Support Rollers are non - separable radial bearings. They are special variants of either radial deep groove ball bearings or double row angular contact ball bearings.

Support rollers run either directly on a guide track or against a surface that has been machined for a guidance.
To achieve this cam rollers feature an extra thick - walled outer ring this enables cam rollers to accept high radial forces, including shock loads.

As support rollers often run misaligned they are generally used with crowned outer ring surfaces.

Support rollers normally run outside the machine compartment, under extreme operating conditions, in the presence of heavy contaminations (i.e. dust and dirt, etc.).

For this reason, support rollers are produced and fitted with contacting seals.
Some types of the Double Row support rollers are also available with shields.
Design variants cam rollers are readily available in several design variants. For the most common designs see drawings below.

Single Row Support Rollers

Support rollers of the narrow series (series 3612.. and 3612.. R, are based on the proven sealed single row deep groove ball bearings, (suffix .2RS) for their internal design.
The NKE cam rollers, series 3612.. and 3612..R, respectively, are produced with .2RS. - type contacting seals as standard. These seals provide a very effective and efficient sealing of the bearing compartment against penetration by foreign particles even under unfavourable operating conditions.
The narrow NKE support rollers, series 3612 are available with either cylindrical (without extra suffix) or crowned outer ring outer diameter (suffix R) as standard.
The radius of crowning on single row support rollers for the series 3612.. R, is standardised at R = 400 mm, irrespective of their outer diameter.
Double Row Cam Rollers
The internal design of NKE double row support rollers (series 305 and 306) are based on the double row angular contact ball bearings of the series 32.. (for series 305) or 33.. (for series 306 cam rollers), respectively.
NKE double row support rollers have contact angles of 25° they also feature polyamide cages as standard.
Double row support rollers are widely used with pressed steel shields, (suffix .2Z), they are also available with rubbing seals (suffix .2RS) as standard.
As for single row support rollers, NKE double row support rollers are produced with either a, cylindrical or sphered outer ring diameters.
The radius of crowning of double row cam roller outer diameter is also standardised at R = 400 mm.

Material of seals

For the contacting seal of sealed NKE - support rollers (suffix .2RS) a wear - resistant synthetic rubber (NBR) is used as standard material.
This seal material is suitable for operating temperatures of -30 deg C up to +120 deg C.

On request, the NKE - support rollers are supplied with alternative seal materials, such as high - temperature FPM - contacting seals.
Grease filling
NKE support rollers incorporating either seals or shields (suffixes) are supplied grease filled from the factory with a proven high quality, lithium soap based rolling bearing grease suitable for operating temperatures of -30 deg C up to +110 deg C.

Although support rollers, operating under normal conditions, run generally maintenance free. Some application require additional lubrication where high speeds, heavy dust, permanent operating temperatures over 70 deg C exist.

Double Row support rollers only feature a lubrication hole in the inner rings to provide a simple and effective relubricating method.

Where relubrication is necessary, it is emphasised that, undue pressure by the regreasing method may cause unnecessary damage to either the seals or shields.

NKE support rollers are be supplied with special grease fills according to customer specification or with variable grease fill volumes than the standard.

Cages

Single Row NKE Support Rollers are standard fitted with pressed steel cages as standard. Double - Row Support Rollers feature solid polyamide cages as standard.

Tolerances

NKE support rollers, with cylindrical outer ring diameter, are produced to normal class tolerances (PN) as standard.
For support rollers with sphered outer ring diameters the outer ring diameter tolerance is double the standard value.

Internal clearance

NKE support rollers are produced with normal internal clearance group (CN) as standard according to DIN 620.
NKE support rollers are also produced to other internal clearances.

Load carrying capability

Unlike the "normal" rolling element bearings, the outer ring of support rollers contact their adjacent mating surface on a very small contacting area, this causes deformations of the outer ring.
These deformations are considered by the recommended maximum values for the permissible dynamic and static radial loads as shown in by the product tables, available on request.

Standards, Boundary dimensions
Standard plans DIN 616

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