NTN KRV19/3AS Kurvenrollen (4x8x32)

As a track or cam roller, this component runs directly on a mating track or cam surface. The mounting dimensions are 4x8x32 mm and the weight is 0.041 kg; technical details beyond these are shown in the specification table. Executed without a sealing element: the rolling chamber of this stud-type track roller is exposed, and lubrication as well as protection are handled by the construction its threaded stud is screwed into.

This version of the stud-type track roller brings no sealing element with it. The frictional torque therefore comes out lowest, which on a roller that is not driven but set turning by the track contact acts directly on the rolling behaviour: the more easily it starts to turn, the more reliably it rolls instead of sliding on its track. At the same time the rolling chamber lies open for lubrication.

The form is therefore intended for mounting situations in which the construction takes over the lubrication — through a relubrication bore in the threaded stud, through oil mist, or within a closed, oil-lubricated area of the machine. Where such a supply is absent and debris, dust or moisture are present at the same time, a sealed or shielded version is preferable; the exposed rolling chamber admits both unhindered.

The fastening is the defining property of this design: 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 seating face, the tightening torque and the squareness of the mounting hole therefore belong to the layout; a roller standing at an angle forces the contact pressure out to the edge of its running surface.

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