Considering the advantageous constructive shape with limited radial dimensions, they can boast a high load capacity and rigidity depending on the number of roller crowns, generally equipped with integral flanges with external ring or internal ring, which, if well dimensioned, also allow a good resistance to the axial loads, always in proportion to the radials; when necessary, they have the ability to allow axial displacements between shaft and bearing seat. They can be filled with rollers for maximum radial load capacity or with a cage of different shapes for applications that favour rotation speed, or in different materials for particularly heavy operating conditions, or in work environments in contact with polluting or aggressive agents.
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.
Cylindrical rollers made of 100Cr6 (UNI 3097) hardened steel with hardness that can reach 62 + 2 HRc. Contact seals produced in NBR nitrile elastomer.
In bearings of the SL 04… series (and in other series), the retaining rings are used to prevent disassembly of the bearing during handling and transport. Once the bearing is mounted on its pin and in its seat, these rings will stop being useful.
The dimensional and running precision of these bearings is generally according to class P0 (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, we supply rings with stabilization which allows them working up to a temperature of 250 ° C
Distitec single and multi-row full complement cylindrical roller bearings are generally constructed with a normal radial internal clearance. Most bearings are also available with higher clearance C3: values comply with ISO 5753: 1991. The clearance limits apply to bearings prior to mounting and with zero load.
The different conditions of movement compared to those of traditional cylindrical roller bearings with cage are due to the fact that the cylindrical surfaces of the rollers are in contact and move in the opposite direction.
Since there is a greater friction, than that existing between rollers and cage, in certain working conditions, we can notice failure modes different from the normal stress , such as wear and carry-over of material. To reduce the risk of premature failures and to increase reliability, DISTITEC also produces full complement cylindrical roller bearings equipped with rollers with treated surfaces; are identified by the suffix B in the name.
Thanks to the improvements in terms of operating time and reliability, bearings with treated rollers are recommended for applications in which occur:
- high speeds (n ≥ 0.5 times the base speed)
- light loads (e.g. idle rotation),
- difficult lubrication (K <1.5)
- strong accelerations.
When extreme working conditions occur and maximum reliability is required, we can supply full complement cylindrical roller bearings with surface treatment also on the rings.
To complete what has been described up to now, cylindrical roller bearings can be supplied, on specific request, also with a bronze cage.