misalignments during running operation.

NKE Single Row Cylindrical Roller Bearings are produced to normal tolerance class (PN) as standard.
On request these bearings are also produced to closer tolerances, such as tolerance classes P6 and P5, etc.

Cages

NKE Single Row Cylindrical Roller Bearings of the non - E design are normally fitted with pressed steel cages as standard.
Exceptions to this standard are the larger cylindrical roller bearings and bearings of the 1000 and 400 series which are produced with machined solid brass cages (suffix M) as standard.
NKE E - Type Cylindrical Roller Bearings are normally fitted with polyamide cages as standard.
NKE Cylindrical Roller Bearings are also available with other cage designs and cage materials on order request.
NKE Single Row Cylindrical Roller Bearings are produced to the normal internal clearance group (CN), as standard.
On request NKE - Cylindrical Roller Bearings are produced with other internal clearances. Values of internal clearance groups are listed in the tables, see pages 6 and 7.
These Values are standardised and conform to both DIN 620/part 4 and ISO 5753-1991, respectively.
Special Clearance For bearing applications where the standard internal clearances and ranges do not satisfy optimum perform NKE cylindrical roller bearings are produced with either individual or special internal clearance groups on order request.
Example:
R100.180 Special Radial clearance between 100 and 180 microns
If required, the values of a internal clearance may be controlled within a part of a standard. Such a restriction is indicated by a letter (H, M or L), that follows the symbol of the bearing clearance group.
Example:
C4H Clearance controlled within upper range of clearance group C4.

All information courtesy and copyright NKE Bearings Austria www.nke.at