RKB produces cylindrical roller bearings in various design styles, sizes and dimension series.
RKB heavy duty radial cylindrical roller bearings are designed to provide the highest possible radial capacity for the given cross section and to perform under heavy radial loads. These bearings incorporate improved internal proportions developed through computer assisted optimization studies, to make the maximum use of the total available cross-sectional area. The rollers have controlled contour to redistribute end stress concentration and provide more uniform distribution of the applied loads (suffix ZB). Their surface finishing maximizes lubricant film formation and optimizes rolling motion.
The standard ISO assortment of RKB production program includes single and double row bearings with a cage that can accommodate heavy radial loads and operation at high speeds.
A complete range in various executions of full complement of rollers suitable for more heavy loads at moderate speeds is also available.
Large size bearings can be supplied with surface treated rollers (suffix B).
In addition to the standard assortment, RKB cylindrical roller bearing range is comprehensive of open and sealed multi row for rolling mills in many executions and designes, backing bearings for cold rolling mills and indexing roller units for continuous furnace.
Besides to the inch dimension series as per AFBMA specifications, RKB offers the American style series 5200 and 5300 metric cylindrical roller bearings with enhanced radial capacity due to its internal design proportions, with double ribbed outer ring and with manufacturing tolerances established for the interchangeable components.
The single row cylindrical roller bearings are manufactured in various constructive versions, depending on the position of the ribs on the rings (e.g. bearing designation NU, NJ, NUP and N).
Depending on size and design, the bearings are equipped as standard with one of the following cages: unhardened pressed steel roller centered, one-piece window type brass inner or outer ring centered, two-piece machined brass roller centered (suffix M) or outer ring centered (suffix MA) or inner ring centered (suffix MB) and steel pin-type for pierced rollers.
Lubrication grooves in the guiding surfaces of machined brass cages are also available (suffix MAS and MBS).
RKB cylindrical roller bearings undergo a special heat treatment of stress relieving which allows them to be operated up to a temperature of +150° C.
The tolerances are in accordance with ISO 492:2002.
The radial internal clearance, even smaller or greater than normal, is in accordance with the range class of ISO 5793 measured for unmounted bearings under zero measuring loads.
The axial internal clearance for fixed design bearings, which can locate the shaft axially in both directions, is specified as per experienced rule.
Bearings with no standard radial clearance or with special stated values required by specific applications can be supplied to special order.
Bearings made of case hardened carburizing alloy steels can be produced for particular applications, where required (suffix HA1, HA2, HA3 and HA4).
Besides, special treatments for rings and rollers are available (e.g. bainite quenching hardened for rings – suffix HB1 -, anti-wear surface treatment, etc.).