NADELLA GCL47 EE Laufrollen (20x47x25,6)

As a track or cam roller, this component runs directly on a mating track or cam surface. The mounting dimensions are 20x47x25.6 mm and the weight is 0.477 kg; technical details beyond these are shown in the specification table. This version sits between the metallically sealed and the open track roller — more closure than the one, less thermal reserve than the other.

This track roller is sealed at both end faces with a plastic element. The material brings three properties that suit this design. It can be produced accurately in form and with consistent geometry, so the sealing geometry can be brought close to the outer ring; it is light, which on a roller acts directly on the inertia at start-up; and it slides against steel with less resistance than steel against steel, which keeps the frictional torque low.

For a roller that is not driven but set turning by the contact with its track, these are not side matters but the quantities that decide whether it rolls or slides. The limit of the version likewise lies in the material: a polymer element tolerates less temperature than the hardened steel of the rolling set, reacts differently to oils, cutting fluids 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 use; where they exceed it, a metallic version is appropriate. The load-carrying construction is unchanged: the thick-walled outer ring, hardened through the running depth, takes the contact pressure from the track contact and rotates through the load; the hardness, surface finish and course of the mating track belong to the layout, and the profile of the running surface determines the tolerance to an angular error relative to the track. Rings and rolling elements are made of standard bearing steel.