Backing bearings are roller bearings with a particularly thick outer ring.
They are mounted on stationary support shafts, forming a cluster together with the work rolls. The forces from the work rolls are transmitted via the support shaft and a system of support saddles to the rolls or machine stands.
The logarithmic profile of the rollers contact allows obtaining an optimum load distribution under all load conditions and even in case of bearing misalignment under load.
UNITEC backing bearings are subjected to heat treatments that improve surface structure and therefore facilitate a reliable lubrication.
UNITEC has developed a wide range of backing rollers for Sendzimir mills which are able to meet different requirements.
Here below three standardized series:
- Design A: 3-row bearings, rollers guided by a bronze cage and outer ring without ribs
- Design B: double row bearings with cage and ribs to guide the rollers
- Design C: single row full complement bearings, outer ring without ribs and inner ring with ribs to contain the rollers
Profile of the outer ring
The outer ring profile of the SCRB bearing is provided with a rounded profile on both sides, in order to contain local overstressing with work rolls.
- Outer rings: in special bearing steel. Isothermal hardening is foreseen in case of big dimensions in order to improve bearings toughness and strength.
- On request: isothermal hardening or case hardening also on smaller sizes.
- The outer ring is conveniently profiled to reduce the stress generated by the contact with the work rolls.
- Inner rings: in special bearing steel, available with lubrication holes.
- Rollers: with modified logarithmic profiles to improve the distribution of stresses.
- Each bearing is measured and identified according to a specific selection of the outer ring’s thickness H.
This refers to the alignment of the outer ring and inner ring.
The maximum thickness of outer and inner rings is marked on the rings sides.
- On request, the bearings can be packed in a sequence of assembly and in groups according to the customer’s requirement.
- UNITEC provides bearing with a number code and stores its main dimensions.