SKF NUKR40 A Kurvenrollen (18x40x58)

As a track or cam roller, this component runs directly on a mating track or cam surface. The dynamic load rating of 26 kN characterises this bearing. The static load rating is 32 kN. A non-contact seal protects the rolling chamber without adding a frictional torque to the rotation — on a roller carried along by its track, that is the decisive point.

This stud-type track roller is executed with a non-contact seal on both sides. The ingress is not wiped away at a contact point but led along a narrow, repeatedly deflected path on which particles and liquid lose their kinetic energy, while the lubricant is retained in the rolling chamber. For this design that fits together well: a stud-type track roller is not driven but set turning by the contact with its track, and every additional frictional torque increases the tendency to slide on the track instead of rolling on it — with wear on the running surface and on the track as the consequence.

A seal without a friction point avoids that contribution entirely and does not limit the permissible speed; at the same time it does not wear, so its effect is retained over the operating life. What it does not achieve belongs equally to the selection: against standing water, high-pressure cleaning and permanently present fine dust, it is no tight closure.

The fastening remains that of the stud-type track roller: the integrally formed threaded stud is screwed into a plate, lever or cheek, the roller cantilevers out on one side, and the bending moment arising from the track force is carried off through the seating face and the bolted joint; the squareness of the mounting hole determines whether the roller runs square to the track.

The thick-walled outer ring, hardened through the running depth, takes the contact pressure from the track contact; the hardness and course of the mating track have a share in determining the load capacity of the pairing. Rings and rolling elements are made of standard bearing steel.