Needle roller thrust bearings are single direction acting separable axial bearings that require less overall height.
Needle roller thrust bearings accept axial loads only and are insensitive to shock loading. Thus, needle roller thrust bearings provide a very rigid thrust bearing arrangement with minimal axial space requirement.
Several variations of thrust bearings are available for consideration dependant upon the space availability, running accuracy precision, or guidance requirements.
As for cylindrical roller thrust bearings, the needle roller thrust bearings are also subject to increased sliding friction.
In order to avoid the negative effects of excessive sliding friction, needle roller thrust bearings are only suitable for low speed applications .

Needle roller thrust bearings require minimum axial loads for their optimum function.
NKE needle roller thrust bearings provide and enable several different solutions for thrust bearing assemblies.
Due to the possible variations of assemblies, single or loose components may be ordered separately.

The simplest form of Needle Roller Thrust bearing consists of a needle roller set and cage assembly (i.e. the cage retains and guides the rollers), namely AXK.
Needle roller and cage thrust assemblies run directly on the counter surfaces of their adjacent machine parts.
These bearing types require a minimum axial space.
All contacting surfaces therefore must be designed and produced as bearing raceways (i.e. hardened and ground etc).

Where it is not feasible to machine the adjacent mating surfaces for either technical, quality or economical reasons, these Needle Roller and Cage assemblies may be combined using various combination of washers.

The simplest design is provided by using needle roller and cage thrust assemblies with AS - thrust washers, AS - thrust washers are thin washers made from hardened spring steel.
They are approximately 1 mm thick and feature polished surfaces.

The use of such thrust bearing arrangements provide economic and space - saving bearing arrangements for cases where the adjacent parts have sufficient strength but no possibility to act as raceways, (e.g. housings made from cast iron).

The expected running accuracy, however, will be low.

Where a more precise running accuracy of the bearing arrangement is required, Raceway washers (LS) must be used.

Raceway washers are made from hardened bearing chromium steel and have ground raceways but only turned surfaces on both outer and bore diameters.
The Raceway washers should be used in applications where low speeds occur and a precise positioning of the raceway washers is unnecessary.

Raceway washers may be used as either shaft or housing washers.

For applications that require precise shaft guidance, AXK - needle roller and cage thrust assemblies may also be combined with shaft and housing washers of the cylindrical roller thrust bearings of series 811.

Double direction acting needle roller thrust bearings can be achieved by using two needle roller and cage thrust assemblies with a ZS - intermediate washer.
Such intermediate washers are part of the NKE special product range and are produced according to customers order requirements.

Misalignment

All needle roller thrust bearing types do not allow any misalignment.
The contacting surfaces of both shaft and housing seats must be parallel.

Cages

Small NKE needle roller and cage thrust assemblies are fitted with shaft - centred solid polyamide cages as standard.
These cages are suitable for permanent operating temperatures up to +120 deg C.