ZEN NATR25-PP Stützrollen (25x52x25)

As a track or cam roller, this component runs directly on a mating track or cam surface. At 25x52x25 mm and a unit weight of 0.275 kg, the installation envelope is fixed; further technical details are held in the specification table. The material of the washer sets the limit: operating temperature and media resistance are governed by it, not by the rolling set.

In this version a plastic axial sliding washer at each end face takes on two functions that are otherwise distributed across two components. On the one hand it guides the roller axially: it lies between the end face of the roller and the support at the pin and absorbs the axial force arising from an inclined position, from lateral contact with the track, or from the guidance itself.

On the other hand it carries an integrally formed sealing lip that closes the rolling chamber. The benefit of this combination is both a design and an operational one: one component is dispensed with, the overall width stays narrow, and the sliding pair of plastic against steel offers less resistance to rotation than a steel washer on steel.

On a support roller that is not driven but carried along by the contact with its track, that acts directly on the rolling behaviour. The limit of the version lies in the material of the washer. A polymer material tolerates less temperature than the hardened steel of the rolling set, reacts differently to oils, solvents and cleaning agents depending on its type, and loses strength under sustained heat; operating temperature and the media present are therefore to be checked against the data for the size before the design is used.

The rest of the construction remains that of the support roller: a thick-walled outer ring, hardened through the running depth, as the running surface, a mating track whose hardness and flatness belong to the layout, and a running surface profile that fixes the tolerance to an angular error. Rings and rolling elements are made of standard bearing steel.