TECHNICAL CHARACTERISTICS OF MULTIROW BEARINGS - MULTIPROLL (Multi track)
External and internal rings made mainly of 100Cr6 or 100CrMo7 (UNI 3097) hardened steel, steel with the best resistance to wear due to fatigue. The surface hardness that can be achieved for these parts is 60 + 2 HRc. Some executions require the use of 18NiCrMo5 (UNI 7846) case hardening steel.
Washers and spacers made of 100Cr6 or 100CrMo7 (UNI 3097) hardened steel whardneith ss that can reach 60 + 2 HRc.
Cages mainly made of brass or bronze subjected to sandblasting treatment to eliminate any possible burr that could detach from it during operation. They are also built, on request, in structural steel subjected to sandblasting and phosphating treatment, for those applications where it is necessary to have a more robust cage.
The dimensional precision class of these bearings is generally according to class P6 (DIN 620). Rotation accuracy is generally according to class P5 (DIN 620).
The rings of these bearings are always subjected to a stabilization treatment that makes it possible to operate up to a temperature of 150 ° without substantial dimensional changes to occur. On request, rings with stabilization are supplied, which allow operation up to a temperature of 250 ° C.
Multi-row cylindrical roller bearings bear only radial loads and are therefore mounted in combination with types that can withstand axial loads, such as angular and radial ball bearings, tapered roller bearings, radial or axial type. The four- and six-row cylindrical roller bearings can be disassembled, i.e. the ring or rings with integral flanges, together with the relative roller-cage assembly can be mounted independently with respect to the other rings and are recognized with the prefix "R". This allows an easy installation, maintenance and inspection. Four-row cylindrical roller bearings are produced with a cylindrical bore, but some of them are available with a tapered bore. Bearings with a tapered bore can be adjusted during assembly to achieve a predetermined radial internal clearance or preload.